Erythrocyte cell membrane phospholipid levels compared against reported dietary intakes of polyunsaturated fatty acids in pregnant Mexican women

The Effect of Prenatal Docosahexaenoic Acid Supplementation on Offspring Fat Mass and Distribution at 24 Months Old

Background

Excessive gestational weight gain (GWG) is related to increased offspring fat accrual, and increased fat mass (FM) is related to obesity development. Prenatal DHA supplementation has been linked to lower levels of offspring FM; however, conflicting data exist.

Objectives

This study aimed to determine if there is a protective effect of prenatal DHA supplementation on offspring fat accrual and adipose tissue deposition at 24 mo in offspring born to females who gain excessive weight compared with nonexcessive weight during pregnancy. We also explored if the effect of DHA dose on FM differed by offspring sex.

Methods

Infants born to females who participated in the Assessment of DHA on Reducing Early Preterm Birth randomized controlled trial (ADORE) were recruited. In ADORE, females were randomly assigned to either a high or low prenatal DHA supplement. Offspring body composition and adipose tissue distribution were measured using dual-energy x-ray absorptiometry (DXA). GWG was categorized as excessive or not excessive based on clinical guidelines.

Results

For total FM, there was a significant main effect for the DHA dose (P = 0.03); however, the dose by GWG status was nonsignificant (P = 0.44). Therefore, a higher prenatal DHA dose was related to greater offspring FM (622.9 g greater) and unrelated to GWG status. When investigating a DHA dose by sex effect, a significant main effect for DHA dose (P = 0.01) was detected for central FM. However, no interaction was detected (P = 0.98), meaning that both boys and girls had greater central FM if their mother was assigned to the higher DHA dose.

Conclusions

Greater prenatal DHA supplementation was associated with greater offspring FM and adipose tissue distribution at 24 mo. It will be important to understand if these effects persist into childhood.This trial was registered at clinicaltrials.gov as NCT03310983.

Growth and adiposity in newborns study (GAINS): The influence of prenatal DHA supplementation protocol

BACKGROUND

Obesity and central fat mass (FM) accrual drive disease development and are related to greater morbidity and mortality. Excessive gestational weight gain (GWG) increases fetal fat accretion resulting in greater offspring FM across the lifespan. Studies associate greater maternal docosahexaenoic acid (DHA) levels with lower offspring FM and lower visceral adipose tissue during childhood, however, most U.S. pregnant women do not consume an adequate amount of DHA. We will determine if prenatal DHA supplementation is protective for body composition changes during infancy and toddlerhood in offspring exposed to excessive GWG.

METHODS AND DESIGN

Infants born to women who participated in the Assessment of DHA on Reducing Early Preterm Birth randomized controlled trial (ADORE; NCT02626299) will be invited to participate. Women were randomized to either a high 1000 mg or low 200 mg daily prenatal DHA supplement starting in the first trimester of pregnancy. Offspring body composition and adipose tissue distribution will be measured at 2 weeks, 6 months, 12 months, and 24 months using dual energy x-ray absorptiometry. Maternal GWG will be categorized as excessive or not excessive based on clinical guidelines.

DISCUSSION

Effective strategies to prevent obesity development are lacking. Exposures during the prenatal period are important in the establishment of the offspring phenotype. However, it is largely unknown which exposures can be successfully targeted to have a meaningful impact. This study will determine if prenatal DHA supplementation modifies the relationship between maternal weight gain and offspring FM and FM distribution at 24 months of age.

ETHICS AND DISSEMINATION

The University of Kansas Medical Center Institutional Review Board (IRB) approved the study protocol (STUDY00140895). The results of the trial will be disseminated at conferences and in peer reviewed publications.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03310983.

Infant Metabolome in Relation to Prenatal DHA Supplementation and Maternal Single-Nucleotide Polymorphism rs174602: Secondary Analysis of a Randomized Controlled Trial in Mexico

BACKGROUND

Although DHA (22:6n-3) is critical for fetal development, results from randomized controlled trials (RCTs) of prenatal DHA supplementation report inconsistent effects on offspring health. Variants in fatty acid desaturase (FADS) genes that regulate the conversion of n-3 and n-6 essential fatty acids into their biologically active derivatives may explain this heterogeneity.

OBJECTIVES

We investigated the effect of prenatal DHA supplementation on the offspring metabolome at age 3 mo and explored differences by maternal FADS single-nucleotide polymorphism (SNP) rs174602.

METHODS

Data were obtained from a double-blind RCT in Mexico [POSGRAD (Prenatal Omega-3 Fatty Acid Supplementation and Child Growth and Development)] in which women (18-35 y old) received DHA (400 mg/d) or placebo from mid-gestation until delivery. Using high-resolution MS with LC, untargeted metabolomics was performed on 112 offspring plasma samples. Discriminatory metabolic features were selected via linear regression (P < 0.05) with false discovery rate (FDR) correction (q = 0.2). Interaction by SNP rs174602 was assessed using 2-factor ANOVA. Stratified analyses were performed, where the study population was grouped into carriers (TT, TC; n = 70) and noncarriers (CC; n = 42) of the minor allele. Pathway enrichment analysis was performed with Mummichog (P < 0.05).

RESULTS

After FDR correction, there were no differences in metabolic features between infants whose mothers received prenatal DHA (n = 58) and those whose mothers received placebo (n = 54). However, we identified 343 differentially expressed features in the interaction analysis after FDR correction. DHA supplementation positively enriched amino acid and aminosugars metabolism pathways and decreased fatty acid metabolism pathways among offspring of minor allele carriers and decreased metabolites within the tricarboxylic acid cycle and galactose metabolism pathways among offspring of noncarriers.

CONCLUSIONS

Our findings demonstrate differences in infant metabolism in response to prenatal DHA supplementation by maternal SNP rs174602 and further support the need to incorporate genetic analysis of FADS polymorphisms into DHA supplementation trials.This trial was registered at clinicaltrials.gov as NCT00646360.

The influence of fish consumption on serum n-3 polyunsaturated fatty acid (PUFA) concentrations in women of childbearing age: a randomised controlled trial (the iFish Study)

PURPOSE

Long-chain polyunsaturated fatty acids (LCPUFA) can be synthesised endogenously from linoleic acid (LA) and α-linolenic acid (ALA) in a pathway involving the fatty acid desaturase (FADS) genes. Endogenous synthesis is inefficient; therefore, dietary intake of preformed LCPUFA from their richest source of fish is preferred. This study investigated the effect of fish consumption on PUFA concentrations in women of childbearing age while stratifying by FADS genotype. The influence of fish consumption on lipid profile, and markers of inflammation and oxidative stress was also examined.

METHODS

Healthy women (n = 49) provided a buccal swab which was analysed for FADS2 genotype (rs3834458; T/deletion). Participants were stratified according to genotype and randomised to an intervention group to receive either no fish (n = 18), 1 portion (n = 14) or 2 portions (n = 17) (140 g per portion) of fish per week for a period of 8 weeks. Serum PUFA was analysed at baseline and post-intervention. Lipid profile, and markers of inflammation and oxidative stress were also analysed.

RESULTS

Participants consuming 2 portions of fish per week had significantly higher concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and total n-3 PUFA, and a lower n-6:n-3 ratio compared to those in the no fish or 1 portion per week group (all p < 0.05). Fish consumption did not have a significant effect on biomarkers of oxidative stress, inflammation and lipid profile in the current study.

CONCLUSION

Consumption of 2 portions of fish per week has beneficial effects on biological n-3 PUFA concentrations in women of childbearing age; however, no effects on oxidative stress, inflammation or lipid profile were observed. This trial was registered at www.clinicaltrials.gov (NCT03765580), registered December 2018.

Validation of a Semi-Quantitative Food-Frequency Questionnaire for Dutch Pregnant Women from the General Population Using the Method or Triads

OBJECTIVE

We aimed to validate a food-frequency questionnaire (FFQ) for Dutch pregnant women, against three 24 h-recalls and blood concentrations of B-vitamins and fatty acids, using the method of triads.

METHODS

We included 83 pregnant women from the general population of Rotterdam, the Netherlands, at a median gestational age of 15.6 weeks. Participants completed three non-consecutive 24 h-recalls, and subsequently filled out the 293-item FFQ. Participants provided blood samples from which we analyzed serum folate and vitamin B12, as well as red blood cell folate, linoleic acid, and total saturated, monounsaturated, and polyunsaturated fatty acids.

RESULTS

Estimated energy intake did not differ between the FFQ and 24 h-recalls. Deattenuated Pearson's correlation coefficients, between energy-adjusted nutrient intake estimates from the FFQ and the 24 h-recalls, ranged from 0.41 (fat) to 0.88 (fiber) for macronutrients, and were around 0.6 for most micronutrients, except for vitamin E (0.27). Using the triad method, we obtained validity coefficients of 0.86 (95% Confidence Interval (CI) 0.36, 1.00) for serum folate, 0.86 (95% CI 0.18, 1.00) for red blood cell folate, and 1.00 (95% CI 0.42, 1.00) for vitamin B12. Validity coefficients for serum fatty acids ranged from 0.22 to 0.67.

CONCLUSION

This FFQ is a reliable tool for estimating intake of energy, macronutrients, folate and vitamin B12 among women in mid-pregnancy.

Influence of sociodemographic, lifestyle and genetic characteristics on maternal DHA and other polyunsaturated fatty acid status in pregnancy: A systematic review

INTRODUCTION

Omega-3 DHA is important for the prevention of preterm birth, however there is limited knowledge of the determinants of omega-3 status during pregnancy. The primary objective of this systematic review was to synthesise data from existing studies assessing relationships between sociodemographic, diet, lifestyle and genetic factors and maternal DHA status.

MATERIALS AND METHODS

The Medline, Embase, Amed, and CINAHL databases were searched for studies reporting measures of maternal omega-3 status and a sociodemographic/lifestyle/genetic characteristic.

RESULTS

Twenty-two studies were included in the final analyses. Higher dietary fish consumption/PUFA intake, higher education level and an older maternal age were associated with higher maternal omega-3 status. Higher alcohol intake, smoking and FADS genotype were each associated with lower maternal omega-3 status.

DISCUSSION

Differences in findings between studies make it difficult to draw clear conclusions about the relationship between these factors and maternal omega-3 DHA status, although socioeconomic status may play a role.

Validation of a Food Frequency Questionnaire to Assess Intake of n-3 Polyunsaturated Fatty Acids in Switzerland

Population-based data suggest that high intake of omega-3 (n-3) polyunsaturated fatty acids (PUFA) may be beneficial in a variety of health conditions. It is likely that mainly those patients with preexisting n-3 deficiency are those that benefit most from n-3 fatty acid supplementation. Therefore, for targeted interventions, a fast and reliable screening tool for n-3 PUFA intake is necessary. Thus, the aim of this project was to adapt and validate a food frequency questionnaire (FFQ) for n-3 PUFA intake in Switzerland while using as references the following: (1) 7-day food records (FR), and (2) n-3 fatty acid composition of red blood cells (RBC). We recruited 46 healthy adults for the first part of the study and 152 for the second. We used the dietary software EBISpro for the analysis of n-3 PUFA intake. RBC fatty acid composition was determined by gas chromatography mass spectrometry (GC-MS). Using correlation analysis, we found a moderate significant association between FFQ and FR for α-linolenic acid (ALA), eicosapentanoic acid (EPA), docosahexanoic acid (DHA), and total n-3 fatty acids (all r between 0.523 and 0.586, all p < 0.001). Bland Altman analysis further showed good agreement between the two methods and no proportional bias. Correlations between FFQ and RBC fatty acid composition were also moderate for EPA and DHA (r = 0.430 and r = 0.605, p < 0.001), but weaker for ALA and total n-3 (r = 0.314 and r = 0.211, p < 0.01). The efficacy of the FFQ to classify individuals into the same or adjacent quartile of RBC PUFA content ranged between 70% and 87% for the different fatty acids. In conclusion, we showed that the Swiss n-3 PUFA FFQ is a valid tool to assess dietary n-3 PUFA intake, especially DHA and EPA, to determine population groups at risk for low intake.

A Correlation Study of DHA Intake Estimated by a FFQ and Concentrations in Plasma and Erythrocytes in Mid- and Late Pregnancy

Adequate docosahexaenoic acid (DHA) is essential for the optimal growth and development of the fetus. Maternal DHA content fluctuates during pregnancy. The correlation of DHA content with dietary intake might be varied over the course of pregnancy. We aimed to compare the dietary DHA intake, estimated by a DHA-specific semiquantitative food frequency questionnaire (FFQ) against its blood content, among mid- and late-term pregnant women. A total of 804 Chinese pregnant women completed the tailored FFQ and provided fasting venous blood samples. Dietary DHA intake (mg/day) in the previous month was calculated from the FFQ using Chinese Food Composition Table. DHA concentrations (weight percent of total fatty acids) in plasma and erythrocytes were measured by capillary gas chromatography. Spearman correlation coefficients (r_s) between DHA intake and its relative concentrations were calculated. After adjustment for maternal age, pre-pregnancy body mass index, stage of pregnancy, parity, education level, ethnicity, and annual family income per capita, the correlation coefficients of DHA intake with its concentrations in plasma and erythrocytes were 0.35 and 0.33, respectively (p < 0.001). The correlations were relatively stronger among women in late pregnancy (r_s = 0.44 in plasma and 0.39 in erythrocytes) than those in mid-pregnancy (r_s = 0.25 and 0.26). The significant correlations were consistently observed in subgroups stratified by regions, except for erythrocytes in women living in a coastland area. Multiple regression analyses also indicated significant positive linear correlations between DHA intake and its plasma or erythrocytes concentrations (p < 0.001). In conclusion, dietary DHA intake, estimated by the FFQ, was positively correlated with its concentrations in plasma and erythrocytes in Chinese pregnant women, especially for women in late pregnancy, with the exception of the erythrocytes of those living in a coastland area.

The profile of polyunsaturated fatty acids in juvenile idiopathic arthritis and association with disease activity

We investigated the association between dietary intake of n-3 and n-6 polyunsaturated fatty acids (PUFAs), serum profiles, and immune and inflammatory markers in juvenile idiopathic arthritis (JIA) in relation to onset, activity, and duration. A total of 66 JIA patients and 42 controls were included. Serum PUFA levels were assessed by gas-liquid chromatography-mass spectrometry, a dietary intake by 7-day dietary record method, and IL-6, IL-10, and IL-17A levels using ELISA. Dietary PUFA intake did not differ between the JIA group and controls. Intakes of n-6 and n-3 PUFA and serum levels were not associated. Levels of total n-6 PUFA and linoleic acid (LA) were higher in inactive JIA than in active JIA. Patients with active and short-lasting disease (less than 3 months from diagnosis) had significantly lower levels of arachidonic acid (AA) and docosahexaenoic acid (DHA) than the control. Serum α-linolenic acid (ALA) levels were significantly higher in poly-JIA than in oligo-JIA and in controls. We found significantly higher serum IL-10 levels in JIA than in controls. Serum n-6 and n-3 levels were significantly negatively correlated with active joint count, erythrocyte sedimentation rate, and C-reactive protein and positively with platelet count. Our study presents the low levels of AA and DHA in the active phase of short-lasting JIA, particularly poly-JIA, and the relationship between n-6 and n-3 PUFA and classic markers of inflammation. PUFAs may contribute to the pathogenesis of JIA and support a necessity to identify new targets suitable for successful interventional studies in JIA patients.

Assessment of DHA on reducing early preterm birth: the ADORE randomized controlled trial protocol

BACKGROUND

Preterm birth contributes to 0.5 million deliveries in the United States (one of eight pregnancies) and poses a huge burden on public health with costs in the billions. Of particular concern is that the rate of earliest preterm birth (<34 weeks) (ePTB), which has decreased little since 1990 and has the greatest impact on the overall infant mortality, resulting in the greatest cost to society. Docosahexaenoic acid (DHA) supplementation provides a potential high yield, low risk strategy to reduce early preterm delivery in the US by up to 75%. We propose a Phase III Clinical Trial (randomized to low or high dose DHA, double-blinded) to examine the efficacy and safety of high dose DHA supplementation to reduce ePTB. We also plan for a secondary pregnancy efficacy analysis to determine if there is a subset of pregnancies most likely to benefit from DHA supplementation.

METHODS

Between 900 and 1200 pregnant women who are ≥ 18 years old and between 12 and 20 weeks gestation will be recruited from three trial experienced academic medical institutions. Participants will be randomly assigned to two daily capsules of algal oil (totaling 800 mg DHA) or soybean and corn oil (0 mg DHA). Both groups will receive a commercially available prenatal supplement containing 200 mg DHA. Therefore, the experimental group will receive 1000 mg DHA/d and the control group 200 mg DHA/d. We will then employ a novel Bayesian response adaptive randomization design that assigns more subjects to the "winning" group and potentially allows for substantially smaller sample size while providing a stronger conclusion regarding the most effective group. The study has an overall Type I error rate of 5% and a power of 90%. Participants are followed throughout pregnancy and delivery for safety and delivery outcomes.

DISCUSSION

We hypothesize that DHA will decrease the frequency of ePTB <34 weeks. Reducing ePTB is clinically important as these earliest preterm deliveries carry the highest risk of neonatal morbidity, as well as contribute significant stress for families and post a large societal burden.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov (identifier: NCT02626299 ) on December 8, 2015. Additional summary details may be found in Table 1.

Gas chromatography determination of fatty acids in the human erythrocyte membranes - A review

Blood fatty acid measurements can reflect exogenously consumed fatty acids allowing to resolve some metabolic disorders (e.g. diabetes, anorexia) or mental disorders (e.g. depression, anxiety, schizophrenia). For this purpose, fatty acids can be determined in the whole blood or various blood fractions such as the plasma, serum or erythrocytes. Measurement of fatty acids in the whole blood by dried blood spot technique is becoming increasingly popular and is often used mainly for the screening of newborns due to the use of the small sample volume. The most popular is determination of fatty acids in plasma or serum samples. While the profile of plasma fatty acids fluctuates based on daily dietary intake, the red blood cell membrane composition of fatty acids reflects the 2-3 month dietary intake. Such results can be more reflective in contrast to the plasma/serum and therefore the present review will summarize available information on gas chromatography determination of fatty acids in human red blood cell membranes. Selection of extraction and derivatization reagents as well as presentation of chromatographic conditions will be discussed here.

Validity of a food frequency questionnaire to estimate long-chain polyunsaturated fatty acid intake among Japanese women in early and late pregnancy

Background

The relative validity of food frequency questionnaires for estimating long-chain polyunsaturated fatty acid (LC-PUFA) intake among pregnant Japanese women is currently unclear. The aim of this study was to verify the external validity of a food frequency questionnaire, originally developed for non-pregnant adults, to assess the dietary intake of LC-PUFA using dietary records and serum phospholipid levels among Japanese women in early and late pregnancy.

Methods

A validation study involving 188 participants in early pregnancy and 169 participants in late pregnancy was conducted. Intake LC-PUFA was estimated using a food frequency questionnaire and evaluated using a 3-day dietary record and serum phospholipid concentrations in both early and late pregnancy.

Results

The food frequency questionnaire provided estimates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake with higher precision than dietary records in both early and late pregnancy. Significant correlations were observed for LC-PUFA intake estimated using dietary records in both early and late pregnancy, particularly for EPA and DHA (correlation coefficients ranged from 0.34 to 0.40, p < 0.0001). Similarly, high correlations for EPA and DHA in serum phospholipid composition were also observed in both early and late pregnancy (correlation coefficients ranged 0.27 to 0.34, p < 0.0001).

Conclusions

Our findings suggest that the food frequency questionnaire, which was originally designed for non-pregnant adults and was evaluated in this study against dietary records and biological markers, has good validity for assessing LC-PUFA intake, especially EPA and DHA intake, among Japanese women in early and late pregnancy.

Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults

Studies reporting blood levels of the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were systematically identified in order to create a global map identifying countries and regions with different blood levels. Included studies were those of healthy adults, published in 1980 or later. A total of 298 studies met all inclusion criteria. Studies reported fatty acids in various blood fractions including plasma total lipids (33%), plasma phospholipid (32%), erythrocytes (32%) and whole blood (3.0%). Fatty acid data from each blood fraction were converted to relative weight percentages (wt.%) and then assigned to one of four discrete ranges (high, moderate, low, very low) corresponding to wt.% EPA+DHA in erythrocyte equivalents. Regions with high EPA+DHA blood levels (>8%) included the Sea of Japan, Scandinavia, and areas with indigenous populations or populations not fully adapted to Westernized food habits. Very low blood levels (≤4%) were observed in North America, Central and South America, Europe, the Middle East, Southeast Asia, and Africa. The present review reveals considerable variability in blood levels of EPA+DHA and the very low to low range of blood EPA+DHA for most of the world may increase global risk for chronic disease.

The validity of a food frequency questionnaire as a measure of PUFA status in pregnancy

Background

Nutritional studies have found conflicting evidence regarding the ability of Food Frequency Questionnaires (FFQs) to demonstrate convergent validity with tissue content of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs). We therefore sought to assess the convergent validity of a FFQ strategy when compared with a blood biomarker of PUFA levels in a sample of pregnant women.

Method

A previously validated PUFA FFQ was completed by 895 pregnant women and compared to erythrocyte membrane of six PUFA variables.

Results

Four of the six correlations were found to be formally significant, however two of these demonstrated minimal associational strength. Moderate-high correlations between the FFQ-derived PUFA intake estimates and blood biomarker PUFA levels were shown only for eicosapentaenoic acid (EPA; 0.55) and docosahexaenoic acid (DHA; 0.61).

Conclusions

Overall, the correlations were lower than those found in general population studies. Findings suggest biological estimates, such as blood samples, may be most appropriate to measure PUFA levels above indirect strategies such as an FFQ in this population. The results, if an indirect strategy is unavoidable, indicate specific PUFAs where an FFQ strategy may be most informative.

Docosahexaenoic acid supplementation during pregnancy: a potential tool to prevent membrane rupture and preterm labor

Polyunsaturated fatty acids (PUFAs) are required to maintain the fluidity, permeability and integrity of cell membranes. Maternal dietary supplementation with ω-3 PUFAs during pregnancy has beneficial effects, including increased gestational length and reduced risk of pregnancy complications. Significant amounts of ω-3 docosahexaenoic acid (DHA) are transferred from maternal to fetal blood, hence ensuring high levels of DHA in the placenta and fetal bloodstream and tissues. Fetal DHA demand increases exponentially with gestational age, especially in the third trimester, due to fetal development. According to the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO), a daily intake of DHA is recommended during pregnancy. Omega-3 PUFAs are involved in several anti-inflammatory, pro-resolving and anti-oxidative pathways. Several placental disorders, such as intrauterine growth restriction, premature rupture of membranes (PROM) and preterm-PROM (pPROM), are associated with placental inflammation and oxidative stress. This pilot study reports on a preliminary evaluation of the significance of the daily DHA administration on PROM and pPROM events in healthy pregnant women. Further extensive clinical trials will be necessary to fully elucidate the correlation between DHA administration during pregnancy and PROM/pPROM occurrence, which is related in turn to gestational duration and overall fetal health.

Validity of the Willett food frequency questionnaire in assessing the iron intake of French-Canadian pregnant women

OBJECTIVE

Maternal intake is crucial to pregnancy outcomes. Evidence shows that both nutrient deficiency and excess can have adverse effects. In pregnancy, changes in iron metabolism occur; therefore, dietary reference intakes increase to support expansion of red cells and maternal-fetal transfer of iron. Appropriate and valid assessment tools are required to investigate nutritional concerns in mothers with and without gestational diabetes mellitus (GDM). The objective of this study was to assess the Willett food frequency questionnaire (FFQ) to assess iron intake in women with (n = 15) and without (n = 45) GDM.

METHODS

To validate the modified FFQ, estimated total iron intake during the third trimester was compared with biomarkers of iron status such as serum ferritin, soluble transferrin receptor (sTfR), and the sTfR:F index at delivery. Data were tested for normality using the D'Agostino-Pearson test. Differences between groups were tested using t tests or Mann-Whitney tests. Correlations were tested using Spearman's ρ. Significance was set at P < 0.05.

RESULTS

Significant crude and energy-adjusted serum ferritin and total iron intake were related (ρ = 0.30; P < 0.05) in women without GDM. Serum ferritin, sTfR, and the sTfR:F index were different (P < 0.05) between women with intakes above and below the recommended levels. Cross-classification showed agreement between methods in mothers with and without GDM; on average, 63% of the women were classified into the same or adjacent quartile when ranked by FFQ and iron status.

CONCLUSION

These findings suggest the Willett FFQ is a good tool for assessing total iron intake of French-Canadian pregnant women.

A prospective study of maternal fatty acids, micronutrients and homocysteine and their association with birth outcome

Our earlier studies both in animals and in humans have indicated that micronutrients (folic acid, vitamin B12) and long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), are interlinked in the one-carbon cycle, which plays an important role in fetal 'programming' of adult diseases. The present study examines the levels of maternal and cord plasma fatty acids, maternal folate, vitamin B12 and homocysteine in healthy mothers at various time points during pregnancy and also examine an association between them. A longitudinal study of 106 normal pregnant women was carried out, and maternal blood was collected at three time points, viz., T1 = 16-20th week, T2 = 26-30th week and T3 = at delivery. Cord blood was collected at delivery. Fatty acids were estimated using a gas chromatograph. Levels of folate, vitamin B12 and homocysteine were estimated by the chemiluminescent microparticle immunoassay (CMIA) technology. Maternal plasma folate (P < 0.05), vitamin B12 (P < 0.01) and DHA (P < 0.05) levels were lowest, while maternal homocysteine levels were highest (P < 0.01) at T3. There was a negative association between maternal DHA and homocysteine at T2 (P < 0.05) and T3 (P < 0.01). There was a positive association between plasma DHA in maternal blood at T3 and cord blood. Furthermore, there was a positive association between maternal folate and vitamin B12 at T3 and baby weight, whereas maternal homocysteine at T1 were inversely associated with baby weight at delivery. Our study provides evidence for the associations of folic acid, vitamin B12, homocysteine with DHA and baby weight, suggesting that a balanced dietary supplementation of folate-vitamin B12-DHA during pregnancy may be beneficial.

Dietary intakes of women during pregnancy in low- and middle-income countries

OBJECTIVE

To provide a better understanding of dietary intakes of pregnant women in low- and middle-income countries.

DESIGN

Systematic review was performed to identify relevant studies which reported nutrient intakes or food consumption of pregnant women in developing countries. Macronutrient and micronutrient intakes were compared by region and the FAO/WHO Estimated Average Requirements. Food consumption was summarized by region.

SETTING

Developing countries in Africa, Asia, and the Caribbean and Central/South America.

SUBJECTS

Pregnant women in the second or third trimester of their pregnancies.

RESULTS

From a total of 1499 retrieved articles, sixty-two relevant studies were analysed. The ranges of mean/median intakes of energy, fat, protein and carbohydrate were relatively higher in women residing in the Caribbean and Central/South America than in Africa and Asia. Percentages of energy from carbohydrate and fat varied inversely across studies in all regions, whereas percentage of energy from protein was relatively stable. Among selected micronutrients, folate and Fe intakes were most frequently below the Estimated Average Requirements, followed by Ca and Zn. Usual dietary patterns were heavily cereal based across regions.

CONCLUSIONS

Imbalanced macronutrients, inadequate micronutrient intakes and predominantly plant-based diets were common features of the diet of pregnant women in developing countries. Cohesive public health efforts involving improving access to nutrient-rich local foods, micronutrient supplementation and fortification are needed to improve the nutrition of pregnant women in developing countries.

Validation of a FFQ for estimating ω-3, ω-6 and trans fatty acid intake during pregnancy using mature breast milk and food recalls

BACKGROUND/OBJECTIVES

To assess the performance of a food frequency questionnaire (FFQ) for estimating ω-3, ω-6 and trans fatty acid intake during pregnancy. Moreover, we determined whether the fatty acid composition of mature breast milk represents a valuable biomarker for fatty acid intake during pregnancy.

SUBJECTS/METHODS

A prospective study in 41 pregnant women, aged 18-35 years, was conducted. Food intake during pregnancy was evaluated by three 24-h recalls (24 hR), and 2 FFQ. The fatty acid composition of mature breast milk was determined by gas chromatography. The method of triads and joint classification between quartiles of intake were applied.

RESULTS

The FFQ was accurate for estimating docosahexanoic (DHA), linoleic and total ω-6 fatty acids according to validity coefficients. Higher agreements (>70%) into the same or adjacent quartiles between the dietary methods were found for α-linolenic, total ω-3, linoleic and trans fatty acid intake. High validity coefficients for eicosapentanoic (EPA) and DHA acids of human milk were found (0.61 and 0.73, respectively), and the method was adequate for categorizing the intake of α-linolenic, total ω-3 and trans fatty acids compared with FFQ estimates, and for arachidonic acid and trans fatty acids compared with food recall estimates, during pregnancy.

CONCLUSIONS

The FFQ was an accurate tool for categorizing α-linolenic, total ω-3 and trans fatty acid intake. According to the validity coefficients observed, the FFQ accurately estimated DHA, linoleic and total ω-6 fatty acids and the composition of mature breast milk was shown to be a suitable biomarker for EPA and DHA fatty acid intake during pregnancy.

Dietary assessment methods for micronutrient intake in pregnant women: a systematic review

The EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence needs clear guidelines for assessing the validity of reported micronutrient intakes among vulnerable population groups. A systematic literature search identified studies validating the methodology used for measuring usual dietary intake during pregnancy. The quality of each validation study selected was assessed using a EURRECA-developed scoring system. The validation studies were categorised according to whether the study used a reference method that reflected short-term intake ( < 7 d) long-term intake ( > or = 7 d) or used biomarkers (BM). A correlation coefficient for each micronutrient was calculated from the mean of the correlation coefficients from each study weighted by the quality of the study. Seventeen papers were selected, which included the validation of fifteen FFQ, two dietary records (DR), one diet history and a Fe intake checklist. Estimates of twenty-six micronutrients by six FFQ were validated against 24-h recalls indicating good correlation for six micronutrients. Estimates of twenty-four micronutrients by two FFQ were validated against estimated DR and all had good or acceptable correlations. Estimates of fourteen micronutrients by three FFQ were validated against weighed DR indicating good correlations for five. Six FFQ were validated against BM, presenting good correlations only for folic acid. FFQ appear to be most reliable for measuring short-term intakes of vitamins E and B6 and long-term intakes of thiamin. Apart from folic acid, BM do not add any more certainty in terms of intake method reliability. When frequency methods are used, the inclusion of dietary supplements improves their reliability for most micronutrients.

Omega-3 fatty acids status in human subjects estimated using a food frequency questionnaire and plasma phospholipids levels

BACKGROUND

Intakes of omega-3 (n-3) fatty acids (FA) are associated with several health benefits. The aim of this study was to verify whether intakes of n-3 FA estimated from a food frequency questionnaire (FFQ) correlate with n-3 FA levels measured in plasma phospholipids (PL).

METHODS

The study sample consisted of 200 French-Canadians men and women aged between 18 to 55 years. Dietary data were collected using a validated FFQ. Fasting blood samples were collected and the plasma PL FA profile was measured by gas chromatography.

RESULTS

Low intakes of n-3 long-chain FA together with low percentages of n-3 long-chain FA in plasma PL were found in French-Canadian population. Daily intakes of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were similar between men and women. Yet, alpha-linolenic acid (ALA) and total n-3 FA intakes were significantly higher in men compared to women (ALA: 2.28 g and 1.69 g, p < 0.0001, total n-3 FA: 2.57 g and 1.99 g, p < 0.0001; respectively). In plasma PL, DPA and DHA percentages were significantly different between men and women (DPA: 1.03% and 0.88%, p < 0.0001, DHA: 3.00% and 3.43%, p = 0.0005; respectively). Moreover, DHA (men: r = 0.52, p < 0.0001; women: r = 0.57, p < 0.0001) and total n-3 FA (men: r = 0.47, p < 0.0001; women: r = 0.52, p < 0.0001) intakes were positively correlated to their respective plasma PL FA levels. In women, EPA (r = 0.44, p < 0.0001) and DPA (r = 0.23, p = 0.02) intakes were also correlated respectively with EPA and DPA plasma PL FA percentages.

CONCLUSION

Estimated n-3 long-chain FA intake among this young and well-educated French-Canadian population is lower than the recommendations. Further, FFQ data is comparable to plasma PL results to estimate DHA and total n-3 FA status in healthy individuals as well as to evaluate the EPA and DPA status in women. Overall, this FFQ could be used as a simple, low-cost tool in future studies to rank n-3 FA status of individuals.

Omega 3 fatty acids, gestation and pregnancy outcomes

Pregnancy is associated with a reduction in maternal serum docosahexaenoic acid (DHA, 22:6 n-3) percentage and its possible depletion in the maternal store. Since the synthesis of long chain polyunsaturated fatty acids (LCPUFA) in the fetus and placenta is low, both the maternal LCPUFA status and placental function are critical for their supply to the fetus. Maternal supplementation with DHA up to 1 g/d or 2·7 g n-3 LCPUFA did not have any harmful effect. DHA supplementation in large studies slightly the enhanced length of gestation (by about 2 days), which may increase the birth weight by about 50 g at delivery. However no advice can be given on their general using to avoid preterm deliveries in low or high risk pregnancies. Several studies, but not all, reported improvements of the offspring in some neurodevelopmental tests as a result of DHA supplementation during gestation, or, at least, positive relationships between maternal or cord serum DHA percentages and cognitive skills in young children. The effect seems more evident in children with low DHA proportions, which raises the question of how to identify those mothers who might have a poor DHA status and who could benefit from such supplementation. Most studies on the effects of n-3 LCPUFA supplementation during pregnancy on maternal depression were judged to be of low-to-moderate quality, mainly due to small sample sizes and failure to adhere to Consolidated Standards of Reporting Trials guidelines. In contrast, the effects of n-3 LCPUFA supplementation on reducing allergic diseases in offspring are promising.

A comparative validation of a child food frequency questionnaire using red blood cell membrane fatty acids

BACKGROUND/OBJECTIVES

There are limited validated tools available for the assessment of dietary intake in pediatric populations. This report describes a comparative validation study of selected fatty acid intakes in children assessed by food frequency questionnaire (FFQ), compared with erythrocyte membrane fatty acids.

SUBJECTS/METHODS

Overall, 46 overweight and 47 healthy-weight children aged 5-12 years (mean±SD, 9.1±1.3years, body mass index 20.5±4.0) were recruited; dietary fatty acid intakes assessed by parent report using a 135-item semi-quantitative FFQ, were compared with selected child erythrocyte membrane fatty acids assessed from fasting samples using gas chromatography. Spearman's rank correlation coefficients were calculated between fatty acid intake estimates (% of energy) and erythrocyte membrane concentrations (%mol/mol).

RESULTS

Significant correlations were found between dietary and erythrocyte eicosapentanoic acid (EPA) concentration (r=0.24, P<0.05) with a statistical trend for total omega three (∑n-3) fatty acids (r=0.22, P=0.06) and linoleic acid (r=0.32, P=0.07) in the healthy-weight children only.

CONCLUSION

Parental report of selected child fatty acid intakes using an FFQ can be used to provide an estimate of child intake of EPA, but further work is required to quantify this relationship for other fatty acids and in other populations.

Inverse association between trans isomeric and long-chain polyunsaturated fatty acids in pregnant women and their newborns: data from three European countries

BACKGROUND

trans unsaturated fatty acids are thought to interfere with essential fatty acid metabolism. To extend our knowledge of this phenomenon, we investigated the relationship between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFA) in mothers during pregnancy and in their infants at birth.

METHODS

Fatty acid composition of erythrocyte phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was determined in Spanish (n = 120), German (n = 78) and Hungarian (n = 43) women at the 20th and 30th week of gestation, at delivery and in their newborns.

RESULTS

At the 20th week of gestation, the sum of trans fatty acids in PE was significantly (p < 0.01) lower in Hungarian [0.73 (0.51), % wt/wt, median (IQR)] than in Spanish [1.42 (1.36)] and German [1.30 (1.21)] women. Docosahexaenoic acid (DHA) values in PE were significantly (p < 0.01) higher in Hungarian [5.65 (2.09)] than in Spanish [4.37 (2.60)] or German [4.39 (3.3.2)] women. The sum of trans fatty acids significantly inversely correlated to DHA in PCs in Spanish (r = -0.37, p < 0.001), German (n = -0.77, p < 0.001) and Hungarian (r = -0.35, p < 0.05) women, and in PEs in Spanish (r = -0.67, p < 0.001) and German (r = -0.71, p < 0.001), but not in Hungarian (r = -0.02) women. Significant inverse correlations were seen between trans fatty acids and DHA in PEs at the 30th week of gestation (n = 241, r = -0.52, p < 0.001), at delivery (n = 241, r = -0.40, p < 0.001) and in cord lipids (n = 218, r = -0.28, p < 0.001).

CONCLUSION

Because humans cannot synthesize trans isomeric fatty acids, the data obtained in the present study support the concept that high maternal trans isomeric fatty acid intake may interfere with the availability of LCPUFA both for the mother and the fetus.

Dietary intakes of polyunsaturated fatty acids among pregnant Mexican women

Nutritional demands for docosahexaenoic acid (DHA) are high during pregnancy. Diets low in DHA and long-chain polyunsaturated fatty-acids (LC-PUFA) in pregnancy are associated with poorer DHA status and slower reestablishment of maternal stores. To assess intakes of LC-PUFA among urban pregnant women in Central Mexico, we conducted a cross-sectional survey in Prenatal Clinic at the General Hospital No. 1 of the Mexican Society Security Institute, Cuernavaca, Morelos, Mexico. We ascertained intakes over past three months of 110 food items using a food frequency questionnaire developed for this population. Among 1364 pregnant women 18-35 years of age (mean age 26.2 ± 4.7 years) who were interviewed at 18-22 weeks gestation, median (inter-quartile range) daily intakes of linoleic acid, alpha-linolenic acid (LA), arachidonic acid, eicosapentaenoic acid and DHA were 17.6 (13.6; 22.2) g, 1.4 (1.0; 2.0) g, 137 (102; 174) mg, 18 (10; 38) mg, and 55 (37; 99) mg respectively. The median ratio of n-6 to n-3 PUFA was 11.8:1. The main dietary contributions to DHA intake were eggs, chicken, and fresh canned fish. Intakes of PUFAs were higher among women who had completed high school (p<0.01). We conclude that intakes of DHA were much lower than recommended values; the high n-6 to n-3 ratio suggests a suboptimal balance of these PUFAs. Very few sources of DHA are commonly eaten.

Docosahexaenoic acid supplementation from mid-pregnancy to parturition influenced breast milk fatty acid concentrations at 1 month postpartum in Mexican women

(n-3) PUFA, including DHA, are essential for neural development and accumulate extensively in the fetal and infant brain. (n-3) PUFA concentrations in breast milk, which are largely dependent on maternal diet and tissue stores, are correlated with infant PUFA status. We investigated the effect of prenatal DHA supplementation on PUFA concentrations in breast milk at 1 mo postpartum. In a double-blind, randomized, controlled trial conducted in Mexico, pregnant women were supplemented daily with 400 mg DHA or placebo from 18-22 wk gestation to parturition. Fatty acid concentrations in breast milk obtained from 174 women at 1 mo postpartum were determined using GLC and were expressed as % by weight of total detected fatty acids. Breast milk DHA concentrations in the DHA and placebo groups were (mean ± SD) 0.20 ± 0.06 and 0.17 ± 0.07 (P < 0.01), respectively, and those of α-linolenic acid (ALA) were 1.38 ± 0.47 and 1.24 ± 0.46 (P = 0.01), respectively. Concentrations of EPA and arachidonic acid did not differ between groups (P > 0.05). Maternal plasma DHA concentrations at 1 mo postpartum correlated positively with breast milk DHA at 1 mo postpartum in both the placebo and DHA groups (r = 0.4; P < 0.01 for both treatment groups). Prenatal DHA supplementation from 18-22 wk gestation to parturition increased concentrations of DHA and ALA in breast milk at 1 mo postpartum, providing a mechanism through which breast-fed infants could benefit.

Validation of a food frequency questionnaire to assess intake of n-3 polyunsaturated fatty acids in subjects with and without major depressive disorder

The role of n-3 polyunsaturated fatty acids (PUFAs) in psychiatric illness is a topic of public health importance. This report describes development and biomarker validation of a 21-item, self-report food frequency questionnaire (FFQ) intended for use in psychiatric research to assess intake of α-linolenic acid (18:3n-3 [ALA]), docosahexaenoic acid (22:6n-3 [DHA]), and eicosapentaenoic acid (20:5n-3 [EPA]). In a cross-sectional study conducted from September 2006 to September 2008, sixty-one ethnically diverse adult participants with (n=34) and without (n=27) major depressive disorder completed this n-3 PUFA FFQ and provided a plasma sample. Plasma levels of n-3 PUFAs EPA and DHA, and n-6 PUFA arachidonic acid (20:4n-6 [AA]) were quantified by gas chromatography. Using Spearman's ρ, FFQ-estimated intake correlated with plasma levels of DHA (r=0.50; P<0.0001) and EPA (r=0.38; P=0.002), but not with ALA levels (r=0.22; P=0.086). Participants were classified into quartiles by FFQ-estimated intake and plasma PUFA concentrations. Efficacy of the FFQ to rank individuals into same or adjacent plasma quartiles was 83% for DHA, 78.1% for EPA, and 70.6% for ALA; misclassification into extreme quartiles was 4.9% for DHA, 6.5% for EPA, and 8.2% for ALA. FFQ-estimated EPA intake and plasma EPA were superior to plasma AA levels as predictors of the plasma AA to EPA ratio. This brief FFQ can provide researchers and clinicians with valuable information concerning dietary intake of DHA and EPA.

Omega-3 index, obesity and insulin resistance in children

OBJECTIVES

Recent studies in adults have suggested that the plasma level of omega-3 fatty acids may be associated with weight status and abdominal adiposity, limited studies exist in paediatric populations. The present study examined the relationship between the omega-3 index, weight status and insulin resistance in children.

METHODS

School-age children between 5-12 years, classified as non-obese or obese on the basis of body mass index (BMI) z-scores, were examined. Fat intake was assessed using a parent reported 135-item semi-quantitative food frequency questionnaire. Erythrocyte fatty acid composition was determined using gas chromatography. The Omega-3 index (O3I) was calculated by adding eicosapentaenoic and docosahexaenoic acid % (weight/weight) values.

RESULTS

Obese children had altered erythrocyte fatty acid composition unrelated to reported dietary intake. A greater proportion of obese (BMI z-score > 2.25) children (33%) had an omega-3 index of < 4.0 (high risk) compared with non-obese children (BMI z-score < 2.25) (17%). Simultaneously, the number of children with a higher omega-3 index (6.0-8.0 lower risk) was lower in the obese (13%) versus non-obese children (25%, respectively). A moderate, but statistically significant correlation was found between O3I and fasting insulin level (r = -0.3, P = 0.03) and with homeostatic model assessment (HOMA) scores (r = -0.3, P = 0.04). CONCLUSION; The observed association between the omega-3 index, weight status and insulin resistance in children highlights the importance of omega-3 fatty acids in the prevention of obesity-related chronic diseases in later life. The results presented merits confirmation in a larger sample of obese children.

Long chain omega 3 polyunsaturated fatty acids supplementation in the treatment of elderly depression: effects on depressive symptoms, on phospholipids fatty acids profile and on health-related quality of life

OBJECTIVE

Recent observations showed that long chain omega 3 polyunsaturated fatty acids (n-3 LCPUFA) could represent a potential treatment for elderly depression. To determine if a n-3 LCPUFA containing supplement improves depressive symptoms, changes phospholipids acids profile and ameliorates Health related quality of life (HRQoL) in depressed elderly patients.

DESIGN

Two-months, randomized, double-blind, placebo-controlled trial.

SETTING

Nursing home in Pavia, Italy.

SUBJECTS

Forty-six depressed females, aged 66-95 years.

INTERVENTION

22 depressed females were included in the intervention group (n-3 group, that received 2.5 g/day of n-3 LCPUFA, with 1.67 grams of EPA and 0.83 grams of DHA), and 24 patients in the placebo group. The primary endpoint was the improvement of depressive symptoms as evaluated by Geriatric Depression Scale (GDS). Secondary endpoints were the evaluation of modifications of erythrocyte membrane phospholipids fatty acid profile and of of HRQoL, by using the Short-Form 36-Item Health Survey (SF-36). All parameters were assessed before and after the treatment period of 8 weeks.

RESULTS

The mean GDS at 2 months was significantly lowered only for the n-3 group. SF-36 physical and mental components were significantly increased in the intervention group. Compliance was good, as confirmed by erythrocyte membrane phospholipid FA concentrations, with significant increase of EPA and DHA in the intervention group.

CONCLUSION

The supplementation of n-3 LCPUFA in elderly female patients reduces the occurrence of depressive symptoms, improves phospholipids fatty acids profile and health-related quality of life.

Validity and reproducibility of a semi-quantitative food frequency questionnaire for use among Portuguese pregnant women

This study aimed to evaluate the validity and reproducibility of a semi-quantitative food frequency questionnaire (FFQ) to estimate nutrient intake among Portuguese pregnant women. A sample of 101 pregnant women completed a 3-day food diary (FD) in each pregnancy trimester (reference method) and an interviewer-administered FFQ in the immediate post-partum period. Ranking women according to their usual intake showed that, on average, 65% were classified into the same +/-1 quintile and 2.4% into opposite quintiles by the two methods. Energy-adjusted and de-attenuated correlation coefficients ranged from 0.20 (protein) to 0.58 (riboflavin). Similar results were obtained when the FFQ was compared to each trimester-specific FD. To assess the FFQ reproducibility, 70 women in their third pregnancy trimester were interviewed twice within a 2-week interval. The level of agreement was high, with > or = 75% of the participants being classified into the same +/-1 quintile by the two administrations for 13 of the 15 nutrients examined. A review of the published literature revealed that this is the first FFQ to take the whole pregnancy as its reference time window. Our findings showed that a single administration of this FFQ in the immediate post-partum period is a valid tool to rank Portuguese pregnant women according to their intakes.

Effects of Docosahexaenoic Acid Supplementation During Pregnancy on Gestational Age and Size at Birth: Randomized, Double-Blind, Placebo-Controlled Trial in Mexico

Background

The need for omega-3 fatty acids, especially docosahexaenoic acid (DHA), during pregnancy has received much attention, but evidence of effects on birth outcomes is limited.

Objective

To evaluate whether prenatal DHA supplementation increases gestational age and birth size.

Methods

We conducted a double-blind, randomized, placebo-controlled trial in Cuernavaca, Mexico. We randomly assigned 1,094 pregnant women (18 to 35 years of age; median DHA dietary intake, 55 mg/day) to 400 mg/day of algal DHA or placebo from 18 to 22 weeks of gestation through delivery. Birth outcomes (968 live births and 5 stillbirths) were ascertained from hospital records within 24 hours of delivery.

Results

Intention-to-treat analysis showed no differences between the control and DHA group (all p > .05) in mean gestational age (39.1 + 1.7 and 39.0 ± 1.9 weeks, respectively), weight (3.20 + 0.47 and 3.21 ± 0.45 kg, respectively), length (50.3 ± 2.7 and 50.3 ± 2.3 cm, respectively) and head circumference (34.3 ± 1.8 and 34.3 ± 1.5 cm, respectively) at birth. Offspring of supplemented primigravidae (n = 370) were heavier (difference, 99.4 g; 95% CI, 5.5 to 193.4) and had larger head circumferences (difference, 0.5 cm; 95% CI, 0.1 to 0.9) than controls; the differences in multigravidae (n = 603) were −53.3 g (95% CI, −126.8 to 20.2) and −0.2 cm (95% CI, −0.4 to 0.1), respectively (p < .05 for heterogeneity).

Conclusions

Prenatal DHA supplementation of primigravid women may result in increased birth size in a population where dietary DHA intakes are very low. Benefits of the intervention on infant health and neurodevelopment are under study.

Validation of an FFQ for evaluation of EPA and DHA intake

Objective

To validate an FFQ for the assessment of dietary EPA and DHA against their relative concentrations in red blood cells (RBC).

Design

Cross-sectional analysis of baseline data. Intakes of marine food products and EPA and DHA were estimated by FFQ on the basis of consumption of marine food products in the last month. Fatty acid composition of RBC membranes was quantified by GC.

Setting

Saint-François d’Assise Hospital, Québec, Canada.

Subjects

A total of sixty-five middle-aged women who participated in a randomized clinical trial.

Results

Spearman’s correlation coefficient between intake of EPA, DHA and EPA + DHA and their corresponding concentration in RBC was 0·46, 0·40 and 0·42, respectively (allP< 0·05). Multiple regression analysis of EPA+DHA intake and RBC EPA + DHA concentration indicated positive and significant correlations for oily fish (β= 0·44, 95 % CI 0·16, 0·72,P= 0·0027), total fish (β= 0·42, 95 % CI 0·19, 0·64,P= 0·0005) and marine food products (β= 0·42, 95 % CI 0·20, 0·64,P= 0·0003). No other marine food products significantly predicted RBC EPA + DHA concentration.

Conclusions

Although the present validation study was undertaken among middle-aged women with low consumption of marine food products (<3 servings/week), our FFQ provided estimates of EPA and DHA intakes that correlated fairly well with their RBC concentrations. However, the absence of correlations between EPA + DHA intakes from different marine species suggests that a minimum EPA + DHA intake is necessary to observe a relationship with RBC EPA + DHA concentrations.

Evidence of inadequate docosahexaenoic acid status in Brazilian pregnant and lactating women

Recently published data concerning dietary intake of fat and food sources of (n-3) long-chain polyunsaturated fatty acids (LCPUFA) in Brazil are reviewed together with data on biochemical indices of PUFA status during pregnancy and lactation and PUFA composition of breast milk in Brazilian adolescents and adults. Potential inadequacies of docosahexaenoic acid (DHA) status among Brazilian pregnant and lactating women have not yet been thoroughly evaluated. The data reviewed show that dietary intake of food sources of n-3 LCPUFA is low and possibly deficient in Brazil, and that biochemical indices of maternal DHA status and breast milk DHA content are low compared to the international literature. These data indicate inadequate DHA status among Brazilian women during pregnancy and lactation, but this evidence needs confirmation through comprehensive and specific population-based studies.

Exploration of biomarkers for total fish intake in pregnant Norwegian women

OBJECTIVE

Few biomarkers for dietary intake of various food groups have been established. The aim of the present study was to explore whether selenium (Se), iodine, mercury (Hg) or arsenic may serve as a biomarker for total fish and seafood intake in addition to the traditionally used n-3 fatty acids EPA and DHA.

DESIGN

Intake of fish and seafood estimated by an FFQ was compared with intake assessed by a 4 d weighed food diary and with biomarkers in blood and urine.

SETTING

Validation study in the Norwegian Mother and Child Cohort Study (MoBa).

SUBJECTS

One hundred and nineteen women.

RESULTS

Total fish/seafood intake (median 39 g/d) calculated with the MoBa FFQ was comparable to intake calculated by the food diary (median 30 g/d, rS = 0.37, P < 0.001). Erythrocyte DHA and blood Hg, Se and arsenic concentrations were positively correlated with intake of fish and seafood, but the association for DHA was weakened by the widespread use of supplements. The main finding was the consistent positive association between the intake of fish/seafood and blood arsenic concentration. In multivariate analyses, blood arsenic was associated with blood Hg and fish and seafood intake. In these models, arsenic turned out to be the best indicator of intake of fish and seafood, both totally and in subgroups of fish/seafood intake.

CONCLUSIONS

While DHA reflected the intake of fatty fish and n-3 PUFA supplements, blood arsenic concentration also reflected the intake of lean fish and seafood. Blood arsenic appears to be a useful biomarker for total fish and seafood intake.

Associations of maternal prenatal dietary intake of n-3 and n-6 fatty acids with maternal and umbilical cord blood levels

Maternal n-3 and n-6 polyunsaturated fatty acid (PUFA) status may influence birth outcomes and child health. We assessed second trimester maternal diet with food frequency questionnaires (FFQs) (n=1666), mid-pregnancy maternal erythrocyte PUFA concentrations (n=1550), and umbilical cord plasma PUFA concentrations (n=449). Mean (SD) maternal intake of total n-3 PUFA was 1.17 g/d (0.43), docosahexaenoic and eicosapentaenoic acids (DHA+EPA) 0.16 g/d (0.17), and total n-6 PUFA 12.25 g/d (3.25). Mean maternal erythrocyte and cord plasma PUFA concentrations were 7.0% and 5.2% (total n-3), 5.0% and 4.6% (DHA+EPA), and 27.9% and 31.4% (total n-6). Mid-pregnancy diet-blood and blood-blood correlations were strongest for DHA+EPA (r=0.38 for diet with maternal blood, r=0.34 for diet with cord blood, r=0.36 for maternal blood with cord blood), and less strong for n-6 PUFA. The FFQ is a reliable measure of elongated PUFA intake, although inter-individual variation is present.

Erythrocyte membrane and plasma non-esterified n-3 and n-6 polyunsaturated fatty acids of pregnant and non-pregnant Brazilian adolescents

The aim of the present study was to evaluate the influence of pregnancy in adolescents on the fatty acid composition of the erythrocyte membrane, which was used as a proxy for status of n-3 and n-6 polyunsaturated fatty acids (PUFA), and also on the composition of plasma non-esterified fatty acids (NEFA) mobilized from the adipose tissue. Two matched groups of healthy adolescents (14-19 years) from Rio de Janeiro, Brazil, were compared: pregnant (n=26; 32.7+/-3.9 weeks of gestation, mean+/-SD) and non-pregnant (n=20). Blood samples were collected after an overnight fast. Mean dietary intakes of total fat and n-3 and n-6 PUFA (energy %) were not different between pregnant and non-pregnant adolescents, and the consumption of food sources of docosahexaenoic acid (DHA) was low. Fasting total NEFA and NEFA 18:2n-6, 18:3n-6 and 20:4n-6 (g/100g fatty acids) were higher in pregnant than in non-pregnant adolescents. Although erythrocyte 20:4n-6 was lower in pregnant adolescents, there were no differences in DHA (g/100g fatty acids), in DHA status indices (22:5n-6/22:4n-6 and 22:6n-3/22:5n-6 ratios) and in the index of n-3+n-6 PUFA status ([Sigman-3+Sigman-6]/[Sigman-7+Sigman-9]) in erythrocytes as compared with those of non-pregnant adolescents. In conclusion, pregnancy did not have an adverse effect on erythrocyte DHA content or on DHA and n-3+n-6 PUFA status indices in the adolescents studied.

Evaluation of relative intake of fatty acids according to the Northern Sweden FFQ with fatty acid levels in erythrocyte membranes as biomarkers

OBJECTIVE

To evaluate the validity of the Northern Sweden eighty-four-item FFQ to estimate intake of fatty acids relative to 24 h diet recalls (24-HDR) and fatty acids in erythrocyte membranes.

DESIGN

Participants, randomly recruited from the population-based Västerbotten Intervention Project, answered the eighty-four-item FFQ. During the following year each participant carried out ten 24-HDR. Intake of fatty acids measured by the FFQ was compared with intake by the 24-HDR and fatty acid levels in erythrocytes.

SETTING

The county of Västerbotten in northern Sweden.

SUBJECTS

Ninety-six men and ninety-nine women.

RESULTS

Spearman correlation coefficients (rs) between intakes of the fatty acids 14 : 0, 15 : 0, 16 : 0, 17 : 0, 18 : 2n-6, 18 : 3n-3, 20 : 5n-3 and 22 : 6n-3 estimated by the FFQ and the 24-HDR were all significant and ranged from 0.29 (22 : 6n-3 in men and women) to 0.60 (16 : 0 in men), whereas significant correlations between FFQ-estimated intake and erythrocyte membrane content were only seen for milk fatty acids 14 : 0, 15 : 0 and 17 : 0 (rs = 0.23-0.34) and fish fatty acids 20 : 5n-3 and 22 : 6n-3 (rs = 0.42-0.51).

CONCLUSION

The Northern Sweden eighty-four-item FFQ gives a satisfactory estimate of the intake of fish fatty acids (20 : 5n-3 and 22 : 6n-3) and milk fatty acids (15 : 0 and 17 : 0), whereas its validity for fatty acids 18 : 2n-6 and 18 : 3n-3, derived mainly from vegetable oils, cannot be shown.

Methodological challenges when monitoring the diet of pregnant women in a large study: experiences from the Norwegian Mother and Child Cohort Study (MoBa)

The aim of this article is to describe the main methodological challenges in the monitoring of dietary intake in the Norwegian Mother and Child Cohort Study (MoBa), a pregnancy cohort aiming to include 100 000 participants. The overall challenge was to record dietary patterns in sufficient detail to support future testing of a broad range of hypotheses, while at the same time limiting the burden on the participants. The main questions to be answered were: which dietary method to choose, when in pregnancy to ask, which time period should the questions cover, which diet questions to include, how to perform a validation study, and how to handle uncertainties in the reporting. Our decisions were as follows: using a semi-quantitative food frequency questionnaire (FFQ) (in use from 1 March 2002), letting the participants answer in mid-pregnancy, and asking the mother what she has eaten since she became pregnant. The questions make it possible to estimate intake of food supplements, antioxidants and environmental contaminants in the future. Misreporting is handled by consistency checks. Reports with a calculated daily energy intake of <4.5 and >20 MJ day(-1) are excluded, about 1% in each end of the scale. A validation study confirmed that the included intakes are realistic. The outcome of our methodological choices indicates that our FFQ strikes a reasonable balance between conflicting methodological and scientific interests, and that our approach therefore may be of use to others planning to monitor diet in pregnancy cohorts.

Essential and long-chain polyunsaturated fatty acid status and fatty acid composition of breast milk of lactating adolescents

The aims of the present study were to evaluate essential fatty acids (EFA) and long-chain PUFA (LCPUFA) status in lactating adolescents and its association with breast milk composition. Healthy nursing adolescents from Rio de Janeiro, Brazil (n 30; 14-19 years; 30-120 d postpartum), exclusively or predominantly breast-feeding, participated in this study. Breast milk and blood samples were collected after overnight fasting. Fatty acid composition of breast milk, erythrocyte membrane (EM) and plasma NEFA were determined by GC. Indices of fatty acid status (mean melting point (MMP); EFA status index; DHA status indices, 22 : 5n-6:22 : 4n-6 and 22 : 6n-3:22 : 5n-6 ratios) were calculated from EM fatty acid composition. Dietary intake of n-3 fatty acids was low when compared with current recommendations for lactating women. MMP was associated with indices of DHA status, some individual fatty acids in EM and years post-menarche and weeks postpartum, suggesting the use of erythrocyte MMP as a possible comprehensive biochemical marker of LCPUFA status in this physiological condition. The DHA status of lactating adolescents and their milk DHA concentrations were similar to the values of Brazilian lactating adults, but lower compared with the values of lactating adults from other countries. Therefore, these lactating adolescents were apparently not disadvantaged, as compared with the Brazilian adults, when EM and breast milk fatty acid composition were considered. In general, PUFA in milk from adolescents presented few associations with their concentrations in plasma NEFA and with maternal status. However, milk DHA was associated with maternal LCPUFA and DHA states.

Do aggregates of multiple questions better capture overall fish consumption than summary questions?

Objective

To compare intake estimates, validity and reliability of two summary questions to measure fish consumption with information from a detailed semi-quantitative food-frequency questionnaire (FFQ) on fish consumption.

Design

Population-based, cross-sectional study. Participants completed an FFQ and provided blood samples for erythrocyte membrane eicosapentaenoic acid (EPA) analysis. Aggregate measures of consumption of fresh/frozen/canned fish (fresh fish) and smoked/salted/dried fish (preserved fish) were generated from the FFQ and were compared with responses to the summary questions regarding intakes of similar items. Both methods were tested for validity, using correlation and linear regression techniques with EPA, and retest reliability.

Setting

Perth metropolitan area, Western Australia.

Subjects

One hundred and nine healthy volunteers of both sexes, aged 21–75 years.

Results

The summary fresh fish measure underestimated frequency and grams per week given by the aggregate question by about 50%, while estimates from the summary preserved fish measure were approximately three times that of the aggregate measure. Multiple linear regression analysis suggested that the aggregates accounted for more of the variation in EPA levels, but the difference was minimal. Intra-class correlations confirmed that both methods were reliable.

Conclusions

Our study indicates that extensive questioning results in different absolute intakes of fish compared with brief questioning, but does not add any information if ranking individuals according to overall consumption of fish.

Maternal dietary omega fatty acid intake and auditory brainstem-evoked potentials in Mexican infants born at term: cluster analysis

OBJECTIVE

To identify biological and socioeconomic factors associated with the neurological development of Mexican infants born at term, as measured by brainstem auditory-evoked potentials (BAEPs).

SUBJECTS AND METHODS

We conducted a cohort study among 76 women with low risk pregnancies recruited in their third trimester of pregnancy and followed their infants until 12 months of age. BAEP tests were conducted on the infants before 3 months of age during physiologic sleep, using 100 msec bipolar clicks. Maternal dietary intake was evaluated by food frequency questionnaire. Two BAEP groups (short latency, long latency) were identified by cluster analysis. The association between BAEP group and maternal PUFAs was estimated using logistic regression models adjusted for socioeconomic and biological factors.

RESULTS

Short latency BAEPs were associated with a maternal diet rich in arachidonic acid (OR=3.63, 95% CI 1.23-10.67) after adjusting for age (in days) sex, head circumference and gestational age but was not significantly associated to a maternal diet rich in docosahexaenoic acid (DHA).

CONCLUSIONS

Our results suggest the importance of arachidonic acid intake during pregnancy for short latency BAEPs and adequate fetal myelination.

Maternal dietary intake of polyunsaturated fatty acids modifies the relationship between lead levels in bone and breast milk

Whereas dietary fats are known to influence bone mineral density, little is known about their effect on the skeletal stores of lead that are a pervasive source of fetal and infant lead exposure from heightened mobilization during pregnancy and lactation. This cross-sectional study examined the potential influence of maternal dietary intake of saturated and unsaturated fats on the relationship of lead levels in bone and breast milk during lactation. Lead was measured in blood, breast milk, and bone (patella and tibia) at 1 mo postpartum in 310 women in Mexico City. Dietary nutrient intake was assessed using a validated FFQ. Multivariate linear regression analyses were used to study the influence of dietary saturated and unsaturated fats on the association between bone and breast milk lead. In multivariate models that included both the dietary intake of SFA and PUFA, an interquartile range increase in patella lead [approximately 20 microg/g (0.097 micromol/g)] was associated with a 24% (95% CI = 5-43) higher increase in breast milk lead in women in the lowest tertile of PUFA intake compared with those in the highest tertile of PUFA intake. Monounsaturated fatty acids did not modify the relationship between lead levels in patella and breast milk. In conclusion, higher maternal dietary intake of PUFA may limit the transfer of lead from bone to breast milk.

Comparison between plasma and erythrocyte fatty acid content as biomarkers of fatty acid intake in US women

BACKGROUND

Erythrocyte fatty acids may be superior to plasma fatty acids for reflecting long-term fatty acid intake because of less sensitivity to recent intake and a slower turnover rate.

OBJECTIVE

The objective was to compare the fatty acid content of erythrocytes with that of plasma with respect to their abilities to reflect usual fatty acid intake.

DESIGN

Fatty acids in plasma and erythrocytes were measured by capillary gas-liquid chromatography in 306 US women aged 43-69 y. Fatty acid intake was assessed with a food-frequency questionnaire, which was validated for measuring intakes of various fatty acids.

RESULTS

Docosahexaenoic acid (DHA, 22:6n-3) in erythrocytes and plasma provided the strongest correlations with its intake, but erythrocyte DHA concentrations [Spearman's partial correlation coefficient (r(s))=0.56] were better than plasma DHA concentrations (r(s)=0.48) as a biomarker. Total trans fatty acids (r(s)=0.43) and total 18:1 trans isomers (r(s)=0.42) in erythrocytes were also more strongly correlated with intake than were those in plasma (r(s)=0.30 and r(s)=0.29, respectively). Moderate correlations were observed for linoleic acid (18:2n-6; erythrocytes, r(s)=0.24; plasma, r(s)=0.25), alpha-linolenic acid (18:3n-3; erythrocytes, r(s)=0.18; plasma, r(s)=0.23), and eicosapentaenoic acid (20:5 n-3; erythrocytes, r(s)=0.38; plasma, r(s)=0.21). For polyunsaturated and trans fatty acids, correlations between intakes and biomarkers improved moderately when average intakes over previous years were used.

CONCLUSION

Erythrocyte n-3 fatty acids of marine origin and trans fatty acid content are suitable biomarkers for long-term intake.