Mercury, Polychlorinated Biphenyls, Selenium, and Fatty Acids in Tribal Fish Harvests of the Upper Great Lakes.

The Chippewa Ottawa Resource Authority monitors fish contaminants in Anishinaabe (Great Lake Native American) tribal fisheries. This article updates previously reported trends in two persistent bioaccumulative toxic (PBT) substances that are the primary contributors to consumption advisory limits for these fish: methylmercury (MeHg) and polychlorinated biphenyls (PCBs). Also, we report, for the first time, an analysis of nutritional benefit bioindicators and metrics in these same Upper Great Lakes fish harvests: selenium (Se) and omega-3 fatty acids (PUFA-3s). A novel risk/benefit quantification originally presented by Ginsberg et al. is reported here to characterize the tradeoffs between fatty acid benefits and toxic MeHg health outcomes. We also report a Se benefit metric to characterize the possible protective value against MeHg neurotoxicity based on Ralston et al. Congruent with Anishinaabe cultural motivations to consume fish from their ancestral fisheries, nutritional content was high in locally caught fish and, in some respects, superior to farmed/store-bought fish. These Great Lakes fish still contained levels of PBTs that require careful education and guidance for consumers. However, the contaminant trends suggest that these fish need not be abandoned as important (both culturally and nutritionally) food sources for the Anishinaabe who harvested them.

Effects of diets high in walnuts and flax oil on hemodynamic responses to stress and vascular endothelial function.

BACKGROUND: Polyunsaturated fatty acids (PUFA) have beneficial effects on cardiovascular risk, although the mechanisms are incompletely understood. In a previous article, we showed significant reductions in low-density lipoprotein cholesterol and several markers of inflammation with increasing intake of alpha-linolenic acid (ALA) from walnuts and flax. OBJECTIVE: To examine effects of ALA on cardiovascular responses to acute stress, flow-mediated dilation (FMD) of the brachial artery, and blood concentrations of endothelin-1 and arginine-vasopressin (AVP). DESIGN: Using a randomized, crossover study design, cardiovascular responses to acute stress were assessed in 20 hypercholesterolemic subjects, a subset of whom also underwent FMD testing (n  =  12). Participants were fed an average American diet (AAD) and 2 experimental diets that varied in the amount of ALA and linoleic acid (LA) that they contained. The AAD provided 8.7% energy from PUFA (7.7% LA, 0.8% ALA). On the LA diet, saturated fat was reduced, and PUFA from walnuts and walnut oil provided 16.4% of energy (12.6% LA, 3.6% ALA). On the ALA diet, walnuts, walnut oil, and flax oil provided 17% energy from PUFA (10.5% LA, 6.5% ALA). RESULTS: The ALA and LA diets significantly reduced diastolic blood pressure (-2 to -3 mm Hg) and total peripheral resistance (-4%), and this effect was evident at rest and during stress (main effect of diet, p < 0.02). FMD increased (+34%) on the diet containing additional ALA. AVP also increased by 20%, and endothelin-1 was unchanged. CONCLUSIONS: These results suggest novel mechanisms for the cardioprotective effects of walnuts and flax, and further work is needed to identify the bioactives responsible for these effects.

Direct diet quantification indicates low intakes of (n-3) fatty acids in children 4 to 8 years old.

Estimates of essential fatty acid intakes, including (n-3) PUFA, are available in pediatric populations based on limited indirect approaches. Furthermore, recommended intakes for short- and long-chain (LC) (n-3) PUFA have emerged for this population. This study provides direct quantification of fatty acid intakes in children aged 4-8 y. Identical portions of all food and natural health products consumed over 3 d were collected. Duplicate samples were analyzed for energy, macronutrients, and fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) by high performance capillary GLC. The results for 41 children [25 females, 16 males; 5.8 +/- 0.2 y (mean age +/- SEM)] showed daily energy intakes of 5879 +/- 211 kJ (mean +/- SEM) and (n-3) PUFA intakes in mg/d as follows: ALA, 1161 +/- 108; EPA, 38.4 +/- 9.3; DPA, 26.3 +/- 3.9; and DHA, 54.1 +/- 11.4. Based on the Dietary Reference Intakes from the Institute of Medicine, 61% of the children met the adequate intake for ALA and 22% met the suggested adequate intake for DHA+EPA (10% of the adequate intake for ALA). These intakes were also compared with the recent Australia/New Zealand recommendations for children, where only 51% met the recommended intake for EPA+DPA+DHA. These results demonstrate a moderate shortfall in ALA intake in Canadian children and a nutrient gap for the LC (n-3) PUFA, including DHA, when comparing intakes for this population to suggested and recommended intakes.

Acute fish oil and soy isoflavone supplementation increase postprandial serum (n-3) polyunsaturated fatty acids and isoflavones but do not affect triacylglycerols or biomarkers of oxidative stress in overweight and obese hypertriglyceridemic men.

Chronic consumption of fish and fish oil high in (n-3) PUFA reduces triacylglycerols (TG) but may increase oxidative stress, whereas consumption of soy isoflavones may reduce oxidative stress. Elevated serum TG and oxidative stress are considered cardiovascular disease (CVD) risk factors, but the effects of acute (n-3) PUFA and soy isoflavones on these CVD risk factors are unknown. The purpose of the study was to determine the effects of acutely supplementing a high-fat, high-fructose meal with fish oil and isoflavone placebo (FO) and fish oil placebo and soy isoflavones (ISO). In a randomized, double-blind, placebo-controlled, crossover study, 10 overweight or obese men consumed a high-fat, high-fructose meal with 4 dietary supplement combinations: fish oil placebo and isoflavone placebo (placebo); fish oil and isoflavone placebo (FO); fish oil placebo and isoflavones (ISO); and fish oil and isoflavones (FO + ISO). Serum collected at baseline and at 2, 4, and 6 h postprandially was analyzed for fatty acids, isoflavones, TG, and oxidative stress biomarkers (lipid hydroperoxides, oxidized-LDL, total antioxidant status). FO significantly increased serum (n-3) PUFA and ISO increased serum isoflavones. The study meal significantly increased serum total fatty acids and TG without affecting oxidative stress biomarkers. Serum TG and oxidative stress biomarkers did not differ between treatments. The FO and ISO were bioavailable but did not attenuate the postprandial rise in serum TG. Neither the study meal nor the FO or ISO induced significant changes in oxidative stress biomarkers. The current study adds to a limited literature on the acute effects of FO and ISO interventions on postprandial biomarkers of CVD risk.

Plasma omega-3 and psychological distress among Nunavik Inuit (Canada).

Marine omega-3 (n-3) fatty acid eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids have been associated with beneficial effects in mental health. Cultural and social changes have been related to a decline in mental health of the Inuit, but the role of diet has received scant attention. We examined the relationship between psychological distress (PD) and plasma n-3 among 368 Nunavik Inuit aged 18-74 years who took part in a survey in 1992. Participants were categorized as high-level PD if they scored over the 80th percentile of the PD Index Santé-Québec Survey (PDISQS-14), and non-distressed subjects were those who scored less than this cutoff. Compared with the non-distressed group, n-3 concentrations in the PD group were significantly lower in women but not in men. Compared with the lowest tertile of EPA + DHA, the odds ratios for high-level PD among women were 0.32 (95% CI: 0.13-0.82) for the second, and 0.30 (95% CI: 0.10-0.90) for the third tertile, after controlling for confounders. In males, there were no significant associations between EPA+DHA and PDISQS-14 scores. Our findings suggest that marine n-3 may play a role in PD among Inuit women. The gender difference observed in our analysis must be examined more carefully in future studies.

Correlation of omega-3 levels in serum phospholipid from 2053 human blood samples with key fatty acid ratios.

BACKGROUND: This research was conducted to explore the relationships between the levels of omega-3 fatty acids in serum phospholipid and key fatty acid ratios including potential cut-offs for risk factor assessment with respect to coronary heart disease and fatal ischemic heart disease. METHODS: Blood samples (n = 2053) were obtained from free-living subjects in North America and processed for determining the levels of total fatty acids in serum phospholipid as omega-3 fatty acids including EPA (eicosapentaenoic acid, 20:5 n-3) and DHA (docosahexaenoic acid, 22:6 n-3) by combined thin-layer and gas-liquid chromatographic analyses. The omega-3 levels were correlated with selected omega-6: omega-3 ratios including AA (arachidonic acid, 20:4n-6): EPA and AA:(EPA+DHA). Based on previously-published levels of omega-3 fatty acids considered to be in a 'lower risk' category for heart disease and related fatality, 'lower risk' categories for selected fatty acid ratios were estimated. RESULTS: Strong inverse correlations between the summed total of omega-3 fatty acids in serum phospholipid and all four ratios (omega-6:omega-3 (n-6:n-3), AA:EPA, AA:DHA, and AA:(EPA+DHA)) were found with the most potent correlation being with the omega-6:omega-3 ratio (R(2) = 0.96). The strongest inverse relation for the EPA+DHA levels in serum phospholipid was found with the omega-6: omega-3 ratio (R(2) = 0.94) followed closely by the AA:(EPA+DHA) ratio at R(2) = 0.88. It was estimated that 95% of the subjects would be in the 'lower risk' category for coronary heart disease (based on total omega-3 >or= 7.2%) with omega-6:omega-3 ratios <4.5 and AA:(EPA+DHA) ratios <1.4. The corresponding ratio cut-offs for a 'lower risk' category for fatal ischemic heart disease (EPA+DHA >or= 4.6%) were estimated at < 5.8 and < 2.1, respectively. CONCLUSIONS: Strong inverse correlations between the levels of omega-3 fatty acids in serum (or plasma) phospholipid and omega-6: omega-3 ratios are apparent based on this large database of 2053 samples. Certain fatty acid ratios may aid in cardiovascular disease-related risk assessment if/when complete profiles are not available.

Plasma n-3 fatty acids and psychological distress in aboriginal Cree Indians (Canada).

OBJECTIVE: To examine the relationship between psychological distress (PD) and plasma n-3 long-chain (LC) PUFA, i.e. EPA, docosapentaenoic acid (DPAn-3) and DHA. DESIGN: Population-based, cross-sectional Santé-Québec Health Survey (1991). Participants were categorized as high-level PD if they scored over the 80th percentile of the PD Index in the Santé-Québec Survey; non-distressed subjects were those who scored less than this cut-off. Associations between tertiles of n-3 fatty acids (FA) and the risk of high-level PD were expressed as odds ratios, with the lowest tertile as the reference group. SETTING: Québec, Canada. SUBJECTS: Data were analysed from a representative sample of 852 James Bay Cree Indian adults aged 18 years and over. RESULTS: Proportions of n-3 FA were statistically significantly lower in the PD than in the non-distressed group. After adjustment for confounders, EPA was the only individual n-3 FA significantly associated with the risk of high-level PD. Combinations of EPA + DHA or EPA + DPAn-3 + DHA or the sum of n-3 were also associated with the risk of high-level PD. Compared with the lowest tertile of EPA + DHA, the OR for high-level PD was 0.89 (95 % CI 0.59, 1.36) for the second and 0.56 (95 % CI 0.32, 0.98) for the third tertile, after controlling for confounders. CONCLUSIONS: In the present retrospective, cross-sectional study, we found that proportions of n-3 LC PUFA in plasma phospholipids, markers of n-3 LC PUFA consumption from fish, were inversely associated with PD.

Relationships between seafood consumption during pregnancy and childhood and neurocognitive development: Two systematic reviews.

Abundant data are now available to evaluate relationships between seafood consumption in pregnancy and childhood and neurocognitive development. We conducted two systematic reviews utilizing methodologies detailed by the Dietary Guidelines for Americans Scientific Advisory Committee 2020-2025. After reviewing 44 publications on 106,237 mother-offspring pairs and 25,960 children, our technical expert committee developed two conclusion statements that included the following: "Moderate and consistent evidence indicates that consumption of a wide range of amounts and types of commercially available seafood during pregnancy is associated with improved neurocognitive development of offspring as compared to eating no seafood. Overall, benefits to neurocognitive development began at the lowest amounts of seafood consumed (∼4 oz/wk) and continued through the highest amounts, above 12 oz/wk, some range up to >100 oz/wk.", "This evidence does not meet the criteria for "strong evidence" only due to a paucity of randomized controlled trials that may not be ethical or feasible to conduct for pregnancy" and "Moderate and consistent evidence indicates that consumption of >4 oz/wk and likely >12 oz/wk of seafood during childhood has beneficial associations with neurocognitive outcomes." No net adverse neurocognitive outcomes were reported among offspring at the highest ranges of seafood intakes despite associated increases in mercury exposures. Data are insufficient for conclusive statements regarding lactation, optimal amounts, categories or specific species characterized by mercury content and neurocognitive development; although there is some evidence that dark/oily seafood may be more beneficial. Research was conducted in healthy women and children and is generalizable to US populations. Assessment of seafood as a whole food integrates inherently integrates any adverse effects from neurotoxicants, if any, and benefits to neurocognition from omega-3 fats, as well as other nutrients critical to optimal neurological development. Understanding of the effects of seafood consumption on neurocognition can have significant public health implications.

An abundance of seafood consumption studies presents new opportunities to evaluate effects on neurocognitive development.

The relationship between seafood eaten during pregnancy and neurocognition in offspring has been the subject of considerable scientific study for over 25 years. Evaluation of this question led two scientific advisory committees to the Dietary Guidelines for Americans (DGAC), the Food and Agriculture Organization of the United Nations with the World Health Organization (FAO/WHO), Health Canada, the European Food Safety Authority (EFSA), and the U.S. Food and Drug Administration (FDA) to conclude through 2014 that seafood consumed by pregnant women is likely to benefit the neurocognitive development of their children. The evidence they reviewed included between four and ten studies of seafood consumption during pregnancy that reported beneficial associations. In contrast there are now 29 seafood consumption studies available describing over 100,000 mothers-child pairs and 15 studies describing over 25,000 children who ate seafood. A systematic review of these studies using Nutrition Evaluation Systematic Review methodology is warranted to determine whether recent research corroborates, builds on, or significantly alters the previous conclusions. Studies that evaluate the integrated effects of seafood as a complete food more directly and completely evaluate impacts on neurocognition as compared to studies that evaluate individual nutritients or toxicological constituents in isolation. Here we address how the findings could add to our understanding of whether seafood consumed during pregnancy and early childhood affects neurocognition, including whether such effects are clinically meaningful, lasting, related to amounts consumed, and affected by any neurotoxicants that may be present, particularly mercury, which is present at varying levels in essentially all seafood. We provide the history, context and rationale for reexamining these questions in light of currently available data.

Dietary cod protein reduces plasma C-reactive protein in insulin-resistant men and women.

Chronic low-grade inflammation has been associated with insulin resistance and type 2 diabetes. Recently, we showed that cod protein (CP) improved insulin sensitivity in insulin-resistant subjects. In this study, we investigated the effects of dietary CP compared with those of other animal proteins on plasma concentrations of inflammatory markers, lipids, and lipoproteins in insulin-resistant subjects. Nineteen Caucasian men and women aged 40-65 y, overweight or obese (BMI > 25 kg/m(2)), and insulin resistant, rotated in a crossover design and consumed a CP diet and a similar diet containing lean beef, pork, veal, eggs, milk, and milk products (BPVEM) for 4 wk each. Diets differed only in protein source and thus provided equivalent amounts of dietary fibers, monounsaturated fat, PUFA [including (n-3) fatty acids], and SFA. Blood samples were collected before and after each experimental diet. Notably, the CP diet decreased high-sensitivity C-reactive protein (hsCRP; P = 0.021), whereas the BPVEM diet tended to increase it (P = 0.063), leading to a significant difference between diets (P = 0.041). Changes in plasma interleukin-6, tumor necrosis factor-alpha, and adiponectin concentrations did not differ between diets. Plasma total cholesterol (P = 0.0007), LDL cholesterol (P = 0.014), and apolipoprotein B (P = 0.005) were reduced only by the BPVEM diet. Thus, changes in total cholesterol differed between diets (P = 0.040), whereas changes in LDL cholesterol (P = 0.052) and apolipoprotein B (P = 0.075) tended to differ. Changes in all other lipids and lipoproteins did not differ between diets. Therefore, these results show that CP can lower hsCRP, a marker of inflammation associated with insulin resistance and type 2 diabetes.

Directly quantified dietary n-3 fatty acid intakes of Canadian toddlers are lower than current dietary recommendations.

To date, few studies have evaluated the intake of dietary n-3 polyunsaturated fatty acids (PUFA) in young North American children and current estimates are based on indirect approaches which have concerning limitations. Furthermore, there is a lack of available knowledge regarding the proportion of children meeting current dietary recommendations for the consumption of long-chain n-3 PUFA as α-linolenic acid (ALA) and eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA). The objective of the present study was to directly quantify the intake of n-3 PUFA in toddlers aged 2 to 3 years and determine if intakes met international recommendations. Given the low intakes of fish in North America, we predicted that n-3 PUFA intakes in toddlers would fall short of recommended intakes. Duplicated diets were collected from 20 Canadian children over a 3-day period. Diets were then directly analyzed by gas chromatography. Daily intakes (means ± SEM) of ALA, EPA, and DHA were as follows: 710.1 ± 69.7, 9.6 ± 2.9, and 19.2 ± 6.8 mg/d, respectively. Compared with North American dietary reference intakes, 45% of our children met the minimal recommended intake of ALA, whereas only 5% consumed the target intake of EPA plus DHA. These results indicate that Canadian children aged 2 to 3 years struggle to consume adequate intakes of the n-3 PUFA ALA and particularly EPA/DHA; efforts to narrow this gap should focus on increasing EPA and DHA intakes by appropriate fish/seafood consumption along with enriched foods or supplements if necessary.

Effects of supplementation with fish oil-derived n-3 fatty acids and gamma-linolenic acid on circulating plasma lipids and fatty acid profiles in women.

BACKGROUND: Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and gamma-linolenic acid (GLA) have lipid-modifying and antiinflammatory properties. The effects of supplement mixtures of these fatty acids on plasma lipids and the fatty acid compositions of serum phospholipids have received little attention. OBJECTIVE: The objective was to determine the effects of different levels of GLA supplementation together with a constant intake of EPA plus DHA on the triacylglycerol-lowering effect of EPA plus DHA alone and on the fatty acid patterns (eicosanoid precursors) of serum phospholipids. DESIGN: Thirty-one women were assigned to 1 of 4 groups, equalized on the basis of their fasting triacylglycerol concentrations. They received supplements providing 4 g EPA+DHA (4:0, EPA+DHA:GLA; control group), 4 g EPA+DHA plus 1 g GLA (4:1), 2 g GLA (4:2), or 4 g GLA (4:4) daily for 28 d. Plasma lipids and fatty acids of serum phospholipids were measured on days 0 and 28. RESULTS: Plasma triacylglycerol concentrations were significantly lower on day 28 than on day 0 in the 4:0, 4:1, and 4:2 groups. LDL cholesterol decreased significantly (by 11.3%) in the 4:2 group. Dihomo-gamma-linolenic acid increased significantly in serum phospholipids only in the 4:2 and 4:4 groups; however, total n-3 fatty acids increased in all 4 groups. CONCLUSIONS: A mixture of 4 g EPA+DHA and 2 g GLA favorably altered blood lipid and fatty acid profiles in healthy women. On the basis of calculated PROCAM values, the 4:2 group was estimated to have a 43% reduction in the 10-y risk of myocardial infarction.

Differential eicosapentaenoic acid elevations and altered cardiovascular disease risk factor responses after supplementation with docosahexaenoic acid in postmenopausal women receiving and not receiving hormone replacement therapy.

BACKGROUND: Dietary docosahexaenoic acid (DHA) has triacylglycerol-lowering potential and undergoes in vivo retroconversion to eicosapentaenoic acid (EPA) in humans. Hormone replacement therapy (HRT) influences circulating lipid concentrations and fatty acid metabolism. DHA supplementation has not been studied in postmenopausal women. OBJECTIVE: We studied the effects of supplementation with DHA (free of EPA) on the resulting elevation in EPA and on selected cardiovascular disease risk factors in postmenopausal women. DESIGN: Women receiving (n = 18) and not receiving (n = 14) HRT completed a randomized, double-blind, placebo-controlled crossover trial with a DHA supplement (2.8 g DHA/d). A washout period of > or =6 wk divided the two 28-d intervention periods. Fasting blood samples were collected for analysis. RESULTS: In all women, DHA supplementation was associated with significant changes (P < 0.05), including 20% lower serum triacylglycerol concentrations, 8% higher HDL-cholesterol concentrations, a 28% lower overall ratio of serum triacylglycerol to HDL cholesterol, and a 7% decrease in resting heart rate. DHA supplementation resulted in a 45% lower net increase (P = 0.02) in EPA and a 42% lower (P = 0.0028) estimated percentage retroconversion of DHA to EPA [DeltaEPA/(DeltaEPA + DeltaDHA) x 100] in women receiving than in those not receiving HRT. CONCLUSION: With DHA supplementation, the accumulation of EPA in serum phospholipids is significantly attenuated in postmenopausal women receiving HRT compared with that in women not receiving HRT. DHA supplementation can also favorably influence selected cardiovascular disease risk factors in postmenopausal women.

Omega-3 fatty acids and risk of cognitive impairment and dementia.

It has been suggested that the dietary intake of omega-3 polyunsaturated fatty acids could be inversely related to the risk of dementia and cognitive decline. This analysis examined the association between plasma concentration of omega-3 polyunsaturated fatty acids and prevalence and incidence of cognitive impairment and dementia. Data are reported on subjects 65 years or older who had a complete clinical evaluation at the first two waves (1991-1992 and 1996-1997) of the Canadian Study of Health and Aging. Main outcome measures were cognitive impairment and dementia by mean relative plasma concentrations of fatty acids in the phospholipid fraction at baseline. Results were adjusted for age, sex, education, smoking, alcohol intake, body mass index, history of cardiovascular disease, and apolipoprotein E e4 genotype. In the cross-sectional analysis, no significant difference in omega-3 polyunsaturated fatty acid concentrations was observed between controls and both prevalent cases of cognitive impairment and dementia. In the prospective analysis, a higher eicosapentaenoic acid (p < 0.01) concentration was found in cognitively impaired cases compared to controls while higher docosahexaenoic acid (p < 0.07), omega-3 (p < 0.04) and total polyunsaturated fatty acid (p < 0.03) concentrations were found in dementia cases. These findings do not support the hypothesis that omega-3 polyunsaturated fatty acids play a protective role in cognitive function and dementia.

Fatty acid composition of serum phospholipid of premenopausal women and postmenopausal women receiving and not receiving hormone replacement therapy.

OBJECTIVE: To compare the fatty acid composition of serum phospholipid of premenopausal women with that of postmenopausal women receiving and not receiving hormone replacement therapy (HRT). DESIGN: Women between the ages of 43 and 70 were recruited for two separate case-comparison studies. Participants were grouped as either premenopausal, postmenopausal receiving HRT, or postmenopausal not receiving HRT. All participants were required to complete a 3-day dietary record before providing a 12-h fasting blood sample. Fatty acid composition of phospholipids and lipid concentrations was determined from serum samples. RESULTS: The postmenopausal women receiving HRT had significantly higher concentrations of palmitic acid (16:0), palmitoleic acid (16:1), and di-homo-gamma-linolenic (20:3n-6) and significantly lower levels of docosapentaenoic acid (22:5n-3) than the other groups in both studies. In addition, the postmenopausal women receiving HRT had lower levels of behenic (22:0), lignoceric (24:0), and nervonic acid (24:1) in comparison with the postmenopausal women not receiving HRT. CONCLUSION: The results of this study indicate that the fatty acid composition of serum phospholipids in women is influenced by menopausal status and hormone use. These results are of interest because high levels of 20:3n-6 and low levels of docosapentaenoic acid have been associated with increased myocardial infarction plus stroke mortality from cardiovascular disease.

Fatty acid compositions of serum phospholipids of postmenopausal women: a comparison between Greenland Inuit and Canadians before and after supplementation with fish oil.

OBJECTIVES: We compared serum phospholipid fatty acid compositions, in particular the status of omega-3 polyunsaturated fatty acid (PUFA), of postmenopausal Greenland Inuit women and postmenopausal Canadian women at baseline and after supplementing the Canadian women with a fish-oil product. METHODS: Fasting serum samples were collected from 15 Inuit subjects from Greenland and 16 non-Inuit subjects from Canada. In addition, eight Canadian subjects provided fasting serum samples after completing a long-chain omega-3 PUFA intervention (2.4 g of eicosapentaenoic acid [EPA] plus 1.6 g of docosahexaenoic acid [DHA] per day) for 28 d. Fatty acid compositions of serum phospholipids of the samples were determined and compared by one-way analysis of variance. RESULTS: In comparison with the Greenlanders, baseline Canadian women had 73% and 46% less EPA (20:5omega-3) and DHA (22:6omega-3), respectively, and 32% and 91% more linoleic acid (LA; 18:2omega-6) and arachidonic acid (AA; 20:4omega-6), respectively. The omega-3 supplementation in Canadian women increased DHA and decreased LA levels to approach those in Greenland Inuit and raised EPA levels to surpass (45% higher) those in Greenland women (P < 0.0001). In contrast, AA was only moderately lowered (by 16% overall) such that AA levels remained 62% higher in the supplemented Canadians than in the Greenlanders (P < 0.0001). CONCLUSIONS: Short-term EPA plus DHA supplementation of postmenopausal North American women can mimic the high EPA and DHA levels and lower LA levels in corresponding Inuit women but not the markedly lower levels of AA. The present findings also support the hypothesis of genetically decreased Delta5-desaturase potential in the Greenland Inuit compared with Canadian postmenopausal women.

Absorption of anthocyanins from blueberries and serum antioxidant status in human subjects.

In recent years, numerous studies have shown that the polyphenolics present in fruit and vegetable products exhibit a wide range of biological effects. However, there is little reliable information on the absorption of glycosylated and acylated anthocyanins in humans. In the present study, the absorption of anthocyanins in humans was investigated after the consumption of a high-fat meal with a freeze-dried blueberry powder containing 25 individual anthocyanins including 6 acylated structures. Nineteen of the 25 anthocyanins present in the blueberries were detected in human blood serum. Furthermore, the appearance of total anthocyanins in the serum was directly correlated with an increase in serum antioxidant capacity (ORAC(acetone), P < 0.01). These results show that anthocyanins can be absorbed in their intact glycosylated and possibly acylated forms in human subjects and that consumption of blueberries, a food source with high in vitro antioxidant properties, is associated with a diet-induced increase in ex vivo serum antioxidant status.

Effect of exercise on FA profiles in n-3 FA-supplemented and -nonsupplemented premenopausal women.

The purpose of this double-blind study was to investigate the influence of exercise on the FA profile of the non-esterified FA (NEFA) and phospholipid fractions in plasma of sedentary women supplemented with n-3 FA vs. women supplemented with oil containing no n-3 FA. Twenty sedentary, premenopausal women were randomly assigned to receive 12 capsules daily of either fish oil (3.5 g EPA and 2.4 g DHA per day, each as the ethyl ester) or evening primrose oil capsules (no detectable EPA or DHA). Each subject consumed the capsules for one menstrual cycle. At the end of the supplementation period, the sedentary subjects underwent an acute exercise trial [55% maximal oxygen consumption (VO2 max), 45 min] on a cycle ergometer. Two subjects in the fish oil group were removed from all calculations owing to noncompliance for reasons not related to side effects. There were no changes in the phospholipid composition of either group of women after exercise. In both control and fish oil-supplemented women, NEFA levels in general rose after exercise. There were no changes in the percentage of any given individual NEFA in either supplementation group. However, absolute levels of certain individual NEFA (16:0, 18:0, 18:1, and 18:3n-3) increased with exercise. Women supplemented with fish oil had increased levels of n-3 NEFA IEPA, DHA, and docosapentaenoic acid (DPA)] prior to exercise. Exercise did not, however, increase the absolute levels of n-3 NEFA in the blood.

Gestational age and birth weight in relation to n-3 fatty acids among Inuit (Canada).

Seafood consumption during pregnancy carries both benefits (high n-3 FA intake) and risks (exposure to environmental contaminants) for the developing fetus. We determined the impacts of marine n-3 FA and environmental contaminants on gestational age (GA) of Nunavik women and the anthropometric characteristics of their newborns. FA and contaminant (polychlorinated biphenyls and mercury) concentrations were measured in cord plasma of Nunavik newborns (n = 454) and compared with those of a group of newborns (n = 29) from southern Québec. Data were collected from hospital records and birth certificates. In Nunavik newborns, arachidonic acid (AA) was two times lower (P < 0.0001), whereas DHA concentration, the sigman-3 / sigman-6 ratio, and the percentage of n-3 highly unsaturated FA (HUFA) (of the total HUFA) were three times higher (P < 0.0001) compared with southern Québec newborns. After controlling for confounders, GA and birth weight were higher by 5.4 d [95% confidence interval (CI): 0.7-10.1] and 77 g (95% CI: -64 to 217) in the third tertile of percentage of n-3 HUFA (of the total HUFA) as compared with the first tertile. There was no evidence that contaminants had negative effects on GA or birth weight. In this seafood-eating population, an increase in the proportion of n-3 HUFA (of the total HUFA), measured in umbilical cord plasma phospholipids, was associated with a significantly longer GA.