α-Linolenic acid metabolism in adult humans: the effects of gender and age on conversion to longer-chain polyunsaturated fatty acids

Mental health in society's margins: poor n-3 PUFA intake and psychological well-being of homeless youth

Dietary intake of long-chain n-3 PUFA (n-3 PUFA), particularly EPA and DHA, has been associated with psychological well-being, but little is known about the n-3 PUFA intake of homeless youth. The current study determined the association between depression and anxiety symptoms and n-3 PUFA intake and erythrocytes status in homeless youth. Totally, 114 homeless youth aged 18-24 years were recruited from a drop-in centre. n-3 PUFA dietary intake was assessed using an FFQ, and erythrocytes status was determined by gas chromatography (GC). Linear regression models were used to determine the relationship between psychological well-being and n-3 PUFA intake and status. The mean intakes of EPA and DHA for all participants (0·06 ± 0·13 g/d and 0·11 ± 0·24 g/d) were well below recommended levels, and mean erythrocytes EPA + DHA (n-3 index) in the cohort (2·42 %) was lower than reported for healthy, housed adolescents and those with clinical depression. There was no association of n-3 PUFA intake and erythrocytes status with either depression or anxiety. However, the relationships of depression with dietary EPA (P = 0·017) and DHA (P = 0·008), as well as erythrocytes DHA (P = 0·007) and n 3-index (P = 0·009), were significantly moderated by sex even after adjusting for confounders. Specifically, among females, as the intake and status of these n-3 PUFA decreased, depression increased. Our findings show poor dietary intake and low erythrocytes status of n-3 PUFA among homeless youth, which is associated with depressive symptoms among females.

New alternative sources of omega-3 fish oil

Long-chain omega-3 polyunsaturated fatty acids such as eicosapentaenoic and docosahexaenoic acids play an important role in brain growth and development, as well as in the health of the body. These fatty acids are traditionally found in seafood, such as fish, fish oils, and algae. They can also be added to food or consumed through dietary supplements. Due to a lack of supply to meet current demand and the potential for adverse effects from excessive consumption of fish and seafood, new alternatives are being sought to achieve the recommended levels in a safe and sustainable manner. New sources have been studied and new production mechanisms have been developed. These new proposals, as well as the importance of these fatty acids, are discussed in this paper.

Effects of plant-based versus marine-based omega-3 fatty acids and sucrose on brain and liver fatty acids in a mouse model of chemotherapy

Chemotherapy can result in toxic side effects in the brain. Intake of marine-based omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), alter brain fatty acids, potentially improving brain function. However, it is unclear if alpha-linolenic acid (ALA), the plant-based n-3, affects brain PUFAs during chemotherapy. The objective of this study was to examine the effects of dietary ALA, EPA and DHA, with high or low sucrose, on brain PUFAs in a mouse model of chemotherapy. Secondarily, the use of liver PUFAs as surrogate measures of brain PUFAs was examined. Lipid peroxidation (4-HNE) and neurotrophic markers (BDNF) were assessed. Female C57Bl/6 mice (n = 90) were randomized to 1 of 5 diets (high EPA + DHA/high or low sucrose, high ALA/high or low sucrose, or control with no EPA + DHA/low ALA/low sucrose) and injected with doxorubicin-based chemotherapy or saline. Brain EPA and DHA were greater (p < 0.0001) with high EPA + DHA diets, regardless of sucrose; there were no significant differences in brain PUFAs between high ALA diets and control. Chemotherapy-treated mice had higher brain and liver DHA (p < 0.05) and lower brain and liver linoleic acid (p < 0.0001). Brain n-3 and n-6 PUFAs were strongly correlated with liver n-3 (r = 0.8214, p < 0.0001) and n-6 PUFAs (r = 0.7568, p < 0.0001). BDNF was correlated with brain total PUFAs (r = 0.36; p < 0.05). In conclusion, dietary ALA in proportions approximately two times greater than consumed by humans did not appreciably increase brain n-3 PUFAs compared to low ALA intake. Liver PUFAs may be a useful surrogate marker of brain PUFAs in this mouse model.

Changes in Metabolic Regulation and the Microbiota Composition after Supplementation with Different Fatty Acids in db/db Mice

Introduction

The effects of fatty acids on health vary and depend on the type, amount, and route of consumption. EPA and DHA have a defined role in health, unlike coconut oil.

Objective

The aim was to investigate the changes in metabolic regulation and the composition of the culture-dependent microbiota after supplementation with different fatty acids in db/db mice. Material and Methods. We were using 32 8-week-old db/db mice, supplemented for eight weeks with EPA/DHA derived from microalgae as well as coconut oil. The lipid, hormonal profiles, and composition of the culture-dependent microbiota and the phylogenetic analysis based on the 16S rRNA gene sequencing were determined for identification of the intestinal microbiota.

Results

Enriched diet with EPA/DHA reduced TNF-α, C-peptide, insulin resistance, resistin, and the plasma atherogenic index, but increased TC, LDL-c, VLDL-c, and TG without changes in HDL-c. Coconut oil raised the HDL-c, GIP, and TNF-α, with TG, insulin resistance, adiponectin, and C-peptide reduced.

Conclusion

The most abundant microbial populations were Firmicutes and the least Proteobacteria. EPA/DHA derived from microalgae contributes to improving the systemic inflammatory status, but depressed the diversity of the small intestine microbiota. Coconut oil only decreased the C-peptide, raising TNF-α, with an unfavorable hormonal and lipid profile.

The review of alpha-linolenic acid: Sources, metabolism, and pharmacology

α-linolenic acid (ALA, 18:3n-3) is a carboxylic acid composed of 18 carbon atoms and three cis double bonds, and is an essential fatty acid indispensable to the human body. This study aims to systematically review related studies on the dietary sources, metabolism, and pharmacological effects of ALA. Information on ALA was collected from the internet database PubMed, Elsevier, ResearchGate, Web of Science, Wiley Online Library, and Europe PMC using a combination of keywords including "pharmacology," "metabolism," "sources." The following findings are mainly contained. (a) ALA can only be ingested from food and then converted into eicosapentaenoic acid and docosahexaenoic acid in the body. (b) This conversion process is relatively limited and affected by many factors such as dose, gender, and disease. (c) Pharmacological research shows that ALA has the anti-metabolic syndrome, anticancer, antiinflammatory, anti-oxidant, anti-obesity, neuroprotection, and regulation of the intestinal flora properties. (d) There are the most studies that prove ALA has anti-metabolic syndrome effects, including experimental studies and clinical trials. (e) The therapeutic effect of ALA will be affected by the dosage. In short, ALA is expected to treat many diseases, but further high quality studies are needed to firmly establish the clinical efficacy of ALA.

Low Levels of Omega-3 Long-Chain Polyunsaturated Fatty Acids Are Associated with Bone Metastasis Formation in Premenopausal Women with Breast Cancer: A Retrospective Study

In the present study, we investigated various biochemical, clinical, and histological factors associated with bone metastases in a large cohort of pre- and postmenopausal women with breast cancer. Two hundred and sixty-one consecutive women with breast cancer were included in this study. Breast adipose tissue specimens were collected during surgery. After having established the fatty acid profile of breast adipose tissue by gas chromatography, we determined whether there were differences associated with the occurrence of bone metastases in these patients. Regarding the clinical and histological criteria, a majority of the patients with bone metastases (around 70%) had tumors with a luminal phenotype and 59% of them showed axillary lymph node involvement. Moreover, we found a negative association between the levels of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in breast adipose tissue and the development of bone metastases in premenopausal women. No significant association was observed in postmenopausal women. In addition to a luminal phenotype and axillary lymph node involvement, low levels of n-3 LC-PUFA in breast adipose tissue may constitute a risk factor that contributes to breast cancer bone metastases formation in premenopausal women.

Dietary supplementation with docosahexaenoic acid rich fish oil increases circulating levels of testosterone in overweight and obese men

Pre-clinical evidence suggests that omega-3 (n-3) polyunsaturated fatty acids (PUFAs), in particular, docosahexaenoic acid (DHA) have been shown to affect testosterone synthesis in males. This study is a secondary analysis of a randomized controlled trial which determined the effect of a DHA-enriched fish oil supplement on insulin resistance. The aim of the current study was to determine whether testosterone levels change in response to a DHA-enriched fish oil intervention. Overweight and obese men and women without diabetes were recruited to the study. Participants were stratified by sex and randomly allocated to intervention (860 mg DHA + 120 g EPA/day; FO) or an isocaloric control (corn oil; CO) for 12 weeks. A fasted blood sample was collected pre- and post-intervention. Fatty acid composition of erythrocyte membranes was measured using gas chromatography. Total testosterone and metabolic parameters were measured by an accredited commercial pathology laboratory. Sixty-one participants (CO/FO: n = 29/32) were included in the current analysis (male: n = 22, 36.07%).  DHA-enriched fish oil supplementation increased total testosterone levels in males after adjusting for baseline levels, age and BMI. There was no treatment effect in females. Changes in testosterone levels in males were positively associated with changes to omega-3 PUFAs EPA and DHA and inversely correlated with omega-6 PUFA, arachidonic acid and dihomo-gamma-linolenic acid content in erythrocyte membranes, and was associated with beneficial changes to fasting insulin and HOMA-IR across the course of the study. DHA-enriched fish oil supplementation increases testosterone levels in overweight and obese men. Further research is warranted to substantiate these findings with a larger sample size and a longer follow-up period.

Controversies and discrepancies in the effect of dietary fat and cholesterol on cardiovascular risk

Cardiovascular disease (CVD) is the leading cause of death worldwide. The top ten causes of death in Singapore include many cardiovascular-related diseases such as ischaemic heart disease. The increasing prevalence of CVD poses a burden to both the economy and healthcare system of a country. Dietary habits, in particular dietary fats and cholesterol intake, have been shown to greatly influence CVD risks. Therefore, reference and adherence to relevant dietary guidelines could be crucial in CVD prevention. Recent research findings have provided novel insights into the relationship between certain dietary fats or cholesterol intake and CVD risks, challenging or reinforcing previous guidelines. These findings may, however, be conflicting, and there are still controversies over the effects of dietary fats and cholesterol as well as their association with cardiovascular risk. This review paper aims to evaluate common controversies, identify gaps in relevant research areas and summarise evidence-based dietary recommendations.

Pollutants from fish feeding recycled for microalgae production as sustainable, renewable and valuable products

Trash fish feeding of cage fish can result in marine pollution. Whole and chopped trash fish can leach pollutants such as ammonia, phosphate and protein into surrounding waters. Reduction of pollution can be achieved by recycling the wastewater generated from trash fish feeding for cultivation of microalgae. Microalgae are potent candidates for the production of renewable and sustainable products such as feed and food, health and pharmaceutical, cosmeceutical, industrial products, and biofuel. Two microalgae, Chlorella saccharophila and Nannochloropsis sp., have the potential to produce high amounts of polyunsaturated fatty acids. Furthermore, high oil content ranging from 10.7 to 13.6% is found in Chlorella saccharophila and up to 9.3% for Nannochloropsis sp. Moreover, these microalgae can also be utilized as a biofuel to give a mean calorific value of 5364 Cal/g which is higher than that of wood for Chlorella saccharophila and 6132 Cal/g which is equivalent to that of coal for Nannochloropsis sp. An alternative biofuel derived from microalgae is feasible due to the fact that they do not compete for arable land for cultivation and land crops for feed and food. This study discusses the synergistic coupling of microalgae mass production with wastewater treatment and carbon sequestration potential for mitigation of environmental impacts and a technically viable alternative energy resource. Additionally, the de-oiled biomass byproduct after oil extraction or its whole biomass can be converted into sustainable and renewal industrial products such as bioplastic, biopaint, bioasphalt, and biobuilding components.

Leaf lipidome and transcriptome profiling of Portulaca oleracea: characterization of lysophosphatidylcholine acyltransferase

Portulaca leaves serve as an alternative bioresource for edible PUFAs. Transcriptome data provide information to explore Portulaca as a model system for galactolipids, leaf lipid metabolism, and PUFA-rich designer lipids. Poly-unsaturated fatty acids (PUFAs) are gaining importance due to their innumerable health benefits, and hence, understanding their biosynthesis in plants has attained prominence in recent years. The most common source of PUFAs is of marine origin. Although reports have identified Portulaca oleracea (purslane) as a leaf source of omega-3 fatty acids in the form of alpha-linolenic acid (ALA), the mechanism of ALA accumulation and its distribution into various lipids has not been elucidated. Here, we present the lipid profiles of leaves and seeds of several accessions of P. oleracea. Among the nineteen distinct accessions, the RR04 accession has the highest amount of ALA and is primarily associated with galactolipids. In addition, we report the transcriptome of RR04, and we have mapped the potential genes involved in lipid metabolism. Phosphatidylcholine (PC) is the major site of acyl editing, which is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), an integral membrane protein that plays a major role in supplying oleate to the PC pool for further unsaturation. Our investigations using mass spectrometric analysis of leaf microsomal fractions identified LPCAT as part of a membrane protein complex. Both native and recombinant LPCAT showed strong acyltransferase activity with various acyl-CoA substrates. Altogether, the results suggest that ALA-rich glycerolipid biosynthetic machinery is highly active in nutritionally important Portulaca leaves. Furthermore, lipidome, transcriptome, and mass spectrometric analyses of RR04 provide novel information for exploring Portulaca as a potential resource and a model system for studying leaf lipid metabolism.

Effects of dietary n-6: n-3 polyunsaturated fatty acid ratios on meat quality, carcass characteristics, tissue fatty acid profiles, and expression of lipogenic genes in growing goats

The present study was conducted to investigate the effects of altering the ratio of n-6 to n-3 fatty acids in the diet on meat quality, fatty acid composition of muscle, and expression of lipogenic genes in the muscle of Boer goats. A total of twenty-one Boer goats (5 months old; 31.66±1.07 kg body weight) were randomly assigned to three dietary treatments with n-6:n-3 fatty acid ratios of 2.27:1 (LR), 5.01:1 (MR) and 10.38:1 (HR), fed at 3.7% of body weight. After 100 days of feeding, all goats were slaughtered and the longissimus dorsi muscle was sampled for analysis of fatty acids and gene expression. The dietary treatments did not affect (P>0.05) the carcass traits, and meat quality of growing goats. The concentrations of cis-9,trans-11 conjugated linoleic acid, trans vaccenic acid, polyunsaturated fatty acids, and unsaturated/saturated fatty acid ratios linearly increased (P<0.01) with decreasing dietary n-6:n-3 fatty acid ratios, especially for LR in the longissimus dorsi muscle of goats. In contrast, the mRNA expression level of the PPARα and PPARγ was down-regulated and stearoyl-CoA desaturase up-regulated in the longissimus dorsi of growing goats with increasing dietary n-6:n-3 fatty acid ratios (P<0.01). In conclusion, the results obtained indicate that the optimal n-6:n-3 fatty acid ratio of 2.27:1 exerted beneficial effects on meat fatty acid profiles, leading towards an enrichment in n-3 polyunsaturated fatty acids and conjugated linoleic acid in goat intramuscular fat.

The effect of feeding with hemp and Camelina cakes on the fatty acid profile of duck muscles

Abstract. Camelina (Camelina sativa L. Crantz) and hemp (Cannabis sativa L.) seed cakes are rich sources of n-3 polyunsaturated fatty acids (PUFAs). This study was carried out to investigate the effects of Camelina and hempseed cakes in the diet of ducks on the intramuscular fatty acid profile. Male ducks (n = 99) were randomly allocated to 3 dietary treatments: Control or C group (wheat–soybean-meal–barley-based diet with 15–20 % rapeseed cake), Experimental 1 or HEM group (with hempseed cake added at 15–20 % instead of rapeseed cake), and Experimental 2 or CAM group (with Camelina cake added at 15–20 % instead of rapeseed cake). All groups received the diets ad libitum. At 49 days of age, six ducks from each group were slaughtered for analysis of the fatty acid composition in the breast and leg muscles. Feeding ducks with the diet enriched with Camelina cake resulted in significantly higher amounts of n-3 α-linolenic fatty acid (ALA) (P≤0.01) and total n-3 PUFA (P≤0.01) in breast and leg muscles, while eicosatrienoic fatty acid (ETE) (P≤ 0.01) was higher in the leg muscle. The ratios of n-6 ∕ n-3 and linoleic ∕ α-linolenic fatty acids (P≤ 0.01) decreased significantly compared to the Control and HEM groups of ducks. Feeding ducks with the diet enriched with hempseed cake resulted in significantly higher amounts of linoleic (LA) (P≤ 0.01), total n-6 PUFA (P≤ 0.05–P≤ 0.01) and n-6 γ-linolenic (GLA) (P≤ 0.01) fatty acid. Our study showed that using Camelina cake as supplementation in duck diets opens a possibility to develop functional food, i.e. meat with a significantly higher content of ALA, total n-3 PUFA and the lowest ratios of n-6 ∕ n-3 fatty acids in ducks' muscles. A duck diet with hempseed cake produces exceptional-quality meat with an enriched content of n-6 GLA.

Effect of selected plant species within biodiverse pasture on in vitro fatty acid biohydrogenation and tissue fatty acid composition of lamb

The effect of botanical diversity on supply of polyunsaturated fatty acids (PUFA) to ruminants in vitro, and the fatty acid (FA) composition of muscle in lambs was investigated. Six plant species, commonly grown as part of UK herbal ley mixtures (Trifolium pratense, Lotus corniculatus, Achillea millefolium, Centaurea nigra, Plantago lanceolata and Prunella vulgaris), were assessed for FA profile, and in vitro biohydrogenation of constituent PUFA, to estimate intestinal supply of PUFA available for absorption by ruminants. Modelling the in vitro data suggested that L. corniculatus and P. vulgaris had the greatest potential to increase 18:3n-3 supply to ruminants, having the highest amounts escaping in vitro biohydrogenation. Biodiverse pastures were established using the six selected species, under-sown in a perennial ryegrass-based sward. Lambs were grazed (~50 days) on biodiverse or control pastures and the effects on the FA composition of musculus longissimus thoracis (lean and subcutaneous fat) and musculus semimembranosus (lean) were determined. Biodiverse pasture increased 18:2n-6 and 18:3n-3 contents of m. semimembranosus (+14.8 and +7.2 mg/100 g tissue, respectively) and the subcutaneous fat of m. longissimus thoracis (+158 and +166 mg/100 g tissue, respectively) relative to feeding a perennial ryegrass pasture. However, there was no effect on total concentrations of saturated FA in the tissues studied. It was concluded that enhancing biodiversity had a positive impact on muscle FA profile reflected by increased levels of total PUFA.

Vegan diets: practical advice for athletes and exercisers

With the growth of social media as a platform to share information, veganism is becoming more visible, and could be becoming more accepted in sports and in the health and fitness industry. However, to date, there appears to be a lack of literature that discusses how to manage vegan diets for athletic purposes. This article attempted to review literature in order to provide recommendations for how to construct a vegan diet for athletes and exercisers. While little data could be found in the sports nutrition literature specifically, it was revealed elsewhere that veganism creates challenges that need to be accounted for when designing a nutritious diet. This included the sufficiency of energy and protein; the adequacy of vitamin B12, iron, zinc, calcium, iodine and vitamin D; and the lack of the long-chain n-3 fatty acids EPA and DHA in most plant-based sources. However, via the strategic management of food and appropriate supplementation, it is the contention of this article that a nutritive vegan diet can be designed to achieve the dietary needs of most athletes satisfactorily. Further, it was suggested here that creatine and β-alanine supplementation might be of particular use to vegan athletes, owing to vegetarian diets promoting lower muscle creatine and lower muscle carnosine levels in consumers. Empirical research is needed to examine the effects of vegan diets in athletic populations however, especially if this movement grows in popularity, to ensure that the health and performance of athletic vegans is optimised in accordance with developments in sports nutrition knowledge.

Physical and Oxidative Stability of Flaxseed Oil-in-Water Emulsions Fabricated from Sunflower Lecithins: Impact of Blending Lecithins with Different Phospholipid Profiles

There is great interest in the formulation of plant-based foods enriched with nutrients that promote health, such as polyunsaturated fatty acids. This study evaluated the impact of sunflower phospholipid type on the formation and stability of flaxseed oil-in-water emulsions. Two sunflower lecithins (Sunlipon 50 and 90) with different phosphatidylcholine (PC) levels (59 and 90%, respectively) were used in varying ratios to form emulsions. Emulsion droplet size, charge, appearance, microstructure, and oxidation were measured during storage at 55 °C in the dark. The physical and chemical stability increased as the PC content of the lecithin blends decreased. The oxidative stability of emulsions formulated using Sunlipon 50 was better than emulsions formulated using synthetic surfactants (SDS or Tween 20). The results are interpreted in terms of the impact of emulsifier type on the colloidal interactions between oil droplets and on the molecular interactions between pro-oxidants and oil droplet surfaces.

Effects of the flavonol quercetin and α-linolenic acid on n-3 PUFA status in metabolically healthy men and women: a randomised, double-blinded, placebo-controlled, crossover trial

Increased dietary intake and tissue status of the long-chain n-3 PUFA, EPA and DHA, is associated with cardiovascular benefits. Epidemiological and animal studies suggest that concomitant nutritive intake of flavonoids may increase the conversion of α-linolenic acid (ALA) to longer-chain n-3 fatty acids EPA and DHA. We investigated the effects of increased ALA intake on fatty acid composition of serum phospholipids and erythrocytes in metabolically healthy men and women and whether fatty acid profiles and ALA conversion were affected by regular quercetin intake or sex. Subjects (n 74) were randomised to receive at least 3·3 g/d ALA with either 190 mg/d quercetin (ALA+quercetin) or placebo (ALA+placebo) in a double-blinded, placebo-controlled, crossover trial with 8-week intervention periods separated by an 8-week washout period. A total of seven subjects dropped out for personal reasons. Data from the remaining sixty-seven subjects (thirty-four males and thirty-three females) were included in the analysis. Both interventions significantly increased serum phospholipid ALA (ALA+placebo: +69·3 %; ALA+quercetin: +55·8 %) and EPA (ALA+placebo: +37·3 %; ALA+quercetin: +25·5 %). ALA + quercetin slightly decreased DHA concentration by 9·3 %. Erythrocyte ALA and EPA significantly increased with both interventions, whereas DHA decreased. Fatty acid composition did not differ between sexes. We found no effect of quercetin. Intake of 3·6 g/d ALA over an 8-week period resulted in increased ALA and EPA, but not DHA, in serum phospholipids and erythrocytes. Neither quercetin supplementation nor sex affected the increment of ALA and relative proportions of n-3 PUFA in serum phospholipids and erythrocytes.

Do ω-3 PUFAs affect insulin resistance in a sex-specific manner? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Evidence has suggested that omega-3 (n-3) polyunsaturated fatty acids (PUFAs) improve obesity-induced insulin resistance (IR); however, results from human intervention trials have been equivocal. Recently it has been reported that n-3 PUFA status is inversely associated with type 2 diabetes in women but not in men, suggesting a sex-dependent effect.

OBJECTIVE

We aimed to determine whether n-3 PUFA interventions affect IR in a sex-dependent manner.

DESIGN

Five databases were searched (Medline, EMBASE, CINAHL, Scopus, and Pre-Medline) for randomized controlled trials. Searches were limited to the English language and to studies with adults aged >18 y. When possible, studies were pooled for a meta-analysis. The principle summary measure was the standardized mean difference (SMD) between groups.

RESULTS

Thirty-one eligible trials were identified with a total of 1848 participants [men: 45.1%; weighted mean ± SD age: 52.5 ± 8.2 y; weighted body mass index (in kg/m²): 28.8 ± 3.0]. Seven studies were conducted in women, 4 studies were conducted in men, and the remaining studies pooled men and women together. Twenty-six trials were pooled for the meta-analysis (men: n = 2; women: n = 6). With all studies (n = 26) pooled, there was no effect of n-3 PUFA on IR at the group level (SMD: 0.089; 95% CI: -0.105, 0.283; P = 0.367). In trials of ≥6 wk, a significant improvement in IR was seen in women (SMD: -0.266; 95% CI: -0.524, -0.007; P = 0.045) but not in men (SMD: 0.619; 95% CI: -0.583, 1.820; P = 0.313).

CONCLUSIONS

With this analysis, we provide preliminary evidence of a sex-dependent response of IR to an n-3 PUFA intervention. Additional studies are needed to confirm sex-dependent associations and to elucidate the potential mechanisms that are involved. This trial was registered at www.crd.york.ac.uk/PROSPERO/ as CRD42015017940.

Distinct fatty acid composition of some edible by-products from bovines fed high or low silage diets

In the present study, it was hypothesized that the incorporation of fatty acids is distinct among ruminant tissues and that it could be modulated by diet composition. To test this hypothesis, fatty acid composition, including conjugated linoleic acid isomers, of the most relevant beef by-products (brain, heart, kidney, liver, pancreas and tongue) from young bulls those fed distinct silage levels was assessed. Data indicated a large variation in fatty acid profile and conjugated linoleic acid composition among edible by-products. The most abundant fatty acids were C16:0 (kidney), C18:0 (heart and liver) and C18:1 c9 (brain, pancreas and tongue) followed by C20:4 n-6, except in brain (C22:6 n-3 predominates). Brain, as shown by principal component analysis, presents a distinct fatty acid composition compared to the other beef by-products analysed. In addition, high silage diet relative to low silage diet promoted an increase of n-3 polyunsaturated fatty acid, t11, t13 and t11, c13 conjugated linoleic acid in heart, kidney, liver and pancreas. Overall, the data suggested that beef by-products had, in general, high contents of cholesterol, saturated fatty acid and trans fatty acid, as well as high levels of conjugated linoleic acid. Therefore, from a nutritional point of view they are recommended only in small amounts as part of a balanced diet.

Effects of Fish Oil Supplementation on Gestational Diabetes Mellitus (GDM): A Systematic Review

Context

One of the most common complications of pregnancy is gestational diabetes mellitus (GDM), which is increasing worldwide. Experimental and epidemiological studies have shown that higher intake of n-3 long-chain polyunsaturated fatty acids may decrease the risk of various diseases such as diabetes. The objective of this study was to assess the effect of fish oil supplementation on the prevention and treatment of GDM.

Evidence Acquisition

This systematic review was performed by searching several databases, including PubMed, Scopus, Google Scholar, the Cochrane Library, ProQuest, Science Direct SID, Magiran and IranMedex since 1983. The researchers also searched for references in reviewed clinical trial articles in which fish oil supplementation was compared with placebo or no supplementation.

Results

Only two published and in-press articles are included in this review. Based on these studies, docosahexaenoic acid (DHA)-enriched fish oil (800 mg/d) had no effect on prevention of GDM [0.97 (95% CI: 0.74, 1.27)]. Furthermore, omega-3 fatty acid supplementation containing 180 mg of eicosapentaenoic acid (EPA) and 120 mg DHA had beneficial effects on insulin resistance in women with GDM (change from baseline: 1.5 ± 7.5 vs ‏3.5 ± 8.5 mIU/mL, P = 0.02) but did not influence fasting plasma glucose, homeostatic model assessment-Beta cell function (HOMA-B), the quantitative insulin sensitivity check index (QUICKI), or lipid profiles (P > 0.05).

Conclusions

There is not enough evidence to support or refute the routine use of fish oil supplements during pregnancy for the prevention or treatment of diabetes. It is suggested that further randomized controlled trials be conducted to evaluate the role of fish oil supplementation in pregnancy.

Dietary fat intake and red blood cell fatty acid composition of children and women from three different geographical areas in South Africa

Dietary fat intake, particularly the type of fat, is reflected in the red blood cell (RBC) fatty acid (FA) profile and is vital in growth, development and health maintenance. The FA profile (%wt/wt) of RBC membrane phospholipids (as determined by gas chromatography) and dietary intake (as determined by 24h recall) was assessed in 2-6y old South African children and their caregivers randomly selected from three communities, i.e. an urban Northern Cape community (urban-NC; n=104), an urban coastal Western Cape community (urban-WC; n=93) and a rural Limpopo Province community (rural-LP; n=102). Mean RBC FA values across groups were compared using ANOVA and Bonferroni post-hoc test while controlling for age and gender (children); median dietary intake values were compared using a Kruskal-Wallis test. Dietary intakes for total fat, saturated FAs and polyunsaturated FAs were higher in the two urban areas compared to the rural area. Total fat intake in rural-LP, and omega-3 FA dietary intake in all three areas were lower than the South African adopted guidelines. Dietary SFA intake in both urban areas was higher than recommended by South African guidelines; this was reflected in the RBC membrane FA profile. Rural-LP children had the lowest intake of omega-3 and omega-6 FAs yet presented with the highest RBC docosahexaenoic acid (DHA) profile and highest arachidonic acid percentage. Although differences observed in dietary fat intake between the two urban and the rural area were reflected in the RBC membrane total phospholipid FA profile, the lowest total fat and α-linolenic acid (ALA) intake by rural children that presented with the highest RBC DHA profile warrants further investigation.

The Differences in Chemical Composition, Physical Quality Traits and Nutritional Values of Horse Meat as Affected by Various Retail Cut Types

The effects of retail cut type on chemical, quality and nutritional characteristics of horse meat were studied. Jeju female breed horses (n = 9) at 32-mo-old were slaughtered and the carcasses at 24 h post-mortem were fabricated into 10 retail cuts including: tender-loin, loin, strip-loin, shoulder-chuck-roll, shoulder-clod, top-round, outside-round, brisket, short-plate-brisket, and shank. The results revealed that all of parameters (chemical, meat quality and nutritional composition) examined significantly (p<0.05) differed between the cuts. The chemical composition range (minimum to maximum) of cuts was found as such: moisture 65.06% to 71.69%; protein 19.07% to 21.28%; collagen 1.40% to 2.45%; fat 2.56% to 12.14% and cholesterol 55.76 to 79.50 mg/100 g. Shoulder-chuck-roll had the highest pH and water-holding capacity, while top-round had the highest cooking loss. Shear force ranged between the cuts from 2.80 kg/cm(2) to 4.98 kg/cm(2). The Cu, Fe, and Zn contents ranged between the cuts from 1.52 mg/kg to 2.75 mg/kg, 21.25 mg/kg to 30.85 mg/kg, and 16.51 mg/kg to 40.42 mg/kg, respectively. Additionally, most of the cuts studied showed favorable polyunsaturated fatty acid/saturated fatty acid, n-3/n-6 and essential amino acid/non-essential amino acid ratios.

Characterization of Chicken By-products by Mean of Proximate and Nutritional Compositions

Though a great amount of chicken by-products are consumed everyday in many countries worldwide, however, no attention has been paid to the investigation of nutritional composition of these by-products. In the present work, the basic information regarding the aspects of nutritional composition of chicken by-products such as; liver, gizzard, heart, lung, crop, small intestines, cecum and duodenum was studied. Our results revealed that the approximate composition range (minimum to maximum) of these by-products was found as such: moisture 76.68-83.23%; fat 0.81-4.53%, protein 10.96-17.70% and calories 983.20-1,426.0 cal/g tissue, in which liver and gizzard had the highest protein content. Liver had higher (p<0.05) vitamin A, B1, B2, B3, B5 and B6 contents in comparison to other remaining by-products. Total saturated fatty acids (SFA), unsaturated fatty acids (UFA), polyunsaturated fatty acids (PUFA) levels ranged between the by-products from 31.82% to 43.96%, 56.04% to 68.19%, and 18.27% to 32.05%, respectively. Remarkably, all of by-products showed desirable PUFA/SFA ratios. Furthermore, all of chicken by-products, especially liver, contained higher levels of trace elements (e.g., Fe, Mn and Zn) in comparison with those from muscle tissues published in literature. Overall, the study indicated that most of chicken by-products examined are good sources of essential nutrients and these obtained results will be the useful information to consumers and meat processors.

Effects of oils rich in linoleic and α-linolenic acids on fatty acid profile and gene expression in goat meat

Alteration of the lipid content and fatty acid (FA) composition of foods can result in a healthier product. The aim of this study was to determine the effect of flaxseed oil or sunflower oil in the goat diet on fatty acid composition of muscle and expression of lipogenic genes in the semitendinosus (ST) muscle. Twenty-one entire male Boer kid goats were fed diets containing different levels of linoleic acid (LA) and α-linolenic acid (LNA) for 100 days. Inclusion of flaxseed oil increased (p < 0.05) the α-linolenic acid (C18:3n-3) concentration in the ST muscle. The diet high in α-linolenic acid (p < 0.05) decreased the arachidonic acid (C20:4n-6) and conjugated linolenic acid (CLA) c-9 t-11 content in the ST muscle. There was a significant (p < 0.05) upregulation of PPARα and PPARγ gene expression and downregulation of stearoyl-CoA desaturase (SCD) gene in the ST muscle for the high α-linolenic acid group compared with the low α-linolenic acid group. The results of the present study show that flaxseed oil as a source of α-linolenic acid can be incorporated into the diets of goats to enrich goat meat with n-3 fatty acids, upregulate the PPARα and PPARγ, and downregulate the SCD gene expression.

A fish is not a fish: patterns in fatty acid composition of aquatic food may have had implications for hominin evolution

From c. 2 Ma (millions of years ago) onwards, hominin brain size and cognition increased in an unprecedented fashion. The exploitation of high-quality food resources, notably from aquatic ecosystems, may have been a facilitator or driver of this phenomenon. The aim of this study is to contribute to the ongoing debate on the possible role of aquatic resources in hominin evolution by providing a more detailed nutritional context. So far, the debate has focused on the relative importance of terrestrial versus aquatic resources while no distinction has been made between different types of aquatic resources. Here we show that Indian Ocean reef fish and eastern African lake fish yield on average similarly high amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA). Hence a shift from exploiting tropical marine to freshwater ecosystems (or vice versa) would entail no material difference in dietary long-chain polyunsaturated fatty acid (LC-PUFA) availability. However, a shift to marine ecosystems would likely mean a major increase in access to brain-selective micronutrients such as iodine. Fatty fish from marine temperate/cold waters yield twice as much DHA and four times as much EPA as tropical fish, demonstrating that a latitudinal shift in exploitation of African coastal ecosystems could constitute a significant difference in LC-PUFA availability with possible implications for brain development and functioning. We conclude that exploitation of aquatic food resources could have facilitated the initial moderate hominin brain increase as observed in fossils dated to c. 2 Ma, but not the exceptional brain increase in later stages of hominin evolution. We propose that the significant expansion in hominin brain size and cognition later on may have been aided by strong directional selecting forces such as runaway sexual selection of intelligence, and nutritionally supported by exploitation of high-quality food resources in stable and productive aquatic ecosystems.

Fatty acid profiles among the Inuit of Nunavik: current status and temporal change

The Inuit undergo substantial changes in their lifestyle, but few data exist on how these changes occur in biomarkers, such as polyunsaturated fatty acids (PUFAs). Here, we report data from a cross-sectional survey conducted in 2004 among 861 representative Nunavik Inuit adults, in whom FAs were measured in red blood cells (RBCs). FAs were also measured in plasma phospholipids (n=452) to assess temporal trend by comparing plasma PUFAs measured in 1992. Food intakes were estimated using a validated food frequency questionnaire. In 2004, marine food intake was 84±4g/d (±SEM). Adjusted-mean of RBC omega-3 was significantly higher, and omega-6 lower, in older age groups (Ptrend<0.001). In 2004, plasma omega-3 was 25% lower, while omega-6 was 9% higher, compared to 1992. Our study revealed that Nunavik Inuit adults still have high RBC omega-3, but show signs of nutritional transition - as indicated by lower omega-3 and higher trans-fats in RBCs of young compared to older.

Effect of the ratio of dietary n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid on broiler breeder performance, egg quality, and yolk fatty acid composition at different breeder ages

When added to the feed of broiler breeder hens, dietary polyunsaturated fatty acids (FA) can be incorporated into the yolk and therefore become available to the progeny during their early development. The mechanism involved in lipid metabolism and deposition in the egg may be influenced by breeder age. Before the effect of an elevated concentration of certain polyunsaturated FA on the embryo can be investigated, the effect at breeder level and egg quality must be further assessed. The aim of the present experiment was to evaluate the effects of dietary n-6/n-3 ratios and dietary eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) ratios, provided to broiler breeder hens, in terms of their zoo technical performance, egg quality, and yolk FA composition. Starting at 6 wk of age, 640 Ross-308 broiler breeder hens were fed 1 of 4 different diets. The control diet was a basal diet, rich in n-6 FA. The 3 other diets were enriched in n-3 FA, formulated to obtain a different EPA/DHA ratio of 1/1 (EPA = DHA), 1/2 (DHA), or 2/1 (EPA). In fact, after analysis the EPA/DHA ratio was 0.8, 0.4, or 2.1, respectively. Dietary EPA and DHA addition did not affect the performance of the breeder hens, except for egg weight. Egg weight was lower (P < 0.001) for all n-3 treatments. Dietary EPA improved number of eggs laid in the first 2 wk of the production cycle (P = 0.029). The absolute and relative yolk weight of eggs laid by EPA = DHA fed hens was lowest (P = 0.004 and P = 0.025, respectively). The EPA and DHA concentrations in the yolk were highly dependent on dietary EPA and DHA concentrations with a regression coefficient equal to 0.89. It can be concluded that dietary EPA and DHA can be incorporated in the breeder egg yolk to become available for the developing embryo, without compromising the performance and egg quality of the flock.

Effects of dietary milled seed mixture on fatty acid status and inflammatory markers in patients on hemodialysis

BACKGROUND

Plant seeds have gained interest for their health benefits due to their fatty acid content. The objective of this study was to determine the effects of dietary consumption of milled sesame/pumpkin/flax seed mixture on glycemic control, serum lipids, phospholipid fatty acid status, and inflammatory factors in patients on hemodialysis.

METHODS

Thirty patients with well nutrition status (18 male, 12 female) were enrolled in the study. Participants consumed 30 g of milled sesame/pumpkin/flax (6 g/6 g/18 g, resp.) seeds mixture added to their habitual diet.

RESULTS

Total n-6 and n-3 polyunsaturated fatty acids and levels of linoleic, dihomo-gamma-linolenic (DGLA), arachidonic, alpha-linolenic (ALA), eicosapentaenoic, docosapentaenoic, and docosahexaenoic (DHA) acid were increased after 12 weeks of supplementation. A significant decrease of the serum triglyceride level (P < 0.001), glucose, insulin, calculated IR HOMA (P < 0.05), and inflammatory markers (TNF-alpha, IL-6, and hs-CRP, P < 0.001) was observed after seed mixture treatment. The serum levels of CRP and TNF-alpha negative correlate with ALA, DHA, and DGLA.

CONCLUSION

Results of this study indicated that dietary milled sesame/pumpkin/flax seed mixture added to a habitual diet lowered triglyceride and CRP, TNF-alpha, IL-6 levels, affect glycemic control and improved fatty acid profile and pruritus symptoms in hemodialysis patients.

Organic production enhances milk nutritional quality by shifting fatty acid composition: a United States-wide, 18-month study

Over the last century, intakes of omega-6 (ω-6) fatty acids in Western diets have dramatically increased, while omega-3 (ω-3) intakes have fallen. Resulting ω-6/ω-3 intake ratios have risen to nutritionally undesirable levels, generally 10 to 15, compared to a possible optimal ratio near 2.3. We report results of the first large-scale, nationwide study of fatty acids in U.S. organic and conventional milk. Averaged over 12 months, organic milk contained 25% less ω-6 fatty acids and 62% more ω-3 fatty acids than conventional milk, yielding a 2.5-fold higher ω-6/ω-3 ratio in conventional compared to organic milk (5.77 vs. 2.28). All individual ω-3 fatty acid concentrations were higher in organic milk—α-linolenic acid (by 60%), eicosapentaenoic acid (32%), and docosapentaenoic acid (19%)—as was the concentration of conjugated linoleic acid (18%). We report mostly moderate regional and seasonal variability in milk fatty acid profiles. Hypothetical diets of adult women were modeled to assess milk fatty-acid-driven differences in overall dietary ω-6/ω-3 ratios. Diets varied according to three choices: high instead of moderate dairy consumption; organic vs. conventional dairy products; and reduced vs. typical consumption of ω-6 fatty acids. The three choices together would decrease the ω-6/ω-3 ratio among adult women by ∼80% of the total decrease needed to reach a target ratio of 2.3, with relative impact “switch to low ω-6 foods” > “switch to organic dairy products” ≈ “increase consumption of conventional dairy products.” Based on recommended servings of dairy products and seafoods, dairy products supply far more α-linolenic acid than seafoods, about one-third as much eicosapentaenoic acid, and slightly more docosapentaenoic acid, but negligible docosahexaenoic acid. We conclude that consumers have viable options to reduce average ω-6/ω-3 intake ratios, thereby reducing or eliminating probable risk factors for a wide range of developmental and chronic health problems.

Effect of linseed oil dietary supplementation on fatty acid composition and gene expression in adipose tissue of growing goats

This study was conducted to determine the effects of feeding oil palm frond silage based diets with added linseed oil (LO) containing high α-linolenic acid (C18:3n-3), namely, high LO (HLO), low LO (LLO), and without LO as the control group (CON) on the fatty acid (FA) composition of subcutaneous adipose tissue and the gene expression of peroxisome proliferator-activated receptor (PPAR)α, PPAR-γ, and stearoyl-CoA desaturase (SCD) in Boer goats. The proportion of C18:3n-3 in subcutaneous adipose tissue was increased (P < 0.01) by increasing the LO in the diet, suggesting that the FA from HLO might have escaped ruminal biohydrogenation. Animals fed HLO diets had lower proportions of C18:1 trans-11, C18:2n-6, CLA cis-9 trans-11, and C20:4n-6 and higher proportions of C18:3n-3, C22:5n-3, and C22:6n-3 in the subcutaneous adipose tissue than animals fed the CON diets, resulting in a decreased n-6:n-3 fatty acid ratio (FAR) in the tissue. In addition, feeding the HLO diet upregulated the expression of PPAR-γ (P < 0.05) but downregulated the expression of SCD (P < 0.05) in the adipose tissue. The results of the present study show that LO can be safely incorporated in the diets of goats to enrich goat meat with potential health beneficial FA (i.e., n-3 FA).

Mononuclear leukocyte fatty acid composition and inflammatory phenotype in periparturient and lactating sows

Increased plasma NEFA concentrations and compromised immune responses are associated with increased disease susceptibility during farrowing and lactation. Increased plasma NEFA concentrations cause changes in the fatty acid (FA) content of plasma lipid fractions and peripheral blood mononuclear cells (PBMC) that could modify inflammatory responses. The goals of this study were to describe changes in plasma lipid composition and to characterize the FA content and proinflammatory phenotype of PBMC in periparturient and lactating sows. Blood samples from 10 sows were collected at 2 wk prefarrow, at 2 d after farrowing (hereafter referred to as farrowing), and at 18 d of lactation (hereafter referred to as lactation). Total lipids and lipid fractions were extracted from plasma and PBMC. Isolated PBMC also were assessed for gene expression of proinflammatory cytokines and enzymes involved in lipid mediator biosynthesis using quantitative PCR. The FA profile of plasma NEFA, phospholipids, neutral lipids, and PBMC phospholipids differed from the composition of total lipids in plasma. At farrowing and lactation, the proportion of palmitic and stearic acids increased (P<0.05) in the plasma NEFA and phospholipid fractions in comparison with prefarrowing concentrations. At the same time, the concentration of palmitic and linoleic acids increased (P<0.05) in the PBMC phospholipid fraction. Omega-3 FA, including docosapentaenoic and docosahexaenoic, increased (P<0.05) at farrowing in plasma and PBMC phospholipids compared with prefarrowing and lactation. Gene expression of IL-1β, IL-6, IL-8, and tumor necrosis factor-α (TNFα) decreased (P<0.05) after farrowing and in lactation. Similarly, cyclooxygenase expression was reduced during lactation when compared with farrowing (P<0.05). This study demonstrated changes in FA composition of serum lipid fractions and PBMC cellular membranes. Furthermore, it provided an initial assessment of inflammatory responses in mononuclear cells as a function of plasma and PBMC content of saturated and omega-3 FA. Future studies need to address the effect of increased NEFA concentrations, the main hallmark of lipid mobilization, and changes in plasma and cellular lipid profiles on immune function.

10-year cognition in preterms after random assignment to fatty acid supplementation in infancy

OBJECTIVE

To test the hypothesis that long-chain polyunsaturated fatty acid (LCPUFA) supplementation in infancy would improve cognition into later childhood (after 9 years) at both general and specific levels.

METHODS

A comprehensive cognitive battery was completed by 107 formerly preterm infants (mean age: 128 months). As infants, they had been assigned randomly to receive LCPUFA-supplemented (N = 50) or control (N = 57) formula, between birth and 9 months; the docosahexaenoic acid level (DHA) in the supplemented formulas was 0.5%. In addition to randomized comparisons, we planned supplementary analyses to examine the effects of both gender and feeding group (those receiving some maternal breast milk versus those receiving none).

RESULTS

There were no significant differences between randomized diet groups on any cognitive measure. There was significant interaction between gender and supplementation; girls only showed beneficial effects of LCPUFAs on literacy. Significant interaction also occurred between feeding group and supplementation; increases of 0.7 SD in verbal IQ, full-scale IQ, and memory scores were found for the LCPUFA group, but only for infants who received only formula and no maternal breast milk.

CONCLUSIONS

The results of this post-9-year cognitive follow-up study in a randomized trial of LCPUFA-supplemented formula for preterm infants suggest no overall group effects but indicate that gender-specific and diet-specific effects may exist. The data provide some evidence that LCPUFAs are a key factor in the cognitive benefits of breast milk. Caution is advised in data interpretation because of the small groups used.

Antidiabetic effect of flax and pumpkin seed mixture powder: effect on hyperlipidemia and antioxidant status in alloxan diabetic rats

Reactive oxygen species play a crucial role in the pathogenesis of diabetes and its complications. This study aims to examine the effects of flax and pumpkin powder seed mixture on alloxan induced diabetes in Wistar rats. Animals were allocated into three groups of six rats each: a control group (CD), diabetic group (DD) and diabetic rats fed with flax and pumpkin seed mixture (DMS) group. The diabetic rats (DD) presented a significant increase in glycemia, plasma and liver lipid parameters such as total lipid, total cholesterol and triglycerides compared to the control group (CD). In addition, plasma and liver malonaldialdehyde levels (MDA, an index of lipid peroxidation) significantly increased compared to (CD). Antioxidant enzymes activities such as catalase, superoxide dismutase, and reduced glutathione (GSH) levels significantly decreased in the plasma and liver of diabetic rats compared to controls. Diet supplemented with flax and pumpkin seed mixture in the DMS group ameliorated antioxidant enzymes activities and level of GSH in diabetic rats and significantly decreased MDA levels. The present study revealed a significant increase in the activities of aspartate aminotransferase and alanine aminotransferase on diabetic status, indicating considerable hepatocellular injury. The administration of flax and pumpkin seed mixture attenuated the increased levels of the plasma enzymes produced by the induction of diabetes and caused a subsequent recovery towards normalization comparable to the control group animals. Our results thus suggest that flax and pumpkin seed mixture supplemented to diet may be helpful in preventing diabetic complications in adult rats.

Dietary α-Linolenic Acid Inhibits Arterial Thrombus Formation, Tissue Factor Expression, and Platelet Activation

Objective—

Plant-derived α-linolenic acid (ALA) may constitute an attractive cardioprotective alternative to fish-derived n -3 fatty acids. However, the effect of dietary ALA on arterial thrombus formation remains unknown.

Methods and Results—

Male C57Bl/6 mice were fed a high-ALA or low-ALA diet for 2 weeks. Arterial thrombus formation was delayed in mice fed a high-ALA diet compared with those on a low-ALA diet (n=7; P <0.005). Dietary ALA impaired platelet aggregation to collagen and thrombin (n=5; P <0.005) and decreased p38 mitogen-activated protein kinase activation in platelets. Dietary ALA impaired arterial tissue factor (TF) expression, TF activity, and nuclear factor-κB activity (n=7; P <0.05); plasma clotting times and plasma thrombin generation did not differ (n=5; P =not significant). In cultured human vascular smooth muscle and endothelial cells, ALA inhibited TF expression and activity (n=4; P <0.01). Inhibition of TF expression occurred at the transcriptional level via the mitogen-activated protein kinase p38 in smooth muscle cells and p38, extracellular signal-regulated kinases 1 and 2, and c-Jun N-terminal kinases 1 and 2 in endothelial cells.

Conclusion—

ALA impairs arterial thrombus formation, TF expression, and platelet activation and thereby represents an attractive nutritional intervention with direct dual antithrombotic effects.

Fish intake, erythrocyten-3 fatty acid status and metabolic health in Danish adolescent girls and boys

Marinen-3 long-chain PUFA (n-3 LCPUFA) may have a beneficial effect on several aspects of the metabolic syndrome (dyslipidaemia, insulin resistance, hypertension and abdominal obesity). The metabolic syndrome is increasing in prevalence during adolescence, but only few studies have investigated the effects ofn-3 LCPUFA in adolescence. The present study examines associations between fish intake (assessed by a 7 d pre-coded food diary), erythrocyte (RBC) DHA status (analysed by GC) and metabolic syndrome measures (anthropometry, blood pressure and plasma lipids, insulin and glucose) in 109 17-year-old children from the Copenhagen Birth Cohort Study. Of the children, 8 % were overweight or obese and few showed signs of the metabolic syndrome, but all the metabolic syndrome variables were correlated. Median fish intake was 10·7 (interquartile range 3·6–21·2) g/d. Boys tended to have a higher fish intake (P = 0·052), but girls had significantly higher RBC levels of DHA (P = 0·001). Sex and fish intake explained 37 % of the variance in RBC-DHA (P < 0·001). After adjusting for confounders, high DHA status was found to be significantly correlated with higher systolic blood pressure (P = 0·014) and increased fasting insulin (P = 0·018), but no adverse association was observed with the mean metabolic syndromez-score. Overall, the present study showed the expected association between fish intake and RBC-DHA, which in contrast to our expectations tended to be associated with a poorer metabolic profile. Whether these results reflect the physiological function ofn-3 LCPUFA, lifestyle factors associated with fish intake in Denmark, or mere chance remains to be investigated.

Engineering plastid fatty acid biosynthesis to improve food quality and biofuel production in higher plants

The ability to manipulate plant fatty acid biosynthesis by using new biotechnological approaches has allowed the production of transgenic plants with unusual fatty acid profile and increased oil content. This review focuses on the production of very long chain polyunsaturated fatty acids (VLCPUFAs) and the increase in oil content in plants using molecular biology tools. Evidences suggest that regular consumption of food rich in VLCPUFAs has multiple positive health benefits. Alternative sources of these nutritional fatty acids are found in cold-water fishes. However, fish stocks are in severe decline because of decades of overfishing, and also fish oils can be contaminated by the accumulation of toxic compounds. Recently, there is also an increase in oilseed use for the production of biofuels. This tendency is partly associated with the rapidly rising costs of petroleum, increased concern about the environmental impact of fossil oil and the attractive need to develop renewable sources of fuel. In contrast to this scenario, oil derived from crop plants is normally contaminant free and less environmentally aggressive. Genetic engineering of the plastid genome (plastome) offers a number of attractive advantages, including high-level foreign protein expression, marker-gene excision and transgene containment because of maternal inheritance of plastid genome in most crops. Here, we describe the possibility to improve fatty acid biosynthesis in plastids, production of new fatty acids and increase their content in plants by genetic engineering of plastid fatty acid biosynthesis via plastid transformation.

Impact of n-3 fatty acids on endothelial function: results from human interventions studies

PURPOSE OF REVIEW

Dysfunction of the endothelium plays an integral role in atherogenesis. This review summarizes recent findings on the effects of marine [eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)] and plant [alpha-linolenic acids (ALA)] n-3 polyunsaturated fatty acids (PUFAs) on endothelial function in healthy individuals and in patients with cardiovascular disease (CVD) risk factors or manifest CVD.

RECENT FINDINGS

We identified 33 intervention trials investigating the effects of n-3 PUFA on fasting and/or postprandial endothelial function. In healthy individuals regular supplementation of EPA/DHA or ALA shows inconsistent results on endothelial function, whereas markers of endothelial function seem to be improved in overweight dyslipidaemic patients and type 2 diabetics. Conflicting results are observed in CVD patients. Reasons for discrepancies between the study results include the health status and age of participants, duration of supplementation, dose and fatty acid composition of the administered n-3 PUFAs as well as methods used to assess endothelial function.

SUMMARY

In individuals with CVD risk factors including overweight, dyslipidemia and type 2 diabetes n-3 PUFAs may improve endothelial function. However, the evidence for a clinical efficacy is not strong enough to make final recommendations with respect to a specific dose and the duration of supplementation.

Dietary n-3 LCPUFA from fish oil but not alpha-linolenic acid-derived LCPUFA confers atheroprotection in mice

The atheroprotective potential of n-3 alpha-linolenic acid (ALA) has not yet been fully determined, even in murine models of atherosclerosis. We tested whether ALA-derived, n-3 long chain polyunsaturated fatty acids (LCPUFA) could offer atheroprotection in a dose-dependent manner. Apolipoprotein B (ApoB)100/100LDLr-/- mice were fed with diets containing two levels of ALA from flaxseed oil for 16 weeks. Fish oil- and cis-monounsaturated-fat-enriched diets were used as positive and negative controls, respectively. The mice fed cis-monounsaturated fat and ALA-enriched diets exhibited equivalent plasma total cholesterol (TPC) and LDL-cholesterol (LDL-c) levels; only mice fed the fish-oil diet had lower TPC and LDL-c concentrations. Plasma LDL-CE fatty acid composition analysis showed that ALA-enriched diets lowered the percentage of atherogenic cholesteryl oleate compared with cis-monounsaturated-fat diet (44% versus 55.6%) but not as efficiently as the fish-oil diet (32.4%). Although both ALA and fish-oil diets equally enriched hepatic phospholipids with eicosapentaenoic acid (EPA) and ALA-enriched diets lowered hepatic cholesteryl ester (CE) levels compared with cis-monounsaturated-fat diet, only fish oil strongly protected from atherosclerosis. These outcomes indicate that dietary n-3 LCPUFA from fish oil and n-3 LCPUFA (mostly EPA) synthesized endogenously from ALA were not equally atheroprotective in these mice.

Utilization of extruded linseed to modify fatty composition of intensively-reared lamb meat: effect of associated cereals (wheat vs. corn) and linoleic acid content of the diet

Sixty male lambs were used in two trials to study the efficiency of transfer and elongation of linolenic acid (ALA) in muscle and caudal adipose tissue and to assess factors affecting this process and related changes in fatty acid (FA) profile. In experiment 1, lambs were fed a control diet or extruded linseed (L) diet either with wheat (W, rapid starch) or corn (C, slow starch). In experiment 2, lambs were fed L with "normal" rapeseed, or high-oleic rapeseed, or soybean. In experiment 1, L increased ALA proportion and total n-3 PUFA in muscle and adipose tissue. In adipose tissue but not in muscle, LC lambs had higher proportion of ALA than LW lambs. In experiment 2, increasing linoleic acid (LA) intake increased LA proportion in muscle and adipose tissue but did not modify ALA proportion. Moreover, in muscle, it did not change the desaturation and elongation processes of ALA to long-chain n-3 PUFA.

Postgraduate Symposium Long-chainn-3 PUFA: intakes in the UK and the potential of a chicken meat prototype to increase them

With the wide acceptance of the long-chain (LC)n-3 PUFA EPA and DHA as important nutrients playing a role in the amelioration of certain diseases, efforts to understand factors affecting intakes of these fatty acids along with potential strategies to increase them are vital. Widespread aversion to oil-rich fish, the richest natural source of EPA and DHA, highlights both the highly suboptimal current intakes in males and females across all age-groups and the critical need for an alternative supply of EPA and DHA. Poultry meat is a popular and versatile food eaten in large quantities relative to other meats and is open to increased LCn-3 PUFA content through manipulation of the chicken's diet to modify fatty acid deposition and therefore lipid composition of the edible tissues. It is therefore seen as a favourable prototype food for increasing human dietary supply of LCn-3 PUFA. Enrichment of chicken breast and leg tissue is well established using fish oil or fishmeal, but concerns about sustainability have led to recent consideration of algal biomass as an alternative source of LCn-3 PUFA. Further advances have also been made in the quality of the resulting meat, including achieving acceptable flavour and storage properties as well as understanding the impact of cooking on the retention of fatty acids. Based on these considerations it may be concluded that EPA- and DHA-enriched poultry meat has a very positive potential future in the food chain.