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Slowly digested and absorbed carbohydrate in traditional bushfoods: a protective factor against diabetes?
Abstract
The aim of this study was to compare the digestibility and metabolic responses of western foods with traditional staples of two populations that show a susceptibility to diabetes, namely Australian Aborigines and Pacific islanders. Rate of starch digestion was studied in vitro in 37 foods (20 Australian Aboriginal bushfoods, 10 Pacific island foods, and 7 western foods), and rate of absorption of 9 foods (8 bushfoods and 1 western food) was studied in human volunteers. In vitro studies showed that 23 of 30 traditional foods were digested more slowly than 7 western foods. Six of 8 bushfoods produced significantly smaller areas under 3-h postprandial plasma glucose curves than potatoes in seven healthy Caucasian volunteers. There was a good correlation between starch digestibility and plasma glucose response. Our findings are consistent with the hypothesis that carbohydrate in traditional diets is slowly digested and absorbed and may once have been protective against diabetes.
... Australian native tubers, seeds, roots, and fruits may contain nutrients with 'antidiabetic' properties. Some studies show that due to their composition being high in fibre, having more resistant starch (more amylose than amylopectin) [33,[53][54][55], and having some phenolic compounds [35], these foods have a low glycaemic index, low insulin responses, and inhibitory effects on enzymes linked to carbohydrate digestion. Thorburn et al. [53,54], in their two studies analysing the digestibility and metabolic responses of native foods, found that some foods such as cheeky yam (D. bulbifera), mulga seed (A. ...
... Some studies show that due to their composition being high in fibre, having more resistant starch (more amylose than amylopectin) [33,[53][54][55], and having some phenolic compounds [35], these foods have a low glycaemic index, low insulin responses, and inhibitory effects on enzymes linked to carbohydrate digestion. Thorburn et al. [53,54], in their two studies analysing the digestibility and metabolic responses of native foods, found that some foods such as cheeky yam (D. bulbifera), mulga seed (A. Aneura), and black bean (C. ...
... Cheeky yam (D.bulbifera), blackbean seed (C australe), wattle seed (Acacia aneura) [33,54], Acacia coriacea [53] native tubers, seeds, and roots [32], T. orientalis (reed or cattail), A. longifolia subsp. sophorae (seeds) and R. candolleana subsp. ...
The current food system and food choices have resulted in the increased human use of natural resources such as water and soil, and have directly impacted the ‘Global Syndemic’—climate change, obesity, and undernutrition. Revitalising Indigenous food systems and incorporating native plant-based foods into current food systems may have the potential to reduce diet-linked chronic diseases and environmental degradation, and are important steps toward Indigenous rights and self-determination. This study aims to identify and describe Aboriginal food practices and Australian native plant-based foods and their social, environmental, and economic impacts on sustainable food systems. A scoping review was conducted using the five-stage framework informed by Arksey and O’Malley. To describe the results, the framework for sustainable food systems from the Food and Agriculture Organization of the United Nations—FAO was used. Articles were included if they described the impacts of Aboriginal food practices on sustainable food systems, were confined to studies that were conducted in the Australian context, and included native Australian plant-based foods. A total of 57 studies were identified that met the inclusion criteria. The major social impacts incorporated the nutritional and health benefits of Australian native plant-based foods, such as antidiabetic properties, anticancer and antioxidant activities, and cultural identification, involving Aboriginal ecological knowledge and their connection to their country. Within the environmental impacts category, studies showed that Australian native plant-based foods have environmental stress tolerance and some ecosystem benefits. The main economic impacts discussed in the literature were the source of income for remote communities and the potential market for Australian native plant-based foods. This review demonstrates that Aboriginal food practices and Australian native plant-based foods can contribute to more sustainable food systems and diets and give more voice and visibility to Aboriginal knowledge and aspirations. More research and investments are needed to face the challenges of including these foods in our current food systems.
... Béo phì và tiểu đường là vấn đề sức khỏe nhận được sự quan tâm lớn của con người hiện nay. Những nghiên cứu mới nhất của các nhà khoa học thực phẩm và dinh dưỡng học đã đưa ra kết luận rằng làm chậm tốc độ tiêu hóa glucose từ các nguồn tinh bột ăn vào sẽ giúp làm giảm đường huyết, giảm nhu cầu insulin và gây cảm giác no [4,5]. Trên thế giới, một số công trình nghiên cứu làm giảm sự thủy phân tinh bột thành glucose bằng các phương pháp biến tính vật lí, hóa học và sinh học để làm biến đổi các tinh bột thủy phân nhanh thành tinh bột thủy phân chậm hoặc tinh bột không thủy phân [4,6]. ...
... Những nghiên cứu mới nhất của các nhà khoa học thực phẩm và dinh dưỡng học đã đưa ra kết luận rằng làm chậm tốc độ tiêu hóa glucose từ các nguồn tinh bột ăn vào sẽ giúp làm giảm đường huyết, giảm nhu cầu insulin và gây cảm giác no [4,5]. Trên thế giới, một số công trình nghiên cứu làm giảm sự thủy phân tinh bột thành glucose bằng các phương pháp biến tính vật lí, hóa học và sinh học để làm biến đổi các tinh bột thủy phân nhanh thành tinh bột thủy phân chậm hoặc tinh bột không thủy phân [4,6]. ...
This study was conducted to modify yam starch to create slowly digestible starch (SDS) by the acid method to create the highest SDS starch on the basis of evaluating the effect of citric acid concentration (15 – 45%), temperature (37.5 – 52.5oC) and hydrolysis time (1.5 – 10.5 h) was performed based on the multivariable modelby CCD method, and the starch content SDSmax was the dependent response. The results showed that the quadratic model obtained is significant (p < 0.05), the reliability of the model R2 = 0.979 showed that the built regression model is suitable for the data set whether 97.9%. As a result, the highest SDS starch content is 18.052% at an acid concentration of 40,009%, a temperature of 39.962oC and a hydrolysis time of 8.933 h.Solubility increases due to temperature, swelling increases in the range temperature of 50 – 70oC and decreases from 70 – 90oC; the viscosity of starch tends to decrease after denaturation.
... Pine cambium is high in sugar but, as our analysis showed, is almost as equally rich in protein. The protein concentration in lodgepole pine cambium consumed as a food may slow the rate of digestion, providing a slower release of the sugars (Jenkins et al. 1987;Thorburn, Brand, and Truswell 1987). This is beneficial for prolonged energy levels needed during physical exertion. ...
... In many instances consumption of traditional carbohydrate sources (usually also containing protein and/or fibre) is beneficial in diabetes prevention and management for slower digestion and release of sugars into the blood stream (Gottesfeld 1992;Östlund et al. 2009). In a comparative study of digestion rates of traditional and western foods in Australia, 23 of 30 traditional foods consumed by Indigenous Australians were all digested more slowly than 7 western foods (Thorburn et al. 1987). This has particular significance in Canada where First Nations People are three to four times more likely than other Canadians to be afflicted by type 2 diabetes, with an increasing incidence of type 2 diabetes among the younger generations (Health Canada 2009). ...
Lodgepole pine (Pinus contorta var. latifolia) is a tree species utilized for succulent edible cambium and secondary phloem in the spring by Interior First Peoples of the Pacific Northwest. In this article we present a nutritional analysis of this food based on a pooled sample of 17 trees harvested in the Chilcotin region of British Columbia. We also present enzymatic sugar analysis of raw, dried, and cooked lodgepole pine cambium harvested from the Chilcotin and Okanagan regions in British Columbia. In the discussion we interpret the nutrient values of raw lodgepole pine cambium in comparison to dried and cooked cambium, results from other nutritional studies of pine cambium, and nutrients in some other traditional and nontraditional foods.
... As economic conditions improved and lifestyles changed, staple foods and diets changed as well. Importation of the more preferred wheat, rice, and other cereal and non-cereal grains to island nations replaced the original intent of breadfruit to combat mass starvation (Balick 2009; Roberts-Nkrumah 2007; Thorburn et al., 1987). Food Data Central has discussed the advantages of breadfruit. ...
Artocarpus altilis is commonly referred to as breadfruit as it is similar to freshly baked bread. It is native to Malaysia, Southern Pacific, and the Caribbean and a mature breadfruit tree can yield between 400 and 2400 kg of breadfruit annually. The amount of different minerals found in breadfruit varies greatly depending on the cultivar and growth area. These minerals include copper, magnesium, phosphorus, potassium, calcium, cobalt, iron, and manganese. It is abundant in calcium, vital minerals, and carbohydrates. It offers infection protection and is beneficial to heart health. It contains fatty acids that are omega 3 and 6. It is increasingly used as a food additive, regulating stability, texture, and sweetness. It is gluten-free, used in bakery products, and has anti-inflammatory, anti-malarial, and atherosclerotic properties. It is also used in value-added products like Murukku, noodles, and alcohol and is also used as bioplastics and coating materials. Therefore, drying and milling breadfruit into starch is one possible solution. In modern studies, some researcher uses many different methods to preserve or alter the properties of starch and flour via modification methods such as gamma-irradiation. This method is also called the cold-sterilization method and is non-toxic by nature that’s why most of the researchers prefer that method to increase the shelf-life of the flour/starch.
... Information about the nutritional quality of native Australian grains is limited, focusing primarily on the proximate composition of species from arid and desert regions, and finding values that are comparable to domesticated cereals (Elphinstone, 1971;Cane, 1987;Brand-Miller et al., 1993;Smith and Smith, 2003;Wurm et al., 2012). However, there is a vast diversity of grains that have been traditionally used, from a broad range of bioregions, and some of these overlooked grains may have significantly better nutritional profiles compared to commonly cultivated domesticated cereals, like rice for example (Thorburn et al., 1987;Konczak et al., 2009). This study aims to provide a more comprehensive nutritional profile of seven species of native Australian grains, while reflecting on the challenges and aspirations of First Nations people looking to engage in this industry. ...
First Nations people of Australia sustained complex grassland grain production systems prior to colonisation. The revival of these foodways could aid in mitigating the interlinked issues of land degradation, reduced landscape resilience and declining food security. For the Gamilaraay people, original custodians of the grasslands of north-west New South Wales and south-west Queensland, efforts are underway to bring their ancient food system into a modern context with authenticity and integrity. The aim of this transdisciplinary study was to investigate the nutritional quality of Australian native grains to identify functional properties that may help promote this nascent industry; complimented by using autoethnography to understand how the original custodians, like the Gamilaraay people, might equitably benefit. Ethnographic findings highlight that Gamilaraay people aspire to improve their health and wellbeing through economic development and consumption of native grains, particularly Elders who disproportionately suffer from non-communicable disease. However, many First Nations people have lived experiences of being systemically exploited and excluded, particularly in the food and agriculture space. To prioritise the interests of the Traditional Custodians, the species used in the biochemical assays were de-identified. Wholegrains from seven culturally significant species, with domesticated brown rice as control, were threshed, milled, and analysed in triplicate for proximate, elemental, non-starch fatty acids, and total free phenolic content. Compared to brown rice, protein was significantly higher in all native species (9.4–32.6 g/100 g); whilst carbohydrates were significantly lower (36.5–53.7 g/100 g). One of the native species had exceptionally high total phenolics (569 mg GAE/100 g) compared to brown rice (60 mg GAE/100 g). All native species had generally higher elemental content, with significantly higher levels of Ca, Fe, Zn, Cu, Mg, P, and K in two native species. All samples were dominated by unsaturated fats with significantly higher polyunsaturated fats in two native species. The generally low carbohydrates, high protein, good fats, high mineral content and high phenolic content suggests that native grains may be beneficial to human health by improving nutrient intake and protecting against non-communicable disease, thus marketable as functional foods. To ensure a flourishing industry where all of Australia benefits from these healthful grains, future research and industry development must be First Nations led.
... Research into the nutritional and functional properties of various non-grass seed sources such as Acacia spp., kurrajong seed, yams and purslane seed has been performed to a greater degree than that of grasses (Thorburn et al. 1987a(Thorburn et al. , 1987bBrand-Miller and Holt 1998;Liu et al. 2000;Shelat et al. 2019). In general, native grains possess higher proportions of desirable nutrients, such as proteins and minerals, than do domesticated crops, although some potential anti-nutritional factors have also been noted, particularly in Acacia spp. ...
Australian native grains have an extended history of human consumption; however, their place in diets was disrupted when colonisation triggered a shift away from traditional lifestyles for Aboriginal people. Despite being time- and energy-intensive to harvest, the inclusion of native grains in diets is thought to have offered considerable adaptive advantage by assisting human occupation of arid and semiarid zones. Ethnographic evidence has shown that Aboriginal people developed specialised tools and techniques to transform grain into more edible forms. Research on native grain consumption has mainly been conducted from an ethnographic perspective, with the objective of furthering understanding of Aboriginal societies, instead of the agricultural or food science significance of these plant species. Consequently, a research gap in all aspects of Australian native grains in modern food-production systems from the paddock to plate has emerged, and is being filled by research projects in multiple parts of the country due to surging interest in this food system. There is a critical need for Aboriginal communities, land managers, food industry professionals and research institutions to come together and set a research agenda that ensures cultural protocols are respected, research investment is not unnecessarily duplicated, and the results are targeted to places where they will be of most benefit to people and the planet.
... Both treatment approaches will be marked by the increased passage of partly digested CHOs to the colon, resulting in bacterial fermentation but also in an attenuation of the postprandial spike in blood glucose concentration that would otherwise occur. Indeed, it has been hypothesized that traditional diets, rich in complex CHOs and fiber, may once have had protective effects against the development of diabetes in some population groups (e.g., the "bushfood" diet of Aboriginal Australians) [33]. It is not surprising that individuals with an inherited deficiency of intestinal AG activity (i.e., with congenital SI deficiency) experience symptoms identical to the side effects associated with high doses of acarbose [34]. ...
Postprandial hyperglycemia is treated with the oral antidiabetic drug acarbose, an intestinal α-glucosidase inhibitor. Side effects of acarbose motivated a growing number of screening studies to identify novel α-glucosidase inhibitors derived from plant extracts and other natural sources. As “gold standard”, acarbose is frequently included as the reference standard to assess the potency of these candidate α-glucosidase inhibitors, with many outperforming acarbose by several orders of magnitude. The results are subsequently used to identify suitable compounds/products with strong potential for in vivo efficacy. However, most α-glucosidase inhibitor screening studies use enzyme preparations obtained from nonmammalian sources (typically Saccharomyces cerevisiae), despite strong evidence that inhibition data obtained using nonmammalian α-glucosidase may hold limited value in terms of identifying α-glucosidase inhibitors with actual in vivo hypoglycemic potential. The aim was to critically discuss the screening of novel α-glucosidase inhibitors from plant sources, emphasizing inconsistencies and pitfalls, specifically where acarbose was included as the reference standard. An assessment of the available literature emphasized the cruciality of stating the biological source of α-glucosidase in such screening studies to allow for unambiguous and rational interpretation of the data. The review also highlights the lack of a universally adopted screening assay for novel α-glucosidase inhibitors and the commercial availability of a standardized preparation of mammalian α-glucosidase.
... 64,67 In addition to the low salt intake, however, there is another similarity in the diet of these cultures: in contrast to current "Western-style" high-glycemic/high-insulinogenic diets (HGHIDs), these ethnic groups subsist on Paleolithic lowglycemic/low-insulinogenic diets (LGLIDs). [119][120][121][122][123][124][125] The fundamental differences between these diets are associated with significant metabolic disturbances that may induce the development of hyperinsulinemia and IR, as the following sections will show. ...
Benign prostatic hyperplasia and hypertension are common age-related comorbidities. Although the etiology of benign prostatic hyperplasia (BPH) is still largely unresolved and poorly understood, a significant age-independent association was found between BPH and hypertension, indicating a common pathophysiological factor for both diseases. It has previously been suggested that the development of essential hypertension may be related to diet-induced hyperinsulinemia. This study follows the question, whether BPH may develop due to the same mechanism, thereby explaining the well-known comorbidity of these 2 disorders. The scientific evidence presented shows that BPH and hypertension share the same pathophysiological changes, with hyperinsulinemia as the driving force. It further shows that significant dietary changes during human history cause disruption of a finely tuned metabolic balance that has evolved over millions of years of evolution: high-insulinemic food, typical of current “Western” diets, has the potential to cause hyperinsulinemia and insulin resistance, as well as an abnormally increased activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, alterations that play a pivotal role in the pathogenesis of BPH and hypertension.
... Refined grain and sugar products nearly always maintain much higher glycemic loads than unprocessed fruits and vegetables (Foster-Powell, Holt, and Brand-Miller, 2002). Unrefined wild-plant foods, like those available to contemporary hunter-gatherers, typically exhibit low glycemic indices (Thorburn, Brand, and Truswell, 1987). Within the past two decades, substantial information has accumulated showing that long-term consumption of high glycemic load carbohydrates can adversely affect (Liu and Willett, 2002;Ludwig, 2002;Cordain, Eades, and Eades, 2003). ...
... Most traditional foods are high in complex carbohydrates, while processed foods are high in simple carbohydrates, sugar, and fat. Thorburn, et al (1987) suggests that diabetes was not found historically because traditional "bushfoods" digested slowly due to the amount of complex carbohydrates. "There is increasing evidence that the replacement of the complex carbohydrates found in desert plants with refined, high caloric, Single carbohydrates does produce a very . ...
Type II diabetes has reached epidemic proportions among Native Americans. It Is estimated that 12.2 percent of all Native Americans in the U.S. have Type II diabetes. This compares with 5.2 percent of the general U.S. population (Diabetes Statistics 1997). The highest rate of diabetes in the world is in the Pima Nation. Half of all Pima Indians age 35 and older have diabetes (West 1974). Diabetes causes severe health complications and is a major cause ofdeath for Native Americans.
... New concepts dealing with the total glycaemic response of carbohydrate foods such as the glycaemic load concept (GL) and glycaemic glucose equivalents (GCEs) are now also available [59,60]. However, in a low-income setting the consumption of traditional carbohydrate foods which are slowly digested with high dietary fibre (DF) content considered to delay the onset of the diabetes and improve the glycaemic control [61,62]. ...
... New developments in food and nutritional science have led to the conclusion that slowing down the rate of digestion of glucose from ingested carbohydrate sources helps to blunt glycemia, reduces insulin requirements, and causes satiety (FAO/WHO, 1997). The food industry has been developing a new, slowly digestible carbohydrate (SDC) (Thorburn et al., 1987;Bjrck and Asp, 1994;Wrsch, 1994;Wolf et al., 2003). Some examples of commercially available products include isomaltulose, trehalose, oligoalternan, pullulans, sucromalt, as well as other slowly digestible syrups. ...
The link between carbohydrate intake and health is becoming increasingly important for consumers, particularly in the areas of glycemic index (GI) and extended energy-releasing starches. From a physiological point of view, slowly digestible starch (SDS) delivers a slow and sustained release of blood glucose along with the benefits resulting from low glycemic and insulinemic response. SDS has been implicated in several health problems, including diabetes, obesity, and cardiovascular diseases (metabolic syndromes). It may also have commercial potential as a novel functional ingredient in a variety of fields, such as nutrition, medicine, and agriculture. The present review assesses this form of digestion by analyzing methods to prepare and evaluate SDS, factors affecting its transformation, its health benefits, and its applications.
... Gelatinization properties of starches depend on the type, granular structure, botanical origin and amylose/amylopectin ratio (Sajilata et al. 2006). Waxy and normal rice gelatinize between 60 and 78°C (Thorburn et al. 1987, Jenkins et al. 1994. Many factors affect preference and acceptability of foods. ...
Rheological and nutritional quality of ready-to-eat rice (Oryza sativa
) -legume viz. black gram (Vigna mungo), green gram (Vigna radiata), lentil (Lens culinaris) and peas (Pisum sativum) based extrudates were studied using low cost collet extruder. Extrudates were prepared keeping constant feed rate (25 kg/h) and moisture content (14% wb) at 0, 5, 10 and 15% legume incorporation levels. Rheological properties of porridge made of extrudate flour were evaluated using Rapid Visco Analyser (RVA). Maximum and minimum peak viscosity for rice extrudates alone and rice extrudates blended with 15% peas were 697 cp and 523 cp, respectively. There was a decreasing trend in degree of gelatinization with increase in legume incorporation level. Other RVA rheological parameters like trough break down and final viscosity were in the range of 266-226 cp, 431-297 cp and 452-375 cp respectively. Maximum values of protein, fat, fibre and ash contents were found in rice extrudates at 15% legumes blend levels. There was an increasing trend in nutrient contents with legume content in rice extrudates. Degree of gelatinization for rice alone extrudate was 29.4% and showed a decrease in gelatinization with increase in legumes extrudate and was minimum (22.4%) for rice blended with 15% dehulled green gram. Sensory evaluation scores for all extrudates showed the most acceptable range of 6 to 8. Thus, legume blend level (up to 15%) of dehulled legumes fetched good scores and showed promising trend for the production of low cost expanded extrudates and its instant flour.
... Studies during the last decade have shown that, de pending on the origin and type of treatment, starch is digested and absorbed at different rates (1)(2)(3)(4). A reduced rate of starch uptake results in lower glucose and in sulin responses, which are beneficial from a nutritional point of view (1,(3)(4)(5)(6)(7)(8). One parameter of prime impor tance is the rate of enzymic starch hydrolysis (2,3,(9)(10)(11)(12). ...
The effects of different thermal processes used to produce ready-to-eat cereals on the glycémie re sponse to whole grain wheat were investigated in rats. The metabolic response to drum dried flour, which constitutes the major component in instant gruel and porridge, was also studied in healthy human subjects. Boiled flour was used for comparison. The degree of starch gelatinization and rate of starch hydrolysis in vitro were also measured. Incompletely gelatinized steam flaked and dry autoclaved products were digested more slowly in vitro and elicited lower glucose responses in rats compared with completely gelatinized drum dried, extrusion cooked or boiled sam ples. The initial glycémie response in rats was closely re lated to the rate of starch hydrolysis in the pepsin/ a-am- ylase assay (r = 0.91, P < 0.04). When pepsin was omitted, no significant correlation was obtained. The peak glucose, insulin and C-peptide responses in humans after breakfast meals of porridge prepared from drum dried flour and from boiled flour were similar, whereas the rate of depression of the glucose curve was more rapid after consuming drum dried porridge. It is concluded that the glycémie response to wheat products is affected by the processing conditions used. The more severe the processing conditions, the more rapid the digestion of starch. J. fiutr. 119:1631-1638, 1989.
... A high proportion of the polymer amylose compared to amylopectin in the starch may explain the necessity of dry heat treatment for complete digestibility of some starches; amylose is harder to digest than amylopectin due to its stronger hydrogen bond and smaller surface area (Thorne et al., 1983). Comparisons of western foods with traditional resources of the Australian Aborigines, Pacific Islanders, and Pima Indians have shown considerable variance in the rates of digestion of starch-rich foods, indicating that not all starches react the same (Thorburn et al., 1987;Brand et al., 1990). Lentils are one starchy food that appear to have best digestion after 12 h of baking with moderate dry heat (Jenkins et al., 1982). ...
Three experiments or simulations were undertaken to obtain a clearer understanding of the role of pit ovens and roots from dry, sagebrush-covered habitats in prehistoric forager subsistence. The archaeological record of north-central Wyoming containing cylindrical pits near dense stands of sego lily served as a model for these studies. They revealed that: (1) the post-encounter return rates for collecting and processing sego lily is relatively low at 207kcal/h; (2) the design of pit ovens of this sort was for long-term moderate heat; and (3) long-term moderate heat transformed the large complex polysaccharides (probably starch) of sego lily into more easily digestible disaccharides and monosaccharides. Given the results of the experiments and archaeological and ethnographic evidence, small groups of foragers probably baked sego lily bulbs or a similar resource near the collection patches for immediate consumption. The use of this predictable, stationary resource would have served to buffer risk and would have provided required carbohydrates in the spring at the end of the nutritionally stressful time of the year.
... P I I : S 0 3 0 8 -8 1 4 6 ( 0 1 ) 0 0 1 2 0 -0 Food Chemistry 75 (2001) 241±247 www.elsevier.com/locate/foodchem advocated universally for the general population at risk of developing obesity, cardiovascular diseases and diabetes (Cummings, Englyst & Wiggins, 1986;Technical Committee, 1995;The Nutrition Sub-Committee, 1983;Thorburn, Brand & Truswell, 1987). Currently, average carbohydrate in Indian dietaries represents about 60-70% of calories of which 75% is starch derived mainly from cereals and pulses. ...
Recent research studies have invalidated the earlier assumptions regarding the rate of digestion of carbohydrates. Hence, in the present study the rate and extent of starch digestion in vitro was measured in 10 cereal-based Indian food preparations (with/without accompaniments). The selected foods included chapathi, dosa, idli, pongal, poori, ragi roti, rice roti, rice flakes upma, semolina idli and upma and the accompaniments — cooked dhal, chutney and potato palya. In view of the nutritional importance of starch, the major starch fractions viz., rapidly digestible starch, slowly digestible starch (SDS) and resistant starch as defined by Englyst [Englyst, H. N., Kingman, S. M., & Cummings, J. H. (1992). Classification and measurement of nutritionally important starch fractions. European Journal Clinical Nutrition, 46(2), 333–350] were measured, by using controlled enzymic hydrolysis with pancreatin and amyloglucosidase. In addition, rapidly available glucose (RAG) was measured and a starch digestion index was derived. Dietary fiber components (soluble and insoluble fiber) were measured by the enzymatic method [Asp, N. G., Johansson, C. G., Hallmer, H., & Siljestrom, M. (1983). Rapid enzymatic assay of insoluble and soluble dietary fiber. Journal of Agricultural Food Chemistry, 31, 476–482]. The results indicate that the course of starch hydrolysis was not only characteristic for each food but also appears to be affected by the addition of accompaniment. Also, while the correlation between RAG and SDS did not attain significance in foods with accompaniment, a significant inverse correlation (r=−0.68, P
... Gelatinization properties of starches depend on the type, granular structure, botanical origin and amylose/amylopectin ratio (Sajilata et al. 2006). Waxy and normal rice gelatinize between 60 and 78°C (Thorburn et al. 1987, Jenkins et al. 1994. Many factors affect preference and acceptability of foods. ...
... It has also been found that an increased incidence of chronic diseases, such as diabetes, is experienced by many indigenous people as they adopt western diets and lifestyles. Plant foods in traditional diets are higher in fibre than western diets and the carbohydrates they contain are digested more slowly (Thorburn et al., 1987). Hence, dietary incorporation or maintenance of indigenous food crops could be highly advantageous to marginal populations or to specific vulnerable groups within populations. ...
Uncooked/sun‐dried (UCSD) and boiled/freeze‐dried (BFD) flours of the Malawian water tuber Nymphaea petersiana (Nyika) were analyzed for selected nutrients and antinutrients. On a wet weight basis, the flours contained 8.1 and 8.0% crude protein; 0.8 and 1.0% crude fat; 12.0 and 13.0% dietary fiber; and 2.2 and 1.9% ash, respectively. The flours also contained 928 and 1300 μg/g of calcium; 2600 and 2200 μg/g of phosphorus; 88 and 20 μg/g of iron; and 22 and 20 μg/g of zinc, respectively. USCD and BFD flours were limiting in lysine and had amino acid scores of 91 and 84. The predominant fatty acids in the tubers were oleic (47%), linoleic (32%), palmitic (21%), and linolenic (7%). Tannin content was 1.5 and 1.0%; phytate content was 5.4 and 3.9 μg/g; trypsin activity was reduced from 400 to 55 TIU/g of tuber and chymotrypsin activity was reduced from 240 to 50 CIU/g by moist heat. Hydrogen cyanide levels were below detection limits (LOD < 16 nmoles/L) for both UCSD and BFD flour samples.
... 17 For the 20 most commonly consumed vegetable foods in the United States, two foods (potatoes and corn) were excluded from the model because corn is a cereal grain, and potatoes maintain nutrient properties (high glycemic and insulin responses) 18 uncharacteristic of traditional hunter-gatherer plant foods. 19 Consequently, the remaining 18 vegetable foods in Table 1 represent the food choices available in the model. ...
Purpose: The intent of the present study was to examine the nutritional characteristics of a contemporary diet based upon Paleolithic food groups and to determine how these characteristics may impact the risk of chronic disease. Methods: Nutritional software was employed to ascertain the macro and trace nutrient characteristics of a diet composed of commonly available modern foods, but devoid of processed foods, dairy products and cereal grains. The rel- ative contribution of plant and animal foods to the experi- mental diet was based upon average values previously determined in 229 hunter gatherer societies. Results: The analysis revealed that except for vitamin D, which would have been supplied by endogenous synthesis in hunter gatherers, it is entirely possible to consume a nutri- tionally balanced diet from contemporary foods that mimic the food groups and types available during the Paleolithic. Despite the elimination of two major food groups, the trace nutrient density of the experimental diet remained excep- tionally high. The macronutrient content of the experimen- tal diet (38 % protein, 39 % fat, 23 % carbohydrate by ener- gy) varied considerably from current western values. Conclusions:
... The recent analyses of bushfoods alluded to above, however, indicate that not all starchy foods are equally digestible. A variety of sweet potato grown in the Pacific islands is two to four times less digestible than the common potato, both of them having been baked for 1 h (Thorburn et al. 1987). Similarly, in their analysis of traditional Pima foods, Brand and colleagues (1990) observed a wide range of in vitro starch digestion; corn was the most digestible and mesquite and acorns the least. ...
Heat treatment is one of the major ways humans change the composition and chemistry of food tissues, making them more digestible, less toxic, and more durable. This paper reviews salient features of food chemistry and food composition and how heat treatment, especially pit-hearth cooking, affects that composition. Ethnographic accounts of cooking indicate that traditional populations relied on pit-hearth cooking especially to alter the composition of foods high in either lipids or complex carbohydrates. Historically, pit hearths were also used to process large quantities of food. Various kinds of pit hearths figure prominently in the archaeological deposits of the American Great Plains and elsewhere. The implications of this recurring phenomenon are discussed in terms of the coevolution of diet, cooking systems, and the appearance of Neel's “thrifty” genotype.
(1) Background: Urgent changes in our food choices are needed for more sustainable, resilient and equitable food systems. Australian native plant-based foods have both environmental and health benefits. Including these foods in our diet may reduce both the risk of chronic diseases and the impact of climate change. This study explored the perceptions and attitudes towards food choices, sustainability and Australian native plant-based food among university students. (2) Methods: A cross-sectional online survey was completed by 212 university students in Australia from October to December 2022. Questions included information about sociodemographic characteristics, food choices, Australian native foods and the impact on sustainability. Logistic regression was used for analyses. (3) Results: Most participants recognised the impact of food choices on sustainability. There was a significant association between recognition of the impact of food choices on sustainability and the environmental and nutritional benefits of Australian native foods (OR = 2.89, 95% CI 1.29, 6.46, p = 0.010). Students who were familiar with or had tried Australian native plant-based foods were significantly more likely to recognise their environmental and nutritional benefits (p < 0.001). (4) Conclusions: Students who recognise the impact of food choices on sustainability and the benefits of Australian native foods are more likely to include native foods in their diet. More studies are needed to investigate the specific native foods consumed and the barriers and facilitators to the intake of these foods.
Genotı̇p Temelli Beslenme Kararlarıİçin Zaman Geldi̇ mı̇? Merve İNCE PALAMUTOĞLU Genetik Geçiş Nasıl Çalışır? Merve İNCE PALAMUTOĞLU Nutrigenetik Farklılıklar Nereden Gelmektedir? Merve İNCE PALAMUTOĞLU Besin Öğeleri Genetikten Nasıl Etkilenir? Simge SİPAHİ, Bartu Eren GÜNEŞLİOL Nutrigenetik Uzun Süreli SağlığıNasıl Etkiler? İpek AĞACA ÖZGER Son Bulguların Ne Anlama Geldi̇ği̇ni̇ Nasıl Bi̇lebi̇liriz? İpek AĞACA ÖZGER Nutrigenetiğin Pratik Kullanımları Bartu Eren GÜNEŞLİOL Genetik Bilgiyi Güvende Tutmak Bartu Eren GÜNEŞLİOL
Antibiotics exposure leads to gut microbiota dysbiosis, which increases the risk of anxiety and depression. However, the impact of ciprofloxacin and metronidazole exposure on chronic unpredictable mild stress-induced anxiety-like and depression-like behavior and underlying regulatory mechanism have not been well established. Here, chronic unpredictable mild stress model was established in adult male Sprague-Dawley rats. 16 S rRNA gene sequencing was used to decipher the gut microbiota. Enzyme-linked immunosorbent assay (ELISA) was used to measure circulating cytokines in blood, gut barrier permeability biomarkers in feces, blood-brain barrier permeability biomarkers in brain. We found that antibiotics exposure significantly reduced the body weight, weight gain and liver health in chronic unpredictable mild stress treated rats. Behavioral testing suggested that antibiotics exposure reduced anxiety-like and depression-like behavior of rat. Antibiotics exposure possessed lower bacterial richness and diversity than that in the chronic unpredictable mild stress treated group. Compared with CUMS or CUMS-e group, higher abundances of Bacteroides, Lactobacillus, Lachnospiraceae and Akkermansia, lower abundances of S24-7, Blautia, Ruminocaceae, Ruminococcus and Prevotella were found in the gut microbiota from antibiotics exposure group. In addition, short-term antibiotics exposure increased the level of 5-hydroxytryptamine (5-HT) in brain. A significant correlation between certain bacteria and behavior of rats was observed, such as Roseburia. Our study uncovers the role for antibiotics in regulating chronic unpredictable mild stress-induced anxiety-like and depression-like behavior and suggest that short-term antibiotics exposure may be could reverse chronic unpredictable mild stress-induced anxiety-like and depression-like behavior.
The evolution of dietary lifestyles in modern society has been promoted by the concomitant creation of new and improved food and beverage products. It can be assumed that the birth and growth of anthropic activities related to food production (agriculture and husbandry) have altered dietary lifestyles, in Western countries at least. The alteration could be considered as the modification of certain nutritional features, including the assumption of nutritive sugars, fibres, and the qualitative and quantitative profile of general foods and beverages when speaking of nutritive compounds such as fatty acids, macro- and micronutrients. With exclusive relation to fats, the production of vegetable oils and hydrogenated products as replacers for animal fats can be considered as a subsector of the entire chain of food production. Advantages include improved food palatability, cheap prices, possible options for different vegetables, the creation and development of new products such as mayonnaise and imitation cheeses, and technological improvement. On the other side, the demonstrated correlation with eating disorders, malnutrition, obesity, and general cardiovascular diseases has to be considered (with other factors). These aspects are discussed in detail, including a practical example: an analogue cheese with different animal-to-vegetable oil ratios.
Eighteen (18) male albino rats were used to determine the glycemic indices of flour and starch component of two varieties, each, of maize and millet grains. The flour was obtained by milling the grains while the starch components were extracted from the grains using the method of Signh and Sadh (2009). Steeping, grinding, sieving and several rounds of centrifugation were carried out to obtain the starch component. The rats were administered with alloxan monohydrate (120mg/Kg body weight) to induce diabetes in them. After a twelve hour fast, fasting blood samples were collected by tail tipping and blood glucose analysed. The animals were then fed within fifteen minutes with test feed and further blood samples collected at 30, 60, 90 and 120 minutes from the commencement of feeding and analysed for blood glucose level using portable active accu-check glucometer. Two rats were fed with anhydrous glucose used as refernece feed. The area under the curve (AUC) for all the test and reference feeds were calculated by plotting the graph of blood glucose level in mg/dL against time in minutes. The glycemic indices were calculated by dividing the AUC of the test feed by that of the reference feed and multiplying by 100. The flour components of both the maize and the millet varieties gave lower glycemic index (maize sammez-11 flour gave G.
Wattle seed (Acacia spp.) is a well-known staple food within indigenous communities in Australia. A detailed investigation of the overall nutritional and sensory profile of four abundant and underutilized Acacia species—A. coriacea, A. cowleana, A. retinodes and A. sophorae—were performed. Additionally, molecular weight of protein extracts from the wattle seeds (WS) was determined. The seeds are rich in protein (23–27%) and dietary fibre (33–41%). Relatively high fat content was found in A. cowleana (19.3%), A. sophorae (14.8%) and A. retinodes (16.4%) with oleic acid being the predominant fatty acid. The seeds contained high amounts of essential amino acids (histidine, lysine, valine, isoleucine and leucine). A. coriacea is rich in iron (43 mg/kg), potassium (10 g/kg) and magnesium (1.7 g/kg). Pentose (xylose/arabinose), glucose, galactose and galacturonic acids were the major sugars found in the four species. Raw seeds from A. sophorae, A. retinodes and A. coriacea have the highest protein molecular weight, between 50–90 kDa, 80 kDa and 50–55 kDa, respectively. There was variation in the sensory profile of the WS species. This study showed that the four WS species have good nutritional value and could be included in human diet or used in food formulations.
This chapter will review the relationship between gastrointestinal events and carbohydrate metabolism in the short and long terms, beginning with the effects of dietary fiber and including the extension of this to more recent work on the glycemic index of foods where fiber, food form, and the so-called “antinutrients” all combine to produce the glycemic response typical of the whole food.
Over the past two decades there has been a radical change in dietary guidelines for diabetes, which now stress high carbohydrate and fiber intakes. The initial impetus for the increase in carbohydrate came from early studies of Himsworth (1935–36) and, later, Stone and Connor (1965), showing improved blood lipids and glucose tolerance on a high-carbohydrate diet. Further motivation for change originated in the early 1970s from Trowell’s suggestion (1973) that the development of diabetes might be related to a lack of fiber in the diet. This spurred many new concepts about the dietary treatment of diabetes and lead to the classic studies of Anderson (Kiehm et al., 1976; Anderson and Ward, 1979) and others (Simpson et al., 1981; Rivellese et al., 1980) showing the beneficial effects of high-carbohydrate, high-fiber diets.
Current dietary recommendations support the use of increased carbohydrate intakes from minimally processed or high-fiber starchy foods. A characteristic of such food is often that it is more slowly digested and absorbed than many refined and highly processed foods. The assumption that slow absorption of nutrients may have benefit is central to the fiber hypothesis and has been described as a new therapeutic principle. Other similar approaches include the use of specific digestive enzyme inhibitors and increased feeding frequency. Slow carbohydrate absorption may result in a number of sequelae, including flatter glucose and endocrine responses and lower blood lipids, reduced blood urea levels through increased NH3 trapping in the colon, increased laxation, and enhanced colonic retrieval of short-chain fatty acids with further potential beneficial effects.
In standard nutritional texts, the digestion and absorption of dietary carbohydrates is usually presented in simple terms. Monosaccharides are absorbed directly, whereas disaccharides are first hydrolysed in the brush border of the mucosal cells by a series of specific disaccharidase enzymes. Dietary polysaccharides have classically been considered to fall into two broad categories: those that are hydrolysed by endogenous enzymes, the available polysaccharides, and those that are not, the unavailable polysaccharides. Only starch and glycogen are considered to fall into the available category of dietary polysaccharides. This simple nutritional concept appears to run counter to many observations of the enzymatic hydrolysis of starch in vitro and in vivo.
As more radical changes are proposed for the diabetic diet, so the practicability of implementing these changes provides an increasing challenge. All forms of lifestyle change are difficult to accomplish, especially when these require individuals to follow a course of action for which there is a lack of support in their environment. Thus, when eating out, standard portion sizes may be too large and food contain excess saturated fat, etc. Even when more acceptable choices are available, peer pressure may deter–mine eating patterns. In a sense the success of the diabetic diet from a practical point of view may be dependent on changes in the eating patterns of the general population. It is therefore fortunate that dietary advice given to the general public by government agencies in many Western countries is similar to that recommended by the diabetes associations [1,2]. As this becomes accepted by the public and is reflected in the food available in shops and restaurants, so we can expect greater dietary compliance from diabetic patients.
While the importance of phytochemicals as the active principles of herbal medicines is well-known, the role of non-nutritive plant constituents consumed on a routine basis as normal mediators of health is more recently being recognized. For human populations engaged in traditional forms of subsistence the ingestion of a range of chemicals from plant foods, condiments, beverages and medicines may be part of their normal ecology. The refined diets of industrial societies differ from those of pre-industrial humans in composition, digestibility and palatability. They may not, however, be equatable with health. Indeed, diseases that are widespread in industrial societies such as diabetes, cancer, cardiovascular disease, and dental caries are recognized as having a dietary basis attributable in large part to consumption of lipids and carbohydrates. Increasingly the role of phytochemicals as factors in these diseases is the subject of investigation.
The upsurge in the incidence and prevalence of diabetes worldwide and in Nigeria in particular is a challenge for urgent action in the adoption of appropriate dietary management in patients with diabetes and also in the prevention of diabetes. Knowledge of the glycemic index (GI) of food types is essential for rational advice on calorie recommendation. Unfortunately, the GI of many food types in Nigeria is not known and so this study was undertaken to determine the GI of four staple and predominantly carbohydrate-based food types in Nigeria (yam, cassava, maize and wheat) by an open-labeled method, and to assess the variability of the GI of the tested food types in healthy subjects and those with diabetes. A total of twenty subjects were included in the study, i.e. ten type 2 diabetes mellitus (DM type 2) patients and ten healthy subjects serving as controls. They were given measured portions of the food containing 50 g of digestible carbohydrate. Blood glucose concentrations were determined from capillary blood drawn half hourly with a portable glucometer for two hours after ingestion of the food. Blood glucose curves were constructed to calculate the GI of the food. Values of the GI of the foods were compared using appropriate statistical methods of Microsoft Excel and SPSS v. 11. The results showed that there was wide variability of the GI in all the foods tested in both groups. In healthy subjects, maize four meal had the lowest GI and cassava flour meal the highest GI. This was in contrast to patients with diabetes, where yam flour had the lowest GI and wheat flour the highest GI. While the method of meal preparation may have an effect on the overall acceptability of the food to our patients with diabetes, it is apparent that carbohydrate from yam should be allowed freely in the menu while that from wheat flour (white bread) should only be allowed sparingly. The results from this study should serve as an encouragement for further studies on the local staple food types in Nigeria to ascertain their suitability or otherwise in their incorporation into the recommended menu in the dietary management of diabetes.
The chapter provides a brief but incisive view on the importance to health of the quantity and quality of carbohydrates in the human diet from ancient times to the present day. Deep insight is given into how carbohydrate-based foods can be assessed to communicate accurately with the consumer. Evidence is also provided that sweeteners and sugar alternatives, as well as low-glycaemic starchy foods, have significant roles in controlling metabolism, which, if let go, commonly leads to metabolic crises, incident diabetes, coronary heart disease, stroke, even cancer and many other conditions. The author shows how food-based advice on fruits, vegetables and whole grains, helpful as it is, only partially communicates about the quality and quantity of carbohydrate foods. Meanwhile, evidence is presented that the appropriate use of sweeteners and sugar alternatives could help to lower the risk of prevalent metabolic disorders, while table sugar in doing little harm when not overly consumed may also do little good.
Potatoes are one of the most popular carbohydrate foods in industrialized and some developing countries. However, contradicting arguments and misconceptions on potatoes as a high glycemic index (GI) food is directly affecting potato consumption during the past years. Potato varieties, maturity level, starch structure, food processing techniques and composition of the meal contribute to the GI of potatoes. Domestic boiling, baking, microwave cooking, oven cooking, extrusion and frying result in different degrees of gelatinization, and the crystallinity of starch in potato. French fried potatoes contain more resistant starch whereas boiled and mashed potatoes contribute to significant digestible starch. Extrusion processing conditions could affect the starch physicochemical structure and resulting nutritional value. Extrusion cooking makes more gelatinized starch than conventional cooking methods. Cooling or storing after processing of potatoes significantly reduces the GI due to retrogradation of starch molecules. This review provides a brief idea about the glycemic index, glycemic load, and their importance to human diseases, and detail information on the effect of food cooking methods on the glycemic index of potatoes.
Until European settlement of Australia 200 years ago, Aborigines lived as nomadic hunter-gatherers all over the continent under widely varying geographic and climatic conditions. Successful survival depended on a comprehensive knowledge of the flora and fauna of their territory. Available data suggest that they were physically fit and lean, and consumed a varied diet in which animal foods were a major component. Despite this, the diet was not high in fat, as wild animal carcasses have very low fat contents through most of the year, and the meat is extremely lean. Everything on an animal carcass was eaten, including the small fat depots and organ meats (which were highly prized), bone marrow, some stomach contents, peritoneal fluid and blood. A wide variety of uncultivated plant foods was eaten in the traditional diet: roots, starchy tubers, seeds, fruits and nuts. The plant foods were generally high in fibre and contained carbohydrates, which was slowly digested and absorbed. Traditional methods of food preparation (usually baked whole or eaten raw) ensured maximum retention of nutrients. In general, traditional foods had a low energy density but high density of some nutrients. The low energy density of the diet and the labour intensity of food procurement provided a natural constraint on energy intake.(ABSTRACT TRUNCATED AT 250 WORDS)
A high-glycemic-index diet increases hepatocyte exposure to insulin, and thus should up-regulate IGF-I activity—both by stimulating IGF-I synthesis and by suppressing hepatic production of IGFBP-1. The resulting increase in IGF-I activity might be expected to have a significant cancer promotional impact in light of IGF-I's role as a progressional growth factor and anti-apoptotic agent in a great many normal and neoplastic tissues. Although direct epidemiological data linking the glycemic index of habitual diets to cancer risk are currently scarce, the profusion of reports suggesting that legumes—one of the lowest-glycemic-index staple foods—are cancer preventive is consistent with the thesis that a low-glycemic-index diet is protective in this regard; the apparent protection associated with high intakes of fruit and of fiber-rich foods may also be partially traceable to reduced glycemia. Slowly digested starch may be stored preferentially in the liver, accounting for its favorable impact on satiety and glycemic regulation; through induction of hepatic glucokinase, high-dose biotin may enhance hepatic uptake of portal glucose and thus reduce the effective glycemic index of meals. Choosing low-glycemic index starchy foods is only one of a number of measures—which include exercise training, a very-low-fat vegan diet, appropriate weight reduction, caloric restriction, and intake of chromium, biguanides, and possibly high-dose biotin—that tend to minimize diurnal insulin secretion in the context of good glycemic control, thereby decreasing risk for atherothrombotic disease, diabetes, obesity, and cancer, and perhaps even slowing the aging process.
This study investigated the effects of myco- protein, a food produced by the continuous fermentation of Fusarium graminearum (Schwabe), on acute glycemia and insulinemia in normal healthy individuals. Subjects partici- pated in two single-meal study periods in a crossover design. After an overnight fast, subjects were given milkshakes con- taming mycoprotein or a control substance, which were isoen- ergetic and nutrient balanced. Each milkshake contained 75 g carbohydrate, equivalent to a standard World Health Ongani- zation oral-glucose-tolerance test. Blood samples were taken fasting and at 30, 60, 90, and 120 mm postprandially for the measurement of serum glucose and insulin. Olycemia was reduced postmeal after mycoprotein compared with the control and was statistically significant at 60 mm (13% reduction). Insulinemia was reduced postmeal after mycoprotein compared with the control and was statistically significant at 30 mm (19% reduction) and 60 mm (36% reduction) postmeal. These results may be significant in the dietary treatment of diabetes. Am J Clin Nutr 1995;61:135-40
The saliva, gastric and intestinal digestion of polysaccharide from Plantago asiatica L. seeds was investigated in vitro. It was found that salivary amylase had no effect on the polysaccharide; however, the polysaccharide was influenced in later gastrointestinal digestion. A steady decrease in molecular weight (M(w)) of the polysaccharide from 1903.1±93.0 to 4.7±0.2kDa was observed as digestion time increased. Meanwhile, the reducing ends were increased from 0.157±0.009 to 0.622±0.026mM, indicating the decrease of M(w) may due to the breakdown of glycosidic bonds. In addition, there was no monosaccharide released throughout the whole digestion period, suggesting that the gastrointestinal digestion did not result in a production of free monosaccharide. These results may provide some information on the digestion of polysaccharide from P. asiatica L. in vitro, and may contribute to the methods of studying the digestion of other carbohydrates.
Profound changes in macronutrient composition of food have taken place since the agricultural revolution, leading to a higher dietary intake of carbohydrates at the expense of protein, and a dramatically increased intake of n-6 polyunsaturated fatty acids (PUFAs) at the expense of n-3 PUFAs. This review focuses on how macronutrients impact on molecular processes central to appetite regulation and energy homeostasis. We discuss the effects on transcription factors, implicated as key players in adipocyte differentiation and function, including PPARs, sterol regulatory element binding proteins and liver X receptors. Furthermore, as energy homeostasis is to a large extent orchestrated by the gut-brain axis, we discuss key hormones involved in the regulation of energy balance and appetite.
The roles of phytochemicals as mediators of chronic degenerative diseases such as cancer, diabetes and coronary heart disease have an evolutionary basis. The omnivorous ancestors of modern humans ingested non-nutrients as well as nutrients from plants, and phytochemicals are a normal component of human dietary physiology. However, humans have a preference for animal fat and protein. Contemporary populations living a traditional subsistence life-style ingest phytochemicals as part of the diet but also from herbal medicines, beverages, food additives, tooth brushes and masticants. Maasai pastoralists who occupy African savannahs with similar ecological conditions experienced by hominids in the Pleistocene derive the majority of their calories from animal products. Their patterns of plant consumption offer insight into how human ancestors in such environments could have thrived as hunters and scavengers without suffering the ill-effects often associated with a high fat diet.
Southwest Native American pre-contact diets varied relative to water availability and subsequent distribution and density of plant and animal resources. Early paleolithic big game hunters consumed a diet high in fat and protein but low in carbohydrates and fiber. Big game extinction led to increased reliance on wild plant foods. Arid-land plants are high in complex carbohydrates, dietary fiber, hypoglycemic chemical compounds and antioxidant micronutrients. These characteristics enhance plant survival by improving water absorption and retention, by providing protection from predation and strong desiccating winds, and by producing colors attractive to potential pollinators. For Native Americans, wild plant foods provided a diet high in fiber, carbohydrates and micronutrients. In some locales, this emphasis on plant foods led to a shift to agriculture. The varieties of plants domesticated, predominantly corn, beans and squash, were lower in simple carbohydrates and higher in mineral content than modern commercial varieties.
The in-vitro availability of starch in Heudebert breads and Lu biscuits was assessed. Starch digestibility increased in the order semi-sweet biscuits, muesli, wholemeal breads, white breads, French toast, extruded crispbread. The results confirm that manufacturing conditions play a determinant role in starch availability in vitro.
The concept of a glycaemic index owes much to the dietary fibre hypothesis; that fibre would reduce the rate of nutrient absorption and increase the value of carbohydrate foods in the maintenance of health and treatment of disease. However, several aspects of food other than its fibre content contribute to the glycaemic and endocrine responses postprandially. The aim of the glycaemic index classification of foods was therefore to assist in the physiological classification of carbohydrate foods that, it was hoped, would be of relevance in prevention and treatment of chronic diseases such as diabetes. In the last 20 years, low glycaemic index diets have been reported to improve glycaemic control in patients with diabetes and reduce serum lipids in hyperlipidaemic subjects. Low glycaemic index or glycaemic load diets (glycaemic index multiplied by total carbohydrates) have also been associated with higher levels of high-density lipoprotein cholesterol, reduced C-reactive protein concentrations and, in large cohort studies, with decreased risk of developing diabetes and cardiovascular disease. Some case-control and cohort studies have also found positive associations between dietary glycaemic index and the risk of colon and breast cancer. Although there are inconsistencies in the data, sufficient positive findings have emerged to suggest that the dietary glycaemic index is an aspect of diet with potential importance in the treatment and prevention of chronic diseases.
The chapter provides a brief but incisive view on the importance to health of the quantity and quality of carbohydrates in the human diet from ancient times to the present day. Deep insight is given into how carbohydrate-based foods can be assessed to communicate accurately with the consumer. Evidence is also provided that sweeteners and sugar alternatives, as well as low-glycaemic starchy foods, have significant roles in controlling metabolism, which, if let go, commonly leads to metabolic crises, incident diabetes, coronary heart disease, stroke, even cancer and many other conditions. The author shows how food-based advice on fruits, vegetables and whole grains, helpful as it is, only partially communicates about the quality and quantity of carbohydrate foods. Meanwhile, evidence is presented that the appropriate use of sweeteners and sugar alternatives could help to lower the risk of prevalent metabolic disorders, while table sugar in doing little harm when not overly consumed may also do little good.
The people of the Torres Strait suffer a disproportionate level of diet-related disease, especially diabetes. The Torres Strait Health Strategy identified the difficulty in obtaining healthy food, particularly fruit and vegetables, as a major problem for people living in the Torres Strait. This study examined traditional plant food supply systems and current local production of fruit and vegetables. The supply system of fruit and vegetables from mainland Australia was also examined. Traditional garden food production was seen to continue (mainly to provide food for ceremonial occasions), but had declined because of easy access to store foods, changes in the physical, social and economic environment, limited access to land and water, and quarantine restrictions on movement of garden produce. Supplies of fruit and vegetables from the Australian mainland were infrequent and the prolonged transit time meant that produce was often in poor condition on arrival and prone to continued rapid deterioration due to limited store-level storage facilities. Demand for fresh produce exceeded supply.
‘A heavy, tasteless, evil-looking but nourishing cake’ was Meggitt’s (1957) description of a damper produced by a desert group of Australian Aboriginals. Over 100 years ago the English botanist and former Director of Kew, J.D. Hooker, writing of Australian edible plants, suggested that many of them were ‘eatable but not worth eating’ (Hooker 1859). To the modern Australian there may seem to be considerable justice in such a view. Nevertheless, the Australian flora together with the fauna, supported the indigenous Aboriginal people. Before the European occupation of Australia, the Aboriginals lived as a hunting and food gathering society for about 40 000 years.
This is a descriptive summary of information on traditional and modern uses of native plants by Alyawara-speaking Australian
Aborigines. It includes data on 157 species, 92 of which are used for food, 28 for medicines and narcotics, and 10 in the
manufacture of tools, weapons and other gear. Descriptions of food plants cover form and distribution, collecting and processing
techniques, caloric yields, and dietary importance. The paper concludes with some comments on traditional plant cultivation
practices.
The Papago and River Pima diets have historically been based on legumes rather than on grains or meats. Their selection of certain legume foods over other potential staples characterizes their ecological niches. The range of bean pod and seed foods utilized by the Northern Pimans are discussed in terms of folk taxonomy, protein content, preparation, and general importance. Their most important wild food, mesquite pods, and a key cultivated food, tepary beans, are contrasted in terms of yield, reliability, procurement, and protein quality. The nutritional implications of a legume dominated diet are analyzed.
Ninety-five nonobese, nonketotic subjects were divided into five groups (one normal and four with varying degrees of glucose intolerance) according to their plasma glucose responses during an oral glucose tolerance test. These five groups were then compared on the basis of their insulin response during the oral glucose tolerance test and on the ability of exogenously infused insulin to limit hyperglycemia during a continuous infusion of glucose and insulin, while endogenous insulin was inhibited by the infusion of epinephrine and propranolol. The mean plasma insulin response of patients with either borderline abnormalities of glucose tolerance or chemical diabetes was equal to or greater than that of normal subjects at all points during the glucose tolerance test. Thus, the glucose tolerance of these two patient groups cannot be attributed to lack of insulin. On the other hand, the mean insulin response of patients with moderate fasting hyperglycemia (plasma glucose of 110 to 150 mg/100 ml) was somewhat attenuated, and patients with severe fasting hyperglycemia (plasma glucose greater than 150 mg/100 ml) had unequivocal insulin deficiency. In contrast, all four patient groups with abnormal carbohydrate metabolism were more resistant than normal subjects to the action of insulin. These results indicate that there is a very complex relationship between insulin deficiency and insulin resistance in patients currently classified as having nonketotic diabetes. Patients with either borderline abnormal glucose tolerance or chemical diabetes are more resistant to insulin than normal subjects, and are not insulin deficient. In these patients it seems reasonable to assume that their glucose intolerance is a direct function of their insulin resistance. Patients with severe fasting hyperglycemia are suffering from both insulin deficiency and insulin resistance, and the relationship between these two variables in the genesis of hyperglycemia in these subjects remains obscure. It seems apparent from these studies that nonketotic diabetes mellitus can no longer be considered to be a simple function of insulin lack, and that in order to understand this syndrome we will need to increase our knowledge of the relationship between insulin deficiency and insulin resistance in these patients.
A diabetes prevalence study on an isolated urbanized Central Pacific Island has established a prevalence rate of 34.4% in individuals aged 15 years and over. Of these, 10.4% had previously known diabetes; in the others the diagnosis was made on the basis of a plasma glucose level of at least 160 mg/100 ml 2h after a 75 gm oral glucose load. A further 11.3% of the subjects had borderline diabetes as judged by a 2-h plasma glucose of between 140 and 159 mg/100 ml. Of the diabetics, 72% had a positive family history of diabetes. The high prevalence rate appears to be related to a number of factors including a diabetic genotype, urbanization, and obesity.
The rates of intestinal uptake of dietary sugars and amino acids, and changes in serum insulin and hepatic lipogenic enzyme responses were determined in male Wistar rats fed either an unrefined starch ( stock ) diet or a 65% readily digestible refined starch (corn) or a poorly digestible refined starch (potato) diet. At 45 days of age, rats fed the corn starch diet had 30% to 50% higher fasting serum insulin levels than did rats fed the stock or potato starch diets; however, the differences were not statisti cally significant. After an average of 9 weeks of being fed the diets, the intestinal uptake of glucose, a-methylglucose and fructose, and the response of hepatic malic enzyme and glucose-6-phosphate dehydrogenase were significantly greater in rats fed the corn starch diet than in rats fed the stock diet, whereas the effect was opposite with leucine and galactose uptake. The intestinal uptake of sugars and amino acids, and hepatic en zyme responses were often similar in rats fed the stock or potato starch diets. Rats fed the potato starch diet had smaller livers than did rats fed the corn starch diet. The livers of rats fed the corn starch or potato starch diets contained less soluble protein than did the livers of rats fed the stock diet. Feeding of the potato starch diet resulted in an abnormally enlarged and bloated gastrointestinal tract and in constrictions of the small intestine which appeared to obstruct the flow of intestinal contents. J. Nutr. 107: 2171-2177, 1977.
A hypothesis is proposed that dietary fiber depleted starchy foods are conducive to the development of diabetes mellitus in susceptible human genotypes.
1. A simple method is described for measuring the hydrogen concentration in alveolar air by end-expiratory sampling, by using a modified Haldane—Priestley tube and gas chromatography. Hydrogen was generated in vivo by ingestion of the non-absorbable sugar lactulose.
2. Alveolar hydrogen concentration showed a highly significant correlation with hydrogen production measured either by a rebreathing technique or by a total collection procedure.
3. The coefficient of variation of the end-expiratory method, assessed by comparing sixty-one paired results, was 11·6%. The coefficient of variation in ten measurements in one subject at 1 min intervals was 17·6%.
The breath hydrogen technique has suggested that a considerable amount of available plus unavailable carbohydrate enters the large intestine after the consumption of starchy foods (white bread 11%, wholemeal bread 8%, and red lentils 18%). Direct measurement of the available carbohydrate in ileal effluent after the consumption of test meals by three individuals with ileostomies gave values similar to those determined by the breath hydrogen technique (white bread 10%, wholemeal bread 8%, and red lentils 22%). These studies confirm that considerable amounts of "available carbohydrate" may be lost to the small intestine and physiologically must be considered as dietary fiber. The implications of this with respect to metabolism and colonic disease remain to be investigated.
The determine the effect of different foods on the blood glucose, 62 commonly eaten foods and sugars were fed individually to groups of 5 to 10 healthy fasting volunteers. Blood glucose levels were measured over 2 h, and expressed as a percentage of the area under the glucose response curve when the same amount of carbohydrate was taken as glucose. The largest rises were seen with vegetables (70 +/- 5%), followed by breakfast cereals (65 +/- 5%), cereals and biscuits (60 +/- 3%), fruit (50 +/- 5%), dairy products (35 +/- 1%), and dried legumes (31 +/- 3%). A significant negative relationship was seen between fat (p less than 0.01) and protein (p less than 0.001) and postprandial glucose rise but not with fiber or sugar content.
The blood glucose response to feeding whole and fiber-depleted cereals and cereal products was studied in healthy volunteers. No difference was seen between white and wholemeal bread and spaghetti or between white and brown rice. This lack of effect of cereal fiber on postprandial blood glucose levels suggests that the reported beneficial long term effects of cereal-based, 'natural' high fiber diets on diabetic control must be due to other aspects of the diet or to a different effect of fiber.
A significant relationship was found between the rate of release of the sugars; glucose, maltose, and maltotriose from amylitic digestion of 10 foods tested in vitro (expressed as the digestibility index) and the blood glucose response to 50-g carbohydrate portions of the same foods eaten by diabetics (expressed as the glycemic index), (r = 0.815, n = 10, p greater than 0.01). The glycemic index related to both the palatability of the foods (r = 0.731, p less than 0.05) and their frequency of use (r = 0.698, p less than 0.05). However, in this group of motivated diabetics food use was not related directly to palatability, but rather to health belief (r = 0.689, p less than 0.05). The results suggest that carbohydrate foods of potential use to the diabetic may be identified by their in vitro digestion characteristics but to a large extent their acceptance will depend on health belief and possibly ease of preparation.
We have investigated plasma glucose and insulin responses to 75 g glucose in 12 young, full-blood Aborigines before and after 2 weeks on a diet derived almost exclusively from seafood. This diet was low in fat, extremely low in carbohydrate and high in protein and was representative of the diet consumed by these people in their traditional lifestyle during those times of the year when very little vegetable food was available.
After an initial weight loss which was probably due to glycogen, salt and water losses associated with the dietary change, body weights stabilised by the end of the first week. Total triglyceride concentrations in fasting plasma fell from 1.32±0.33 before the diet to 0.61±0.08 mmol/l after it, while total cholesterol, which was low initially, did not fall significantly.
There was a small but significant improvement in glucose tolerance and a small reduction in insulin response indicating that the Aborigines had adapted effectively to the very low carbohydrate-high protein diet in the 2 week period. The insulin response to 50 g protein also fell significantly after the seafood diet. The results suggest that glucose tolerance is not determined solely by the carbohydrate content of the diet, but rather by the availability of carbohydrate either directly or indirectly in precursor form as dietary protein.
Recent epidemiologic studies have revealed a high prevalence of maturity-onset diabetes in certain populations that have undergone comparatively rapid urbanization. There is evidence suggesting that Australian Aborigines may respond to urbanization in this way. Thirteen full-blood Aborigines from the Mowanjum Community, Derby, Western Australia, cooperated in the present study. They spent 3 mo living in their traditional hunter-gatherer life-style, after which their insulin response to glucose was measured in a starch tolerance test. The findings were compared in follow-up studies conducted 3 mo after returning to their urban environment. Similar studies were conducted in Caucasians of comparable age and weight. Fasting glucose concentrations were lower in Aborigines than in Caucasians and were unaffected by life-style changes. Although basal insulin levels were similar in the three groups, there were striking intergroup differences in the insulin responses to glucose. The areas under the insulin curves in the first hour after starch ingestion were: urban Aborigines 4478 +/- 465 microU/ml-1/min, traditional Aborigines 2959 +/- 301 microU/ml-1/min, and Caucasians 2097 +/- 224 microU/ml-1/min. This appeared to reflect differences in the early rates of change of glucose concentrations. The data suggest that these Aborigines have an abnormally high insulin response to glucose, which is ameliorated, but not normalized, by reverting to their traditional life-style.
Despite the use of a wide range of different methodologies and diagnostic criteria, epidemiological studies have shown that Type 2 (non-insulin-dependent) diabetes has a global distribution and its prevalence varies from country to country, in different ethnic groups in the same country, and between the same ethnic group undergoing internal or external migration. Rural-urban and migration studies indicate that change towards a 'Westernized' lifestyle is associated with a dramatic increase in the prevalence rates for Type 2 diabetes. Between populations, comparisons are confounded by a wide range of different ascertainment rates, survey methodologies, and diagnostic criteria for diabetes. However, low prevalence rates for Type 2 diabetes are seen in Eskimos and populations of the Far East, while the highest are seen in American Indians, urbanized Pacific Island populations, and migrant Asian Indians. Available evidence suggests that these latter groups have a genetic susceptibility to Type 2 diabetes ('diabetes genotype') and that the disease is unmasked by environmental factors. There appears to be a spectrum of interaction between genetic and environmental factors--in certain populations the genetic role may be more important than environmental, or vice versa. Epidemiological studies, apart from their value in population screenings and case-finding, have contributed to the new classification and diagnostic criteria for diabetes and our understanding of risk factors and host characteristics in the aetiology of Type 2 diabetes.
We have investigated plasma glucose and immunoreactive insulin responses to 75-g oral glucose in lean, young, full-blood Aboriginal men from urban and rural communities and made comparisons with age- and weight-matched Caucasoids. Fasting glucose concentrations were lower in the rural Aborigines than in the urban Aborigines or the Caucasoids. Plasma glucose concentrations 2 h postprandially were significantly higher in both Aboriginal groups (urban 6.7 +/- 0.6 mmol/l, rural 6.4 +/- 0.4 mmol/l) than in the Caucasoids (5.0 +/- 0.3 mmol/l). Insulin responses in the two Aboriginal groups were almost identical and 50% higher than in the Caucasoids. We also investigated glucose tolerance and plasma lipids in 67 full-blood Aborigines living in an isolated rural community. Only three people (two men and one woman) had diabetes while a further eight (six men and two women) had impaired glucose tolerance. Fasting plasma cholesterol concentrations did not increase with age and were significantly lower in the rural Aboriginal community than in either the urban Aborigines or the Caucasoids. These results suggest that elevations in fasting cholesterol and glucose concentrations are lifestyle-associated, but that mild impairment of glucose tolerance and high insulin response in the Aborigines may be inherited metabolic characteristics.
A study of the prevalence of diabetes mellitus in the predominantly Melanesian population of the Torres Strait region indicated a rate of 19% in the outer island area and a rate of 13% in the Thursday Island and Bamaga areas. The disease, predominantly of the mature-onset type, was not sex dependent except in subjects over the age of 50 years, in whom there was a significantly greater prevalence amongst females. A positive correlation between blood or plasma glucose levels and blood pressure was found.
Carbohydrate portions (2 g) of lentils, soya beans, and wholemeal bread were incubated for three hours with human digestive juices and the effect of digestibility on blood glucose examined. Lentils and soya beans released only 39% and 8% respectively of the sugars and oligosaccharides liberated from bread. In healthy volunteers 50 g carbohydrate portions of cooked lentils and soya beans raised blood glucose concentrations by only 42% (p < 0.001) and 14% (p < 0.001) of the bread value. There was a similar response in diabetics. These results suggest that rate of digestion might be a important factor determining the rise in blood glucose concentration after a meal and that supplementing chemical analysis with in-vitro and in-vivo food testing might permit identification of especially useful foods for diabetics.
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