Maternal Factors Associated with Levels of Fatty Acids,Specifically n-3 PUFA during Pregnancy: ECLIPSES Study

An optimal fatty acid (FA) profile during pregnancy, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), is essential for the health of the mother and child. Our aim was to identify the socioeconomic and maternal lifestyle factors associated with serum FA concentration in pregnant women. A longitudinal study was conducted on 479 pregnant women, who were assessed during the first (T1) and third (T3) trimesters of pregnancy. Data on maternal characteristics, food consumption, and lifestyle were collected. Serum FA concentrations were analysed by a gas chromatography–mass spectrometry combination. The multiple linear regression showed that high educational level and older age were significantly associated with higher EPA and DHA concentrations and lower values of n-6/n-3 and arachidonic acid (AA)/EPA in T1 and/or T3. Regarding diet—fish and seafood consumption increased EPA concentration and reduced n-6/n-3 and AA/EPA values in both trimesters, whereas its consumption increased DHA concentration only in T1. Smoking was associated with lower DHA concentration in T1 and higher values of n-6/n-3 ratio in both trimester. Overweight and obesity were associated with higher values of n-6/n-3 ratio and AA/EPA ratio in T1. A statistically non-significant association was observed with saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA). In conclusion, high educational levels, older age, fish, seafood consumption, and/or non-smoking, are factors that influence better omega-3 polyunsaturated fatty acid (n-3 PUFA) profile in both trimesters of pregnancy. Further research is needed to go in-depth into these findings and their health consequences.     

不同水产品消费地区孕妇脂肪酸摄入量调查

目的分析我国不同水产品消费地区孕妇脂肪酸摄入状况。方法应用食物频率法分别在淡水产品消费量较高的江苏省句容市、海产品消费量较高的山东省即墨市以及水产品消费量很低的河南省辉县市,对180名22~35岁孕妇进行妊娠中、晚期膳食调查,分析脂肪酸摄入状况。结果句容、即墨、辉县孕妇膳食中饱和脂肪酸(SFA),单不饱和脂肪酸(MUFA),多不饱和脂肪酸(PUFA)的比例分别为1:2.50:1.05、1:1.44:1.31、1:1.48:1.24。n-6PUFA/n-3PUFA分别为5.51、17.62、13.85。辉县孕妇膳食中SFA和n-6PUFA摄入量最高;句容孕妇膳食中MUFA和n-3PUFA摄入量最高;即墨孕妇膳食中二十碳五烯酸(EPA,20:5n-3)和二十二碳六烯酸(DHA,22:6n-3)摄入量最高。句容和辉县孕妇膳食中的花生四烯酸(AA,20:4n-6)摄入量均高于即墨。三地孕妇膳食中EPA和DHA均主要来自水产品;AA主要来自畜禽肉类和蛋类;亚麻酸(ALA,18:3n-3)和亚油酸(LA,18:2n-6)主要来自食用油、畜禽肉类、坚果和主食及糕点类。结论三地区SFA、MUFA、PUFA的摄入比例合理。即墨、辉县孕妇膳食中n-6/n-3PUFA比例偏高;即墨市孕妇膳食中DHA和EPA摄入量高于其它两地,但仍明显低于推荐量。建议增加孕妇膳食n-3PUFA,特别是DHA和EPA的摄入量。     

Long-chain n-3 polyunsaturated fatty acid dietary recommendations are moderately efficient in optimizing their status in healthy middle-aged subjects with low fish consumption: a cross-over study

Several dietary recommendations have been made for marine n-3 polyunsaturated fatty acid (PUFA) intake; however, the effectiveness of these fatty acids has not been thoroughly examined. The aim of this study was to investigate whether public-aimed dietary recommendations for long-chain n-3 PUFA from oily fish or fish oil supplements are efficient in optimizing their status in red blood cells (RBCs) and platelets of healthy middle-aged subjects with low customary fish consumption. In a randomized, cross-over trial conducted over an 8-week period and separated by a 6-month washout period, 33 participants received an oily fish (salmon), providing 274 mg eicosapentaenoic acid (EPA) + 671 mg docosahexaenoic acid (DHA) per day, or a commercial fish oil supplement, providing 396 mg EPA + 250 mg DHA per day. Blood samples were collected before and after each intervention period, and RBCs and platelets were used for analysis of fatty acids. After 8 weeks, there were significant increases in EPA and DHA content in RBCs and platelets with both salmon and fish oil capsules. The increase in EPA in both RBCs and platelets was higher with capsules, whereas the increase in DHA in both RBCs and platelets was higher with salmon. In spite of the quantitative and qualitative differences between n-3 fatty acid profiles in salmon and the fish oil supplement, the overall incorporation of these fatty acids into RBCs and platelets did not differ in our short-term study (P > .05). The sum of EPA + DHA significantly increased in both compartments following dietary recommendations for oily fish and fish oil supplements intake in middle-aged healthy subjects with low baseline long-chain n-3 PUFA status, although targeted values with optimal cardioprotective effect of more than 8% were not achieved.     

Proportions of Polyunsaturated Fatty Acids in Umbilical Cord Blood at Birth Are Related to Atopic Eczema Development in the First Year of Life

Atopic eczema, the most common atopic disease in infants, may pave the way for sensitization and allergy later in childhood. Fatty acids have immune-regulating properties and may regulate skin permeability. Here we examine whether the proportions of fatty acids among the infant and maternal plasma phospholipids at birth were associated with maternal dietary intake during pregnancy and development of atopic eczema during the first year of age in the Nutritional impact on Immunological maturation during Childhood in relation to the Environment (NICE) birth cohort. Dietary data were collected with a semi-quantitative food frequency questionnaire, fatty acids were measured with GC-MS and atopic eczema was diagnosed by a pediatric allergologist at 12 months of age. We found that higher proportions of n-6 PUFAs (including arachidonic acid) but lower proportions of n-3 PUFAs (including DPA) in the infant’s phospholipids at birth were associated with an increased risk of atopic eczema at 12 months of age. The n-6 and n-3 PUFAs were related to maternal intake of meat and fish, respectively. Our results suggest that prenatal exposure to unsaturated fatty acids is associated with eczema development in the infant. Maternal diet during pregnancy may partly explain the fatty acid profiles in utero.     

Assessing the environment for regulatory change for eicosapentaenoic acid and docosahexaenoic acid nutrition labeling

This review examines issues related to the development of a recommended daily allowance or adequate intake, two of the categories of dietary reference intakes, for the long-chain omega-3 polyunsaturated fatty acids (omega-3 PUFAs), eicosapentaenoic acid (EPA, 20:5 n-3), and docosahexaenoic acid (DHA, 22:6 n-3). Although some have suggested a dietary intake of two servings of fatty fish per week or supplement intake of 500 mg/day EPA plus DHA, based on evidence from epidemiologic and clinical studies of cardiovascular benefit from regular fish or fish-oil consumption, supplementation with EPA and/or DHA may also have antidepressant and mood-stabilizing effects. Omega-3 PUFA biology is complex and chronic disease outcomes are sometimes difficult to prove, yet the possibility of benefit for a substantial portion of the population from increased omega-3 PUFA intake is a public health issue that must be addressed responsibly and be based on significant scientific evidence.     

Ethnic differences in early pregnancy maternal n-3 and n-6 fatty acid concentrations: an explorative analysis

Ethnicity-related differences in maternal n-3 and n-6 fatty acid status may be relevant to ethnic disparities in birth outcomes observed worldwide. The present study explored differences in early pregnancy n-3 and n-6 fatty acid composition of maternal plasma phospholipids between Dutch and ethnic minority pregnant women in Amsterdam, the Netherlands, with a focus on the major functional fatty acids EPA (20 : 5n-3), DHA (22 : 6n-3), dihomo-gamma-linolenic acid (DGLA; 20 : 3n-6) and arachidonic acid (AA; 20 : 4n-6). Data were derived from the Amsterdam Born Children and their Development (ABCD) cohort (inclusion January 2003 to March 2004). Compared with Dutch women (n 2443), Surinamese (n 286), Antillean (n 63), Turkish (n 167) and Moroccan (n 241) women had generally lower proportions of n-3 fatty acids (expressed as percentage of total fatty acids) but higher proportions of n-6 fatty acids (general linear model; P < 0.001). Ghanaian women (n 54) had higher proportions of EPA and DHA, but generally lower proportions of n-6 fatty acids (P < 0.001). Differences were most pronounced in Turkish and Ghanaian women, who, by means of a simple questionnaire, reported the lowest and highest fish consumption respectively. Adjustment for fish intake, however, hardly attenuated the differences in relative EPA, DHA, DGLA and AA concentrations between the various ethnic groups. Given the limitations of this observational study, further research into the ethnicity-related differences in maternal n-3 and n-6 fatty acid patterns is warranted, particularly to elucidate the explanatory role of fatty acid intake v. metabolic differences.     

Maternal dietary n-6 polyunsaturated fatty acid deprivation does not exacerbate post-weaning reductions in arachidonic acid and its mediators in the mouse hippocampus

Objectives: The present study examines how lowering maternal dietary n-6 polyunsaturated fatty acids (PUFA) (starting from pregnancy) compared to offspring (starting from post-weaning) affect the levels of n-6 and n-3 fatty acids in phospholipids (PL) and lipid mediators in the hippocampus of mice.

Methods: Pregnant mice were randomly assigned to consume either a deprived or an adequate n-6 PUFA diet during pregnancy and lactation (maternal exposure). On postnatal day (PND) 21, half of the male pups were weaned onto the same diet as their dams, and the other half were switched to the other diet for 9 weeks (offspring exposure). At PND 84, upon head-focused high-energy microwave irradiation, hippocampi were collected for PL fatty acid and lipid mediator analyses.

Results: Arachidonic acid (ARA) concentrations were significantly decreased in both total PL and PL fractions, while eicosapentaenoic acid (EPA) concentrations were increased only in PL fractions upon n-6 PUFA deprivation of offspring, regardless of maternal exposure. Several ARA-derived eicosanoids were reduced, while some of the EPA-derived eicosanoids were elevated by n-6 PUFA deprivation in offspring. There was no effect of diet on docosahexaenoic acid (DHA) or DHA-derived docosanoids concentrations under either maternal or offspring exposure.

Discussion: These results indicate that the maternal exposure to dietary n-6 PUFA may not be as important as the offspring exposure in regulating hippocampal ARA and some lipid mediators. Results from this study will be helpful in the design of experiments aimed at testing the significance of altering brain ARA levels over different stages of life.     

Persistent changes in the fatty acid composition of erythrocyte membranes after moderate intake of n-3 polyunsaturated fatty acids: study design implications.

To examine the incorporation of n-3 polyunsaturated fatty acids (PUFAs) into erythrocyte membranes during and after moderate n-3 PUFA intake, 12 healthy men were fed three diets for 6-wk periods in a 3 x 3 crossover design, supplying different amounts of eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3): a control diet, a fish diet (0.15 g EPA/d, 0.41 g DHA/d), and a fish + oil diet (5 g fish oil/d; 0.99 g EPA/d and 0.99 g DHA/d). A 6-wk washout period was allowed between diets. Between 6 and 12 wk after the fish + oil diet, erythrocyte EPA and DHA were still declining and it was only after 18 wk that erythrocyte EPA had returned to baseline whereas DHA had not. Investigators examining variables that are influenced by altered membrane fatty acid composition should be aware of these prolonged effects when designing studies. Protracted washout periods (greater than 18 wk) make the classic crossover design prohibitive and a parallel design becomes essential.     

Seasonal Variations in Fatty Acid Composition and the N-6/N-3 Fatty Acid Ratio of Pikeperch (Sander LUCIOPERCA) Muscle Lipids

Total lipid, fatty acid composition and the N-6/N-3 fatty acid ratios of muscle of pikeperch (Sander lucioperca) was determined once every two months. The ratio of unsaturated fatty acids (UFA) was higher than half of the total fatty acid content, and the monounsaturated fatty acid (MUFA) was higher than the polyunsaturated fatty acid (PUFA) ratio. The n-3 fatty acids were present in excess of the n-6 fatty acids. Eicosapentaenoic (EPA), docosahexaenoic (DHA), and arachidonic (AA) acids were the most abundant PUFA. The fatty acid composition and n-6/n-3 fatty acids ratio in the muscle of pikeperch are significantly influenced by spawning and the season. Relative proportions of PUFA (especially n-3 fatty acids) diminished significantly with the maturation of gonads. The ratio of n-6/n-3 fatty acids was less than one except during the reproduction period. This result suggests that meat quality of pikeperch is very good except during the spawning period with respect to the n-6/n-3 fatty acids ratio.     

The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA) is correspondingly decreased, the effect on other fatty acids (FA) is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0–4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA) multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC), cholesteryl ester (CE) and triglyceride (TAG) and for blood mononuclear cells (MNC), red blood cells (RBC) and platelets (PLAT). Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA) in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%–64% of placebo in the four portions group). We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology.     

Long-chain n-3 PUFA: plant v. marine sources

Increasing recognition of the importance of the long-chain n-3 PUFA, EPA and DHA, to cardiovascular health, and in the case of DHA to normal neurological development in the fetus and the newborn, has focused greater attention on the dietary supply of these fatty acids. The reason for low intakes of EPA and DHA in most developed countries (0.1-0.5 g/d) is the low consumption of oily fish, the richest dietary source of these fatty acids. An important question is whether dietary intake of the precursor n-3 fatty acid, alpha-linolenic acid (alphaLNA), can provide sufficient amounts of tissue EPA and DHA by conversion through the n-3 PUFA elongation-desaturation pathway. alphaLNA is present in marked amounts in plant sources, including green leafy vegetables and commonly-consumed oils such as rape-seed and soyabean oils, so that increased intake of this fatty acid would be easier to achieve than via increased fish consumption. However, alphaLNA-feeding studies and stable-isotope studies using alphaLNA, which have addressed the question of bioconversion of alphaLNA to EPA and DHA, have concluded that in adult men conversion to EPA is limited (approximately 8%) and conversion to DHA is extremely low (<0.1%). In women fractional conversion to DHA appears to be greater (9%), which may partly be a result of a lower rate of utilisation of alphaLNA for beta-oxidation in women. However, up-regulation of the conversion of EPA to DHA has also been suggested, as a result of the actions of oestrogen on Delta6-desaturase, and may be of particular importance in maintaining adequate provision of DHA in pregnancy. The effect of oestrogen on DHA concentration in pregnant and lactating women awaits confirmation.     

A Food-Based Intervention in a Military Dining Facility Improves Blood Fatty Acid Profile

Enhancing dietary omega-3 highly unsaturated fatty acids (n-3 HUFA) intake may confer neuroprotection, brain resiliency, improve wound healing and promote cardiovascular health. This study determined the efficacy of substituting a few common foods (chicken meat, chicken sausage, eggs, salad dressings, pasta sauces, cooking oil, mayonnaise, and peanut butter) lower in omega-6 polyunsaturated fatty acids (n-6 PUFA) and higher in n-3 HUFA in a dining facility on blood fatty acid profile. An eight-week prospective, between-subjects (n = 77), repeated measures, parallel-arm trial was conducted. Participants self-selected foods consumed from conventionally produced foods (control), or those lower n-6 PUFA and higher n-3 HUFA versions (intervention). Changes in blood omega-3 index, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), n-6 PUFA, lipid profile, and food satisfaction were main outcomes. Between-group differences over time were assessed using a linear mixed model to measure the effect of diet on blood serum fatty acids and inflammatory markers. The intervention group achieved a higher omega-3 index score (3.66 ± 0.71 vs. 2.95 ± 0.77; p < 0.05), lower total n-6 (10.1 ± 4.6 vs. 15.3 ± 6.7 µg/mL; p < 0.05), and higher serum concentration of EPA (5.0 ± 1.31 vs. 4.05 ± 1.56 µg/mL; p < 0.05) vs. controls. Satisfaction in intervention foods improved or remained consistent. Substitution of commonly eaten dining facility foods with like-items higher in DHA and EPA and lower in n-6 PUFA can favorably impact fatty acid status and the omega-3 index.     

Very long chain n-3 polyunsaturated fatty acids in the food chain in the UK and the potential of animal-derived foods to increase intake

Summary  The very long chain (VLC) n -3 polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are widely recognised to have beneficial effects on human health. However, recommended intakes of VLC n -3 PUFA (450 mg/day) are not being met by the diet in the majority of the population mainly because of low consumption of oil-rich fish. Current mean intake of VLC n -3 PUFA by adults is estimated to be about 282 mg/day with EPA and DHA contributing about 244 mg/day. Furthermore, the fact that only about 27% of adults eat any oil-rich fish (excluding canned tuna) and knowledge of the poor conversion of α-linolenic acid to EPA and DHA in vivo , particularly in men, leads to the need to review current dietary sources of these fatty acids. Animal-derived foods are likely to have an important function in increasing intake and studies have shown that feeding fish oils to animals can increase the EPA and DHA content of the resulting food products. This paper highlights the importance of examining current and projected consumption trends of meat and other animal products when exploring the potential impact of enriched foods by means of altering animal diets. When related to current food consumption data, potential dietary intakes of EPA+DHA from foods derived from animals fed enriched diets are calculated to be about 231 mg/day. If widely consumed, such foods could have a significant impact on progression of conditions such as cardiovascular disease. Consideration is also given to the sources of VLC n -3 PUFA in animal diets, with the sustainability of fish oil being questioned and the need to investigate the use of alternative dietary sources such as those of algal origin.     

Animal nutrition and lipids in animal products and their contribution to human intake and health

Few EU countries meet targets for saturated fatty acid (SFA) intake. Dairy products usually represent the single largest source of SFA, yet evidence indicates that milk has cardioprotective properties. Options for replacing some of the SFA in milk fat with cis-monounsaturated fatty acids (MUFA) through alteration of the cow's diet are examined. Also, few people achieve minimum recommended intakes (~450-500 mg/d) of the long chain n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Enrichment of EPA+DHA in poultry meat via bird nutrition is described and how this would impact on habitual intake is discussed.     

Dietary intakes of arachidonic acid and alpha-linolenic acid are associated with reduced risk of hip fracture in older adults

PUFA are hypothesized to influence bone health, but longitudinal studies on hip fracture risk are lacking. We examined associations between intakes of PUFA and fish, and hip fracture risk among older adults (n = 904) in the Framingham Osteoporosis Study. Participants (mean age ~75 y at baseline) were followed for incident hip fracture from the time they completed the baseline exam (1988-1989) until December 31, 2005. HR and 95% CI were estimated for energy-adjusted dietary fatty acid exposure variables [(n-3) fatty acids: α-linolenic acid (ALA), EPA, DHA, EPA+DHA; (n-6) fatty acids: linoleic acid, arachidonic acid (AA); and the (n-6):(n-3) ratio] and fish intake categories, adjusting for potential confounders and covariates. Protective associations were observed between intakes of ALA (P-trend = 0.02) and hip fracture risk in a combined sample of women and men and between intakes of AA (P-trend = 0.05) and hip fracture risk in men only. Participants in the highest quartile of ALA intake had a 54% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.46; 95% CI = 0.26-0.83). Men in the highest quartile of AA intake had an 80% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.20; 95% CI = 0.04-0.96). No significant associations were observed among intakes of EPA, DHA, EPA+DHA, or fish. These findings suggest dietary ALA may reduce hip fracture risk in women and men and dietary AA may reduce hip fracture risk in men.     

A practical approach to increasing intakes of n-3 polyunsaturated fatty acids: use of novel foods enriched with n-3 fats

OBJECTIVES: To assess the effects of providing a wide range of foodstuffs containing n-3 polyunsaturated fatty acids (PUFA), occurring naturally or from fortification, on intake and blood and tissue proportions of n-3 PUFA. DESIGN: Before/after dietary intervention study. SETTING: Adelaide, Australia. SUBJECTS: 16 healthy males recruited from the community. INTERVENTIONS: Subjects were provided with a range of foodstuffs naturally containing n-3 PUFA (fresh fish, canned fish, flaxseed meal, canola oil) and items fortified with fish oil (margarine spread, milk, sausages, luncheon meat, french onion dip). Food choices were left to the discretion of each subject. Intake was estimated by diet diary. Blood was collected at-2, 0, 2, and 4 weeks for fatty acid analysis. MAIN OUTCOME MEASURES: Dietary intakes; plasma, platelet, and mononuclear cell phospholipid fatty acids. RESULTS: Consumption of n-3 PUFA increased significantly: alpha-linolenic acid (ALA) from 1.4 to 4.1 g/day (P<0.001), eicosapentaenoic acid (EPA) from 0.03 to 0.51 g/day (P<0.001), and docosahexaenoic acid (DHA) from 0.09 to 1.01 g/day (P<0.001). Linoleic acid (LA) intake decreased from 13.1 to 9.2 g/day (P<0.001). The proportions of EPA and DHA increased significantly in all phospholipid pools examined; plasma EPA from 1.13% of total fatty acids to 3.38% (P<0.001) and DHA from 3.76 to 7.23% (P<0.001); mononuclear cell EPA from 0.40 to 1.25% (P<0.001) and DHA from 2.33 to 4.08% (P<0.001); platelet EPA from 0.41 to 1.2% (P<0.001) and DHA from 1.64 to 3.07% (P<0.001). CONCLUSION: Incorporating fish oil into a range of novel commercial foods provides the opportunity for wider public consumption of n-3 PUFA with their associated health benefits. SPONSORSHIP: Dawes Scholarship, Royal Adelaide Hospital.     

Current intakes of EPA and DHA in European populations and the potential of animal-derived foods to increase them

The beneficial effects of long-chain (C chain >or=20) n-3 PUFA are well documented and, overall, increased intake reduces risk of CVD. Recent evidence also points to a role in reducing age-related decline in cognitive function. The two key fatty acids are EPA (20:5) and DHA (22:6), with current UK recommendation for adults being 450 mg EPA+DHA/d. Whilst some EPA and DHA can be synthesised in vivo from alpha-linolenic acid, recent data indicate this source to be very limited, suggesting that EPA and DHA should be classified as dietary essentials. In many parts of Europe the daily intake of EPA+DHA by adults and especially young adults (18-24 years) is <100 mg/d, since many never eat oily fish. Poultry meat contributes small but worthwhile amounts of EPA+DHA. Studies to enrich the EPA+DHA content of animal-derived foods mainly use fish oil in the diet of the animal. Recent work has shown that such enrichment has the potential to provide to the UK adult diet a daily intake of EPA+DHA of about 230 mg, with poultry meat providing the largest amount (74 mg). There are, however, concerns that the continued and possibly increased use of fish oils in animals' diets is not sustainable and alternative approaches are being examined, including the genetic modification of certain plants to allow them to synthesise EPA and DHA from shorter-chain precursors.     

High α-linolenic acid and fish oil ingestion promotes ovulation to the same extent in rats

Prostaglandins (PG) have a regulatory influence on ovulation. α-Linolenic acid (ALA) vs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) differently influence PG biosynthesis. Whereas high EPA/DHA reduces PGE₂, enhancing ovulation, we hypothesized that ALA would not affect ovulation. Our objective was to determine the effect of low and high ALA intake vs EPA/DHA on ovarian phospholipids, ovulation, and PG synthesis in rats. Following 27 days on diet and ovulation induction, ovaries were isolated and analyzed in 22 pups per diet. Ovarian phospholipid (n-3) polyunsaturated fatty acid (PUFA) incorporation increased with EPA/DHA ingestion. With significant ovarian (n-3) PUFA or EPA (P < .05) enrichment in the high–n-3 PUFA diets, ova release increased. Although high ALA did not enrich total (n-3), it increased ova release and tissue EPA over low ALA or control. Dietary EPA/DHA more effectively reduced ovarian arachidonic acid levels than dietary ALA. Dietary ALA increased PGF and very high intake reduced PGE, whereas EPA/DHA did not alter PGE or PGF. Enhanced ova release with high (n-3) PUFA intake may be induced via multiple mechanisms including reduced ovarian arachidonic acid. Significant ovarian retention of EPA and DHA enhanced ovulation with unchanged total PGE and PGF. Lack of change in PGE may have resulted from reduced PGE₂ combined with increased PGE₃. When EPA alone was elevated, PGE was reduced, whereas PGF was increased. Results indicate that very high ALA intake enhances ovulation similar to very high EPA/DHA ingestion, an effect potentially mediated via similar patterns of PGF₂α and PGE₂ synthesis.     

Inhibition of tumour necrosis factor-alpha and interleukin 6 production by mononuclear cells following dietary fish-oil supplementation in healthy men and response to antioxidant co-supplementation

Increased dietary consumption of the n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (20 : 5n-3; EPA) and docosahexaenoic acid (22 : 6n-6; DHA) is associated with their incorporation into circulating phospholipid and increased production of lipid peroxide metabolites. The relationship between peripheral blood mononuclear cell (PBMC) function, n-3 PUFA intake and antioxidant co-supplementation is poorly defined. We therefore investigated tumour necrosis factor (TNF)-alpha and interleukin (IL) 6 production by PBMC and phospholipid fatty acid composition in plasma and erythrocytes of healthy male subjects (n 16) receiving supplemental intakes of 0.3, 1.0 and 2.0 g EPA+DHA/d, as consecutive 4-week courses. All subjects were randomised in a double-blind manner to receive a concurrent antioxidant supplement (200 microg Se, 3 mg Mn, 30 mg D-alpha-tocopheryl succinate, 90 mg ascorbic acid, 450 microg vitamin A (beta-carotene and retinol)) or placebo. There was a positive dose-dependent relationship between dietary n-3 PUFA intake and EPA and DHA incorporation into plasma phosphatidylcholine and erythrocyte phosphatidylethanolamine, with a tendency towards a plateau at higher levels of intake. Production of TNF-alpha and IL-6 by PBMC decreased with increasing n-3 PUFA intake but tended towards a 'U-shaped' dose response. Both responses appeared to be augmented by antioxidant co-supplementation at intermediate supplementary n-3 PUFA intakes. Thus, increased dietary n-3 PUFA consumption resulted in defined but contrasting patterns of modulation of phospholipid fatty acid composition and PBMC function, which were further influenced by antioxidant intake.     

Maternal intake of fatty acids during pregnancy and allergies in the offspring

Fatty acids (FA) are known to have a number of immunological effects and, accordingly, may play a role in the development of allergic diseases. We investigated the effect of maternal intake of FA during pregnancy on the risk of allergic rhinitis, wheeze and atopic eczema in children aged 5 years. The present study analysed data from the Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study, a population-based birth cohort study with a 5-year follow-up. Complete information on maternal diet (assessed by a validated FFQ) and International Study of Asthma and Allergies in Childhood-based allergic outcomes was available for 2441 children. Cox proportional regression and logistic regression were used for the analyses. After adjusting for potential confounding variables, high maternal consumption of butter and butter spreads (hazard ratio (HR) 1.33; 95 % CI 1.03, 1.71) and higher ratio of n-6:n-3 FA (HR 1.37; 95 % CI 1.07, 1.77) during pregnancy were associated with an increased risk of allergic rhinitis in the offspring by 5 years of age. High maternal intakes of total PUFA (HR 0.71; 95 % CI 0.52, 0.96) and α-linolenic FA (HR 0.73; 95 % CI 0.54, 0.98) were associated with a decreased risk of allergic rhinitis. However, these results lost their significance after adjustment for multiple comparisons. Overall, our data suggest that maternal consumption of butter, the ratio of n-6:n-3 FA and intake of PUFA and α-linolenic FA during pregnancy may be potential determinants of allergic rhinitis in the offspring.