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Mycoprotein ingestion stimulates protein synthesis rates to a greater extent than milk protein in rested and exercised skeletal muscle of healthy young men: a randomized controlled trial
Abstract
Background:
Mycoprotein is a fungal-derived sustainable protein-rich food source, and its ingestion results in systemic amino acid and leucine concentrations similar to that following milk protein ingestion.
Objective:
We assessed the mixed skeletal muscle protein synthetic response to the ingestion of a single bolus of mycoprotein compared with a leucine-matched bolus of milk protein, in rested and exercised muscle of resistance-trained young men.
Methods:
Twenty resistance-trained healthy young males (age: 22 ± 1 y, body mass: 82 ± 2 kg, BMI: 25 ± 1 kg·m-2) took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of L-[ring-2H5]phenylalanine and ingested either 31 g (26.2 g protein: 2.5 g leucine) milk protein (MILK) or 70 g (31.5 g protein: 2.5 g leucine) mycoprotein (MYCO) following a bout of unilateral resistance-type exercise (contralateral leg acting as resting control). Blood and m. vastus lateralis muscle samples were collected before exercise and protein ingestion, and following a 4-h postprandial period to assess mixed muscle fractional protein synthetic rates (FSRs) and myocellular signaling in response to the protein beverages in resting and exercised muscle.
Results:
Mixed muscle FSRs increased following MILK ingestion (from 0.036 ± 0.008 to 0.052 ± 0.006%·h-1 in rested, and 0.035 ± 0.008 to 0.056 ± 0.005%·h-1 in exercised muscle; P <0.01) but to a greater extent following MYCO ingestion (from 0.025 ± 0.006 to 0.057 ± 0.004%·h-1 in rested, and 0.024 ± 0.007 to 0.072 ± 0.005%·h-1 in exercised muscle; P <0.0001) (treatment × time interaction effect; P <0.05). Postprandial FSRs trended to be greater in MYCO compared with MILK (0.065 ± 0.004 compared with 0.054 ± 0.004%·h-1, respectively; P = 0.093) and the postprandial rise in FSRs was greater in MYCO compared with MILK (Delta 0.040 ± 0.006 compared with Delta 0.018 ± 0.005%·h-1, respectively; P <0.01).
Conclusions:
The ingestion of a single bolus of mycoprotein stimulates resting and postexercise muscle protein synthesis rates, and to a greater extent than a leucine-matched bolus of milk protein, in resistance-trained young men. This trial was registered at clinicaltrials.gov as 660065600.
... 18,121 Progress regarding the refinement of dietary protein recommendations for healthy and active muscle aging will inexorably highlight the pressing need to assess how the sources of protein can be exploited. As dietary protein sources have divergent anabolic capacities (eg, [34][35][36][37]122,123 ), this will mean that protein requirements should ultimately be refined to the extent of indicating where certain (animal or non-animal) protein sources can be used to meet increased protein demands in aging populations (ie, "source-specific" recommendations in which amounts may differ depending on source). Consequently, to contemplate the anabolic potential, and therefore viability, of a protein source, it is necessary to evaluate the current understanding of the factors determining the anabolic capacity of dietary protein ingestion and how this pertains to the major subcategories of dietary protein. ...
... 259 The latter translated to bolus mycoprotein ingestion robustly stimulating resting and post-resistance exercise muscle protein synthesis rates in young men. 123,260 In fact, mycoprotein ingestion stimulated muscle protein synthesis rates to a greater extent than a leucine-matched bolus of isolated milk protein, which may be attributed to a greater amount of total protein ingested, the specific amino acid composition, and/or, alternatively, its existence within a whole food/matrix. 123 Growing evidence is emerging to suggest a potentiating anabolic effect of consuming protein as part of a whole food, presumably due to the presence of other macro-and micro-nutrients and/or other bioactive compounds, and their "nutrient-nutrient interactions" within the matrix. ...
... 123,260 In fact, mycoprotein ingestion stimulated muscle protein synthesis rates to a greater extent than a leucine-matched bolus of isolated milk protein, which may be attributed to a greater amount of total protein ingested, the specific amino acid composition, and/or, alternatively, its existence within a whole food/matrix. 123 Growing evidence is emerging to suggest a potentiating anabolic effect of consuming protein as part of a whole food, presumably due to the presence of other macro-and micro-nutrients and/or other bioactive compounds, and their "nutrient-nutrient interactions" within the matrix. 123,187 For instance, as highlighted above, shortchain fatty acids produced by gut fermentation following dietary fiber ingestion may modulate (positively or negatively) postprandial muscle anabolism. ...
To mitigate the age-related decline in skeletal muscle quantity and quality, and the associated negative health outcomes, it has been proposed that dietary protein recommendations for older adults should be increased alongside an active lifestyle and/or structured exercise training. Concomitantly, there are growing environmental concerns associated with the production of animal-based dietary protein sources. The question therefore arises as to where this dietary protein required for meeting the protein demands of the rapidly aging global population should (or could) be obtained. Various non-animal–derived protein sources possess favorable sustainability credentials, though much less is known (compared with animal-derived proteins) about their ability to influence muscle anabolism. It is also likely that the anabolic potential of various alternative protein sources varies markedly, with the majority of options remaining to be investigated. The purpose of this review was to thoroughly assess the current evidence base for the utility of alternative protein sources (plants, fungi, insects, algae, and lab-grown “meat”) to support muscle anabolism in (active) older adults. The solid existing data portfolio requires considerable expansion to encompass the strategic evaluation of the various types of dietary protein sources. Such data will ultimately be necessary to support desirable alterations and refinements in nutritional guidelines to support healthy and active aging, while concomitantly securing a sustainable food future.
... Eight studies have evaluated the effects of mycoprotein consumption in relation to markers of health in early and young adulthood [28][29][30][31][32][33][34][35]. A range of outcomes were studied including effects of ingestion on the plasma lipidome [28], cholesterol levels [35] protein synthesis rates [31,32], postprandial amino acid, glucose and insulin levels [29,30,33] and energy intake and appetite [34]. ...
... Eight studies have evaluated the effects of mycoprotein consumption in relation to markers of health in early and young adulthood [28][29][30][31][32][33][34][35]. A range of outcomes were studied including effects of ingestion on the plasma lipidome [28], cholesterol levels [35] protein synthesis rates [31,32], postprandial amino acid, glucose and insulin levels [29,30,33] and energy intake and appetite [34]. ...
... Monteyne et al. (2020) allocated participants (22 ± 1 year) to receive ingest either 70 g mycoprotein or 31 g milk protein following a bout of resistance exercise [31]. Results showed that the myoprotein consumption enhanced postexercise and resting muscle protein synthesis rates to a greater extent than the control [31]. ...
Mycoprotein is a filamentous fungal protein that was first identified in the 1960s. A growing number of publications have investigated inter-relationships between mycoprotein intakes and aspects of human health. A narrative review was undertaken focusing on evidence from randomized controlled trials, clinical trials, intervention, and observational studies. Fifteen key publications were identified and undertaken in early/young adulthood, adulthood (mid-life) or older/advanced age. Main findings showed that fungal mycoprotein could contribute to an array of health benefits across the lifespan including improved lipid profiles, glycaemic markers, dietary fibre intakes, satiety effects and muscle/myofibrillar protein synthesis. Continued research is needed which would be worthwhile at both ends of the lifespan spectrum and specific population sub-groups.
... Plant-based proteins currently account for 30-50% of total dietary protein intake in many countries [15], with numbers exceeding 60% in less developed countries [16]. More research is emerging on how plant-based proteins affect muscle health [17][18][19] and muscle remodelling, especially in combination with resistance training [20][21][22][23]. Considerable efforts have been made recently to understand how non-animal-based proteins affect the acute protein synthetic response [24][25][26][27], but studies assessing the direct effects on acute mTORC1 signalling are lacking. ...
... Numerous studies have shown potent activation of downstream mTORC1 signalling with whole animal-based protein sources [28,45,46], but data on mTORC1 activation with non-animal-based protein blends is scarce. Recent human data showed a reduced increase in blood leucine with ingestion of fungal derived protein (mycoprotein) compared to milk protein, even though total ingested leucine was matched [23]. Despite lower leucine availability, MPS was higher with mycoprotein in both resting and exercised conditions, while mTOR phosphorylation at ser2448 was unaffected. ...
... Our data supports this as both vegan mixes induced lower rise in BCAA, which resulted in a 1.5-fold lower increase in phosphorylation of various downstream mTORC1 kinases such as p-S6K1 and p-S6 compared to whey. Plant and insect protein are often described as slow-digesting [32,48] leading to a prolonged increase in protein synthetic rate, despite lower overall postprandial amino acid concentrations, also at later time-points [23,24]. Although we only measured markers of protein synthesis, we did not observe a prolonged mTORC1 response 2.5 h after plant-or insect protein administration, suggesting that mTORC1 activation closely mirrors the rise in plasma leucine, while its downstream effects on protein synthesis might be delayed. ...
Increased amino acid availability acutely stimulates protein synthesis partially via activation of mechanistic target of rapamycin complex 1 (mTORC1). Plant-and insect-based protein sources matched for total protein and/or leucine to animal proteins induce a lower postprandial rise in amino acids, but their effects on mTOR activation in muscle are unknown. C57BL/6J mice were gavaged with different protein solutions: whey, a pea–rice protein mix matched for total protein or leucine content to whey, worm protein matched for total protein, or saline. Blood was drawn 30, 60, 105 and 150 min after gavage and muscle samples were harvested 60 min and 150 min after gavage to measure key components of the mTORC1 pathway. Ingestion of plant-based proteins induced a lower rise in blood leucine compared to whey, which coincided with a dampened mTORC1 activation, both acutely and 150 min after administration. Matching total leucine content to whey did not rescue the reduced rise in plasma amino acids, nor the lower increase in mTORC1 compared to whey. Insect protein elicits a similar activation of downstream mTORC1 kinases as plant-based proteins, despite lower postprandial aminoacidemia. The mTORC1 response following ingestion of high-quality plant-based and insect proteins is dampened compared to whey in mouse skeletal muscle.
... As shown in Tables 2, 3 the trials identified focused on the specified outcomes, including total cholesterol (Udall et al., 1984;Turnbull et al., 1990Turnbull et al., , 1992Ruxton and McMillan, 2010;Coelho et al., 2020b), energy intake (Burley et al., 1993;Turnbull et al., 1993;Williamson et al., 2006;Bottin et al., 2016), glucose levels (Turnbull and Ward, 1995;Ruxton and McMillan, 2010;Bottin, 2011;Bottin et al., 2016;Coelho et al., 2020a,b), insulin levels (Turnbull and Ward, 1995;Bottin, 2011;Bottin et al., 2016;Dunlop et al., 2017;Coelho et al., 2020a,b;Monteyne et al., 2020a) and protein response (Udall et al., 1984;Dunlop et al., 2017;Monteyne et al., 2020a,b). As shown in Table 4 seven were good quality, scoring 3 or more after the application of the Jadad criteria (Turnbull et al., 1990;Burley et al., 1993;Bottin et al., 2016;Dunlop et al., 2017;Monteyne et al., 2020a,b). ...
... Seven trials have studied the effects of acute mycoprotein ingestion in relation to insulin levels (Turnbull and Ward, 1995;Bottin, 2011;Bottin et al., 2016;Dunlop et al., 2017;Coelho et al., 2020a,b;Monteyne et al., 2020a). Turnbull and Ward (1995) first found that post meal insulinemia was significantly reduced in the mycoprotein compared with the control group at 30 and 60 min post ingestion (Turnbull and Ward, 1995). ...
... Dunlop et al. (2017) demonstrated that mycoprotein ingestion led to slower but more sustained hyperinsulinaemia when compared with protein-match milk (Dunlop et al., 2017). Similarly, Monteyne et al. (2020a) found that mycoprotein ingestion (70 g) resulted in a less rapid but more sustained increase in serum insulin levels, peaking at 30 min after consumption when compared with milk protein . Coelho et al. (2020a,b) did not report any differences in serum insulin responses after mycoprotein ingestion when compared against meat/fish and nucleotide depleted mycoprotein controls (Coelho et al., 2020a,b). ...
Mycoprotein is a protein-rich fungal-derived sustainable food source that was first discovered in the early 1960's. Since then, a sizeable body of research has investigated the health benefits of mycelium protein. Given this, the present publication aims to systematically review the effects of mycoprotein on human health. A literature search of human studies was conducted using PubMed Central, ClinicalTrials.Gov , Google Scholar and a manual search. Sixteen controlled trials, totaling 432 participants were included – of these 5 studies reported total cholesterol, 5 reported on energy intake, 7 on insulin levels, 8 on glucose levels and 4 studied protein response. Risk of bias showed that 7 studies were good quality although heterogeneity was apparent between studies. Results showed that acute mycoprotein ingestion was associated with reduced total cholesterol levels, particularly amongst those with hyperlipidemia. Evidence was less conclusive for effects on blood glucose and insulin levels. Mycoprotein also appears to be a promising bioavailable source of essential amino acids that could induce muscle protein synthesis. Overall, given growing interest in sustainable proteins and accruing health evidence for mycoprotein, firmer embedment with food-based dietary guidelines is now worthy of consideration.
... Mycoprotein is a sustainable, protein-rich whole-food source produced by the continuous cultivation of the filamentous fungus Fusarium venenatum. We recently reported that the ingestion of a large (70 g; containing 31.5 g protein) bolus of mycoprotein robustly stimulates MPS rates in rested and exercised muscle of young men (7). From a practical and sustainability perspective, it is relevant to investigate and maximize the MPS response to the ingestion of smaller boluses of effective alternative dietary protein sources. ...
... Serum insulin concentrations were analyzed using a commercially available ELISA kit (DRG Insulin ELISA; EIA-2935; DRG International, Inc.). Plasma BCAA (leucine, isoleucine, and valine), phenylalanine, and tyrosine concentrations, and l-[ring-2 H 5 ]phenylalanine, l-[3,3-2 H 2 ]tyrosine, and l-[ring-2 H 4 ]tyrosine enrichments were determined by GC-MS, as described previously (7,21). ...
... Muscle biopsy tissue samples were analyzed for protein-bound and free intracellular l-[ring-2 H 5 ]phenylalanine, determined by GC-MS, as previously described (7,21). Briefly, 20-30 mg of frozen muscle tissue was homogenized by a mechanical tissue grinder. ...
Background:
We have shown that ingesting a large bolus (70 g) of the fungal-derived, whole food mycoprotein robustly stimulates muscle protein synthesis (MPS) rates.
Objective:
The aim of this study was to determine if a lower dose (35 g) of mycoprotein enriched with branched-chain amino acids (BCAAs) stimulates MPS to the same extent as 70 g of mycoprotein in resistance-trained young men.
Methods:
Nineteen men [aged 22 ± 1 y, BMI (kg/m2): 25 ± 1] took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of l-[ring-2H5]phenylalanine and ingested either 70 g mycoprotein (31.5 g protein; MYCO; n = 10) or 35 g BCAA-enriched mycoprotein (18.7 g protein: matched on BCAA content; ENR; n = 9) following a bout of unilateral resistance exercise. Blood and bilateral quadriceps muscle samples were obtained before exercise and protein ingestion and during a 4-h postprandial period to assess MPS in rested and exercised muscle. Two- and 3-factor ANOVAs were used to detect differences in plasma amino acid kinetics and mixed muscle fractional synthetic rates, respectively.
Results:
Postprandial plasma BCAA concentrations increased more rapidly and to a larger degree in ENR compared with MYCO. MPS increased with protein ingestion (P ≤ 0.05) but to a greater extent following MYCO (from 0.025% ± 0.006% to 0.057% ± 0.004% · h-1 in rested muscle, and from 0.024% ± 0.007% to 0.072% ± 0.005% · h-1 in exercised muscle; P < 0.0001) compared with ENR (from 0.031% ± 0.003% to 0.043% ± 0.005% · h-1 in rested muscle, and 0.027% ± 0.005% to 0.052% ± 0.005% · h-1 in exercised muscle; P < 0.01) ingestion. Postprandial MPS rates were greater in MYCO compared with ENR (P < 0.01).
Conclusions:
The ingestion of lower-dose BCAA-enriched mycoprotein stimulates resting and postexercise MPS rates, but to a lesser extent compared with the ingestion of a BCAA-matched 70-g mycoprotein bolus in healthy young men. This trial was registered at clinicaltrials.gov as 660065600.
... However, the mycoprotein response lasted longer (45 min) than milk (30 min) (Dunlop et al., 2017). A similar result was observed by Monteyne et al. (2020), with the insulin peak being observed 15 and 30 min after the ingestion of milk or mycoprotein, respectively, and the return to the fasting level after 45 and 60 min, respectively. On the other hand, the consumption of chicken or mycoprotein yielded no difference in the glucose profile during the 3 h after the meal, while the insulin peak was significantly lower when the fungal protein was the choice of food (Bottin et al., 2016). ...
... Moreover, some studies suggest that mycoprotein stimulates muscle protein synthesis. Comparing milk and mycoprotein by the same amount of the amino acid leucine, the fungal product stimulates resting and postexercise muscle protein synthesis at higher rates (Monteyne et al., 2020). Ingestion of mycoprotein has also been demonstrated to increase the amino acid levels in the blood, with a peak between 45 and 120 min, and maintaining the levels above those of fasting for up to 240 min. ...
This chapter reviews the uses of processed fungal cells as protein-rich foods in substitution to meat. Yeasts, mushrooms, and filamentous fungi have long been part of the human diet, improving the nutritional quality and taste of different foods. Recently, because of the populational growth and environmental impact caused by animal farming, the use of animal-derived protein has been raising concerns in public and scientific debates. Fungal biomass represents a nutritious, safe meat alternative that can help society in the reduction of greenhouse gases emissions and improve public health. Additionally, it provides all essential amino acids and has an interesting fatty acid profile. Current research is involved in finding new strains with improved efficiency, the investigation of new substrates (especially agro-industrial wastes) to reduce the environmental impact, and the development of new formulations to use mycoprotein in different dishes.
... Moreover, it means that mycoproteins could be a useful dietary protein source with an noticeable anabolic effect in muscles (75). More recently, Monteyne et al. (76), performed a randomized controlled trial, in which they compared the ergogenic effect that a simple 70 g bolus of whole food mycoproteins or leucine-enriched milk protein could have on athlete's MPS. The results showed that mycoproteins exerted a higher postprandial induction on protein synthesis (0.040 ± 0.006 %/h) than leucine enriched milk proteins (0.018 ± 0.005 %/h), regardless of their consumption before or after training. ...
... The results showed that mycoproteins exerted a higher postprandial induction on protein synthesis (0.040 ± 0.006 %/h) than leucine enriched milk proteins (0.018 ± 0.005 %/h), regardless of their consumption before or after training. This research indicates that this source of proteins could have a superior anabolic effect than traditional proteins used in sport supplements (76). These authors also investigated whether a simple bolus with a lower whole food mycoprotein content (35 g) enriched with BCAAs could exert the same effect as a simple 70 g bolus of whole food mycoprotein. ...
Nutrition and sport play an important role in achieving a healthy lifestyle. In addition to the intake of nutrients derived from the normal diet, some sport disciplines require the consumption of supplements that contribute positively to improved athletic performance. Protein intake is important for many aspects related to health, and current evidence suggests that some athletes require increased amounts of this nutrient. On the other hand, society's demand for more environmentally friendly products, focus on the search for alternative food sources more sustainable. This review aims to summarize the latest research on novel strategies and sources for greener and functional supplementation in sport nutrition. Alternative protein sources such as insects, plants or mycoproteins have proven to be an interesting substrate due to their high added value in terms of bioactivity and sustainability. Protein hydrolysis has proven to be a very useful technology to revalue by-products, such as collagen, by producing bioactive peptides beneficial on athletes performance and sport-related complications. In addition, it has been observed that certain amino acids from plant sources, as citrulline or theanine, can have an ergogenic effect for this target population. Finally, the future perspectives of protein supplementation in sports nutrition are discussed. In summary, protein supplementation in sports nutrition is a very promising field of research, whose future perspective lies with the search for alternatives with greater bioactive potential and more sustainable than conventional sources.
... Recent work has addressed the anabolic properties of a food source derived from cultivating a fungus (Fusarium venenatum), resulting in what has been coined mycoprotein [103][104][105]. This protein source has been reported to have a high protein content (~ 45%) with the protein showing an amino acid composition that does not differ much from dairy protein [106]. ...
... Prior work suggested good digestibility based upon the observation that post-prandial plasma essential amino acid (and leucine) concentrations were comparable following ingestion of mycoprotein when compared with the ingestion of an equivalent amount of milk protein. More recently, these investigators followed up by showing that ingestion of a single bolus of mycoprotein (70 g, providing 31.5 g protein) increased both resting and post-exercise muscle protein synthesis rates in young males, with a postprandial muscle protein synthetic response that was greater than the response observed after ingesting a leucine-matched bolus of milk protein (31 g, providing 26.2 g protein) [103]. These data show that fungi can provide a viable, high-quality protein source that is effective in stimulating muscle protein synthesis. ...
There is a global trend of an increased interest in plant-based diets. This includes an increase in the consumption of plant-based proteins at the expense of animal-based proteins. Plant-derived proteins are now also frequently applied in sports nutrition. So far, we have learned that the ingestion of plant-derived proteins, such as soy and wheat protein, result in lower post-prandial muscle protein synthesis responses when compared with the ingestion of an equivalent amount of animal-based protein. The lesser anabolic properties of plant-based versus animal-derived proteins may be attributed to differences in their protein digestion and amino acid absorption kinetics, as well as to differences in amino acid composition between these protein sources. Most plant-based proteins have a low essential amino acid content and are often deficient in one or more specific amino acids, such as lysine and methionine. However, there are large differences in amino acid composition between various plant-derived proteins or plant-based protein sources. So far, only a few studies have directly compared the muscle protein synthetic response following the ingestion of a plant-derived protein versus a high(er) quality animal-derived protein. The proposed lower anabolic properties of plant- versus animal-derived proteins may be compensated for by (i) consuming a greater amount of the plant-derived protein or plant-based protein source to compensate for the lesser quality; (ii) using specific blends of plant-based proteins to create a more balanced amino acid profile; (iii) fortifying the plant-based protein (source) with the specific free amino acid(s) that is (are) deficient. Clinical studies are warranted to assess the anabolic properties of the various plant-derived proteins and their protein sources in vivo in humans and to identify the factors that may or may not compromise the capacity to stimulate post-prandial muscle protein synthesis rates. Such work is needed to determine whether the transition towards a more plant-based diet is accompanied by a transition towards greater dietary protein intake requirements.
... A full description of the nutritional properties of mycoprotein can be found in the review by Coelho et al. (24) . We recently reported that an ingested bolus of mycoprotein is effectively digested and its amino acids absorbed (25) , which results in a robust stimulation of MPS rates in rested and exercised muscle of young men (26) . This suggests that mycoprotein may be a suitable alternative to animal-or plant-derived proteins to incorporate within the diet of older adults to support daily MPS rates. ...
... The inclusion of mycoprotein as the basis for the vegan dietary intervention is also of relevance. To date, mycoprotein is the only vegan protein source whose bolus ingestion has been shown to acutely stimulate postprandial MPS rates to a comparable extent as an animal-derived control (26) . Accordingly, it cannot be assumed that our current data are generalisable to vegan diets predicated on other protein sources, particularly those lower in leucine and/or other essential amino acids. ...
Animal-derived dietary protein ingestion and physical activity stimulate myofibrillar protein synthesis rates in older adults. We determined whether a non-animal-derived diet can support daily myofibrillar protein synthesis rates to the same extent as an omnivorous diet. Nineteen healthy older adults (age 66±1 y; BMI 24±1 kg·m ⁻² ; m=12, f=7) participated in a randomised, parallel-group, controlled trial during which they consumed a 3-day isocaloric high-protein (1.8 g·kg body mass ⁻¹ ·d ⁻¹ ) diet, where the protein was provided from predominantly (71%) animal (OMNI; n =9; m=6, f=3) or exclusively vegan (VEG; n =10; m=6, f=4; mycoprotein providing 57% of daily protein intake) sources. During the dietary control period participants conducted a daily bout of unilateral resistance-type leg extension exercise. Prior to the dietary control period participants ingested 400 mL deuterated water, with 50 mL doses consumed daily thereafter. Saliva samples were collected throughout to determine body water deuterium ( ² H) enrichments, and muscle samples were collected from rested and exercised muscle to determine daily myofibrillar protein synthesis rates. Deuterated water dosing resulted in body water ² H enrichments of ~0.78±0.03%. Daily myofibrillar protein synthesis rates were 13±8 ( P= 0.169) and 12±4% ( P= 0.016) greater in the exercised compared with rested leg (1.59±0.12 vs 1.77±0.12 %·d ⁻¹ and 1.76±0.14 vs 1.93±0.12 %·d ⁻¹ ) in OMNI and VEG groups, respectively. Daily myofibrillar protein synthesis rates did not differ between OMNI and VEG in either rested or exercised muscle ( P >0.05). Over the course of a three day intervention, omnivorous or vegan derived dietary protein sources can support equivalent rested and exercised daily myofibrillar protein synthesis rates in healthy older adults consuming a high-protein diet.
... Mycoprotein ingestion led to slower and more sustained EAA and branched chain amino acid levels compared with milk, with evidence of a plateau at intakes of 60 to 80 g bolus of mycoprotein [74]. In addition, such high bioavailability has now been shown to stimulate muscle protein synthesis rates to a greater extent than milk protein in rested and exercised skeletal muscle of healthy young men [75]. Table 3. Essential amino acid profile of different protein sources (g amino acids per 100 g). ...
... Table 3. Essential amino acid profile of different protein sources (g amino acids per 100 g). Interestingly, further research has suggested that it is the whole-food nature of the mycelium that is important in delivering this anabolic response [75]-a feature also demonstrated for whole egg where the consumption of whole eggs promotes greater stimulation of post-exercise muscle protein synthesis than the ingestion of isonitrogenous amounts of egg whites in young men [76]. Subsequently, both the bioavailability and the amino acid composition of mycoprotein position make it a promising dietary protein source-having potential to support skeletal muscle protein metabolism [7]. ...
In the 21st century, we face a troubling trilemma of expanding populations, planetary and public wellbeing. Given this, shifts from animal to plant food protein are gaining momentum and are an important part of reducing carbon emissions and consumptive water use. However, as this fast-pace of change sets in and begins to firmly embed itself within food-based dietary guidelines (FBDG) and food policies we must raise an important question—is now an opportunistic time to include other novel, nutritious and sustainable proteins within FBGD? The current paper describes how food proteins are typically categorised within FBDG and discusses how these could further evolve. Presently, food proteins tend to fall under the umbrella of being ‘animal-derived’ or ‘plant-based’ whilst other valuable proteins i.e., fungal-derived appear to be comparatively overlooked. A PubMed search of systematic reviews and meta-analytical studies published over the last 5 years shows an established body of evidence for animal-derived proteins (although some findings were less favourable), plant-based proteins and an expanding body of science for mycelium/fungal-derived proteins. Given this, along with elevated demands for alternative proteins there appears to be scope to introduce a ‘third’ protein category when compiling FBDG. This could fall under the potential heading of ‘fungal’ protein, with scope to include mycelium such as mycoprotein within this, for which the evidence-base is accruing.
... According to Dunlop et al., [16] mycoprotein intake resulted in delayed but prolonged hyperinsulinemia more than protein-match milk. Likewise, Monteyne et al. [28] observed that, compared to milk protein, mycoprotein consumption (70 g) resulted in a slower but more prolonged rise in insulin serum levels, with a climax at 30 minutes after intake. Coelho et al. [17,29] found no variations in plasma insulin responses following mycoprotein intake when comparing fish/meat and nucleotide-deficient mycoprotein controls. ...
2023) Role of mycoprotein as a non-meat protein in food security and sustainability: a review, ABSTRACT Malnutrition is increasing across the globe owing to urbanization, poverty, and climatic changes. In the current circumstances, alternative and unex-plored sources of food and nutrients are getting attention. The current sources of food cannot meet the ever-increasing population demand. The demand for animal-source protein is estimated be double due to a projected 50% rise in the world population by the year 2050. Moreover, global animal protein supply chains are not only vulnerable to natural disasters but also a significant source of greenhouse gas emissions. Mycoprotein is considered an excellent alternative to animal protein due to its amino acid profile and cost-effectiveness. Mycoprotein is produced by Fusarium venenatum, a naturally occurring fungus that can be used as a substitute for conventional animal protein sources. Mycoprotein is high in protein and fiber while low in cholesterol, fat, sugar, and salt. Mycoprotein offers excellent functional and therapeutic potential in mitigating various health disorders. Furthermore, it helps maintain muscle synthesis and optimal plasma and cholesterol levels, regulating insulin, glucose, and satiety. This review is focused on the myco-protein's origin and production, with a particular emphasis on its nutritional, health, and economic opportunities and challenges. ARTICLE HISTORY
... According to Dunlop et al., [16] mycoprotein intake resulted in delayed but prolonged hyperinsulinemia more than protein-match milk. Likewise, Monteyne et al. [28] observed that, compared to milk protein, mycoprotein consumption (70 g) resulted in a slower but more prolonged rise in insulin serum levels, with a climax at 30 minutes after intake. Coelho et al. [17,29] found no variations in plasma insulin responses following mycoprotein intake when comparing fish/meat and nucleotide-deficient mycoprotein controls. ...
... Mycoprotein is rich in protein, vitamins specially B vitamins, minerals including such as iron, zinc, sodium, selenium, manganese, calcium, phosphorus, carbohydrates, essential amino acids and less fat contents [37]. Also, mycoprotein improves the lipid profile [38], and plays a key role in muscle protein synthesis in young individuals [39]. ...
Microbes in general and fungi especially are promising biotechnological tools that are used for green synthesis of numerous products. Fungi in particular are potent producers of many important compounds used in different applications. Hence, this review aims to explore fungi and their potential as a source of various bioactive compounds like mycoprotein.
... b Gut microbial genera identified as significant for change in abundance from baseline after the Meat phase. Changes within study phases assessed using generalised mixed-effects models (P ˂0.05 considered significant) reaching the colon [46]. While observational data are conflicting, with studies showing Alistipes to be associated with both health and disease [47], Oscillobacter has been linked with weight gain, metabolic dysfunction and a leaky gut [48]. ...
Purpose
The high-meat, low-fibre Western diet is strongly associated with colorectal cancer risk. Mycoprotein, produced from Fusarium venanatum, has been sold as a high-fibre alternative to meat for decades. Hitherto, the effects of mycoprotein in the human bowel have not been well considered. Here, we explored the effects of replacing a high red and processed meat intake with mycoprotein on markers of intestinal genotoxicity and gut health.
Methods
Mycomeat (clinicaltrials.gov NCT03944421) was an investigator-blind, randomised, crossover dietary intervention trial. Twenty healthy male adults were randomised to consume 240 g day−1 red and processed meat for 2 weeks, with crossover to 2 weeks 240 g day−1 mycoprotein, separated by a 4-week washout period. Primary end points were faecal genotoxicity and genotoxins, while secondary end points comprised changes in gut microbiome composition and activity.
Results
The meat diet increased faecal genotoxicity and nitroso compound excretion, whereas the weight-matched consumption of mycoprotein decreased faecal genotoxicity and nitroso compounds. In addition, meat intake increased the abundance of Oscillobacter and Alistipes, whereas mycoprotein consumption increased Lactobacilli, Roseburia and Akkermansia, as well as the excretion of short chain fatty acids.
Conclusion
Replacing red and processed meat with the Fusarium-based meat alternative, mycoprotein, significantly reduces faecal genotoxicity and genotoxin excretion and increases the abundance of microbial genera with putative health benefits in the gut. This work demonstrates that mycoprotein may be a beneficial alternative to meat within the context of gut health and colorectal cancer prevention.
... Participants associated several health benefits with the consumption of fungi-based food. Health benefits that have been studied with regard to fungi-based food include reduced total cholesterol levels [46][47][48][49][50] as well as induced muscular protein synthesis [46,[51][52][53]. At the same time, the evidence of the effects of consuming this type of food on blood glucose and insulin levels is not conclusive [54]. ...
Fungi-based food is expected to contribute to more sustainable food systems. The present study has three focus areas: (i) aspects that affect food choices food in daily life, (ii) aspects that affect choices of fungi-based food in particular, and (iii) drivers that motivate, and barriers that prevent, engagement in cultivating fungi and cooking fungi-based food at home. One hundred and sixty participants, who were recruited using convenience sampling, filled out qualitative questionnaires. The results show that there are numerous aspects (e.g., environmental benefits, nutrition, sensory characteristics, production practices and ingredients) that are important when people choose food in daily life. In addition to curiosity, many of these aspects also affect the choice of fungi-based food. The study identified more drivers (e.g., self-providing, curiosity, awareness of ingredients) than barriers (time, knowledge, concerns about contamination) to cultivation and cooking of fungi-based food at home. The findings are relevant for the development of fungi-based food so that this type of food is engaged with, and so that it can contribute to more sustainable food systems.
... In terms of blood glucose and insulin levels, there is no conclusive evidence of an effect of the consumption of fungi-based food (Derbyshire & Delange, 2021). Yet, fungi-based food is a source of essential amino acids which are important in muscular protein synthesis (Dunlop et al., 2017;Monteyne et al., 2020aMonteyne et al., , 2020bUdall et al., 1984). When developing and marketing fungi-food products, it is important to acknowledge that Derbyshire & Delange (2021) only found seven good quality studies as part of their review about health evidence of fungi-based food. ...
Filamentous fungi serve as potential candidates in the production of different value-added products. In the context of food, there are several advantages of using filamentous fungi for food. Among the main advantages is that the fungal biomass used food not only meets basic nutritional requirements but that it is also rich in protein, low in fat, and free of cholesterol. This speaks to the potential of filamentous fungi in the production of food that can substitute animal-derived protein sources such as meat. Moreover, life-cycle analyses and techno-economic analyses reveal that fungal proteins perform better than animal-derived proteins in terms of land use efficiency as well as global warming. The present article provides an overview of the potential of filamentous fungi as a source of food and food supplements. The commercialization potential as well as social, legal and safety issues of fungi-based food products are discussed.
... The postprandial rise in circulating plasma EAAs following ingestion of the plant-derived protein blend strongly increased muscle protein synthesis rates when compared with basal, postabsorptive values ( Figure 4). The response tended to be of a similar magnitude when compared with previous responses observed following ingestion of similar amounts of high-quality animal-derived proteins (25,38,39). In the present study, we included a control treatment in which 30 g highquality milk protein concentrate was ingested. ...
Background: Plant-derived proteins are considered to have lesser anabolic properties when compared with animal-derived proteins. The attenuated rise in muscle protein synthesis rates following ingestion of plant-derived compared with animal-derived protein has been, at least partly, attributed to deficiencies in specific amino acids such as leucine, lysine, and/or methionine. Combining different plant-derived proteins could provide plant-derived protein blends with a more balanced amino acid profile.Objectives: This study aimed to compare postprandial muscle protein synthesis rates following the ingestion of 30 g milk protein with a 30 g blend combining wheat, corn, and pea protein in healthy young men.Methods: In a randomized, double-blind, parallel-group design, 24 young males (aged 24 ± 4 y) received a primed continuous l-[ring-13C6]-phenylalanine infusion after which they ingested 30 g milk protein (MILK) or a 30 g plant-derived protein blend combining 15 g wheat, 7.5 g corn, and 7.5 g pea protein (PLANT-BLEND). Blood and muscle biopsies were collected frequently for 5 h to assess postprandial plasma amino acid profiles (secondary outcome) and subsequent muscle protein synthesis rates (primary outcome). Data were analyzed by 2-factor repeated measures ANOVA and 2-samples t tests.Results: MILK increased plasma essential amino acid concentrations more than PLANT-BLEND over the 5 h postprandial period (incremental AUC = 151 ± 31 compared with 79 ± 12 mmol·300 min·L−1, respectively; P Conclusions: Ingestion of 30 g plant-derived protein blend combining wheat-, corn-, and pea-derived protein increases muscle protein synthesis rates in healthy young males. The muscle protein synthetic response to the ingestion of 30 g of this plant-derived protein blend does not differ from the ingestion of an equivalent amount of a high-quality animal-derived protein
... Moreover, the high bioavailability and amino acid composition of mycoproteins can stimulate a greater rate of muscle protein synthesis compared to milk protein in healthy young men (Dunlop et al. 2017). Subsequently, mycoproteins show great promise as a source of dietary protein that has the potential to support skeletal muscle protein metabolism (Coelho et al. 2021;Monteyne et al. 2020). Several studies have reported that mycoprotein consumption can change blood lipid levels by reducing plasma cholesterol and improving high-density lipoproteins (Turnbull et al. 1992;Ishikawa 1994;Ruxton and McMilan 2010;Coelho et al. 2021). ...
Fungi are an understudied resource possessing huge potential for developing products that can greatly improve human well-being. In the current paper, we highlight some important discoveries and developments in applied mycology and interdisciplinary Life Science research. These examples concern recently introduced drugs for the treatment of infections and neurological diseases; application of –OMICS techniques and genetic tools in medical mycology and the regulation of mycotoxin production; as well as some highlights of mushroom cultivaton in Asia. Examples for new diagnostic tools
in medical mycology and the exploitation of new candidates for therapeutic drugs, are also given. In addition, two entries illustrating the latest developments in the use of fungi for biodegradation and fungal biomaterial production are provided.
Some other areas where there have been and/or will be significant developments are also included. It is our hope that this paper will help realise the importance of fungi as a potential industrial resource and see the next two decades bring forward
many new fungal and fungus-derived products.
... These properties make Quorn ™ mycoprotein well-suited to regions with high prevalence rates of obesity-related diseases such as North America and Europe (1, 78). A series of recent studies in human physiology by have examined the capacity for mycoprotein to regulate skeletal muscle protein metabolism in young and older adults, with encouraging results (79). ...
... These properties make Quorn ™ mycoprotein well-suited to regions with high prevalence rates of obesity-related diseases such as North America and Europe (1, 78). A series of recent studies in human physiology by have examined the capacity for mycoprotein to regulate skeletal muscle protein metabolism in young and older adults, with encouraging results (79). ...
A waste-to-protein system that integrates a range of waste-to-protein upgrading technologies has the potential to converge innovations on zero-waste and protein security to ensure a sustainable protein future. We present a global overview of food-safe and feed-safe waste resource potential and technologies to sort and transform such waste streams with compositional quality characteristics into food-grade or feed-grade protein. The identified streams are rich in carbon and nutrients and absent of pathogens and hazardous contaminants, including food waste streams, lignocellulosic waste from agricultural residues and forestry, and contaminant-free waste from the food and drink industry. A wide range of chemical, physical, and biological treatments can be applied to extract nutrients and convert waste-carbon to fermentable sugars or other platform chemicals for subsequent conversion to protein. Our quantitative analyses suggest that the waste-to-protein system has the potential to maximise recovery of various low-value resources and catalyse the transformative solutions toward a sustainable protein future. However, novel protein regulation processes remain expensive and resource intensive in many countries, with protracted timelines for approval. This poses a significant barrier to market expansion, despite accelerated research and development in waste-to-protein technologies and novel protein sources. Thus, the waste-to-protein system is an important initiative to promote metabolic health across the lifespan and tackle the global hunger crisis.
... Indeed, mycoprotein ingestion has been reported to induce slower but longer-lasting high postprandial levels of insulin and amino acids compared to milk protein, with a dose-response effect which seems to plateau at 60-80 g (Dunlop, Kilroe et al., 2017). Greater muscle protein synthesis rates were described by Monteyne and colleagues after a single bolus of mycoprotein compared to a bolus of milk protein, in both rested and resistance-trained young men (Monteyne, Coelho et al., 2020). In addition, older adults on a high protein diet eating exclusively vegan sources of protein, with the majority being from mycoprotein (57%), showed protein synthesis rates similar to people ingesting predominantly (71%) animal-derived protein, during both resting and resistance training conditions (Monteyne, Dunlop et al., 2021). ...
Background
The drive to reduce the negative impact of the global food system on the environment and human health, and to feed a growing global population, has led to the rapid development of meat alternatives, including plant-based and mycoprotein-based products such as burgers, cured meat and nuggets. These are generally food items manufactured with highly refined ingredients, so health professionals interested in promoting plant-based diets, or a reduction in meat consumption, need a deeper understanding about the potential health effects of these products in order to present them to the public in an objective and helpful manner.
Scope and approaches
In this narrative review, a search of the current available scientific literature was performed with the aim of exploring all these foods by delving into the way they are manufactured, their nutritional characteristics, their impact on health, as well as trying to understand their place in modern, diets.
Key findings and conclusion
Processed meat alternatives, despite being highly refined products, can be a good source of healthy food groups and nutrients often underrepresented in omnivores diets such as grains, legumes, plant protein and fibre, although attention must be paid to their salt and saturated fat content. For people wanting to move away from a meat-heavy diet, the consumption of these items can represent a stepping stone towards the adoption of more healthful dietary patterns centred on whole plant-foods. In addition, they might help to increase compliance with the new lifestyle as they tend to replicate some of the organoleptic properties of meat.
... The authors predicted that the utilization of polysaccharides contained in edible fungi for food and nutraceutical applications will have broad applications and large socioeconomic values. Studies have also demonstrated reductions in total cholesterol levels, postmeal insulinemia, and energy intake following modest inclusions of fungi into the diet (Bottin et al., 2016;Coelho et al., 2021;Dunlop et al., 2017;Monteyne et al., 2020;Ruxton & McMillan, 2010;Turnbull et al., 1992). Souza Filho et al. (2019) presented an excellent review of the health aspects of mycoprotein consumption. ...
Cells cultivated in bioreactors offer many possibilities for the production of novel and nutritious food products. Scientific and technological advances in cellular agriculture and processing technologies have allowed for the development of new techniques to utilize in vitro animal cells, plant cells, and microorganisms to mimic the organoleptic and nutritional properties of traditional foods as well as to potentially develop entirely new product classes. This review compiles and discusses the state-of-the-art cellular production and processing systems including 3D printing of customizable cell-cultivated food products. In addition to the technological state-of-the art, this article reviews the nutritional characteristics of cell-cultivated foods, introduces examples of new food products, and compiles economic characteristics and environmental impacts of each production system as assessed through technoeconomic analyses and lifecycle assessments. The factors influencing consumer acceptance of cell-cultivated foods are articulated and the potential implications of these new technologies on traditional agricultural industries and food chains are discussed. Lastly, future research and development trajectories are introduced with suggestions for continued development. K E Y W O R D S cellular agriculture, cultured meat, filamentous fungi, future foods, microalgae
... In these trials, mycoprotein appeared to represent a bioavailable and insulinotropic protein food source, resulting in slower and more sustained hyperinsulinaemia and hyperaminoacidaemia compared with protein-matched milk [55]. Other work has further shown that 70 g of mycoprotein (31.5 g protein: 2.5 g leucine) stimulated both resting and postexercise muscle protein synthesis rates in resistance-trained young males, and this was to a level greater than a leucine-matched bolus of milk protein [56]. Most recently, a 3-day intervention has shown that vegan-derived dietary protein (primarily in the form of mycoprotein) compares with animal-derived protein and can support both rested and exercised daily myofibrillar protein synthesis rates (MPS) in healthy aged adults (mean age 66 years) consuming a high-protein diet [57]. ...
Food-Based Dietary Guidelines (FBDG) lack uniformity globally, with the integration of protein food sources being highly variable. Protein guidance tends to be dichotomous, e.g., animal versus plant with other categories such as fungal proteins being overlooked. In 2019 the EAT Lancet Food in the Anthropocene report was a chief driver questioning the need to supply healthy diets from sustainable food systems. Some countries are developing FBDG that integrate these aspects, but these are quite often protracted, too subtle or misaligned with other countries, diluting the effects of meaningful global change. Protein quality metrics also underpin the dissemination of dietary guidance. However, for protein, these remain based on a food’s essential amino acid profile and digestibility scores, thus are nutritionally and physiologically centric. It has been proposed that this definition is becoming increasingly myopic from a wider societal perspective. Updated indices should include contemporary issues such as protein diversity and environmental outcomes. Taken together, there is opportunity for renewed thinking about both FBDG and protein quality definitions, with scope to include both health and environmental outcomes and need to move towards the concept of protein diversification.
... Myofibrillar protein synthesis was found to be equivalent for mycoprotein compared with animal protein foods and whey protein in both exercised and rested leg muscle [69]. Mycoprotein stimulated greater post-exercise muscle protein synthesis and was superior in supporting acute tissue remodelling, compared with (lysine-matched) milk protein [70], whereas enrichment of mycoprotein with branched-chain amino acids (BCAA) failed to further enhance muscle protein synthesis [71]. ...
Future food security for healthy populations requires the development of safe, sustainably-produced protein foods to complement traditional dietary protein sources. To meet this need, a broad range of non-traditional protein foods are under active investigation. The aim of this review was to evaluate their potential effects on human health and to identify knowledge gaps, potential risks, and research opportunities. Non-traditional protein sources included are algae, cereals/grains, fresh fruit and vegetables, insects, mycoprotein, nuts, oil seeds, and legumes. Human, animal, and in vitro data suggest that non-traditional protein foods have compelling beneficial effects on human health, complementing traditional proteins (meat/poultry, soy, eggs, dairy). Improvements in cardiovascular health, lipid metabolism, muscle synthesis, and glycaemic control were the most frequently reported improvements in health-related endpoints. The mechanisms of benefit may arise from their diverse range of minerals, macro- and micronutrients, dietary fibre, and bioactive factors. Many were also reported to have anti-inflammatory, antihypertensive, and antioxidant activity. Across all protein sources examined, there is a strong need for quality human data from randomized controlled intervention studies. Opportunity lies in further understanding the potential effects of non-traditional proteins on the gut microbiome, immunity, inflammatory conditions, DNA damage, cognition, and cellular ageing. Safety, sustainability, and evidence-based health research will be vital to the development of high-quality complementary protein foods that enhance human health at all life stages.
... Instead, a 60 g bolus of wheat protein was required to stimulate an increased response of MPS in older adults. Moreover, the ingestion of 30 g of corn protein (63) and 70 g of mycoprotein (64) was recently demonstrated to increase the stimulation of MPS in healthy young males. Taken together, these findings have implications for future dietary guidelines that might, besides supporting optimal nutritional guidelines, also support a more sustainable future for protein nutrition. ...
This narrative review summarizes key concepts in dairy nutrition for supporting human health throughout the life course. Milk and dairy products have been a staple component of our diet for thousands of years and provide a wide range of important nutrients that are otherwise difficult to obtain from dairy-free diets. In this review, we provide a broad perspective on the nutritional roles of iodine and dairy protein in supporting human health during pregnancy and early life, childhood and adolescence, mid- and later-life. New methodologies to identify biomarkers of dairy intake via high-throughput mass spectrometry are discussed, and new concepts such as the role of the food matrix in dairy nutrition are introduced. Finally, future policy and research related to the consumption of dairy and non-dairy alternatives for health are discussed with a view to improving nutritional status across the lifespan.
... New protein sources have been studied as alternatives to animal proteins in recent years. Studies evaluating the anabolic response to a fungi protein, namely, "mycoprotein", were conducted in both young [177] and older individuals [178]. Mycoprotein has high protein density with similar amino acid content to dairy proteins and seems to present good digestibility [179]. ...
Sarcopenia is one of the main issues associated with the process of aging. Characterized by muscle mass loss, it is triggered by several conditions, including sedentary habits and negative net protein balance. According to World Health Organization, it is expected a 38% increase in older individuals by 2025. Therefore, it is noteworthy to establish recommendations to prevent sarcopenia and several events and comorbidities associated with this health issue condition. In this review, we discuss the role of these factors, prevention strategies, and recommendations, with a focus on protein intake and exercise.
... Hashempour-Baltork et al. (2020) compared the quality of the mycoproteins with that of meat proteins and demonstrated that nutritional indices of these two sources were almost similar. Monteyne et al. (2020) reported that mycoproteins were good food sources enriched with EAAs. Table 4. ...
Processed meat is one of the most consumed products worldwide. Naturally, production of proteins with animal origins includes limitations such as costs, energy, time, and environmental problems. Thus, replacement of meats by alternative biomaterials such as mycoproteins can be promising. Mycoproteins with hyphal morphologies, including branches and lengths, have close structures to meat and can be a potential alternative for meat products. Therefore, the major objectives of this study included complete replacement of sausage meats by mycoproteins and comparing characteristics of the novel formula with those of meat. In general, physicochemical, microbial, nutritional, and mechanical characteristics of the formulas were assessed. Results showed that the mycoprotein substitution improved the nutritional and health effects due to the higher valuable protein and lower lipid contents. Besides, it had a high content of essential amino acid and unsaturated fatty acid, compared to meat sausage. Absence of yeasts, molds, Salmonella spp., Eshrichia (E.)coli, and Staphiloccocus (S.)aureus verified the effectiveness of the heat treatment and also the effectiveness of the hygienic procedures in both samples. With regard to phycicochemical properties, more contents of moisture and lipids in sausages containing mycoprotein were linked to further water binding capacity (WBC) (P < 0.05) and oil binding capacity (OBC) in them, compared to beef samples. Besides, the mycoprotein sample had lower (P < 0.05) values of carbohydrates, ash, and pH, compared to the beef sample. In contrast, beef sausages had better textural characteristics, such as hardness, cohesiveness, gumminess, and springiness indexes, compared to mycoprotein sausages. Higher water and OBC values of the mycoproteins led to the filling of the protein interstitial spaces as well as decreasing of the textural attributes. Thus, it resulted in the use of less oil and water in mycoprotein formulations. In conclusion, mycoproteins can be addressed as appropriate replacements for meats in sausages.
... Several human studies have investigated the effects of edible fungi in relation to cholesterol levels, insulin levels, and energy intake [80][81][82][83][84][85]. Those studies demonstrated that incorporating modest amounts of fungi into the diet could reduce total cholesterol levels, post meal insulinemia, and energy intake. ...
The rapid growth of human civilizations has led to imminent pressures to develop new food products with increased nutritional characteristics and decreased environmental footprints. Filamentous fungi, a class of microorganisms that have been utilized in a wide variety of foods for thousands of years, have recently garnered widespread attention in research communities and commercial ventures seeking to explore new and innovative applications in a diverse array of food products including, but not limited to, their more established applications as alternative proteins. Technological advances in the cultivation and processing of filamentous fungi have created new frontiers in the control of textures, flavors, and nutritional properties of fungi-based foods. This review highlights technological advances in the production of fungi-based foods from cultivation to product manufacturing, presents the current state of the art in fungi-based food products, and offers thoughts on their future trajectories. Emphasis is given to circular bioprocessing concepts for the sustainable utilization of agricultural and food processing byproducts.
... Seaweed and fungi derived pigments or vegetable derived inks such as beetroot ink can be employed to manufacture faux meat. Quorn a fungi-derived mycoprotein rich in essential amino acids and fibre has been reported to support post exercise recovery better than milk protein (Monteyne et al. 2020). Thus, in our search for more sustainable and nutritionally superior protein sources, the trend shifts towards incorporation of low carbon food ingredients such as algae, fungi and insects for manufacturing functional food products aimed at promoting longevity. ...
Epidemiological studies have shown certain diets such as Mediterranean diet, Okinawa diet, New Nordic diet and vegetarian diets to promote longevity. Omega-3 fatty acids, bioactive peptides, polyphenols and antioxidants are some of the implicated molecules derived from both plant and animal food that provide protection against cellular ageing. The role of gut microbiome and its interaction with dietary components has provided novel ways to understand the process of ageing. Beyond the inherent biochemical composition of plants and animals consumed, the methods employed for farming and agriculture (such as organic farming) as well as food preparation techniques (such as frying, grilling, steaming) have a major effect on the health benefits derived from the dietary source. In conclusion, health promoting effect of animal and plant based diets depend on obtaining recommended daily allowances of health promoting ingredients from a portion and minimizing intake of harmful components such as saturated fats, nitrites, nitrates, anti-nutrients amongst others. A well balanced personalized diet catering to an individual’s age, genetic predisposition to allergies and diseases and microbiome needs to be followed for longevity. Novel food processing technologies such as 3-D printing that incorporates both plant & animal ingredients will inch us closer to fabricating ideal functional food products aimed at promoting longevity in a sustainable way.
... The digestibility results obtained with MP were not considered suitable to derive a reliable IVDIAAS value. We like to refer to several in vitro and in vivo studies that concluded a high digestibility of mycoprotein (Udall et al., 1984, Edwards & Cummings, 2010, Dunlop et al., 2017, Monteyne et al., 2020a, Monteyne et al., 2020b although from none of these studies a DIAAS value could be concluded. ...
We studied several sustainable alternative protein concentrates and a whey protein concentrate as reference, to determine their protein composition, digestibility and quality using the harmonized INFOGEST static protocol. The proteins concentrates were analyzed to determine their conversion factor, degree of hydrolysis, true ileal digestibility, in vitro digestible indispensable amino acid score (IVDIAAS) and total absorbable amino acids and total essential amino acids. The results revealed that whey, blood plasma concentrate and yeast protein concentrate have a high mean true ileal indispensable amino acid in vitro digestibility (91.1–85.8%), closely followed by corn, pea, potato and proteins derived from lesser meal worms (ranging between 82.5 and 77.9%). Mycoprotein gave a much lower score in the mass balance, so that its other results could not be interpreted as being reliable. Whey, potato, blood plasma and yeast protein concentrates ranked highest in IVDIAAS (between 119 and 97.2), followed by lesser meal worm and pea (between 73.8 and 57.8) with corn protein concentrate having the lowest IVDIAAS due to underrepresentation of lysine. The method and data presented in this paper can form a start for further applying the INFOGEST in vitro digestion protocol to evaluate protein quality.
... For example, despite providing equivalent total protein, whole eggs have been shown to more effectively activate mTORC1 [62] and support MyoPS after resistance exercise in young adults than egg whites [152]. It has also been reported that mycoprotein, a sustainably produced fungal protein, supports greater rates of mixed muscle protein synthesis after resistance exercise than a leucine-matched (but not isoprotein) quantity of milk protein [153]. Therefore, Master athletes should prioritize the consumption of nutrient and protein dense foods to meet their meal and daily protein targets. ...
It is established that protein requirements are elevated in athletes to support their training and post-exercise recovery and adaptation, especially within skeletal muscle. However, research on the requirements for this macronutrient has been performed almost exclusively in younger athletes, which may complicate their translation to the growing population of Master athletes (i.e. > 35 years old). In contrast to older (> 65 years) untrained adults who typically demonstrate anabolic resistance to dietary protein as a primary mediator of the ‘normal’ age-related loss of muscle mass and strength, Master athletes are generally considered successful models of aging as evidenced by possessing similar body composition, muscle mass, and aerobic fitness as untrained adults more than half their age. The primary physiology changes considered to underpin the anabolic resistance of aging are precipitated or exacerbated by physical inactivity, which has led to higher protein recommendations to stimulate muscle protein synthesis in older untrained compared to younger untrained adults. This review puts forth the argument that Master athletes have similar muscle characteristics, physiological responses to exercise, and protein metabolism as young athletes and, therefore, are unlikely to have protein requirements that are different from their young contemporaries. Recommendations for protein amount, type, and pattern will be discussed for Master athletes to enhance their recovery from and adaptation to resistance and endurance training.
... Likewise, a randomized, single-blind, cross-over design study from Dunlop et al. (2017) conducted on young males subjects (n = 15) suggested that the insulin response is lower and more sustained on a mass-matched meal bolus, but comparable between mycoprotein and milk protein on a protein-matched meal bolus. This was supported by similar findings from the Monteyne et al. (2020) randomized, double-blind, parallel-group study in healthy resistance-trained male subjects (n = 20). The study showed that a leucine-matched bolus of mycoprotein had a lower insulin response in the first 15 min when compared to milk, but comparable in the subsequent time points. ...
Background; The structure of many plant- and fungal-based foods is determined by cell walls which are the primary source of dietary fiber. Several studies have shown that consumption of cell wall fibers from plants and fungi can modulate digestion leading to health-promoting effects such as increasing satiety and reducing the risk of cardiovascular diseases and type-2 diabetes.
Scope and Approach; We focus on the impact of the food structure determined by plant and fungal cell walls on digestion and subsequent physiological responses. The underlying mechanisms promoting health effects may differ between plant and fungal cell walls, considering their different structural and biochemical organizations. Fungal cell walls have been vastly understudied compared to plant cell walls in this regard. Therefore, we highlight differences and similarities of plant- and fungal-based foods that may underlie the observed health benefits.
Key Findings and Conclusions; The ability of the plant cell walls in our diet to influence digestion and improve human health has been intensely investigated over many years. The health outcomes observed following plants and fungi consumption appear similar, despite fundamental differences between the two kingdoms of life. The possible mechanisms underlying the health effects are the control of nutrient bioaccessibility, binding and sequestration of digestive components, increasing viscosity, and colonic fermentation. Mechanisms by which cell walls influence bioaccessibility of nutrients from fungal and plant cell walls are discussed. Moreover, consistent evidence for the fungal counterpart is still lacking, and further studies focusing on the whole structure of fungi are required.
... Although we found a small number of studies whereby the mean difference in postprandial MPS favored lower-quality sources (45,48), this may be due to this study providing an optimal dose of protein to stimulate MPS or that the comparator proteins (i.e., casein and milk compared with whey) were still of relatively high quality (10). Nevertheless, although the superior muscle anabolic properties of higher, predominantly isolated, quality protein sources were apparent, it is important to note that such conclusions are based on dose-matched protein sources, and it may be possible to ingest larger doses or combinations of lower-quality proteins to elicit a similar MPS response to higher-quality sources (24,48,72,73). ...
Background:
There is much debate regarding the source/quality of dietary proteins in supporting indices of skeletal muscle anabolism.
Objective:
We performed a systematic review and meta-analysis to determine the effect of protein source/quality on acute muscle protein synthesis (MPS) and changes in lean body mass (LBM) and strength, when combined with resistance exercise (RE).
Methods:
A systematic search of the literature was conducted to identify studies that compared the effects of ≥2 dose-matched, predominantly isolated protein sources of varying "quality." Three separate models were employed as follows: 1) protein feeding alone on MPS, 2) protein feeding combined with a bout of RE on MPS, and 3) protein feeding combined with longer-term resistance exercise training (RET) on LBM and strength. Further subgroup analyses were performed to compare the effects of protein source/quality between young and older adults. A total of 27 studies in young (18-35 y) and older (≥60 y) adults were included.
Results:
Analysis revealed an effect favoring higher-quality protein for postprandial MPS at rest [mean difference (MD): 0.014%/h; 95% CI: 0.006, 0.021; P < 0.001] and following RE (MD: 0.022%/h; 95% CI: 0.014, 0.030; P < 0.00001) in young (model 1: 0.016%/h; 95% CI: -0.004, 0.036; P = 0.12; model 2: 0.030%/h; 95% CI: 0.015, 0.045; P < 0.0001) and older (model 1: 0.012%/h; 95% CI: 0.006, 0.018; P < 0.001; model 2: 0.014%/h; 95% CI: 0.007, 0.021; P < 0.001) adults. However, although higher protein quality was associated with superior strength gains with RET [standardized mean difference (SMD): 0.24 kg; 95% CI: 0.02, 0.45; P = 0.03)], no effect was observed on changes to LBM (SMD: 0.05 kg; 95% CI: -0.16, 0.25; P = 0.65).
Conclusions:
The current review suggests that protein quality may provide a small but significant impact on indices of muscle protein anabolism in young and older adults. However, further research is warranted to elucidate the importance of protein source/quality on musculoskeletal aging, particularly in situations of low protein intake.
... In a recent study comparing postprandial myofibrillar protein synthesis (myoPS) in healthy older adults, 35 g of casein protein stimulated an increase in myoPS, whereas, a 35 g of wheat protein did not [42]. However, a 65 g dose of wheat protein (delivering the same amount of Leu as 35 g of casein) robustly stimulated myoPS [42], and in a separate study 32 g of fungal protein (Fusarium venenatum) stimulated postprandial myoPS to a greater extent than a Leu-matched 26 g bolus of milk protein [43]. ...
The quality and nutritional value of dietary proteins are determined by the quantity, digestibility and bioavailability of essential amino acids (EAA), which play a critical role in human growth, longevity and metabolic health. Plant-source protein is often deficient in one or more EAAs (e.g., branched-chain amino acids, lysine, methionine and/or tryptophan) and, in its natural form, is less digestible than animal-source protein. Nevertheless, dietary intake of plant-source protein has been promoted because of its potential health benefits, lower cost of production and lower environmental impact compared to animal-source protein. Implementation of dietary strategies that improve both human and planetary health are of critical importance and subject to growing interest from researchers and consumers. Therefore, in this review we analyse current plant protein intake patterns and discuss possible countermeasures that can enhance plant protein nutrition, examples include: (1) combining different plant proteins with complementary EAA profiles; (2) identification and commercial cultivation of new and novel high-quality plant proteins; (3) industrial and domestic processing methods; and (4) genome-editing techniques.
... In this issue of The American Journal of Clinical Nutrition, a potential meat replacer, a single-cell fungal Myco, is reported to stimulate MPS to a greater extent than milk protein in both rested and exercised leg muscle of healthy young men (17). The filamentous microfungus Fusarium venenatum is attractive as a meat replacer because it can be grown in continuous culture to produce a high-fiber (β-glucan and chitin), proteindense (>50% energy) product with a favorable fatty acid profile (mainly PUFAs), with high concentrations of zinc and selenium, with an iron concentration about the same as that of chicken but with no vitamin B-12, which can be processed to make various meat replacers (18). ...
Background:
It remains unclear whether non-animal-derived dietary protein sources (and therefore vegan diets) can support resistance training-induced skeletal muscle remodeling to the same extent as animal-derived protein sources.
Methods:
In Phase 1, 16 healthy young adults (m = 8, f = 8; age: 23 ± 1 y; BMI: 23 ± 1 kg/m2) completed a 3-d dietary intervention (high protein, 1.8 g·kg bm-1·d-1) where protein was derived from omnivorous (OMNI1; n = 8) or exclusively non-animal (VEG1; n = 8) sources, alongside daily unilateral leg resistance exercise. Resting and exercised daily myofibrillar protein synthesis (MyoPS) rates were assessed using deuterium oxide. In Phase 2, 22 healthy young adults (m = 11, f = 11; age: 24 ± 1 y; BMI: 23 ± 0 kg/m2) completed a 10 wk, high-volume (5 d/wk), progressive resistance exercise program while consuming an omnivorous (OMNI2; n = 12) or non-animal-derived (VEG2; n = 10) high-protein diet (∼2 g·kg bm-1·d-1). Muscle fiber cross-sectional area (CSA), whole-body lean mass (via DXA), thigh muscle volume (via MRI), muscle strength, and muscle function were determined pre, after 2 and 5 wk, and postintervention.
Objectives:
To investigate whether a high-protein, mycoprotein-rich, non-animal-derived diet can support resistance training-induced skeletal muscle remodeling to the same extent as an isonitrogenous omnivorous diet.
Results:
Daily MyoPS rates were ∼12% higher in the exercised than in the rested leg (2.46 ± 0.27%·d-1 compared with 2.20 ± 0.33%·d-1 and 2.62 ± 0.56%·d-1 compared with 2.36 ± 0.53%·d-1 in OMNI1 and VEG1, respectively; P < 0.001) and not different between groups (P > 0.05). Resistance training increased lean mass in both groups by a similar magnitude (OMNI2 2.6 ± 1.1 kg, VEG2 3.1 ± 2.5 kg; P > 0.05). Likewise, training comparably increased thigh muscle volume (OMNI2 8.3 ± 3.6%, VEG2 8.3 ± 4.1%; P > 0.05), and muscle fiber CSA (OMNI2 33 ± 24%, VEG2 32 ± 48%; P > 0.05). Both groups increased strength (1 repetition maximum) of multiple muscle groups, to comparable degrees.
Conclusions:
Omnivorous and vegan diets can support comparable rested and exercised daily MyoPS rates in healthy young adults consuming a high-protein diet. This translates to similar skeletal muscle adaptive responses during prolonged high-volume resistance training, irrespective of dietary protein provenance. This trial was registered at clinicaltrials.gov as NCT03572127.
A waste-to-protein system that integrates a range of waste-to-protein upgrading technologies has the potential to converge innovations on zero-waste and protein security to ensure a sustainable protein future. We present...
According to the results obtained from the present research, which was
carried out aimed at improving the nutritional value, health and texture of
protein products containing meat, the complete replacement of meat with
myco-protein leads to a significant reduction in the texture characteristics
of the product, such as firmness, elasticity, gumminess and on the other
hand, there was no significant change in the moisture content of the samples. Also, the results indicated that the samples with fungus mycoprotein contain higher level of unsaturated fat and protein and less carbohydrates and ash than the samples containing meat, and therefore, the sausages made from these products have higher nutritional and health value than the beef products.
The rapid increase in the world’s population leads to an increase in food demand. As a matter of fact, it is predicted that consumption of animal protein will double by 2050. However, increased consumption of animal protein raises climate crisis concerns as it may lead to an increased carbon and water footprint and more land use. Therefore, a sustainable sports nutrition concept is emerging for athletes with high animal protein consumption. As an alternative to animal protein sources, new protein sources are considered that can be used in athletes. In this review, the effects of plant, insect, fungal and algae-based protein sources on body composition, performance, and recovery by athletes were examined. Findings from the limited current literature reveal that: 1) vegetable protein sources are cost-effective and environmentally friendly, but they are low in sulfur containing essential amino acids, and must be consumed in large portions; 2) insect-based products have higher quality and higher protein content, but there is no consumption habit in many cultures; 3) although mycoproteins and microalgae have high protein content, they are not widely used yet due to their high production costs. In the future, it is expected that with the increase in awareness of the possible effects of animal protein production on the climate crisis, interest and research on alternative protein sources for sustainable sports nutrition will increase.
Ingestion of mycoprotein stimulates skeletal muscle protein synthesis (MPS) rates to a greater extent than concentrated milk protein when matched for leucine content, potentially attributable to the whole-food nature of mycoprotein. We hypothesised that bolus ingestion of mycoprotein as part of its whole food matrix would stimulate MPS rates to a greater extent compared with a leucine matched bolus of protein concentrated from mycoprotein. Twenty-four healthy young (age; 21±2 y, BMI; 24±3 kg.m ² ) males received primed, continuous infusions of L-[ ring - ² H 5 ]phenylalanine and completed a bout of unilateral resistance leg exercise before ingesting either 70 g mycoprotein (MYC; 31.4 g protein, 2.5 g leucine; n =12) or 38.2 g of a protein concentrate obtained from mycoprotein (PCM; 28.0 g protein, 2.5 g leucine; n =12). Blood and muscle samples ( vastus lateralis ) were taken pre- and (4 h) post- exercise/protein ingestion to assess postabsorptive and postprandial myofibrillar protein fractional synthetic rates (FSRs) in resting and exercised muscle. Protein ingestion increased plasma essential amino acid and leucine concentrations ( P <0.0001), but more rapidly (both 60 vs 90 min; P <0.0001) and to greater magnitudes (1367 vs 1346 μmol·L ⁻¹ and 298 vs 283 μmol·L ⁻¹ , respectively; P <0.0001) in PCM compared with MYC. Protein ingestion increased myofibrillar FSRs ( P <0.0001) in both rested (MYC, Δ0.031±0.007%·h ⁻¹ and PCM, Δ0.020±0.008%·h ⁻¹ ) and exercised (MYC, Δ0.057±0.011%·h ⁻¹ and PCM, Δ0.058±0.012%·h ⁻¹ ) muscle, with no differences between conditions ( P >0.05). Mycoprotein ingestion results in equivalent postprandial stimulation of resting and post-exercise myofibrillar protein synthesis rates irrespective of whether it is consumed within or without its whole-food matrix.
Interrupting prolonged sitting with intermittent exercise enhances postprandial glycemic control but has unknown effects on sensitizing skeletal muscle to dietary amino acids. We hypothesized that brief walking or body weight squats would enhance the utilization of dietary phenylalanine for myofibrillar protein synthesis (MyoPS) during prolonged sitting. Participants (7 males and 5 females; ~23y; ~25.1kg/m ² ; ~7300 steps/d) completed three 7.5h trials consisting of prolonged sitting (SIT) or sitting with intermittent (every 30 minutes) walking (WALK) or body weight squatting (SQUAT). Two mixed-macronutrient meals (~55:30:15% carbohydrate:fat:protein), enriched with L-[ring- ² H 5 ]phenylalanine or L-[ring- ¹³ C 6 ]phenylalanine, were provided to mimic breakfast and lunch. Tracer incorporation into myofibrillar protein was determined from the vastus lateralis with MyoPS estimated using plasma enrichment as precursor surrogate. Phosphorylation of candidate anabolic signaling proteins were determined by immunoblotting. There was no difference between conditions (p≥0.78) in the time course or area under the curve for plasma phenylalanine enrichment. MyoPS was greater (p<0.05, weighted planned comparison) in SQUAT (0.103±0.030%/h) and WALK (0.118±0.037%/h) compared to SIT (0.080±0.032%/h). Compared to SIT, there were moderate-to-large effect sizes, respectively, for SQUAT (ES=0.75; 95% CI -0.10-1.55) and WALK (ES=1.10; 95% CI 0.20-1.91). Fold change in rpS6 Ser240/244 phosphorylation was greater in SQUAT compared to SIT (7.6±2.7 vs. 1.6±0.45 fold, p<0.05) with no difference (p≥0.21) in any other targets measured (4E-BP1 Thr37/46 , eEF2 Thr56 , mTOR Ser2448 , ERK1/2 Thr202/Tyr204 ). Interrupting prolonged sitting with short 'activity snacks' improves the utilization of dietary amino acids for MyoPS. The long term impact of this practical lifestyle modification for muscle mass or quality should be investigated.
This review aimed to compare alternative protein sources in terms of nutritional composition and health benefits with the purpose of disseminating up-to-date knowledge and contribute for diversification of the food marked and consumers decision-making. Plant-based is the most well-established category of alternative proteins, but there is still room for diversification. Less conventional species such as chia seeds are prominent sources of ω-3 (∼60% total lipids), while hempseed and quinoa are notable sources of ω-6 (up to 58% and 61%, respectively). Edible insects and microalgae are alternative foods rich in protein (up to 70%), fibers (∼30%), as well as peptides and polysaccharides with antimicrobial, antioxidant, anti-hypertensive, antidiabetic, antidepressant, antitumor, and immunomodulatory activities. Additionally, lipid contents in insect larvae can be as high as 50%, on a dry weight basis, containing fatty acids with anti-inflammatory and antitumor properties. In contrast, edible fungi have low lipid contents (∼2%), but are rich in carbohydrates (up to 79%) and have balanced amino acid profiles. The results suggest that food formulations combining different alternative protein sources can meet dietary requirements. Further studies on flavoring and texturing processes will help to create meat and dairy analogs, thus helping to broaden acceptance and applicability of alternative protein sources.
The interest in a diet with a higher proportion of plant-based foods to animal-based foods is a global food pattern trend. However, there are concerns regarding adopting plants as the main dietary protein source to support muscle protein synthesis (MPS) and muscle mass. These concerns are centered on three issues: lower protein bioavailability due to antinutritional compounds in plants, lower per-serve scores of protein at similar energy intake, and amino acid scores of plants being lower than optimal. We aimed here to synthesize and discuss evidence around plant protein in human nutrition focusing on the capacity of these proteins to stimulate MPS as a key part of gaining or maintaining muscle mass. In this review, we addressed the issues of plant protein quality and provided evidence for how plant proteins can be made more effective to stimulate MPS and support muscle mass in partial or total replacement of consumption of products of animal origin.
Novelty:
Plant proteins are known, in general, to have lower protein quality scores than animal proteins, and this may have important implications, especially for those aiming to increase their skeletal muscle mass through exercise. A plant-based diet has been postulated to have lower protein quality limiting MPS responses and potentially compromising exercise-induced gains in muscle mass. Current evidence shows that plant proteins can stimulate MPS, as can whole foods, especially when combining food groups, increasing portion sizes, and optimizing amino acid bioavailability through processing or common preparation methods.
Background
Worldwide, the demand for healthier protein is rapidly increasing due to the population growth and health concerns associated with the consumption of red meat. Animal welfare, disease prevention and environmental challenges are the key driving factors for the development of meat analogues. Mycoprotein is a fungal-derived protein source that has been introduced as a more sustainable and healthier meat alternative due to its fibrous structure and unique functional profile.
Scope and approach
In this review, the historical perspective of mycoprotein development, nutritional composition, and the functional properties of mycoprotein are discussed. Next, the extraction of mycoprotein from agro-industrial waste by using different strains of microorganisms via submerged fermentation (SmF), solid-state fermentation (SSF) and surface culture method is summarized. Lastly, the health aspects of mycoprotein consumption including effects on energy intake, appetite regulation, glycemic response, total blood cholesterol, and muscle protein synthesis are also highlighted.
Key findings and conclusions
Recent studies have concluded that the mycoprotein has a higher nutritional value, meat-like texture and diverse functional properties which make it a promising source of protein to replace plant-based as well as animal-based meat proteins. By using various microbial strains on a diverse array of substrates under different conditions (pH, temperature, moisture, relative humidity (RH), and inoculum size and age), the extracted biomasses of mycoproteins have shown significantly higher yield and nutritional value via SmF fermentation. Finally, the intake of mycoprotein improves the lipid profile, lowers the energy intake, and stimulates muscle protein synthesis.
Mycoprotein was first discovered in the 1960s, yet today, its consumption and applications within the food industry continue to grow. This protein is derived from the soil-dwelling fungus Fusarium venenatum A3/5 and is used to produce mycoprotein found in Quorn—the leading fungal-derived protein source that is commercially available for consumption of human globally. Consumers are seeking alternative proteins—a shift driven by expanding global populations and mounting concerns about animal welfare, human and environmental health. The evidence-base for mycoprotein and its roles in promoting benefits to human health are well-established. It is a complete protein that is both bioavailable and to stimulate muscle protein synthesis post-exercise. Its consumption has been further linked to improved lipoprotein profiles, energy intake, and satiety levels, as well as potential benefits for glucose and insulin regulation. Increasingly, consumers are paying more attention to the environmental impacts of the foods they choose. Mycoprotein performs particularly well from this perspective, using significantly less land and water for production than animal-derived protein sources, contributing to its lower carbon footprint. Commercial mycoprotein production is also forecast to be net positive by 2030, thus putting more back into society, the global environment, and the economy than is taken out.
In the foreseeable future, mycoprotein consumption is projected to grow. It is envisioned to be consumed more frequently by reducetarians and flexitarians, the vegan market, generation alpha, the aged, and the environmentally aware. Given rising awareness of fungal biotechnology as a natural means of tackling contemporary problems, it is hoped that fungal protein will become increasingly recognized within food-based dietary guidelines. Given accruing science it is also likely that mycoprotein will be consumed for “functional health” and as part of future preventative health care. For example, its consumption could help to regulate appetite, satiety and subsequent body weight, blood lipid, and metabolic profiles, and prevent frailty/sarcopenia. This chapter explains how mycoprotein came about, how it is produced, and describes its ongoing roles from a futuristic perspective.
Background:
Protein ingestion increases muscle protein synthesis rates. However, limited data are currently available on the effects of branched-chain amino acid (BCAA) and branched-chain ketoacid (BCKA) ingestion on postprandial muscle protein synthesis rates.
Objective:
To compare the impact of ingesting 6 g BCAA, 6 g BCKA, and 30 g milk protein (MILK) on the postprandial rise in circulating amino acid concentrations and subsequent myofibrillar protein synthesis rates in older males.
Methods:
In a parallel design, 45 older males (age: 71 ± 1 y; BMI: 25.4 ± 0.8 kg/m2) were randomly assigned to ingest a drink containing 6 g BCAA, 6 g BCKA, or 30 g MILK. Basal and postprandial myofibrillar protein synthesis rates were assessed by primed continuous l-[ring-13C6]phenylalanine infusions with the collection of blood samples and muscle biopsies.
Results:
Plasma BCAA concentrations increased following test drink ingestion in all groups, with greater increases in the BCAA and MILK groups compared with the BCKA group (P < 0.05). Plasma BCKA concentrations increased following test drink ingestion in all groups, with greater increases in the BCKA group compared with the BCAA and MILK groups (P < 0.05). Ingestion of MILK, BCAA, and BCKA significantly increased early myofibrillar protein synthesis rates (0-2 h) above basal rates (from 0.020 ± 0.002%/h to 0.042 ± 0.004%/h, 0.022 ± 0.002%/h to 0.044 ± 0.004%/h, and 0.023 ± 0.003%/h to 0.044 ± 0.004%/h, respectively; P < 0.001), with no differences between groups (P > 0.05). Myofibrillar protein synthesis rates during the late postprandial phase (2-5 h) remained elevated in the MILK group (0.039 ± 0.004%/h; P < 0.001), but returned to baseline values following BCAA and BCKA ingestion (0.024 ± 0.005%/h and 0.024 ± 0.005%/h, respectively; P > 0.05).
Conclusions:
Ingestion of 6 g BCAA, 6 g BCKA, and 30 g MILK increases myofibrillar protein synthesis rates during the early postprandial phase (0-2 h) in vivo in healthy older males. The postprandial increase following the ingestion of 6 g BCAA and BCKA is short-lived, with higher myofibrillar protein synthesis rates only being maintained following the ingestion of an equivalent amount of intact milk protein. This trial was registered at Nederlands Trial Register (www.trialregister.nl) as NTR6047.
AIMS/HYPOTHESIS: We aimed to investigate the role of insulin in regulating human skeletal muscle metabolism in health and diabetes.
METHODS: We conducted a systematic review and meta-analysis of published data that examined changes in skeletal muscle protein synthesis (MPS) and/or muscle protein breakdown (MPB) in response to insulin infusion. Random-effects models were used to calculate weighted mean differences (WMDs), 95% CIs and corresponding p values. Both MPS and MPB are reported in units of nmol (100 ml leg vol.)(-1) min(-1).
RESULTS: A total of 104 articles were examined in detail. Of these, 44 and 25 studies (including a total of 173 individuals) were included in the systematic review and meta-analysis, respectively. In the overall estimate, insulin did not affect MPS (WMD 3.90 [95% CI -0.74, 8.55], p = 0.71), but significantly reduced MPB (WMD -15.46 [95% CI -19.74, -11.18], p < 0.001). Overall, insulin significantly increased net balance protein acquisition (WMD 20.09 [95% CI 15.93, 24.26], p < 0.001). Subgroup analysis of the effect of insulin on MPS according to amino acid (AA) delivery was performed using meta-regression analysis. The estimate size (WMD) was significantly different between subgroups based on AA availability (p = 0.001). An increase in MPS was observed when AA availability increased (WMD 13.44 [95% CI 4.07, 22.81], p < 0.01), but not when AA availability was reduced or unchanged. In individuals with diabetes and in the presence of maintained delivery of AA, there was a significant reduction in MPS in response to insulin (WMD -6.67 [95% CI -12.29, -0.66], p < 0.05).
CONCLUSIONS/INTERPRETATION: This study demonstrates the complex role of insulin in regulating skeletal muscle metabolism. Insulin appears to have a permissive role in MPS in the presence of elevated AAs, and plays a clear role in reducing MPB independent of AA availability.
Translocation and colocalization of mechanistic target of rapamycin complex 1 (mTORC1) with regulatory proteins represents a critical step in translation initiation of protein synthesis in vitro. However, mechanistic insight into the control of postprandial skeletal muscle protein synthesis rates at rest and after an acute bout of endurance exercise in humans is lacking. In crossover trials, eight endurance-trained men received primed-continuous infusions of L-[ring-2H5]phenylalanine and consumed a mixed-macronutrient meal (18 g protein, 60 g carbohydrates, 17 g fat) at rest (REST) and after 60 min of treadmill running at 70% VO2peak (EX). Skeletal muscle biopsies were collected to measure changes in phosphorylation and colocalization in the mTORC1-pathway, in addition to rates of myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis. MyoPS increased (P < 0.05) above fasted in REST (~2.1-fold) and EX (~twofold) during the 300 min postprandial period, with no corresponding changes in MitoPS (P > 0.05). TSC2/Rheb colocalization decreased below fasted at 60 and 300 min after feeding in REST and EX (P < 0.01). mTOR colocalization with Rheb increased above fasted at 60 and 300 min after feeding in REST and EX (P < 0.01), which was consistent with an increased phosphorylation 4E-BP1Thr37/46 and rpS6ser240/244 at 60 min. Our data suggest that MyoPS, but not MitoPS, is primarily nutrient responsive in trained young men at rest and after endurance exercise. The postprandial increase in MyoPS is associated with an increase in mTOR/Rheb colocalization and a reciprocal decrease in TSC2/Rheb colocalization and thus likely represent important regulatory events for in vivo skeletal muscle myofibrillar mRNA translation in humans.
Skeletal muscle supports locomotion and serves as the largest site of postprandial glucose disposal; thus it is a critical organ for physical and metabolic health. Skeletal muscle mass is regulated by the processes of muscle protein synthesis (MPS) and muscle protein breakdown (MPB), both of which are sensitive to external loading and aminoacidemia. Hyperaminoacidemia results in a robust but transient increase in rates of MPS and a mild suppression of MPB. Resistance exercise potentiates the aminoacidemia-induced rise in MPS that, when repeated over time, results in gradual radial growth of skeletal muscle (i.e., hypertrophy). Factors that affect MPS include both quantity and composition of the amino acid source. Specifically, MPS is stimulated in a dose-responsive manner and the primary amino acid agonist of this process is leucine. MPB also appears to be regulated in part by protein intake, which can exert a suppressive effect on MPB. At high protein doses the suppression of MPB may interfere with skeletal muscle adaptation following resistance exercise. In this review, we examine recent advancements in our understanding of how protein ingestion impacts skeletal muscle growth following resistance exercise in young adults during energy balance and energy restriction. We also provide practical recommendations for exercisers who wish to maximize the hypertrophic response of skeletal muscle during resistance exercise training.
Mechanistic target of rapamycin (mTOR) resides as two complexes within skeletal muscle. mTOR complex 1 (mTORC1-Raptor positive) regulates skeletal muscle growth, whereas mTORC2 (Rictor positive) regulates insulin sensitivity. To examine the regulation of these complexes in human skeletal muscle, we utilised immunohistochemical analysis to study the localisation of mTOR complexes prior to and following protein-carbohydrate feeding (FED) and resistance exercise plus protein-carbohydrate feeding (EXFED) in unilateral exercise model. In basal samples, mTOR and the lysosomal marker LAMP2 were highly co-localized and remained so throughout. In the FED and EXFED states, mTOR/LAMP2 complexes were redistributed to the cell periphery (WGA positive staining) (time effect; p=.025), with 39% (FED) and 26% (EXFED) increases in mTOR/WGA association observed 1h post-feeding/exercise. mTOR/WGA colocalisation continued to increase in EXFED at 3h (48% above baseline) whereas colocalisation decreased in FED (21% above baseline). A significant effect of condition (p=.05) was noted suggesting mTOR/WGA co-localization was greater during EXFED. This pattern was replicated in Raptor/WGA association, where a significant difference between EXFED and FED was noted at 3h post-exercise/feeding (p=.014). Rictor/WGA colocalization remained unaltered throughout the trial. Alterations in mTORC1 cellular location coincided with elevated S6K1 kinase activity, which rose to a greater extent in EXFED compared to FED at 1h post-exercise/feeding (p<.001), and only remained elevated in EXFED at the 3h time point (p=.037). Collectively these data suggest that mTORC1 redistribution within the cell is a fundamental response to resistance exercise and feeding, whereas mTORC2 is predominantly situated at the sarcolemma and does not alter localisation.
Background
Resistance training is a potent stimulus to induce muscle hypertrophy. Supplemental protein intake is known to enhance gains in muscle mass through activation of the mammalian target of rapamycin complex 1 (mTORC1) pathway, which initiates protein translation. While the optimal dose of high quality protein to promote post exercise anabolism in young or older men has been investigated, little is known about the minimum doses of protein required to potentiate the resistance exercise activation of anabolic signalling in middle aged men.
Methods
Twenty healthy men (46.3 ± 5.7 years, BMI: 23.9 ± 6.6 kg/m²) completed a single bout of unilateral resistance exercise consisting of 4 sets of leg extension and press at 80% of 1 repetition maximum. Participants were randomised to consume either formulated milk product containing 9 g milk protein (FMP) or an isoenergetic carbohydrate placebo (CHO) immediately post exercise, in a double blind fashion. A single muscle biopsy was collected at pre-exercise baseline and then bilateral biopsies were collected 90 and 240 min after beverage consumption.
Results
P70S6KThr389 phosphorylation was increased with exercise irrespective of group, P70S6KThr421/Ser424 was increased with exercise only in the FMP group at 240 min. Likewise, rpS6 Ser235/236 phosphorylation was increased with exercise irrespective of group, rpS6 Ser240/244 increased to a greater extent following exercise in the FMP group. mRNA expression of the amino acid transporter, LAT1/ SLC7A5 increased with both exercise and beverage consumption irrespective of group. PAT1/ SLC36A1, CAT1/ SLC7A1 and SNAT2/ SLC38A2 mRNA increased only after exercise regardless of group.
Conclusions
Nine grams of milk protein is sufficient to augment some measures of downstream mTORC1 signalling after resistance exercise but does not potentiate exercise induced increases in amino acid transporter expression. Formulated products containing nine grams of milk protein would be expected stimulate muscle anabolism after resistance exercise.
Trial registration
New Zealand Clinical Trials Registry ACTRN12615001375549. Registered: 17 December, 2015.
Background:
Amino acid availability stimulates protein synthesis via the mTORC1 (mechanistic target of rapamycin complex 1) signaling pathway. In response to an increase in cellular amino acid availability, translocation of cytosolic mTORC1 to the lysosomal surface is required to stimulate mTORC1 kinase activity. However, research elucidating the amino acid responsive mechanisms have thus far only been conducted in in vitro models. Our primary objective was to determine whether an increase in amino acid availability within human skeletal muscle in vivo would alter the expression of genes associated with amino acid sensing, transport and mTORC1 regulation. Our secondary objective was to determine whether an acute perturbation in lysosomal function would disrupt the normal pattern of muscle amino acid responsive gene expression.
Methods:
We recruited 13 young adults into one of two groups: The first group ingested 10 g of essential amino acids (EAA). The second group ingested 10 g of EAA in the presence of chloroquine (CQ), a lysosomotropic agent. The subjects from each group had biopsies of the vastus lateralis taken before and after EAA ingestion. We determined the relative mRNA expression of 51 potential amino acid responsive genes using RT-qPCR.
Results:
There was a differential mRNA expression for 22 genes, with 15 mRNAs significantly changing (P < 0.05) in response to EAA ingestion (e.g., REDD1: +209 ± 35%; SLC38A9: +31 ± 9%; SLC38A10: +57 ± 15%). In the CQ group, EAA ingestion resulted in a differential expression as compared to EAA alone (i.e., 11 out of the 22 genes were different (P < 0.05) between the two groups.).
Conclusions:
Expression of several amino acid sensing, transport, and mTORC1 regulatory genes in human skeletal muscle are responsive to an increase in amino acid availability. Furthermore, potential acute disruption of lysosomal function by ingestion of chloroquine interferes with the normal pattern of gene expression following feeding. Our in vivo data in humans provide preliminary support for the in vitro work linking amino acid sensing pathways to mTORC1 translocation to the lysosome.
Trial registration:
NCT00891696. Registered 29 April 2009.
The mechanistic target of rapamycin complex 1 (mTORC1) protein kinase is a master growth regulator that becomes activated at the lysosome in response to nutrient cues. Here, we identify cholesterol, an essential building block for cellular growth, as a nutrient input that drives mTORC1 recruitment and activation at the lysosomal surface. The lysosomal transmembrane protein, SLC38A9, is required for mTORC1 activation by cholesterol through conserved cholesterol-responsive motifs. Moreover, SLC38A9 enables mTORC1 activation by cholesterol independently from its arginine-sensing function. Conversely, the Niemann-Pick C1 (NPC1) protein, which regulates cholesterol export from the lysosome, binds to SLC38A9 and inhibits mTORC1 signaling through its sterol transport function. Thus, lysosomal cholesterol drives mTORC1 activation and growth signaling through the SLC38A9-NPC1 complex.
Protein supplementation during resistance exercise training augments hypertrophic gains. Protein ingestion and the resultant hyperaminoacidemia provides the building blocks (indispensable amino acids – IAA) for, and also triggers an increase in, muscle protein synthesis (MPS), suppression of muscle protein breakdown (MPB), and net positive protein balance (i.e., MPS > MPB). The key amino acid triggering the rise in MPS is leucine, which stimulates the mechanistic target of rapamycin complex-1, a key signalling protein, and triggers a rise in MPS. As such, ingested proteins with a high leucine content would be advantageous in triggering a rise in MPS. Thus, protein quality (reflected in IAA content and protein digestibility) has an impact on changes in MPS and could ultimately affect skeletal muscle mass. Protein quality has been measured by the protein digestibility-corrected amino acid score (PDCAAS); however, the digestible indispensable amino acid score (DIAAS) has been recommended as a better method for protein quality scoring. Under DIAAS there is the recognition that amino acids are individual nutrients and that protein quality is contingent on IAA content and ileal (as opposed to fecal) digestibility. Differences in protein quality may have important ramifications for exercise-induced changes in muscle mass gains made with resistance exercise as well as muscle remodelling. Thus, the purpose of this review is a critical appraisal of studies examining the effects of protein quality in supplementation on changes in muscle mass and strength as well as body composition during resistance training.
Background:
Muscle mass maintenance is largely regulated by basal muscle protein synthesis and the capacity to stimulate muscle protein synthesis after food intake. The postprandial muscle protein synthetic response is modulated by the amount, source, and type of protein consumed. It has been suggested that plant-based proteins are less potent in stimulating postprandial muscle protein synthesis than animal-derived proteins. However, few data support this contention.
Objective:
We aimed to assess postprandial plasma amino acid concentrations and muscle protein synthesis rates after the ingestion of a substantial 35-g bolus of wheat protein hydrolysate compared with casein and whey protein.
Methods:
Sixty healthy older men [mean ± SEM age: 71 ± 1 y; body mass index (in kg/m(2)): 25.3 ± 0.3] received a primed continuous infusion of l-[ring-(13)C6]-phenylalanine and ingested 35 g wheat protein (n = 12), 35 g wheat protein hydrolysate (WPH-35; n = 12), 35 g micellar casein (MCas-35; n = 12), 35 g whey protein (Whey-35; n = 12), or 60 g wheat protein hydrolysate (WPH-60; n = 12). Plasma and muscle samples were collected at regular intervals.
Results:
The postprandial increase in plasma essential amino acid concentrations was greater after ingesting Whey-35 (2.23 ± 0.07 mM) than after MCas-35 (1.53 ± 0.08 mM) and WPH-35 (1.50 ± 0.04 mM) (P < 0.01). Myofibrillar protein synthesis rates increased after ingesting MCas-35 (P < 0.01) and were higher after ingesting MCas-35 (0.050% ± 0.005%/h) than after WPH-35 (0.032% ± 0.004%/h) (P = 0.03). The postprandial increase in plasma leucine concentrations was greater after ingesting Whey-35 than after WPH-60 (peak value: 580 ± 18 compared with 378 ± 10 μM, respectively; P < 0.01), despite similar leucine contents (4.4 g leucine). Nevertheless, the ingestion of WPH-60 increased myofibrillar protein synthesis rates above basal rates (0.049% ± 0.007%/h; P = 0.02).
Conclusions:
The myofibrillar protein synthetic response to the ingestion of 35 g casein is greater than after an equal amount of wheat protein. Ingesting a larger amount of wheat protein (i.e., 60 g) substantially increases myofibrillar protein synthesis rates in healthy older men. This trial was registered at clinicaltrials.gov as NCT01952639.
A new method of total RNA isolation by a single extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described. The method provides a pure preparation of undegraded RNA in high yield and can be completed within 4 h. It is particularly useful for processing large numbers of samples and for isolation of RNA from minute quantities of cells or tissue samples.
Background:
Protein turnover in skeletal muscle tissue is highly responsive to nutrient intake in healthy adults.
Objective:
To provide a comprehensive overview of post-prandial protein handling, ranging from dietary protein digestion and amino acid absorption, the uptake of dietary protein derived amino acids over the leg, the post-prandial stimulation of muscle protein synthesis rates, to the incorporation of dietary protein derived amino acids in de novo muscle protein.
Design:
12 healthy young males ingested 20 g intrinsically [1-13C]-phenylalanine labeled protein. In addition, primed continuous L-[ring-2H5]-phenylalanine, L-[ring-2H2]-tyrosine, and L-[1-13C]-leucine infusions were applied, with frequent collection of arterial and venous blood samples, and muscle biopsies throughout a 5 h post-prandial period. Dietary protein digestion, amino acid absorption, splanchnic amino acid extraction, amino acid uptake over the leg, and subsequent muscle protein synthesis were measured within a single in vivo human experiment.
Results:
55.3±2.7% of the protein-derived phenylalanine was released in the circulation during the 5 h post-prandial period. The post-prandial rise in plasma essential amino acid availability improved leg muscle protein balance (from -291±72 to 103±66 μM·min-1·100 mL leg volume-1; P<0.001). Muscle protein synthesis rates increased significantly following protein ingestion (0.029±0.002 vs 0.044±0.004%·h-1 based upon the muscle protein bound L-[ring-2H5]-phenylalanine enrichments (P<0.01)), with substantial incorporation of dietary protein derived L-[1-13C]-phenylalanine into de novo muscle protein (from 0 to 0.0201±0.0025 MPE).
Conclusion:
Ingestion of a single meal-like amount of protein allows ~55% of the protein derived amino acids to become available in the circulation, thereby improving whole-body and leg protein balance. About 20% of the dietary protein derived amino acids released in the circulation are taken up in skeletal muscle tissue following protein ingestion, thereby stimulating muscle protein synthesis rates and providing precursors for de novo muscle protein synthesis.
Trial registration:
trialregister.nl 3638.
The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring (13)C₆ phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h(-1) in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h(-1) in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.
Clinical and consumer market interest is increasingly directed toward the use of plant-based proteins as dietary components aimed at preserving or increasing skeletal muscle mass. However, recent evidence suggests that the ingestion of the plant-based proteins soy and wheat results in a lower muscle protein synthetic response when compared with several animal-based proteins. The possible lower anabolic properties of plant-based protein sources may be attributed to the lower digestibility of plant-based sources, in addition to greater splanchnic extraction and subsequent urea synthesis of plant protein-derived amino acids when compared with the ingestion of animal-based proteins. The latter may be related to the relative lack of specific essential amino acids in plant- as opposed to animal-based proteins. Furthermore, most plant proteins have a relatively low leucine content, which may further reduce their anabolic properties when compared with animal proteins. However, few studies have actually assessed the postprandial muscle protein synthetic response to the ingestion of plant proteins, with soy and wheat protein being the primary sources studied. Despite the proposed lower anabolic properties of plant vs. animal proteins, various strategies may be applied to augment the anabolic properties of plant proteins. These may include the following: 1) fortification of plant-based protein sources with the amino acids methionine, lysine, and/or leucine; 2) selective breeding of plant sources to improve amino acid profile; 3) consumption of greater amounts of plant-based protein sources; or 4) combining the ingestion of multiple protein sources to provide for a more balanced amino acid profile. However, the efficacy of such dietary strategies on postprandial muscle protein synthesis remains to be studied. Future research comparing the anabolic properties of a variety of plant-based proteins should define the preferred protein sources to be used in nutritional interventions to support skeletal muscle mass gain or maintenance in both healthy and clinical populations.
© 2015 American Society for Nutrition.
Myostatin, a member of the transforming growth factor-β superfamily, is a potent negative regulator of skeletal muscle growth and is conserved in many species, from rodents to humans. Myostatin inactivation can induce skeletal muscle hypertrophy, while its overexpression or systemic administration causes muscle atrophy. As it represents a potential target for stimulating muscle growth and/or preventing muscle wasting, myostatin regulation and functions in the control of muscle mass have been extensively studied. A wealth of data strongly suggests that alterations in skeletal muscle mass are associated with dysregulation in myostatin expression. Moreover, myostatin plays a central role in integrating/mediating anabolic and catabolic responses. Myostatin negatively regulates the activity of the Akt pathway, which promotes protein synthesis, and increases the activity of the ubiquitin-proteasome system to induce atrophy. Several new studies have brought new information on how myostatin may affect both ribosomal biogenesis and translation efficiency of specific mRNA subclasses. In addition, although myostatin has been identified as a modulator of the major catabolic pathways, including the ubiquitin-proteasome and the autophagy-lysosome systems, the underlying mechanisms are only partially understood. The goal of this review is to highlight outstanding questions about myostatin-mediated regulation of the anabolic and catabolic signaling pathways in skeletal muscle. Particular emphasis has been placed on (1) the cross-regulation between myostatin, the growth-promoting pathways and the proteolytic systems; (2) how myostatin inhibition leads to muscle hypertrophy; and (3) the regulation of translation by myostatin.
Increasing amino acid availability (via infusion or ingestion) at rest or post-exercise enhances amino acid transport into human skeletal muscle. It is unknown whether alterations in amino acid availability, from ingesting different dietary proteins, can enhance amino acid transport rates and amino acid transporter (AAT) mRNA expression. We hypothesized that the prolonged hyperaminoacidemia from ingesting a blend of proteins with different digestion rates post-exercise would enhance amino acid transport into muscle and AAT expression as compared to the ingestion of a rapidly digested protein. In a double-blind, randomized clinical trial we studied 16 young adults at rest and after acute resistance exercise coupled with post-exercise (1h) ingestion of either a (soy-dairy) protein blend or whey protein. Phenylalanine net balance and transport rate into skeletal muscle were measured using stable isotopic methods in combination with femoral A-V blood sampling and muscle biopsies obtained at rest, 3 and 5h post-exercise. Phenylalanine transport into muscle and mRNA expression of select amino acid transporters (LAT1/SLC7A5, CD98/SLC3A2 SNAT2/SLC38A2, PAT1/SLC36A1, CAT1/SLC7A1) increased to a similar extent in both groups (P<0.05). However, the ingestion of the protein blend resulted in a prolonged and positive net phenylalanine balance during post-exercise recovery as compared to whey protein (P<0.05). Post-exercise myofibrillar protein synthesis increased similarly between groups. We conclude that while both protein sources enhanced post-exercise AAT expression, transport into muscle and myofibrillar protein synthesis, post-exercise ingestion of a protein blend results in a slightly prolonged net amino acid balance across the leg as compared to whey protein.
Leucine is a key amino acid involved in the regulation of skeletal muscle protein synthesis.
We assessed the effect of the supplementation of a lower-protein mixed macronutrient beverage with varying doses of leucine or a mixture of branched chain amino acids (BCAAs) on myofibrillar protein synthesis (MPS) at rest and after exercise.
In a parallel group design, 40 men (21 ± 1 y) completed unilateral knee-extensor resistance exercise before the ingestion of 25 g whey protein (W25) (3.0 g leucine), 6.25 g whey protein (W6) (0.75g leucine), 6.25 g whey protein supplemented with leucine to 3.0 g total leucine (W6+Low-Leu), 6.25 g whey protein supplemented with leucine to 5.0 g total leucine (W6+High-Leu), or 6.25 g whey protein supplemented with leucine, isoleucine, and valine to 5.0 g total leucine. A primed continuous infusion of l-[ring-(13)C6] phenylalanine with serial muscle biopsies was used to measure MPS under baseline fasted and postprandial conditions in both a rested (response to feeding) and exercised (response to combined feeding and resistance exercise) leg.
The area under the blood leucine curve was greatest for the W6+High-Leu group compared with the W6 and W6+Low-Leu groups (P < 0.001). In the postprandial period, rates of MPS were increased above baseline over 0-1.5 h in all treatments. Over 1.5-4.5 h, MPS remained increased above baseline after all treatments but was greatest after W25 (∼267%) and W6+High-Leu (∼220%) treatments (P = 0.002).
A low-protein (6.25 g) mixed macronutrient beverage can be as effective as a high-protein dose (25 g) at stimulating increased MPS rates when supplemented with a high (5.0 g total leucine) amount of leucine. These results have important implications for formulations of protein beverages designed to enhance muscle anabolism. This trial was registered at clinicaltrials.gov as NCT 1530646.
Background:
Older individuals generally experience a reduced food-chewing efficiency. As a consequence, food texture may represent an important factor that modulates dietary protein digestion and absorption kinetics and the subsequent postprandial protein balance.
Objective:
We assessed the effect of meat texture on the dietary protein digestion rate, amino acid availability, and subsequent postprandial protein balance in vivo in older men.
Design:
Ten older men (mean ± SEM age: 74 ± 2 y) were randomly assigned to a crossover experiment that involved 2 treatments in which they consumed 135 g of specifically produced intrinsically L-[1-(13)C]phenylalanine-labeled beef, which was provided as beef steak or minced beef. Meat consumption was combined with continuous intravenous L-[ring-(2)H5]phenylalanine and L-[ring-(2)H2]tyrosine infusion to assess beef protein digestion and absorption kinetics as well as whole-body protein balance and skeletal muscle protein synthesis rates.
Results:
Meat protein-derived phenylalanine appeared more rapidly in the circulation after minced beef than after beef steak consumption (P < 0.05). Also, its availability in the circulation during the 6-h postprandial period was greater after minced beef than after beef steak consumption (61 ± 3% compared with 49 ± 3%, respectively; P < 0.01). The whole-body protein balance was more positive after minced beef than after beef steak consumption (29 ± 2 compared with 19 ± 3 μmol phenylalanine/kg, respectively; P < 0.01). Skeletal muscle protein synthesis rates did not differ between treatments when assessed over a 6-h postprandial period.
Conclusions:
Minced beef is more rapidly digested and absorbed than beef steak, which results in increased amino acid availability and greater postprandial protein retention. However, this does not result in greater postprandial muscle protein synthesis rates. This trial was registered at clinicaltrials.gov as NCT01145131.
Aging impairs the sensitivity of skeletal muscle to anabolic stimuli, such as amino acids and resistance exercise. Beef is a nutrient-rich source of dietary protein capable of stimulating muscle protein synthesis (MPS) rates in older men at rest. To date, the dose-response of myofibrillar protein synthesis to graded ingestion of protein-rich foods, such as beef, has not been determined. We aimed to determine the dose-response of MPS with and without resistance exercise to graded doses of beef ingestion. Thirty-five middle-aged men (59 ± 2 years) ingested 0 g, 57 g (2 oz; 12 g protein), 113 g (4 oz; 24 g protein), or 170 g (6 oz; 36 g protein) of (15% fat) ground beef (n = 7 per group). Subjects performed a bout of unilateral resistance exercise to allow measurement of the fed state and the fed plus resistance exercise state within each dose. A primed constant infusion of l-[1-(13)C]leucine was initiated to measure leucine oxidation and of l-[ring-(13)C(6)]phenylalanine was initiated to measure myofibrillar MPS. Myofibrillar MPS was increased with ingestion of 170 g of beef to a greater extent than all other doses at rest and after resistance exercise. There was more leucine oxidation with ingestion of 113 g of beef than with 0 g and 57 g, and it increased further after ingestion of 170 g of beef (all p < 0.05). Ingestion of 170 g of beef protein is required to stimulate a rise in myofibrillar MPS over and above that seen with lower doses. An isolated bout of resistance exercise was potent in stimulating myofibrillar MPS, and acted additively with feeding.
Background
A blunted muscle protein synthetic response to protein ingestion may contribute to the age related loss of muscle tissue. We hypothesized that the greater endogenous insulin release following co-ingestion of carbohydrate facilitates post-prandial muscle protein accretion after ingesting a meal-like bolus of protein in older males.
Methods
Twenty-four healthy older men (75±1 y) were randomly assigned to ingest 20 g intrinsically L-[1-13C] phenylalanine-labeled casein protein with (PRO-CHO) or without (PRO) 40 g carbohydrate. Ingestion of specifically produced intrinsically L-[1-13C] phenylalanine labeled protein allowed us to assess post-prandial incorporation of dietary protein derived amino acids into muscle protein. Blood samples were collected at regular intervals, with muscle biopsies being obtained prior to and 2 and 6 h after protein ingestion.
Results
Plasma glucose and insulin concentrations showed a greater increase in PRO-CHO compared with PRO (P<0.001). Muscle protein-bound L-[1-13C] phenylalanine enrichments tended to increase to a greater extent in PRO-CHO compared with PRO during the first 2 h after protein ingestion (0.0072±0.0013 vs 0.0046±0.010 MPE, respectively; P=0.13). However, 6 h after protein ingestion, differences in muscle protein-bound L-[1-13C] phenylalanine enrichments were no longer observed between experiments (0.0213±0.0024 vs 0.0185±0.0010 MPE, respectively; P=0.30).
Conclusions
This study shows that carbohydrate ingestion may accelerate, but does not further augment post-prandial incorporation of dietary protein derived amino acids into muscle protein in healthy elderly men.
During muscle atrophy, myofibrillar proteins are degraded in an ordered process in which MuRF1 catalyzes ubiquitylation of thick filament components (Cohen et al. 2009. J. Cell Biol. http://dx.doi.org/10.1083/jcb.200901052). Here, we show that another ubiquitin ligase, Trim32, ubiquitylates thin filament (actin, tropomyosin, troponins) and Z-band (α-actinin) components and promotes their degradation. Down-regulation of Trim32 during fasting reduced fiber atrophy and the rapid loss of thin filaments. Desmin filaments were proposed to maintain the integrity of thin filaments. Accordingly, we find that the rapid destruction of thin filament proteins upon fasting was accompanied by increased phosphorylation of desmin filaments, which promoted desmin ubiquitylation by Trim32 and degradation. Reducing Trim32 levels prevented the loss of both desmin and thin filament proteins. Furthermore, overexpression of an inhibitor of desmin polymerization induced disassembly of desmin filaments and destruction of thin filament components. Thus, during fasting, desmin phosphorylation increases and enhances Trim32-mediated degradation of the desmin cytoskeleton, which appears to facilitate the breakdown of Z-bands and thin filaments.
Increased amino acid availability stimulates muscle protein synthesis, however, aged muscle appears less responsive to the anabolic effects of amino acids when compared to the young. We aimed to compare changes in myofibrillar protein synthesis (MPS) in elderly men at rest and after resistance exercise following ingestion of different doses of soy protein and compare the responses to those we previously observed with ingestion of whey protein isolate.
Thirty elderly men (age 71 ± 5 y) completed a bout of unilateral knee-extensor resistance exercise prior to ingesting no protein (0 g), or either 20 g or 40 g of soy protein isolate (0, S20, and S40 respectively). We compared these responses to previous responses from similar aged men who had ingested 20 g and 40 g of whey protein isolate (W20 and W40). A primed constant infusion of L-[1-13 C]leucine and L-[ring-13 C6]phenylalanine and skeletal muscle biopsies were used to measure whole-body leucine oxidation and MPS over 4 h post-protein consumption in both exercised and non-exercised legs.
Whole-body leucine oxidation increased with protein ingestion and was significantly greater for S20 vs. W20 (P = 0.003). Rates of MPS for S20 were less than W20 (P = 0.02) and not different from 0 g (P = 0.41) in both exercised and non-exercised leg muscles. For S40, MPS was also reduced compared with W40 under both rested and post-exercise conditions (both P < 0.005); however S40 increased MPS greater than 0 g under post-exercise conditions (P = 0.04).
The relationship between protein intake and MPS is both dose and protein source-dependent, with isolated soy showing a reduced ability, as compared to isolated whey protein, to stimulate MPS under both rested and post-exercise conditions. These differences may relate to the lower postprandial leucinemia and greater rates of amino acid oxidation following ingestion of soy versus whey protein.
Leucine is a nutrient regulator of muscle protein synthesis by activating mTOR and possibly other proteins in this pathway. The purpose of this study was to examine the role of leucine in the regulation of human myofibrillar protein synthesis (MPS). Twenty-four males completed an acute bout of unilateral resistance exercise prior to consuming either: a dose (25 g) of whey protein (WHEY); 6.25 g whey protein with total leucine equivalent to WHEY (LEU); or 6.25 g whey protein with total essential amino acids (EAAs) equivalent to WHEY for all EAAs except leucine (EAA-LEU). Measures of MPS, signalling through mTOR, and amino acid transporter (AAT) mRNA abundance were made while fasted (FAST), and following feeding under rested (FED) and post-exercise (EX-FED) conditions. Leucinaemia was equivalent between WHEY and LEU and elevated compared to EAA-LEU (P=0.001). MPS was increased above FAST at 1–3 h post-exercise in both FED (P <0.001) and EX-FED (P <0.001) conditions with no treatment effect.At 3–5 h, only WHEY remained significantly elevated above FAST in EX-FED(WHEY 184% vs. LEU 55% and EAA-LEU 35%; P =0.036). AAT mRNA abundance was increased above FAST after feeding and exercise with no effect of leucinaemia. In summary, a low dose of whey protein supplemented with leucine or all other essential amino acids was as effective as a complete protein (WHEY) in stimulating postprandial MPS; however only WHEY was able to sustain increased rates of MPS post-exercise and may therefore be most suited to increase exercise-induced muscle protein accretion.
Skeletal muscle atrophy during bed rest is attributed, at least in part, to slower basal muscle protein synthesis (MPS). Essential amino acids (EAA) stimulate mammalian target of rapamycin (mTORC1) signaling, amino acid transporter expression, and MPS and are necessary for muscle mass maintenance, but there are no data on the effect of inactivity on this anabolic mechanism. We hypothesized that bed rest decreases muscle mass in older adults by blunting the EAA stimulation of MPS through reduced mTORC1 signaling and amino acid transporter expression in older adults. Six healthy older adults (67 ± 2 yr) participated in a 7-day bed rest study. We used stable isotope tracers, Western blotting, and real-time qPCR to determine the effect of bed rest on MPS, muscle mTORC1 signaling, and amino acid transporter expression and content in the postabsorptive state and after acute EAA ingestion. Bed rest decreased leg lean mass by ∼4% (P < 0.05) and increased postabsorptive mTOR protein (P < 0.05) levels while postabsorptive MPS was unchanged (P > 0.05). Before bed rest acute EAA ingestion increased MPS, mTOR (Ser(2448)), S6 kinase 1 (Thr(389), Thr(421)/Ser(424)), and ribosomal protein S6 (Ser(240/244)) phosphorylation, activating transcription factor 4, L-type amino acid transporter 1 and sodium-coupled amino acid transporter 2 protein content (P < 0.05). However, bed rest blunted the EAA-induced increase in MPS, mTORC1 signaling, and amino acid transporter protein content. We conclude that bed rest in older adults significantly attenuated the EAA-induced increase in MPS with a mechanism involving reduced mTORC1 signaling and amino acid transporter protein content. Together, our data suggest that a blunted EAA stimulation of MPS may contribute to muscle loss with inactivity in older persons.