n-6 Docosapentaenoic acid is not a predictor of low docosahexaenoic acid status in Canadian preschool children

Dietary intake of different ratios of ARA/DHA in early stages and its impact on infant development

Long-chain polyunsaturated fatty acids (LC-PUFAs), arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3) are essential in the development of infants. ARA and DHA from breast milk or infant formula are the main sources of access for infants to meet their physiological and metabolic needs. The ratio of ARA to DHA in breast milk varies among regions and different lactation stages. Different ratios of ARA and DHA mainly from algal oil, animal fat, fish oil, and microbial oil, are added to infant formula in different regions and infant age ranges. Supplementing with appropriate ratios of ARA and DHA during infancy promotes brain, neural, visual, and other development aspects. In this review, we first introduced the current intake status of ARA and DHA in different locations, lactation stages, and age ranges in breast milk and infant formula. Finally, we discussed the effect of different ratios of ARA and DHA on infant development. This review provided a comprehensive research basis for the nutritional research of infants who consume different ratios of ARA and DHA.

Investigating the catalytic efficiency of C22-Fatty acids with LOX human isozymes and the platelet response of the C22-oxylipin products

Polyunsaturated fatty acids (PUFAs) have been extensively studied for their health benefits because they can be oxidized by lipoxygenases to form bioactive oxylipins. In this study, we investigated the impact of double bond placement on the kinetic properties and product profiles of human platelet 12-lipoxygenase (h12-LOX), human reticulocyte 15-lipoxygenase-1 (h15-LOX-1), and human endothelial 15-lipoxygenase-2 (h15-LOX-2) by using 22-carbon (C22) fatty acid substrates with differing double bond content. With respect to kcat/KM values, the loss of Δ4 and Δ19 led to an 18-fold loss of kinetic activity for h12-LOX, no change in kinetic capability for h15-LOX-1, but a 24-fold loss for h15-LOX-2 for both C22-FAs. With respect to the product profiles, h12-LOX produced mainly 14-oxylipins. For h15-LOX-1, the 14-oxylipin production increased with the loss of either Δ4 and Δ19, however, the 17-oxylipin became the major species upon loss of both Δ4 and Δ19. h15-LOX-2 produced mostly the 17-oxylipin products throughout the fatty acid series. This study also investigated the effects of various 17-oxylipins on platelet activation. The results revealed that both 17(S)-hydroxy-4Z,7Z,10Z,13Z,15E,19Z-DHA (17-HDHA) and 17-hydroxy-4Z,7Z,10Z,13Z,15E-DPAn6 (17-HDPAn6) demonstrated anti-aggregation properties with thrombin or collagen stimulation. 17-hydroxy-7Z,10Z,13Z,15E,19Z-DPAn3 (17-HDPAn3) exhibited agonistic properties, and 17-hydroxy-7Z,10Z,13Z,15E-DTA (17-HDTA) showed biphasic effects, inhibiting collagen-induced aggregation at lower concentrationsbut promoting aggregation at higher concentrations. Both 17-hydroxy-13Z,15E,19Z-DTrA (17-HDTrA), and 17-hydroxy-13Z,15E-DDiA (17-HDDiA) induced platelet aggregation. In summary, the number and placement of the double bonds affect platelet activation, with the general trend being that more double bonds generally inhibit aggregation, while less double bonds promote aggregation. These findings provide insights into the potential role of specific fatty acids and their metabolizing LOX isozymes with respect to cardiovascular health.

Intakes of PUFA are Low in Preschool-aged Children in the Guelph Family Health Study Pilot Cohort

This study investigated intakes of total, n-3, and n-6 polyunsaturated fatty acids (PUFA) in 109 preschool-aged children who participated in the Guelph Family Health Study pilot. Intakes of total, n-3, and n-6 PUFA did not meet recommendations. This study highlights the need for additional monitoring and potential interventions to improve PUFA intake in preschool-aged children. Clinical trial #NCT02223234. Novelty: Canadian preschool-aged children are not consuming enough n-3 and n-6 polyunsaturated fatty acids.

Total Fat and Fatty Acid Intake among 1-7-Year-Old Children from 33 Countries: Comparison with International Recommendations

This work reviews available data on dietary intakes of total fat, saturated fatty acids (SFA) and individual polyunsaturated fatty acids (PUFA) in children in different countries worldwide and for the first time, compares them with recent international recommendations. Studies published before June 2021 reporting total fat, total SFA and individual PUFA intakes in children aged 1-7 y were included. Observed intakes were evaluated against FAO/WHO and EFSA recommendations. 65 studies from 33 countries were included. Fat intake was too low in 88% of studies in young children (1-3 y). SFA intake was >10%E in 69-73% of children, especially in Europe. Linoleic acid intake was <3%E in 24% of studies in 1-2 y olds and within FAO/WHO recommendations among all other ages. Alpha-linolenic acid intake was <0.5%E in almost half of studies. Docosahexaenoic acid (DHA) or eicosapentaenoic acid + DHA intakes were below recommendations in most studies. In summary, while total fat intake was too low among younger children, SFA intake was above, especially in Europe and n-3 PUFA intake, especially DHA, were below recommendations for all ages. Intake of n-3 PUFA, especially DHA, is generally suboptimal. More data, particularly from developing countries, are required to refine these findings and guide implementation of adapted nutrition policies.

Increased adiposity in children with obesity is associated with low red blood cell omega-3 fatty acid status and inadequate polyunsaturated fatty acid dietary intake

The association between total dietary fat intake and measures of body fatness in children with obesity remains inconsistent. This study aimed to determine whether dietary long-chain polyunsaturated fatty acids (LCPUFA) and LCPUFA status relate to body composition in children with obesity. Children (n = 63, 9.0 ± 0.2 year, BMI Z-score 3.1 ± 0.2) were divided into tertiles of percentage body fat assessed by dual-energy X-ray absorptiometry. Diet was assessed 3-days food diaries. Fatty acid proportions in red blood cells (RBC) were measured by gas chromatography. Data stratified by sex and Tanner stages were compared with a MIXED model ANOVA. Associations between RBC fatty acid status and dietary intakes were examined with Spearman correlation. Moderate correlations were observed between RBC eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) proportions, dietary EPA and DHA (r = 0.39, P < .05) as well as fish servings (r = 0.33, P < .05). Dietary LCPUFA did not differ among tertiles. Children in tertile 3 had lower RBC α-linolenic acid (-40%) and EPA + DHA (-15%) proportions adjusted for age, Tanner stages and race compared with tertile 1. The lower omega-3 LCPUFA status in children with greater adiposity is consistent with suboptimal intakes of omega-3 LCPUFA and fish in the diet.

Association between dietary intake and serum biomarkers of long-chain PUFA in Japanese preschool children

OBJECTIVE

Recent research supports the importance of PUFA intake in children, particularly of EPA and DHA; however, few verified methods to assess whether PUFA intake is adequate are available.

DESIGN

We assessed the correlation between serum PUFA and lipid concentrations with seafood and PUFA intake measured using a brief-type self-administered diet history questionnaire for Japanese preschool children (BDHQ3y).

SETTING

Single centre birth cohort in Japan.

PARTICIPANTS

A total of 152 36-month-old Japanese children.

RESULTS

Average dietary intake of daily seafood, EPA and DHA was 13·83 (sd 10·36) g, 49·4 (sd 43·5) mg and 98·3 (sd 64·6) mg, respectively. Significant weak-to-moderate correlations were observed between dietary intake and serum EPA (Spearman rho = 0·41, P < 0·001; Pearson r = 0·44, P < 0·001); DHA (Spearman rho = 0·40, P < 0·001; Pearson r = 0·42, P < 0·001) and AA (arachidonic acid) (Spearman rho = 0·33, P < 0·001; Pearson r = 0·32, P < 0·001), whereas no significant correlation was observed for dihomo-γ-linolenic acid (DGLA) (Spearman rho = 0·06, P = 0·484; Pearson r = 0·07, P = 0·387). Correlations between seafood intake and serum EPA and DHA were also moderate (0·39-0·43). A negative correlation between serum TAGs and serum EPA, as well as positive correlations between serum cholesterol (total cholesterol, LDL and HDL) with serum EPA and DHA were observed, whereas no significant correlations between seafood intake and serum lipid profiles. Based on this model, we estimated 61-98 g/week of seafood intake is required to meet current EPA/DHA intake recommendations by the WHO (100-150 mg/d).

CONCLUSIONS

For children of 2-4 years of age, weekly intake of 61-98 g of seafood is required to meet WHO recommendations of EPA/DHA intake.

Biomarkers of Docosahexaenoic Acid but Not Arachidonic Acid Reflect Dietary Intakes in Toddlers at Ages 1 and 2 Years Who Are Not Meeting Dietary Recommendations

BACKGROUND

Long-chain n-6 and n-3 PUFAs are important for growth and development. However, little is known about requirements and current dietary intakes of these fatty acids in toddlers.

OBJECTIVES

This study assessed dietary intakes of n-6 and n-3 PUFAs and determined the relation to circulating PUFAs in toddlers at ages 1 and 2 y.

METHODS

This is a secondary analysis of data from toddlers enrolled in a double-blind randomized controlled trial of arachidonic acid (ARA) and DHA supplementation between ages 1 and 2 y. Dietary intakes of fatty acids were estimated by 3-d food records, and fatty acid composition in plasma total phospholipids, red blood cell phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were assessed by GC at baseline in all subjects (n = 110; mean age 1.12 y; 64% male) and in the control subjects at 2 y (n = 43).

RESULTS

The dietary intakes of ARA, EPA, and DHA at age 1 y (baseline) were [mean (median)] 36.8 (30.0), 16.0 (0.00), and 31.1 (10.0) mg/d, respectively. Dietary intakes increased to 52.7 (45.0), 35.8 (0.00), and 64.8 (20.0) mg/d, respectively, at age 2 y (P < 0.05). The predominant dietary source of EPA and DHA was fish/seafood; eggs were an important source of ARA and DHA. Dietary DHA intakes were positively associated with plasma PE and PC DHA (P < 0.05). No relations between dietary ARA intakes and plasma PE and PC ARA (P > 0.05) were observed.

CONCLUSIONS

These findings suggest that most toddlers are not meeting the recommendation for dietary PUFA intakes and that higher dietary DHA intakes are reflected in plasma PE and PC DHA composition. Further work is required to investigate a biomarker for dietary ARA intake. This trial is registered at clinicaltrials.gov as NCT01263912.

Microencapsulated Tuna Oil Results in Higher Absorption of DHA in Toddlers

Docosahexaenoic acid (DHA) is an essential component for brain and visual acuity development during foetal and early postnatal life. A newly released directive under the European Commission stipulates DHA as a mandatory ingredient in infant formula. This poses challenges to manufacturers in preserving the stability and bioavailability of DHA at levels akin to human breast milk. The aims of this study were (a) to investigate the bioavailability of microencapsulated omega-3 DHA formulations in healthy toddlers compared with high DHA fish oil for a one-month period and (b) to assess the effect of DHA supplementation on children’s sleep and cry patterns. Sixty toddlers were randomly allocated to four groups: 1. unfortified formula, 2. unfortified formula plus high DHA tuna oil, 3. fortified formula with dairy-based microencapsulated high DHA tuna oil powder, and 4. fortified formula with allergenic-free microencapsulated high DHA tuna oil powder. Bioavailability was assessed from both blood and faecal fatty acid levels. The results showed an enhanced bioavailability with significantly greater concentrations of blood DHA levels in formulas with microencapsulated powders. There were no significant effects of treatment on sleep and cry patterns. Application and delivery of microencapsulated DHA tuna oil powder in toddlers’ formula provided better bioavailability of the active DHA.

The Essentiality of Arachidonic Acid in Infant Development

Arachidonic acid (ARA, 20:4n-6) is an n-6 polyunsaturated 20-carbon fatty acid formed by the biosynthesis from linoleic acid (LA, 18:2n-6). This review considers the essential role that ARA plays in infant development. ARA is always present in human milk at a relatively fixed level and is accumulated in tissues throughout the body where it serves several important functions. Without the provision of preformed ARA in human milk or infant formula the growing infant cannot maintain ARA levels from synthetic pathways alone that are sufficient to meet metabolic demand. During late infancy and early childhood the amount of dietary ARA provided by solid foods is low. ARA serves as a precursor to leukotrienes, prostaglandins, and thromboxanes, collectively known as eicosanoids which are important for immunity and immune response. There is strong evidence based on animal and human studies that ARA is critical for infant growth, brain development, and health. These studies also demonstrate the importance of balancing the amounts of ARA and DHA as too much DHA may suppress the benefits provided by ARA. Both ARA and DHA have been added to infant formulas and follow-on formulas for more than two decades. The amounts and ratios of ARA and DHA needed in infant formula are discussed based on an in depth review of the available scientific evidence.

Dietary intake of polyunsaturated fatty acids and fish among US children 12-60 months of age

This study aimed to estimate intake of individual polyunsaturated fatty acids (PUFAs), identify major dietary sources of PUFAs and estimate the proportion of individuals consuming fish among US children 12-60 months of age, by age and race and ethnicity. The study employed a cross-sectional design using US National Health and Nutrition Examination Survey data. Representative sample of US population based on selected counties.

SUBJECTS

2496 US children aged 12-60 months. Mean daily intake of n-6 PUFAs and eicosapentaenoic acid (EPA) varied by age, with children 12-24 months of age having lower average intakes (mg or g day(-1) ) than children 49-60 months of age and the lowest n6 : n3 ratio, upon adjustment for energy intake. Docosahexaenoic acid (DHA) intake was low (20 mg day(-1) ) compared to typical infant intake and did not change with age. Compared to non-Hispanic white children, Mexican American children had higher DHA and arachidonic acid (AA) intake. In the previous 30 days, 53.7% of children ever consumed fish. Non-Hispanic black children were more likely than non-Hispanic white children to have consumed fish (64.0% vs. 53.0%). Results indicate low prevalence of fish intake and key n-3 PUFAs, relative to n-6 fatty acids, which suggests room for improvement in the diets of US children. More research is needed to determine how increasing dietary intakes of n-3 PUFAs like DHA could benefit child health.

Cross-sectional associations of food consumption with plasma fatty acid composition and estimated desaturase activities in Finnish children

Plasma fatty acid (FA) composition is known to be an indicator of dietary fat quality, but the associations of other dietary factors with plasma FA composition remain unknown in children. We investigated the cross-sectional associations of food consumption with the proportions of FA and estimated desaturase activities in plasma cholesteryl esters (CE) and phospholipids (PL) among children. The subjects were a population sample of 423 children aged 6–8 years examined at baseline of The Physical Activity and Nutrition in Children (PANIC) Study. We assessed food consumption by food records and plasma FA composition by gas chromatography. We used linear regression models adjusted for age, sex, physical activity and total energy intake to analyze the associations. A higher consumption of vegetable oil-based margarine (fat 60–80 %) was associated with a higher proportion of linoleic and α-linolenic acids in plasma CE and PL. A higher consumption of high-fiber grain products was related to a lower proportion of oleic acid in CE and PL. The consumption of candy was directly associated with the proportion of palmitoleic and oleic acid in plasma CE. The consumption of vegetable oil-based margarine was inversely associated with estimated stearoyl-CoA-desaturase activity in plasma CE and PL and the consumption of candy was directly related to it in plasma CE. The results of our study suggest that plasma FA composition is not only a biomarker for dietary fat quality but also reflects the consumption of high-fiber grain products and foods high in sugar among children.

Usual dietary fatty acid intakes and red-blood-cell membrane fatty acid composition in Inuit children attending child-care centres in Nunavik, northern Québec, Canada

OBJECTIVES

To assess dietary fatty acid intakes and to examine the relationship between dietary sources of n-3 and n-6 PUFA and red-blood-cell (RBC) n-3 and n-6 PUFA composition.

DESIGN

A cross-sectional study. Dietary intakes were assessed with a 24 h dietary recall. A second recall was performed for 44 % of the children. Usual dietary intakes were estimated with the Software for Intake Distribution Estimation (SIDE). The fatty acid composition was measured in RBC membranes. Multivariate linear regression analyses were performed to explain RBC n-3 and n-6 PUFA concentrations.

SETTING

Child-care centres in Nunavik, northern Québec, Canada.

SUBJECTS

One hundred and sixty-seven Inuit children aged 11-53 months.

RESULTS

A high proportion of the participants had inadequate n-3 and n-6 PUFA intakes (47·9 % and 93·5 %, respectively). Breast-feeding status and consumption of traditional food during the first 24 h dietary recall were significantly associated with RBC n-3 PUFA levels. Older children also tended to have higher RBC n-3 PUFA levels (P = 0·0528), whereas sex, infant formula status and n-3 PUFA dietary intakes were not associated with RBC n-3 PUFA concentrations. RBC n-6 PUFA concentrations were positively associated with breast-feeding status and n-6 PUFA dietary intakes, whereas age, sex and infant formula status were not.

CONCLUSIONS

The present findings highlight the fact that Inuit pre-school children are not consuming enough n-3 and n-6 PUFA for optimum health. These observations call for actions to increase traditional food intake among Inuit children and to help them and their parents make healthier store-bought food choices.

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.

Sex differences in the relationship of dietary Fatty acids to cognitive measures in american children

Because the first neurons evolved in an environment high in the n−3 (omega-3) fatty acid docosahexaenoic acid (DHA), this fatty acid became a major component of neural structure and function and makes up 10% of the dry weight of the human brain. Since n−3 fatty acids must come from the diet, this suggests a possible positive role for dietary n−3 fatty acids in cognition and a possible negative role for n−6 fatty acids, which compete with n−3 for access to critical enzymes. Because human females must provide DHA for the growth of the unusually large brains of their offspring from maternal fat stored during childhood, their need for DHA is especially great. We used stepwise regression to determine whether particular dietary fatty acids and other nutrients were related to cognitive performance in over 4000 American children aged 6–16 from the Third National Health and Nutrition Examination Survey; a variety of possible biological, social, and environmental risk factors were statistically controlled. In this context the only dietary factors related to cognitive performance were n−3 and n−6 fatty acids. Dietary n−3 fatty acids were positively related to cognitive test scores in male and female children, while n−6 showed the reverse relationship, significantly so in females. In female children the positive effects of n−3 intake were twice as strong as in males and exceeded the negative effects of lead exposure. This suggests that increasing dietary intake of n−3 and decreasing n−6 fatty acids may have cognitive benefits in children, especially in females.

The relation between the omega-3 index and arachidonic acid is bell shaped: synergistic at low EPA+DHA status and antagonistic at high EPA+DHA status

INTRODUCTION

The relation between docosahexaenoic (DHA) and eicosapentaenoic (EPA) vs. arachidonic acid (AA) seems characterized by both synergism and antagonism.

MATERIALS AND METHODS

Investigate the relation between EPA+DHA and AA in populations with a wide range of EPA+DHA status and across the life cycle. EPA+DHA and AA were determined in erythrocytes (RBC; n=1979), umbilical arteries (UA; n=789) and umbilical veins (UV; n=785).

RESULTS

In all compartments, notably RBC, the relation between EPA+DHA and AA appeared bell-shaped. Populations with low RBC-EPA+DHA (<2g%) exhibited positive relationships; those with high RBC-EPA+DHA (>8g%) negative relationships. Antagonism in UA and UV could not be demonstrated.

CONCLUSION

Both synergism and antagonism might aim at a balance between ω6 and ω3 long-chain polyunsaturated fatty acid (LCP) to maintain homeostasis. Synergism might be a feature of low LCPω3 status. AA becomes suppressed by antagonism from an RBC-EPA+DHA >8g%.

Supplementation of N-3 LCPUFA to the diet of children older than 2 years: a commentary by the ESPGHAN Committee on Nutrition

The aim of this commentary is to review data on the effect of supplementation of paediatric patients ages 2 years or older with n-3 long-chain polyunsaturated fatty acids (LCPUFA). Some evidence for a positive effect on functional outcome in children with attention-deficit/hyperactivity disorder (ADHD) was found; however, benefit was seen in only about half of the randomised controlled trials (RCT), and studies varied widely not only in dose and form of supplementation but also in the functional outcome parameter tested. The committee concludes that there are insufficient data to recommend n-3 LCPUFA supplementation in the treatment of children with ADHD, but further research on n-3 LCPUFA supplementation in ADHD may be worthwhile. The committee was unable to find evidence of a favourable effect of n-3 LCPUFA supplementation on cognitive function in children. Although no benefit of n-3 LCPUFA supplementation was seen for major clinical outcome parameters in children with cystic fibrosis, a potentially beneficial shift towards less-inflammatory eicosanoid profiles seen in 2 studies provides grounds for further investigation; it is possible that earlier and longer supplementation periods may be needed to demonstrate clinical effect. For children with phenylketonuria, the limited data available suggest that supplementation of n-3 LCPUFA to the diet is both feasible and safe, but offers only transient benefit in visual function. For children with bronchial asthma there are insufficient data to suggest that LCPUFA supplementation has a beneficial effect. The committee advises paediatricians that most health claims about supplementation of n-3 LCPUFA in various diseases in children and adolescents are not supported by convincing scientific data.

Dietary intake of polyunsaturated fatty acids among breast-feeding and non-breast-feeding 24- to 48-month-old children in Bangladesh

OBJECTIVE

The aim of the study was to assess the adequacy of polyunsaturated fatty acid intake by rural Bangladeshi children 24 to 48 months old in relation to their breast-feeding status.

MATERIALS AND METHODS

Multistage sampling was used to select a representative sample of children 24 to 48 months of age from 2 rural districts in Bangladesh (n = 479). Two nonconsecutive 24-hour periods of dietary data were collected via 12-hour daytime in-home observations and recall. Breast milk intake was estimated using test weighing. The National Cancer Institute (NCI) method for episodically consumed foods was used to estimate distributions of usual food and nutrient intakes.

RESULTS

Based on the estimated intake distributions, >95% of the children had usual fat intakes <30% of total energy. Among 24- to 35-month-old (younger) and 36- to 48-month-old (older) children, respectively, 4% and 16% of breast-feeding children and 31% and 41% of non-breast-feeding children were estimated to consume <10% of total energy from fat. An estimated 80% of all of the children consumed <4% of total energy as linoleic acid, and 99% consumed <1% of energy as α-linolenic acid. Younger breast-feeding children had higher estimated average docosahexaenoic acid (DHA) intakes (0.04 g DHA/day) than their non-breast-feeding counterparts (0.01 g DHA/day; P = 0.0005). Both breast-feeding and non-breast-feeding older children had estimated mean DHA intakes of 0.02 g/day (P = 0.74).

CONCLUSIONS

Rural Bangladeshi children 24 to 48 months old, and especially those who have discontinued breast-feeding, may benefit from increased fat consumption.

Role of FADS1 and FADS2 polymorphisms in polyunsaturated fatty acid metabolism

Tissue availability of polyunsaturated fatty acids (PUFAs) depends on dietary intake and metabolic turnover and has a major impact on human health. Strong associations between variants in the human genes fatty acid desaturase 1 (FADS1, encoding Delta-5 desaturase) and fatty acid desaturase 2 (FADS2, encoding Delta-6 desaturase) and blood levels of PUFAs and long-chain PUFAs (LC-PUFAs) have been reported. The most significant associations and the highest proportion of genetically explained variability (28%) were found for arachidonic acid (20:4n-6), the main precursor of eicosanoids. Subjects carrying the minor alleles of several single nucleotide polymorphisms had a lower prevalence of allergic rhinitis and atopic eczema. Therefore, blood levels of PUFAs and LC-PUFAs are influenced not only by diet, but to a large extent also by genetic variants common in a European population. These findings have been replicated in independent populations. Depending on genetic variants, requirements of dietary PUFA or LC-PUFA intakes to achieve comparable biological effects may differ. We recommend including analyses of FADS1 and FADS2 polymorphism in future cohort and intervention studies addressing biological effects of PUFAs and LC-PUFAs.

Effects of long-chain polyunsaturated fatty acid supplementation on neurodevelopment in childhood: a review of human studies

Omega-3 and omega-6 long-chain polyunsaturated fatty acids (LCPUFA) are critical for infant and childhood brain development, but levels of the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are often low in the Western diet. Increasing evidence from both epidemiological and intervention studies, reviewed here, indicates that DHA supplementation, during pregnancy, lactation, or childhood plays an important role in childhood neurodevelopment. Arachidonic acid (ARA) is also important for infant growth and development. Several studies have demonstrated positive associations between blood DHA levels and improvements on tests of cognitive and visual function in healthy children. Controlled trials also have shown that supplementation with DHA and EPA may help in the management of childhood psychiatric disorders, and improve visual and motor functions in children with phenylketonuria. In all studies, DHA and EPA supplementation is typically well tolerated. Further research is needed to determine optimal doses for efficacy at different developmental ages. The potential long-term benefits of early LCPUFA supplementation also require consideration.

Toddler formula supplemented with docosahexaenoic acid (DHA) improves DHA status and respiratory health in a randomized, double-blind, controlled trial of US children less than 3 years of age

Studies of docosahexaenoic acid (DHA) intake and status in US toddlers are lacking. One national survey found low DHA intakes. The objectives of this double-blind, randomized study were to (a) determine usual DHA intakes, (b) measure the effect of consuming formulas with DHA on red blood cell (RBC) and plasma DHA and (c) record adverse events in US children between 18 and 36 months of age. Children aged 18-36 months were provided 237-ml formula with 0, 43, or 130 mg DHA per day for 60 days. Blood was obtained at 0 and 60 days and 24-hour dietary recalls at 0, 30 and 60 days. Usual median daily DHA intake was 13.3 mg. RBC DHA increased in a dose-dependent manner with increasing DHA intake (p<0.05). Toddlers consuming the formula with 130 mg DHA per day have fewer adverse events (p=0.007) and a lower incidence of respiratory illness (p=0.024), compared to the formula without DHA. US toddlers have low DHA intake and status. Modest increases in DHA intake in toddlers might improve development, including respiratory health.

omega-3 oil intake during weight loss in obese women results in remodelling of plasma triglyceride and fatty acids

Previous studies have shown that a combination of weight loss and fish oil supplementation reduce cardiovascular disease and diabetes risks by increasing adiponectin and reducing triacylglyceride concentrations, while weight loss alone significantly improves insulin sensitivity and reduces inflammation. Here, a metabolomic approach, using a combination of (1)H-Nuclear Magnetic Resonance spectroscopy, and gas and liquid chromatography and mass spectrometry, was employed to elucidate the metabolic changes in blood plasma following weight loss and fish oil supplementation. The intervention study was conducted over 24 weeks, with 93 female subjects randomised to one of three groups. Two groups followed a 12-week weight loss program, followed by a 12-week weight maintenance period and were randomised to fish or placebo oil capsules; a control group did not follow the weight loss program and were given placebo oil capsules. Lipid profiles changed dramatically upon fish oil intake and subtly across the two weight loss groups. While the fish oil supplementation increased the proportion of various phospholipid species, previously reported reductions in total triacylglycerides (TAGs) upon fish oil intake were shown to be driven by a reduction in a specific subset of the measured TAGs. This remodelling of triglycerides may represent further beneficial effects of fish oil supplementation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11306-009-0161-7) contains supplementary material, which is available to authorized users.

Age dependence of plasma phospholipid fatty acid levels: potential role of linoleic acid in the age-associated increase in docosahexaenoic acid and eicosapentaenoic acid concentrations

Limited information is available with respect to the association between age and the plasma phospholipid fatty acid profile. Therefore we investigated the association between plasma phospholipid fatty acid status and age after correction for sex, smoking, alcohol use, BMI and fish intake. Plasma phospholipid fatty acid composition was measured and information on fish intake and other potential covariates was collected in 234 participants of the Maastricht Aging Study. The participants were healthy individuals of both sexes with an age range between 36 and 88 years. Hierarchical linear regression analyses were applied to study the relationship between age and fatty acid concentrations. After correction for fish consumption and other relevant covariates, a significant positive relationship was observed between age of the subjects and their plasma phospholipid concentrations of DHA (22 : 6n-3, P = 0·006) and EPA (20 : 5n-3; P = 0·001). Age contributed 2·3 and 3·9 % to the amount of explained variance, respectively. The higher n-3 long-chain PUFA status at advanced age was confirmed by lower concentrations of their putative ‘shortage marker’ Osbond acid (ObA, 22 : 5n-6; P = 0·022 for the relationship with age after correction for covariates and fish intake, R2 0·022). Concentrations of linoleic acid (LA; 18 : 2n-6) were negatively associated with age (P < 0·001; R2 0·061). In conclusion, DHA and EPA concentrations appeared to be higher in older age groups, partly because of a higher fish intake and partly because of another age-associated mechanism, possibly involving the well-known competition with LA.

Fetal learning and memory: weak associations with the early essential polyunsaturated fatty acid status

To study the potential associations between fetal brain functions and the early essential polyunsaturated fatty acid (ePUFA) status, fetal learning and memory were assessed by repeated habituation rate measurements (HR) in fetuses of 30, 32, 34 or 36 weeks gestational age (GA). HR tests were repeated 10 min later. Both measurements were replicated in a second session at GA 38. Fetal short-term memory (STM) and long-term memory (LTM) were calculated from these habituation rates and related to concentrations of ePUFAs and their status markers, measured in umbilical artery wall phospholipids. The only relevant associations observed were positive trends (0.010<p<0.050) between STM measured before 38 weeks GA and concentrations of the ePUFA status markers Mead acid and Mead acid+dihomo-Mead acid, and between LTM and levels of Osbond acid, a marker of the n-3 LCPUFA status. Although these weak associations may imply some negative relationships between fetal brain functions and the early ePUFA status, we concluded that physiological differences in the availability of these fatty acids may probably not determine the differences in these primitive brain functions during the third trimester of fetal development.

Omega-3 Fatty acids and neural development to 2 years of age: do we know enough for dietary recommendations?

The omega (omega)-3 fatty acids are essential nutrients, explained by the absence of a Delta-15 desaturase in mammalian cells. The omega-3 fatty acids are found in the diet as alpha-linolenic acid (18:3omega-3) and eicosapentaenoic acid (20:5omega-3), as well as docosahexaenoic acid (DHA), with different functions of each of the omega-3 fatty acids in different cells. One essential role of the omega-3 fatty acids is fulfilled by the 22 carbon DHA (22:6omega-3). Depletion of DHA from brain and retina interferes with normal neurogenesis and neurological function, and visual signaling pathways. Observation and intervention studies with pregnant and lactating women, and with infants fed some formulas show that dietary DHA is associated with higher scores on tests of visual and neural development in infants and children. The estimated average requirement and variability in requirement among individuals both of which are needed to set dietary recommended intakes (DRIs) for the different omega-3 fatty acids are unknown. However, because omega-3 fatty acids are essential, adequate intakes to minimize risk of poor neural development and function can be justified, but dose-response data to provide a safe upper limit with different omega-6 fatty acid intakes are needed. Dietary recommendations do affect the food supply and supplements and are used in labeling, all impacting population health. When scientific information is incomplete, consideration must be given to the implications of recommendations that focus on individual nutrients, rather than dietary patterns such as breast-feeding and consuming fish that promote health and minimize disease risk.

Dietary omega 3 fatty acids and the developing brain

The omega-3 fatty acids are essential dietary nutrients and one of their important roles is providing the fatty acid with 22 carbons and 6 double bonds known as docosahexaenoic acid (DHA) for nervous tissue growth and function. Inadequate intakes of omega-3 fatty acids decrease DHA and increase omega-6 fatty acids in the brain. Decreased DHA in the developing brain leads to deficits in neurogenesis, neurotransmitter metabolism, and altered learning and visual function in animals. Western diets are low in omega-3 fatty acids, including the 18 carbon omega-3 fatty acid alpha linolenic acid found mainly in plant oils, and DHA, which is found mainly in fish. The DHA status of the newborn and breast-fed infant depends on the maternal intake of DHA and varies widely. Epidemiological studies have linked low maternal DHA to increased risk of poor child neural development. Intervention studies have shown improving maternal DHA nutrition decreases the risk of poor infant and child visual and neural development. Thus, sufficient evidence is available to conclude that maternal fatty acid nutrition is important to DHA transfer to the infant before and after birth, with short and long-term implications for neural function. However, genetic variation in genes encoding fatty acid desaturases also influence essential fatty acid metabolism, and may increase requirements in some individuals. Consideration of omega-3 fatty acid to include brain development, optimizing omega-3 and omega-6 fatty acids in gestation and lactation, and in fatty acid nutrition support for intravenous and formula-fed neonates is important.

Essential n-3 fatty acids in pregnant women and early visual acuity maturation in term infants

BACKGROUND

Docosahexaenoic acid (DHA) is important to neural development. Whether DHA intakes are low enough in some pregnant women to impair infant development is uncertain.

OBJECTIVE

We sought to determine whether DHA deficiency occurs in pregnant women and contributes to poor infant development.

DESIGN

Biochemical cutoffs, dietary intakes, or developmental scores indicative of DHA deficiency are not defined. Infant development has a distribution in which an individual's potential development is unknown. This was a randomized intervention to establish a distribution of developmental scores for infants of women with DHA intakes considered to be above requirements against which to compare the development of infants of mothers consuming their usual diet. DHA (400 mg/d; n = 67) or a placebo (n = 68) was consumed by the women from 16 wk gestation until delivery. We determined maternal red blood cell ethanolamine phosphoglyceride fatty acids, dietary intakes at 16 and 36 wk gestation, and infant visual acuity at 60 d of age.

RESULTS

We described an approach to identify DHA deficiency when biochemical and functional markers of deficiency are unknown. In multivariate analyses, infant visual acuity was related to sex (beta = 0.660, SE = 0.93, and odds ratio = 1.93) and maternal DHA intervention (beta = 1.215, SE = 1.64, and odds ratio = 3.37). More infant girls in the placebo than in the DHA intervention group had a visual acuity below average (P = 0.048). Maternal red blood cell ethanolamine phosphoglyceride docosatetraenoic acid was inversely related to visual acuity in boys (rho = -0.37, P < 0.05) and girls (rho = -0.48, P < 0.01).

CONCLUSIONS

These studies suggest that some pregnant women in our study population were DHA-deficient.

Dietary lipids in early development and intestinal inflammatory disease

Inflammatory bowel diseases are life-long reoccurring inflammatory disorders of the gastrointestinal tract and have been increasing in incidence in recent decades, notably in the pediatric population. Although genetic predisposition remains an important factor, this increased incidence most likely reflects an environmental change. One potential contributor to this is the change in dietary fat intake, with dietary intake of n-6 polyunsaturated fatty acids (PUFAs) following a similar temporal pattern to the change in inflammatory bowel disease incidence. Dietary n-6 PUFAs comprise a major, modifiable, environmental factor known to promote a heightened inflammatory response through a number of pathways, including their role as precursors for synthesis of eicosanoids and their inhibitory effect on the synthesis of the n-3 PUFAs eicosapentanoic acid and docosahexanoic acid. The increase in n-6 PUFA intake affects individuals of all ages, with fetal PUFA accretion and infant dietary PUFA intake from breast milk reflecting maternal dietary intake. A high level of n-6 PUFA in milk results in increased n-6 PUFA in colonic phospholipids and an exaggerated inflammatory response to chemically induced colitis. Conversely, during development, a diet low in n-6 PUFAs and high in n-3 PUFAs increases colonic n-3 fatty acids, attenuates the inflammatory response, and lowers colonic damage. High dietary n-6 PUFA intake may be an important environmental modifier that contributes to inflammatory bowel diseases.

Dietary lipids in early development: relevance to obesity, immune and inflammatory disorders

PURPOSE OF REVIEW

Regardless of social, cultural and behavioural environments, obesity is usually caused by an energy intake above requirements, which is accommodated by the accumulation of triacylglycerols. The composition of dietary fat impacts tissue fatty acids, which are important modulators of multiple cell functions, including differentiation, lipogenesis, lipolysis and the generation of inflammatory mediators. This review focuses on the possible contribution of fatty acids to the link between obesity and inflammation in young children.

RECENT FINDINGS

Adipose tissue is a complex organ that functions to regulate fatty acid balance, clearing and releasing fatty acids, and synthesizing protein and signaling molecules that act as local and distant inflammatory mediators. Obesity, even in young children, is associated with increased circulating inflammatory mediators. As a result of changes in dietary fat compositions, infants are exposed to high n-6, saturated and trans fatty acids and low n-3 fatty acids. Saturated and trans fatty acids increase and n-3 fatty acids decrease many metabolic and inflammatory changes that accompany diet-induced triacylglycerol storage. High linoleic acid is associated with increased oxidative stress.

SUMMARY

There is a biological reason to consider that dietary fatty acids may contribute to oxidative stress and heightened inflammatory responses in young children.

n-6 and n-3 PUFA intakes of pre-school children in Flanders, Belgium

In this study, the intake of n-6 and n-3 PUFA of pre-school children in Flanders, Belgium, was evaluated, and recommendations to address the very low intake of long-chain PUFA are presented. Food consumption data (based on parentally reported 3 d dietary records obtained from October 2002 to February 2003) of 661 children (338 boys, 323 girls) between 2.5 and 6.5 years of age and the PUFA concentrations obtained from various food composition databases were used. The actual PUFA intake levels were compared to Belgian, European and American recommendations. Only the intake of linoleic acid (LA) fell within the recommended ranges. Margarine, bread, biscuits and chocolate products contributed most to LA intake. The intake of alpha-linolenic acid (LNA) was low compared to the recommendations and was obtained mostly from the consumption of margarines and fatty sauces. This resulted in a high LA/LNA ratio. The intake of all long-chain PUFA was far below the recommended levels. Meat and meat products were the most important sources of arachidonic acid. Consumption of fish and other seafood was very low, though these were the most important sources of long-chain n-3 PUFA. In conclusion, Flemish pre-school children should consume more n-3-rich products in order to increase their LNA intake and decrease their LA/LNA ratio. Furthermore, the replacement of meat products rich in SFA by poultry would increase the arachidonic acid intake. As well, fatty fish consumption needs to be increased, as it is a rich source of long-chain n-3 PUFA.

Decreasing linoleic acid with constant alpha-linolenic acid in dietary fats increases (n-3) eicosapentaenoic acid in plasma phospholipids in healthy men

High linoleic acid (LA) intakes have been suggested to reduce alpha-linolenic acid [ALA, 18:3(n-3)] metabolism to eicosapentaenoic acid [EPA, 20:5(n-3)] and docosahexaenoic acid [DHA, 22:6(n-3)], and favor high arachidonic acid [ARA, 20:4(n-6)]. We used a randomized cross-over study with men (n = 22) to compare the effect of replacing vegetable oils high in LA with oils low in LA in foods, while maintaining constant ALA, for 4 wk each, on plasma (n-3) fatty acids. Nonvegetable sources of fat, except fish and seafoods, were unrestricted. We determined plasma phospholipid fatty acids at wk 0, 2, 4, 6, and 8, and triglycerides, cholesterol, serum CRP, and IL-6, and platelet aggregation at wk 0, 4, and 8. LA and ALA intakes were 3.8 +/- 0.12% and 1.0 +/- 0.05%, and 10.5 +/- 0.53% and 1.1 +/- 0.06% energy with LA:ALA ratios of 4:0 and 10:1 during the low and high LA diets, respectively. The plasma phospholipid LA was higher and EPA was lower during the high than during the low LA diet period (P < 0.001), but DHA declined over the 8-wk period (r = -0.425, P < 0.001). The plasma phospholipid ARA:EPA ratios were (mean +/- SEM) 20.7 +/- 1.52 and 12.9 +/- 1.01 after 4 wk consuming the high or low LA diets, respectively (P < 0.001); LA was inversely associated with EPA (r = -0.729, P < 0.001) but positively associated with ARA:EPA (r = 0.432, P < 0.001). LA intake did not influence ALA, ARA, DPA, DHA, or total, LDL or HDL cholesterol, CRP or IL-6, or platelet aggregation. In conclusion, high LA intakes decrease plasma phospholipid EPA and increase the ARA:EPA ratio, but do not favor higher ARA.

Dietary polyunsaturated fatty acids in gestation alter fetal cortical phospholipids, fatty acids and phosphatidylserine synthesis

Docosahexaenoic acid (DHA; 22:6 n-3) is high in brain phosphatidylserine (PS) and phosphatidylethanolamine (PE), but low in phosphatidylcholine (PC). PS is synthesized from PE or PC by exchange of ethanolamine or choline for serine. PS can be decarboxylated to PE, and PC is synthesized from PE by phosphatidylethanolamine N-methyltransferase (PEMT). We characterized the perinatal changes in rat brain cortex phospholipids and metabolism and determined if maternal dietary n-3 fatty acid intake alters newborn brain cortex phospholipids, serine base exchange, PS decarboxylase or PEMT activities. PE became increasingly predominant, with an increase in the cortex PC/PE ratio from 2:1 at gestation day 19 to 1:1 at postnatal day 20. DHA increased and n-6 docosapentaenoic acid (DPA; 22:5 n-6) decreased in all phospholipids during development. [3H]serine incorporation into PS was higher in the fetal than neonatal brain cortex. Newborn rats of dams fed an n-3 fatty acid-deficient diet with 0.02% energy alpha-linolenic acid (ALA; 18:3 n-3) had approximately 50% lower DHA and higher DPA in cortex PE, PS and PC than newborns of rats fed a control diet with 1.5% energy ALA. [3H]serine incorporation into PS was significantly lower in the brain cortex of n-3 fatty acid-deficient than control newborns. n-3 Fatty acid deficiency had no effect on newborn brain PEMT or serine decarboxylase activities. These studies show that maternal dietary n-3 fatty acid deprivation impairs fetal brain DHA accretion and PS metabolism; altered PS metabolism may change release of lipid mediators and neurotransmitter precursors important in brain function.

Synthesis of structured lipids containing medium-chain and omega-3 fatty acids

The ability of different lipases to incorporate omega3 fatty acids, namely, eicosapentaenoic acid (EPA, C20:5n-3), docosapentaenoic acid (DPA, C22:5n-3), and docosahexaenoic acid (DHA, C22:6n-3), into a high-laurate canola oil, known as Laurical 35, was studied. Lipases from Mucor miehei (Lipozyme-IM), Pseudomonas sp. (PS-30), and Candida rugosa (AY-30) catalyzed optimum incorporation of EPA, DPA, and DHA into Laurical 35, respectively. Other lipases used were Candida anatrctica (Novozyme-435) and Aspergillus niger (AP-12). Response surface methodology (RSM) was used to obtain a maximum incorporation of EPA, DPA, and DHA into high-laurate canola oil. The process variables studied were the amount of enzyme (2-6%), reaction temperature (35-55 degrees C), and incubation time (12-36 h). The amount of water added and mole ratio of substrates (oil to n-3 fatty acids) were kept at 2% and 1:3, respectively. The maximum incorporation of EPA (62.2%) into Laurical 35 was predicted at 4.36% of enzyme load and 43.2 degrees C over 23.9 h. Under optimum conditions (5.41% enzyme; 38.7 degrees C; 33.5 h), the incorporation of DPA into high-laurate canola oil was 50.8%. The corresponding maximum incorporation of DHA (34.1%) into Laurical 35 was obtained using 5.25% enzyme, at 43.7 degrees C, over 44.7 h. Thus, the number of double bonds and the chain length of fatty acids had a marked effect on the incorporation omega3 fatty acids into Laurical 35. EPA and DHA were mainly esterified to the sn-1,3 positions of the modified oils, whereas DPA was randomly distributed over the three positions of the triacylglycerol molecules. Meanwhile, lauric acid remained esterified mainly to the sn-1 and sn-3 positions of the modified oils. Enzymatically modified Laurical 35 with EPA, DPA, or DHA had higher conjugated diene (CD) and thiobarbituric acid reactive substance (TBARS) values than their unmodified counterpart. Thus, enzymatically modified oils were more susceptible to oxidation than their unmodified counterparts, when both CD and TBARS values were considered.

Increased levels of mercury associated with high fish intakes among children from Vancouver, Canada

OBJECTIVE

To assess exposure to mercury (Hg) among children in population subgroups whose traditional dietary practices include fish.

STUDY DESIGN

We determined blood Hg, red blood cell phosphatidylethanolamine omega-3 eicosapentaenoic acid as a marker of fish intake, and assessed indexes of childhood behavior in preschool children 1.5 to 5 years of age (n = 228) living in an ethnically diverse neighborhood in Vancouver, British Columbia, Canada.

RESULTS

The median blood Hg was 4.6 nmol/L, range 0-67.9 nmol/L. Twelve (6%) children, all of whom were Chinese, had a blood Hg > 28.9 nmol/L. Blood Hg, total fish intake, and eicosapentaenoic acid were higher among Chinese than Caucasian children; however, higher fish intake did not predict blood Hg. Blood Hg was inversely associated with attentional focusing in children over 3 years of age after adjusting for confounding family variables, iron deficiency anemia, and zinc deficiency. Major sources of fish among Chinese children were imported fish rather than local fish.

CONCLUSION

Children from population subgroups within populations not considered at risk may be at increased risk of neurotoxicity caused by Hg exposure from fish.

Essential polyunsaturated fatty acids in plasma and erythrocytes of children with inborn errors of amino acid metabolism

Essential fatty acids (EFAs), and their longer-chain more-unsaturated derivatives (LCPUFAs) in particular, are essential for normal growth and cognitive development during childhood. Children with inborn errors of amino acid metabolism represent a risk population for a reduced LCPUFA status because their diet is low in EFAs and LCPUFAs. We have investigated the EFA and LCPUFA status of children with various amino acid metabolism disorders (not PKU) under treatment. Fatty acid profiles of plasma and erythrocyte phospholipids of 33 patients (aged 0-18 years) and 38 matched controls were determined by gas-liquid chromatography. Food-frequency questionnaires were used to assess the mean fatty acid intake. The dietary intake of the EFAs linoleic acid (LA) and alpha-linolenic acid (ALA) was comparable in both groups, while the LCPUFA intake was much lower in patients. This was associated with lower relative concentrations (% of total fatty acids) of n-3 docosahexaenoic acid (DHA) in plasma and erythrocyte phospholipids. Concentrations of arachidonic acid (AA) did not differ. The same was observed for the two EFAs LA and ALA. Thus, as compared to healthy controls, children with amino acid metabolism disorders have a lower intake of LCPUFAs and have lower concentrations of DHA but not of AA in plasma and erythrocyte phospholipids. This suggests that endogenous AA synthesis might guarantee an adequate AA status. The lower DHA status, however, warrants further investigations regarding the impact of DHA supplementation on growth and development of these children.

Trans fatty intakes during pregnancy, infancy and early childhood

All of the essential n-6 and n-3 fatty acids accumulated by the fetus must be derived by transfer from the maternal circulation, and ultimately must originate from the maternal diet. After birth, the breast-fed infant receives essential fatty acids via mother's milk, or human milk substitutes and later complementary foods. Trans fatty acids (TFA) may have adverse effects on growth and development through interfering with essential fatty acid metabolism, direct effects on membrane structures or metabolism, or secondary to reducing the intakes of the cis essential fatty acids in either mother or child. TFA are transported across the placenta and secreted in human milk in amounts that depend on the maternal dietary intake. Inverse associations have been shown between TFA and the essential n-6 and n-3 fatty acids in newborn infants, human milk and preschool children. This support the need to reduce industrially produced trans fatty acids (IP-TFA) and improve dietary fat quality, particularly by increasing intake of n-3 fatty acids.

Polyunsaturated fatty acids and anthropometric indices of children in rural China

OBJECTIVE

To define fatty acid and macronutrient intakes in a rural Chinese preschool population, and relate these intakes to anthropometric indices.

DESIGN

Cross-sectional survey of anthropometry and diet (three 24-h recalls). National Centers for Health Statistics/World Health Organization growth reference charts were used to determine the prevalence of malnutrition (z-scores less than -2 standard deviation (s.d.) below the mean): height-for-age (stunted), weight-for-age (underweight), weight-for-height (wasted) and mid-upper-arm-circumference-for-age (low fat/muscle).

SUBJECTS AND SETTING

A total of 196 children aged 1-5 years old were volunteered by their families to participate in the survey, located in Heqing County, Yunnan Province, China.

RESULTS

The respective prevalence of stunting, underweight, wasting and low fat/muscle was: 38, 21, 2 and 8%. Daily intakes of linoleic acid (LA; 18:2n-6), alpha-linolenic acid (LNA; 18:3n-3), arachidonic acid (AA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3), averaged for all children, were 2 100+/-1200, 300+/-250, 55+/-35 and 30+/-140 mg/day, respectively. As percent of total fat intake, LA contributed 11.9%, LNA 1.8%, AA 0.3% and DHA 0.2%. Height-for-age and weight-for-age z-scores were negatively correlated with g/kg/day intake of LA and AA (P<0.05). Weight-for-height z-score was negatively correlated with AA g/kg/day intake (P<0.05).

CONCLUSIONS

This study provided polyunsaturated fatty acids (PUFA) intakes in rural preschool children in a developing country. The associations of PUFA intake with early childhood growth suggest that growth in preschool-aged children could be significantly and specifically related to n-6 fatty acid intakes.

The composition of polyunsaturated fatty acids in erythrocytes of lactating mothers and their infants

Long-chain polyunsaturated fatty acids (LCPUFA) in breastmilk, specifically docosahexaenoic acid (DHA), are important for infant brain development. Accretion of DHA in the infant brain is dependent on DHA-status, intake and metabolism. The aim of this study was to describe changes in maternal and infant erythrocyte (RBC) DHA-status during the first four months of lactation. We examined 17 mothers and their term infants at 1, 2 and 4 months of age. Milk samples and RBC from the mothers and infants were obtained and analysed for fatty acid composition. Comparative analysis of the results showed that the content of DHA in maternal RBC-phosphatidylcholine (PE) decreased over the four month period and this was not accompanied by a decrease in DHA in infant RBC-PE (P = 0.005). The ratio of n-6 PUFA to n-3 PUFA increased over time in maternal RBC-PE, but not in infant RBC-PE (P < 0.001). The level of 22:5n-6 and the ratio of LCPUFA to precursor PUFAs in infant RBC was higher than in maternal RBC phospholipids. (P = and P < 0.001 respectively). We found a decrease in the level of LCPUFA in milk, specifically AA. However, we did not observe a significant decrease in milk DHA, which may have been due to two outliers. These results indicate better DHA-status and a higher n-3/n-6 PUFA in RBC of infants than in mothers. Whether these differences reflect preferential n-3 PUFA transfer via breastmilk or differences in PUFA-metabolism and utilization remains to be shown.

Essential fatty acid transfer and fetal development

Docosahexaenoic acid (22:6n-3) and arachidonic acid (20:4n-6) are important structural components of the central nervous system. These fatty acids are transferred across the placenta, and are accumulated in the brain and other organs during fetal development. Depletion of 22:6n-3 from the retina and brain results in reduced visual function and learning deficits: these may involve critical roles of 22:6n-3 in membrane-dependent signaling pathways and neurotransmitter metabolism. Transfer of 22:6n-3 across the placenta involves specific binding and transfer proteins that facilitate higher concentrations of 22:6n-3 and 20:4n-6, but lower linoleic acid (18:2n-6) in fetal compared with maternal plasma, or in the breast-fed or formula-fed infant. However, human and animal studies both demonstrate that maternal diet impacts fetal 22:6n-3 and 20:4n-6 accretion. After birth, parenteral lipid, human milk and infant formula feeding all result in a marked decrease in plasma 22:6n-3 and 20:4n-6 and an increase in 18:2n-6. Estimation of fetal tissue fatty acid accretion suggests that current preterm infant feeds are unlikely to meet in utero rates of 22:6n-3 accretion. Consideration needs to be given to whether fetal plasma 22:6n-3 and 20:4n-6 enrichment and the low 18:2n-6 facilitates accretion of 22:6n-3 and 20:4n-6 in developing tissues.

Comparison of bloodstream fatty acid composition from African-American women at gestation, delivery, and postpartum

Our aim was to examine the docosahexaenoic acid (DHA; 22:6n-3) status of pregnant African-American women reporting to the antenatal clinic at Wayne State University in a longitudinal study design. Fatty acid compositions of plasma and erythrocyte total lipid extracts were determined and food frequency surveys were administered at 24 weeks of gestation, delivery, and 3 months postpartum for participants (n = 157). DHA (mean +/- SD) in the estimated total circulating plasma was similar at gestation (384 +/- 162 mg) and delivery (372 +/- 155 mg) but was significantly lower at 3 months postpartum (178 +/- 81 mg). The relative weight percentage of DHA and docosapentaenoic acid n-6 (DPAn-6; 22:5n-6) decreased postpartum, whereas their respective metabolic precursors, eicosapentaenoic acid (EPA; 20:5n-3) and arachidonic acid (AA; 20:4n-6), increased. Similar results were found in erythrocytes. Dietary intake of DHA throughout the study was estimated at 68 +/- 75 mg/day. The relative amounts of circulating DHA and DPAn-6 were increased during pregnancy compared with 3 months postpartum, possibly via increased synthesis from EPA and AA. The low dietary intake and blood levels of DHA in this population compared with others may not support optimal fetal DHA accretion and subsequent neural development.