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Seafood, nutrition and human health: A synopsis of the nutritional benefits of consuming seafood.



Seafood as a whole food is highly nutritious. Benefits to human health associated with the consumption of seafood are noted for multiple bodily organs and physiological functions. Seafood compares favourably with other protein sources as it offers superior macronutrients in the ideal form of lean proteins combined with healthy omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs), and a wide array of highly bioavailable micronutrients. This exposition investigates the role of key nutrients present in seafood on human health. Particular focus is placed on marine sourced omega 3 fatty acids, protein, vitamins A, B12, D and E, iodine, selenium, calcium, zinc and iron. Centre of Excellence Science, Seafood & Health, Curtin Health Innovation Research Institute, Curtin University, Perth.
Prepared by
Centre of Excellence Science Seafood &
Health (CESSH)
Curtin Health Innovation Research Institute
Curtin University of Technology
March 2011
Seafood, nutrition and
human health
A synopsis of the nutritional benefits of consuming seafood
Professor Alexandra McManus
Director, Centre of Excellence Science Seafood & Health (CESSH)
Curtin Health Innovation Research Institute
Faculty of Health Sciences
Curtin University of Technology
Dr Wendy Newton
Post Doctoral Scientist
Centre of Excellence Science Seafood & Health (CESSH)
Preferred citation:
McManus A, Newton W. Seafood, nutrition and human health: A synopsis of the nutritional benefits of
consuming seafood. Centre of Excellence Science, Seafood & Health, Curtin Health Innovation Research
Institute, Curtin University of Technology, Perth. 2011.
Seafood, nutrition and human health
A synopsis of the nutritional benefits of consuming seafood
1.0 Abstract 1
2.0 Introduction 1
3.0 Nutrients found in seafood 1
3.1 Marine sourced omega 3 fatty acids 1
3.2 Protein 2
3.3 Vitamin D 2
3.4 Iodine 2
3.5 Selenium 3
3.6 Calcium 3
3.7 Vitamin B12 3
3.8 Vitamin A 3
3.9 Vitamin E 4
3.10 Zinc 4
3.11 Iron 4
4.0 Discussion 4
References 5
Table of contents
1.0 Abstract
Seafood as a whole food is highly nutritious. Benefits to human health associated with the consumption of seafood are noted for
multiple bodily organs and physiological functions. Seafood compares favourably with other protein sources as it offers superior
macronutrients in the ideal form of lean proteins combined with healthy omega-3 long chain polyunsaturated fatty acids (n-3 LC-
PUFAs), and a wide array of highly bioavailable micronutrients.
This exposition investigates the role of key nutrients present in seafood on human health. Particular focus is placed on marine sourced
omega 3 fatty acids, protein, vitamins A, B12, D and E, iodine, selenium, calcium, zinc and iron.
2.0 Introduction
In the 1950’s it was noted that Eskimos native to Greenland had a low incidence of heart disease despite having a diet high in oil.
Furthermore, observational studies of Alaskan and Greenland Eskimo and Japanese populations revealed lower incidence and
morbidity associated with coronary heart disease (1). Consequently, there has been intense interest in the health benefits associated
with marine sourced omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs). Mounting evidence has shown that the
consumption of marine n-3 LC-PUFAs, fish, seafood or fish oils has been positively linked with cognitive development and a reduced
risk of chronic conditions including coronary heart disease, some cancers, diabetes, rheumatoid arthritis, dementia and Alzheimer’s
Disease (2).
While the health benefits of n-3 LC-PUFAs are now widely accepted, the benefits of fish or seafood consumption have largely been
obscured by the intense interest in n-3 LC-PUFA fortified foods and supplements. Food products fortified with n-3 LC-PUFAs abound
in the market place and the growth in the popularity of fish oil supplements has been extraordinary. Fish or seafood as whole foods
provide health benefits beyond those that can be attributed to n-3 LC-PUFAs alone. Furthermore, the superior bioavailability of
nutrients in seafood leads to the conclusion that seafood as a whole food is among the best dietary source of many nutrients (3).
This resource summarises the range of macro and micronutrients in seafood with a view to promoting the consumption of fish and
seafood as whole foods that are highly valuable to a balanced diet.
3.0 Nutrients found in seafood
3.1 Marine sourced omega 3 fatty acids
The there is mounting evidence of health benefits associated with ingestion of n-3 LC-PUFAs. These include brain and retinal
fetal development, cognitive development, mental health improvements (depression, schitzophrenia, dementia and attention
deficit hyperactivity disorder), lower risk of coronary heart disease and protection against heart arrhythmia, greater plaque
stability and anti-thombosis properties (4). Additionally, there is evidence of the role of n-3 LC-PUFAs in maintaining immune
function and reducing inflammation for the treatment of all forms of inflammatory arthritis (4). Marine sourced n-3 LC-PUFAs
are found in all seafood with the richest source being oily fish.
Marine sourced n-3 LC-PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are the important fatty acids
for which substantial scientific support for health benefit exists. EPA and DHA may be converted at a very low rate from plant
sources of a shorter chain omega-3 fatty acid, alpha-linoleic acid (ALA); recent reviews however conclude that supplementation
with ALA is not effective in raising blood DHA levels (5). Conversion rates of ALA to EPA and DHA are typically low and are
influenced by background dietary lipid profiles (6). Consumption of preformed EPA and DHA from marine food sources is the
most efficacious method to increase physiological status of EPA and DHA for the purpose of achieving the documented health
benefits associated with these n-3 LC-PUFAs.
Despite the commercial popularity of n-3 LC-PUFA fortified foods and supplements, recent research indicates bioavailability of
supplements varies dramatically (7). The shelf life of omega 3 fortified foods and supplements has been questioned in light of
their susceptibility to oxidation and further, the safety concerns about the peroxides and other products of oxidation (8) .
3.0 Nutrients found in seafood (contd.)
3.2 Protein
The importance of protein is now recognised as being more complex than long realised roles of maintenance of bodily
structures including muscles, bones, fingernails and hair. Protein, peptides and amino acid derivatives are important
components in bone health, regulation of body composition, glucose metabolism, satiety, cell signalling, gastrointestinal
health and bacterial flora (9).
Quality of protein has traditionally been assessed through the amino acid content, ratio of amino acids, source, susceptibility
hydrolysis during digestion and the influence of any processing carried out (10). Animal sourced dietary proteins tend to be
complete sources of protein in that they contain the full complement of essential amino acids. Fish protein tends to be high in
lysine, sulphur containing amino acids and threonine; these amino acids are limiting in cereal based diets and add significance
to the quality of fish and seafood protein sources.
Evidence suggests a link between high levels of red and processed meat consumption and bowel cancer (11). In contrast,
there is mounting evidence that consumption of seafood can be protective against some cancers (2). Further, consumption
of seafood protein has been associated with increased insulin sensitivity in diabetics (12-13), reduced inflammation (14)
and animal studies are consistently revealing that seafood protein results in lower blood pressure (15-18). Most commonly
consumed items of seafood are rich in complete protein.
3.3 Vitamin D
Vitamin D can be obtained from sunlight or dietary sources. Vitamin D is important in regulating calcium and phosphorous
in bone mineralization. Vitamin D also features in thyroid function, rennin and insulin production, immunity, skin condition,
muscle strength and has been linked to the prevention of some cancers (19-20). The roles of vitamin D in regulating bone
mineralization and adsorption of calcium inherently makes vitamin D important in the prevention of osteoporosis. As seafood
is a good source of calcium and vitamin D, research has found that increasing consumption of seafood in the diet significantly
improves bone mineral density in women(19).
Widespread awareness of the link between sun exposure and skin cancer in Australia and New Zealand has diminished vitamin
D obtained from the sun. Sunscreen and clothing act as a barrier preventing not only sun damage but also the synthesis of
vitamin D (20). Vitamin D deficiency and rickets (osteomalacia) are a current concern in paediatric health in Australia and
New Zealand (21). Additionally, at risk populations including dark-skinned individuals, the elderly, the infirm who have
limited mobility, and those who cover themselves due to adherence to religious beliefs, are especially susceptible to vitamin D
deficiency and may need an alternative source of this essential vitamin.
The food chain of marine animals concentrates vitamin D and makes seafood the best dietary source of vitamin D (22).
Although, seafood consumption can be beneficial in raising vitamin D levels, diet in isolation is unlikely to supply the
recommended daily requirement for vitamin D (23); some sunlight exposure is recommended. Standard 2.4.2 of the Australian
and New Zealand Food Standards Code specifies a minimal level of vitamin D to be contained in edible oils and spreads in an
effort to boost dietary vitamin D in the general populace (24). Prevention of vitamin D deficiency can be achieved with a diet
high in oily fish (20).
3.4 Iodine
Iodine deficiency disorders are diverse and include metal and physical disorders that can be debilitating (25). Iodine is vital
for the effective functioning of the thyroid gland and thyroid hormone production thereby having profound influence on
facilitating normal growth, metabolism, cell oxygen consumption and the development of the central nervous system.
Historically, iodine deficiency occurred in areas where the soil was low in iodine content and endemic goitre would be noted
in local populations. Until recently, the trade in fresh produce in modern times had overcome geographic soil limitations.
In contrast to the early 1990s where the iodine status of Australians was satisfactory, the iodine intake of the Australian
population was recently considered inadequate, prompting calls for iodine fortification of all edible salts (25). The primary
reason behind the decrease in iodine status over the last two decades has been the growth in popularity of chlorine based
cleaning products in dairies and their preferential use over iodine based products (25). October 2009 heralded a change to the
Australian and New Zealand Food Standards Code; Standard 2.1.1 now mandates that all salt used in bread making must be
iodized. Recent mandatory fortification of The NHMRC has recommended that ‘women who are pregnant, breastfeeding or
considering pregnancy take an iodine supplement of 150μg each day (26).
Iodine is found in most seafood, with shellfish containing the most abundant quantities. Further, fish and seafood have the
highest concentration of iodine relative to other foods commonly consumed in most diets (27). Seafood as a part of a healthy
diet will improve iodine status.
3.0 Nutrients found in seafood (contd.)
3.5 Selenium
Selenium plays an important role in the body. Selenium prevents cellular damage and is protective against oxidative stress (28).
Selenium also assists in regulating the function of the thyroid and supports healthy immune function. Selenium deficiency is
more likely to occur in areas such as New Zealand due to reduced selenium levels in the soil. Low soil levels of selenium results
in reduced selenium throughout the agricultural food chain.
Selenium is present in most finfish. Selenium in fish is highly bioavailable suggesting that fish is a superior source of dietary
selenium relative to other sources including yeast (29). Recent research comparing a diet that includes salmon and one that
includes salmon oil capsules, revealed that consumption of fish oil supplements deprived subjects of the dietary benefit of
selenium (30).
Further to the nutritional benefit of selenium consumption, there is a growing foundation of research suggesting that
selenium acts as a counteractive agent to mercury (28, 31-33). Studies have shown that when test organisms are exposed to
toxic levels of mercury, an equal dose of selenium can substantially reduce the detrimental effects. It is possible that concerns
of methylmercury accumulation in some fish populations may be moderated by selenium.
3.6 Calcium
Calcium is important for developing and maintaining bones and teeth as well as supporting the healthy functioning of
muscles, nerves and the heart. Skeletal calcium serves as a reservoir for the supply of calcium for other body functions such as
intracellular messaging(34) and as such after a long latency period, calcium deficiency results in osteoporosis (35). Adequate
dietary calcium is required throughout life to prevent low bone mineral density, increased risk of fragility fractures and
osteoporosis at a mature age (34).
Bony fish such as sardines and tinned salmon are very rich in calcium. Intakes of seafood greater than 250g per week, have
been associated with greater bone mineral density (19). Of note however, is that calcium adsorption is dependent on adequate
vitamin D and can be reduced by dietary interactions including dietary fibre and alcohol (34). It can be construed from
evidence that seafood can promote bone density when consumed within an otherwise healthy diet due to the susceptibility of
calcium to macro and micro nutrient interactions.
3.7 Vitamin B12
Vitamin B12 is important to DNA synthesis, red blood cell and neurological function. Deficiency of vitamin B12 can be
associated with megoblastic anaemia, neurological disorders, myelopathy, memory impairment, dementia, depression and
cerebrovascular disorders (36).
Most fish and shellfish contain vitamin B12. Clams, octopus, oysters, fish and fish roe are excellent sources of vitamin B12 (37).
Dietary intake of fish has been linked to significant improvements in plasma B12 status (36). Researchers have identified that
dietary vitamin B12 sourced from fish and a dairy product is more bioavailable than that from meat and eggs (36).
3.8 Vitamin A
Vitamin A plays an important role in supporting normal vision, reproduction, bone growth, immune functions and healthful
maintenance of the eye, respiratory and urinary tract linings, the skin and mucous membranes (38). Deficiency in vitamin A
is associated with increased infections from diarrhoea to respiratory infections. In developing countries supplementation can
prevent approximately a quarter of childhood deaths (38).
Most fish and shellfish contain Vitamin A though the best marine sources are oily fish. Animal sourced vitamin A is in the fat
soluble retinol that is converted to an active form such as retinal or retinoic acid; these are efficiently adsorbed and used by
the body (38). Plant sources of vitamin A are the water soluble pigment group of carotenoids. Carotenoids are less efficiently
adsorbed than preformed retinol (38)and are subject to a conversion factor when calculating retinol equivalents.
3.0 Nutrients found in seafood (contd.)
3.9 Vitamin E
Vitamin E is a highly efficacious antioxidant that is important to the skin, nervous system, heart and circulatory system.
Although deficiency in vitamin E is uncommon, the various forms of vitamin E are protective of vitamins A and C by preventing
their oxidation (38). Vitamin E is found in oils, nuts and green leafy vegetables (38); the highest marine source of vitamin E is
oily fish.
3.10 Zinc
While only small amounts of this essential trace element are required, zinc acts as a catalyst for over 100 specific enzymes
necessary for human metabolism (38). Zinc plays a role in optimal growth and development and functioning of the immune
system. Zinc deficiency may result in stunted growth, vulnerability to infection and pregnancy outcomes (38).
Widespread zinc deficiency is an issue affecting Australian arable land (39), and thus crops raised in Australia may not
continue to contribute significantly to human zinc requirements. Consequently, alternative sources such as zinc rich food
should be consumed so that optimal zinc levels are met and maintained. As zinc binds to protein, foods such as seafood, which
are sources of both zinc and protein, optimise bioavailability of dietary zinc (39). Oysters are known to be one of the richest
natural sources of zinc.
3.11 Iron
Iron plays a vital role in facilitating the transportation of oxygen throughout the body within the haemoglobin complex and is
associated with growth, healing and immune function. It is also critical for energy production within cells and DNA synthesis.
Research suggests that Australian women in particular may not be consuming adequate iron, and increasing the consumption
of iron rich seafood within a balanced diet can play an important role in addressing this imbalance (40). Heam iron, found in
seafood and animal sources is more readily bioavailable than non- heam sourced from plants.
4.0 Summary
The value of seafood within a healthy diet is clear from this overview of nutritional composition. Evidence on the health benefit of
marine sourced omega 3 fatty acids is mounting with the strongest evidence associated with DHA. Conversion of plant sourced omega
3 PUFAs is less effective in producing the health benefits. It is unlikely that the average consumer is aware of the differentiation in
function and education of the general public is required.
The importance of seafood as a whole food, in addition to n-3 LC-PUFA, cannot be underestimated. Seafood offers a range of nutrients
that are frequently under-represented in habitual diets, including iodine, calcium, vitamin D, zinc and iron.
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... Oysters contain high-quality proteins, omega-3 long-chain polyunsaturated fatty acids (n-3 PUFA) and bioavailable micronutrients (e. g., zinc and taurine) (McManus & Newton, 2011). However, the consumer preference of raw oysters has been associated with its taste profile, which is contributed by free amino acids (FAAs), 5 ′ -nucleotides, organic acids, inorganic ions, etc. (Liu et al., 2021). ...
... In this study, HHP-treated oysters caused minor changes in the fatty acid profiles compared to raw oysters, which is in agreement with the results reported in Hong Kong oyster, Pacific oyster and green-lipped mussel Perna canaliculus (Cruz-Romero, Kerry, & Kelly, 2008;Zhou, Balaban, Gupta, & Fletcher, 2014;Liu et al., 2021). Seafood can provide superior lipids containing high amounts of healthy n-3 PUFA and highly unsaturated phospholipids (McManus & Newton, 2011). The ratios of n-3 PUFA to n-6 PUFA are considered important to human health (Torstensen, Frøyland, Ørsnrud, & Lie, 2004). ...
The effects of HHP and storage temperature on bacterial counts, color, fatty acids and flavor compounds of oysters Crassostrea ariakensis were investigated. Counts of Vibrio vulnificus and Vibrio parahaemolyticus decreased to undetectable levels in ≥400 MPa-treated oysters. Storage at -20°C significantly restrained microbial growth compared to 4°C (P < 0.05). L* values of HHP-treated oysters significantly increased compared to raw oysters (P < 0.05). Storage slightly affected the color according to total color difference (ΔE*) values. Fatty acid profiles and betaine contents in 400 and 600 MPa-treated oysters at 0 and 15 d were almost the same as raw samples. Contents of total free amino acids (FAAs), Na⁺ and Ca²⁺ were significantly higher in 400 and 600 MPa-treated oysters than those in raw oysters at 0 d (P < 0.05), while the opposite results were observed in 5’-adenosine monophosphate (AMP), 5’-guanosine monophosphate (GMP), citric acid, succinic acid, K⁺ and PO4³⁻ (P < 0.05). At 400 and 600 MPa, FAAs significantly decreased after 15-d storage at 4°C and -20°C (P < 0.05), while no significant changes were observed in nucleotides, organic acids and inorganic ions.
... Fish muscle is basically composed of water (66-81%), protein (16-21%), carbohydrates (<0.5%), lipids (0.2-25%) and ash (1.2 to 1.5%) (Shikha et al. 2020). It is considered to have important biological value due to the contribution of essential amino acids (Hatae et al. 1990) and micronutrients (McManus and Newton 2011), as well as, its high levels of fatty acids omega-3 and omega-6, higher than in most meat sold for human consumption (Gjedrem et al. 2012). The human body requires these elements and the deficiency in these principal nutritional elements induces a lot of malfunctioning; as it reduces productivity and causes diseases. ...
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The study was conducted to investigate the sensory quality and proximate composition of export oriented and locally consumed fishes collected from four fish processing plants, four super shops and four local fish markets of Bangladesh. Sample of Clarias batrachus, Amblypharyngodon mola, Ompok pabda, Labeo rohita and Anabas testudineus were subjected to sensory evaluation for color, odor, taste, flavor and texture characteristics by organoleptic method and proximate composition for nutritional quality assessment using standard AOAC methods. Sensory quality evaluation revealed that average defect points of fish samples collected from processing plants, super shops and local markets were between 1.40 to 1.57, 1.67 to 2.31 and 1.36 to 2.64 respectively, indicating excellent quality of samples collected from processing plants compared to good/acceptable quality for those collected from super shops and local markets. The study of proximate composition revealed that moisture ranged from 79.71±0.07% to 66.77±0.7%, crude protein 19.05±0.31% to 16.01±0.13%, crude lipid 10.41±0.02% to1.25±0.19% and ash 3.73±0.07% to 1.43±0.04% in different fish species collected from different sources. In conclusion, the organoleptic assessment and proximate composition of collected samples indicated that the fish samples of fish processing plants were of good condition for export and consumption. The fish samples from local fish markets and super shops were within the acceptable level but not as good as the fish samples of fish processing plants.
... In order to avoid low bone mineral density, reduce the risk of fragility fractures, and osteoporosis at a mature age, sufficient dietary calcium is required during life. Higher bone mineral density has been correlated with seafood intakes greater than 250g a week (McManus and Newton, 2011). It should be understood from the evidence that seafood, because of the sensitivity of calcium to macro and micro nutrient interactions, can improve bone density when eaten within an otherwise balanced diet. ...
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The purpose of the current study was to determine certain mineral components in edible tissue in different species of fish from Greater Zab River, Erbil Governorate- Kurdistan Region-Iraq. A total of 180 fish namely Capoeta trutta, Chondrostoma regium and Leuciscus cephalus were collected from Gali Balinda, Bn Khiveta, Galiesule, Pirsal and Bekhme between July and November 2019. After removal of eviscerated, deboned, head and fins, fish were washed with purified water and muscle samples were collected above the lateral line between the dorsal fin and the caudal fin, then dried for important and non-essential metals examination at 750 C for 48 h. Results showed that levels of K, Na, P, Ca, Cd and Hg in the edible tissue of Chondrostoma regium fish were significantly higher than in the Capoeta trutta and Luciobarbus esocinus fish, whereas the edible tissue in Capoeta trutta exhibited the highest mean values for lead, barium and arsenic. In all species, the highest concentrations of K, Na, and Mg were recorded in Gali Balinda, whereas the highest concentration of P and Ca were recorded in Pirsal during studied period. According to the results, the government should have environmental policies to improve, keep and enrich the water quality assessment in Greater Zab River
... Foods from the aquatic environment are a unique source of the essential nutrients (FAO 1999). Fish meat is basically composed of water (66-81%), protein (16-21%), carbohydrates (<0.5%), lipids (0.2-25%) and ash (1.2-1.5%) and is considered to have important biological value (Santaella et al. 2007), due to the contribution of Essential Amino Acids (EAA) and micronutrients (McManus and Newton 2011), as well as, its high levels of fatty acids omega-3 and omega-6, higher than in most meat sold for human consumption (Gjedrem et al. 2012). Begum et al. (2016) determine the nutritional value of hilsa fish from the six selected regions in Bangladesh and they found-the moisture, protein, fat, carbohydrate and energy values 66.94±7.34 to 72.04±5.77%, ...
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Biochemical, microbiological and sensory quality parameters of mustard hilsa prepared from Hilsa shad (Tenualosa ilisha) were examined to observe the changes in quality during storage at refrigeration temperature (5° to 8°C) for 60 days and at frozen temperature (-18°C to-20°C) for 180 days. The moisture, protein, lipid, and ash content and pH value in mustard hilsa decreased compared to those obtained for fresh fish. On the other hand, TVB-N and peroxide values increased compared to the values found in fresh fish. At refrigeration temperature and frozen temperature moisture and ash contents increased but protein and lipid content decreased gradually throughout the storage period. pH value of the mustard hilsa reduced from 7.22 to 6.01 and 6.59 at refrigeration and frozen temperatures, respectively. The TVB-N value and peroxide value increased progressively throughout the storage period irrespective of storage temperatures. Rate of changes in different parameters of mustard hilsa was slower in vacuum sealed packs than non-sealed and sealed packs. The aerobic plate count of bacteria was increased in refrigeration temperature but the load of microbes was reduced at frozen temperatures. The result of sensory quality change showed that, irrespective of storage temperature and packing condition the scores of sensory quality parameters decreased with the progress of storage time though the decreasing rate was slower at frozen temperature. The study concluded that, at refrigeration temperature mustard hilsa might remain in acceptable condition up to 60 days and at frozen temperature for about 180 days in vacuum sealed pack.
... The consumer preference of food has been primarily associated with its nutritional composition and taste profile (Zheng, Tao, Gong, Gu, & Xu, 2015). Seafood could provide superior macronutrients, such as essential amino acid (EAA), healthy omega-3 long chain polyunsaturated fatty acids (n-3 PUFA) and several bioavailable micronutrients (McManus & Newton, 2011). Moreover, non-volatile taste compounds, such as free amino acids (FAA), 5 ′ -nucleotides, organic acids, betaine and inorganic ions, could contribute to the characteristic flavor of seafood (Liu et al., 2018). ...
In this study, the effects of high hydrostatic pressure (HHP) and steam on biochemical composition and non-volatile taste active compounds of oysters Crassostrea hongkongensis were investigated. The moisture content in steamed oysters significantly decreased when compared to raw samples, subsequently their crude protein, crude lipid, glycogen and ash contents (% wet weight) were all increased (P < 0.05). In addition, though the moisture content in HHP oysters decreased, no significant differences were observed in proximate compositions compared to raw oysters, except crude protein. There were no significant differences in saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) profiles between raw and HHP oysters, however, C20:3n6 content in HHP oysters was significantly higher than that in raw samples (P < 0.05). The PUFA profile of steamed oysters, mostly contributed by n-3 PUFA, was significantly higher than that of both raw and HHP samples (P < 0.05). Major free amino acids (FAA) (taste activity value, TAV > 1) in oysters with three treatments were alanine, glycine, glutamic acid and histidine, and their contents were significantly higher in raw and HHP groups than that in steamed group. The 5 ′-inosine monophosphate (IMP) and 5 ′-gua-nosine monophosphate (GMP) in HHP and steamed oysters decreased compared to raw samples, while AMP content in steam oysters were significantly increased (P < 0.05). The equivalent umami concentration (EUC) of oysters of raw, HHP and steamed groups were 8.80, 3.66 and 1.44 g MSG/100 g, respectively, with significant differences observed among different treatments (P < 0.05). Succinic acid was the major organic acid in raw and HHP oysters, while lactic acid was the major organic acid in steamed groups. Further, Na + , K + , PO 4 3− and Cl − were the main inorganic ions (TAV > 1), and their contents were significantly higher in raw and HHP groups than that in steamed group (P < 0.05). This study demonstrated that HHP treatment slightly influenced the changes in the biochemical composition and non-volatile taste active compounds to raw oysters, compared to steamed process.
... Some fish especially sea fish, shell fish etc. are rich in iodine which can be recommended for persons with iodine deficiencies. Phosphorus is a vital constituent of cell membranes and can be availed from softboned fish [10] . Vitamins are essential micronutrients help to maintain optimal health. ...
... Moreover, seafood is low in saturated fat and sodium, rich in vitamins and minerals, and its protein can be easily digested (Lake, 2015). When seafood is compared with other protein-rich food sources, seafood proteins offer superior macronutrients in the ideal form of lean proteins combined with healthy omega-3 long chain polyunsaturated fatty acids (ω-3 LC-PUFAs), and a wide array of highly bioavailable micronutrients (McManus and Newton, 2011). ...
... The greater mean Zn concentration at Yawkey (1255 ± 228 ng/g, Table 1) could be due to a dietary difference at this location and the location's proximity to a pulp mill and coal-fired power plant. Alligators at this site are known to forage in the ocean, and the dietary bioavailability of Zn is optimized by the high protein content of marine organisms (McManus and Newton, 2011). Interestingly, the Zn concentrations in Yawkey alligators were not significantly influenced by Location, but the Zn concentrations observed at Yawkey may have played a role in the significant influence of Sex across all samples for Zn concentrations in our MLE model (Table S5). ...
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Toxic trace element exposure occurs through release of the ubiquitous and naturally occurring elements arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). The unique environmental conditions of the wetland ecosystems along the southeastern Atlantic coast of the United States lead to the accumulation of Hg which is greater than in most other ecosystems in the country. There are also point sources of As, Cd, and Pb in this region. To effectively monitor trace element concentrations, and consequently the potential human exposure, accessible local sentinel species are needed. In this study, concentrations of As, Cd, Pb, Hg and six other trace elements (Al, Ni, Cu, Zn, Se, Mo) were examined in American alligators (Alligator mississippiensis) from seven wetland sites in South Carolina and Florida and assessed for their utility as a sentinel species for human trace element exposure. Alligators were chosen as a potential sentinel as they share a common exposure with the local human population through their aquatic diet, and they are directly consumed commercially and through recreation hunting in this region. Sex was significantly related to the concentration of Zn, Mo, and Al, but not As, Pb, Hg, Cd, Se, or Cu. Site specific differences in element concentrations were observed for As, Pb, Hg, Cd, Se, Zn, and Mo. Size/age was significantly related to the element Hg and Pb concentrations observed. The observed concentration ranges for the four toxic elements, As (6-156 ng/g), Cd (0.3-1.3 ng/g), Pb (3-4872 ng/g), and Hg (39-2765 ng/g), were comparable to those previously reported in diverse human populations. In this region alligators are hunted recreationally and consumed by the local community, making them a vehicle of direct human toxic element exposure. We propose that the similarity in As, Cd, Pb, and Hg concentrations between alligators observed in this study and humans underscores how alligators can serve as a useful sentinel species for toxic element exposure.
... To produce 1 kg of grain required to feed livestock roughly 1000 l of water are used (2001( , Brown, 1999. Consequently, as fish and other marine animals are considered good sources of nutrients containing high levels of protein comparable with red meat as well as omega-3 fatty acids and high concentrations of vitamins and minerals (McManus & Newton, 2011), aquaculture presents a far more efficient solution to meeting growing protein demands than further expanding land-based livestock production. The greatest benefit is provided by aquaculture conducted in the ocean with species accustomed to salt water as this does not put additional pressure on already shrinking freshwater resources and doesn't further occupy valuable space on land (Verdegem, Bosma, & Verreth, 2006). ...
In the coming decades humanity will be confronted with a number of complex challenges affecting the prosperity and livelihood of billions of people around the globe. The root of these challenges lies in the downright explosion in global population over the last decades combined with a staggering increase of urbanization rates leading to an unprecedented level of demand for food, water, materials and space. Consequently, growing scarcity of essential resources are an ever increasing threat towards global peace and stability. This conflict potential is exacerbated by global warming and the associated sea level rise, which can once again be traced back to the rapidly growing demand for energy and food of the world's economies. In this paper we develop a comprehensive chain of cause and effect surrounding these global developments. Furthermore, we discuss how floating infrastructure, through its application to renewable energy generation, food production, flood protection and even urban expansion, is capable of decoupling multiple linkages in the chain, thus presenting itself as a promising mid- to long-term strategy for addressing these global challenges.
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From an increasing awareness of sustainable food production, the promise of the “blue revolution” and campaigns to ameliorate the marine environment, seafood gardening has emerged from motivated local citizenry as a local food production phenomenon. Bivalve gardening, primarily manifested as oyster gardening, is a relatively new concept, slowly gaining traction worldwide. Terrestrial and marine gardening share the same principles of cultivating organisms and providing ecosystem goods and services. The main differences concern the growing medium – and legislation regarding use and access to gardens. Bivalves appear to be an ideal group of marine organisms for local production, they are low maintenance and do not require external food supplies as they feed directly by filtrating their surrounding growing medium. However, the cultural services provided by bivalve gardening range from social organisation to sustainable engagement; and require certain pillars such as clear objectives, support from the local community and government, dedicated volunteers, native bivalve seed availability, training, and realistic objectives. Moreover, the development of new gardens raises fundamental issues including food safety, regulation, and marine spatial planning. We use two case studies to illustrate different approaches to bivalve gardening: (1) in the U.S. several bivalve gardening initiatives are taking place, it is often referred as oyster gardening and initiated as a bivalve habitat recovery efforts, (2) in Denmark in Europe, several projects have started directly as bivalve gardens for food provisioning and are managed by local associations. Link to full text:
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The health and well being of children depend upon the interaction between their genetic potential and exogenous factors like adequacy of nutrition, safety of the environment, social interaction and stimulation. Micronutrients which are nutrients that are only needed by the body in minute amounts play leading roles in the production of enzymes, hormones and other substances and also help to regulate growth activity, development and functioning of the immune and reproductive systems. Micronutrient deficiency, which has been considered as a major risk factor in child survival in Nigeria, increases the risk of death from common diseases such as acute gastroenteritis, pneumonia and measles. Dietary practices frequently seen in children from both developed and developing countries such as frequent consumption of nutrient-poor foods (as unhealthy snacks), and the "refusal" to take green leafy vegetables and fruits compromise their intake of micronutrients (such as zinc, iodine, vitamin A, iron, folate and selenium) from dietary sources. This paper reviews the role of micronutrients in child health and the importance of consuming green leafy vegetables, soy beans, seasonal fruits, milk, dairy products, fish, eggs, chicken and other food stuffs. The consumption of these foods will prevent the occurrence of common day to day infections in children, enable the society produce healthy children with solid foundation and ensure optimal human resource development.
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Limited information is available on the association between vitamin B-12 status and intake from different dietary sources. We investigated the relation of dietary intake of different food items with plasma vitamin B-12 concentrations in the general population. A cross-sectional, population-based study of 5937 subjects in 2 age groups (47-49 and 71-74 y) from the Hordaland Homocysteine Study in Norway was conducted by using a food-frequency questionnaire and measurements of plasma vitamin B-12 concentrations. A significant difference in plasma vitamin B-12 concentrations was observed with increasing total vitamin B-12 intake. A plateau was reached at an intake of approximately 10 microg/d. Plasma vitamin B-12 was associated with intakes of increasing amounts of vitamin B-12 from dairy products or fish (P for trend <0.001 for both) but not with intakes of vitamin B-12 from meat or eggs. For the same content of vitamin B-12, intake from dairy products led to the greatest increase in plasma vitamin B-12. Total intake of vitamin B-12, particularly from milk and fish, decreased the risk of vitamin B-12 concentrations <200 pmol/L and impaired vitamin B-12 function (vitamin B-12 <200 pmol/L and methylmalonic acid >0.27 micromol/L) in the total group and in 71-74-y-old subjects. Dietary intake of dairy products and fish are significant contributors to plasma vitamin B-12 and may improve plasma vitamin B-12 status. Vitamin B-12 appears to be more bioavailable from dairy products; guidelines for improving vitamin B-12 status should take this into consideration.
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During the last decades, fish and milk consumption has decreased considerably in Iceland, especially among adolescents. As these food items are important dietary iodine (I) sources, the aim of the study was to assess the iodine status and dietary pattern of adolescent girls in a population changing from a high to lower consumption of milk and fish. Subjects were randomly selected adolescent girls (16-20 years old, n=112). A validated Food Frequency Questionnaire (FFQ) was used to evaluate food consumption and compare it with food-based dietary guidelines for milk and dairy products (2-3 portions/day) and fish (> or =2 times/week). Urine samples were collected for measuring urinary iodine (U-I) and creatinine (Cr) and blood samples for measuring serum thyroid-stimulating hormone (TSH). Milk and dairy products provided 43% and fish provided 24% of the total dietary I. More than 65% of the girls consumed fish less than twice a week, and 40% consumed less than two portions of milk and dairy products per day. The median U-I concentration was 200 microg/l and the U-I/Cr ratio 138 microg I/g Cr. High intake of milk was associated with higher urinary iodine concentration, but fish intake was not found to be directly associated with urinary iodine concentration. Iodine status of Icelandic adolescent girls is within the optimal range defined by the World Health Organization. It is important to monitor both iodine status and the iodine concentration of important sources of iodine, as both dietary habits and composition of food might change with time.
Technical Report
Review of literature and resources relating to the health benefit of regular consumption of seafood as part of a health diet (plus separate Executive Summary) Curtin Health Innovation Research Institute, Curtin University, Perth.
The nutritional value or quality of structurally different proteins varies and is governed by amino acid composition, ratios of essential amino acids, susceptibility to hydrolysis during digestion, source, and the effects of processing. To optimize the biological utilization of proteins, a better understanding is needed of the various interrelated parameters that influence their nutritive value. This review attempts to contribute to this effort. It discusses methods used for protein quality evaluation, research needs to facilitate labeling foods for protein quality, and factors influencing protein quality including amino acid analysis, digestion, food processing, antinutrients, and protein-energy relationships. Recent studies on the nutritional quality of more than 50 common and uncommon protein sources including cereals, legumes, other seeds, meat, seafood, insects, leaves, mushrooms, and potatoes are reviewed. Also described are advantages of consuming low-quality proteins fortified with essential amino acids, nutritional benefits of mixtures of complementary protein sources, plant genetic approaches to improving the nutritive value of foods, problems associated with liquid diets for adults and infants, socioeconomic aspects of new protein foods, and the influence of protein type and quality on lactation, the immune system, and serum lipids. This integrated overview is intended to stimulate interest in the introduction and use of new protein sources for feeding the ever-growing world population. Keywords: Amino acids; digestibility; food protein sources; health; malnutrition; mixed proteins; nutritional quality; protein quality
Numerous studies have demonstrated the beneficial effects of fish consumption on inflammatory markers. Until now, these beneficial effects of fish consumption have been mostly linked to the omega-3 fatty acids (FA). The objective of the present study was to examine, in vitro, whether expression levels of genes involved in the inflammatory response differ in human macrophages incubated with casein hydrolysates (CH) or fish protein hydrolysates (FPH) in the presence or absence of omega-3 FA compared with omega-3 FA alone. Peripheral blood monocytes differentiated into macrophages from 10 men were incubated in the presence of omega-3 FA (10 microM eicosapentaenoic acid and 5 microM docosahexaenoic acid) or CH or FPH (10, 100, 1,000 microg) with or without omega-3 FA for 48 h. Results demonstrate that expression levels of tumor necrosis factoralpha (TNFalpha) had a tendency to be lower after the addition of FPH alone or CH with omega-3 FA compared with omega-3 FA treatment. Furthermore, the combination of FPH and omega-3 FA synergistically decreased expression levels of TNFalpha compared to treatment with omega-3 FA or FPH alone. No difference on gene expression levels of interleukin-6 was observed between treatments. In conclusion, these preliminary results suggest that the anti-inflammatory effects of fish consumption can be explained by a synergistic effect of the omega-3 FA with the protein components of fish on TNFalpha expression and therefore contribute to the beneficial effects of fish consumption. Hence, follow-up studies should be performed to confirm the effects of a diet rich in FPH and omega-3 FA on serum proinflammatory cytokine concentrations.
The ability of selenium (Se) to moderate mercury (Hg) toxicity is well established in the literature. Mercury exposures that might otherwise produce toxic effects are counteracted by Se, particularly when Se:Hg molar ratios approach or exceed 1. We analyzed whole body Se and Hg concentrations in 468 fish representing 40 species from 137 sites across 12 western U.S. states. The fish samples were evaluated relative to a published wildlife protective Hg threshold (0.1 sg Hg x g(-1) wet wt.), the currenttissue based methylmercury (MeHg) water quality criterion (WQC) for the protection of humans (0.3 microg Hg x g(-1) wet wt) and to presumed protections against Hg toxicity when Se:Hg molar ratios are >1. A large proportion (56%) of our total fish sample exceeded the wildlife Hg threshold, whereas a smaller, but significant proportion (12%), exceeded the MeHg WQC. However, 97.5% of the total fish sample contained more Se than Hg (molar ratio >1) leaving only 2.5% with Se: Hg ratios <1. All but one of the fish with Se:Hg <1, were of the genus Ptychochelius (pikeminnow). Scientific literature on Se counteracting Hg toxicity and our finding that 97.5% of the freshwater fish in our survey have sufficient Se to potentially protect them and their consumers against Hg toxicity suggests that Se in fish tissue (Se:Hg molar ratio) must be considered when assessing the potential toxic effects of Hg.