Tissue levels of polyunsaturated fatty acids during early human development

Reevaluation of the DHA requirement for the premature infant

The long-chain polyunsaturated fatty acid (LC-PUFA) intake in preterm infants is crucial for normal central nervous system development and has the potential for long-lasting effects that extend beyond the period of dietary insufficiency. While much attention has focused on improving their nutritional intake, many premature infants do not receive an adequate DHA supply. We demonstrate that enterally fed premature infants exhibit daily DHA deficit of 20mg/kg.d, representing 44% of the DHA that should have been accumulated. Furthermore, the DHA content of human milk and current preterm formulas cannot compensate for an early DHA deficit which may occur during the first month of life. We recommend breast-feeding, which supplies preformed LC-PUFA, as the preferred method of feeding for preterm infants. However, to fulfill the specific DHA requirement of these infants, we recommend increasing the DHA content of human milk either by providing the mothers with a DHA supplement or by adding DHA directly to the milk. Increasing the DHA content above 1% total fatty acids appears to be safe and may enhance neurological development particularly that of infants with a birth weight below 1250 g. We estimate that human milk and preterm formula should contain approximately 1.5% of fatty acid as DHA to prevent the appearance of a DHA deficit and to compensate for the early DHA deficit.

Dietary docosahexaenoic acid but not arachidonic acid influences central nervous system fatty acid status in baboon neonates

The influence of dietary docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) on infant central nervous system (CNS) composition has implications for neural development, including vision, cognition, and motor function. We consider here combined results of three published studies of DHA/AA-containing formulas and breastfeeding to evaluate the CNS tissue response of baboon neonates with varied concentration and duration of DHA/AA consumption [G.Y. Diau, A.T. Hsieh, E.A. Sarkadi-Nagy, V. Wijendran, P.W. Nathanielsz, J.T. Brenna, The influence of long chain polyunsaturate supplementation on docosahexaenoic acid and arachidonic acid in baboon neonate central nervous system, BMC Med. 3 (2005) 11; A.T. Hsieh, J.C. Anthony, D.A. Diersen-Schade, et al., The influence of moderate and high dietary long chain polyunsaturated fatty acids (LCPUFA) on baboon neonate tissue fatty acids, Pediatr. Res. 61 (2007) 537-45; E. Sarkadi-Nagy, V. Wijendran, G.Y. Diau, et al., The influence of prematurity and long chain polyunsaturate supplementation in 4-week adjusted age baboon neonate brain and related tissues, Pediatr. Res. 54 (2003) 244-252]. A total of 43 neonates born spontaneously at term, or preterm by Cesarean section, consumed diets with DHA-AA (%w/w) at several levels: none (0,0), moderate (0.3, 0.6), or high (>0.6, 0.67 or 1.2). CNS fatty acids were analyzed at 4 and 12 weeks postpartum for term baboons and 7.5 weeks for preterm neonates. CNS DHA was consistently greater by 5-30% in neonates consuming DHA and nearer 30% for cortex. In contrast, CNS AA was unaffected by dietary AA and decreased in all structures with age. Dietary DHA consistently supports greater CNS DHA and maintenance of cortex DHA concentration with feeding duration, while CNS AA is not related to dietary supply. These data on structure-specific LCPUFA accretion may provide insight into neural mechanisms responsible for suboptimal functional outcomes in infants consuming diets that do not support the highest tissue DHA levels.

Toward optimizing vision and cognition in term infants by dietary docosahexaenoic and arachidonic acid supplementation: a review of randomized controlled trials

The question of whether a dietary supply of docosahexaenoic acid (DHA) and arachidonic acid (ARA) imparts advantages to visual or cognitive development in term infants has been debated for many years. DHA and ARA are present in human milk, and nursing infants consume these fatty acids needed for rapid synthesis of cell membranes, particularly neural cells. The reported mean DHA and ARA levels of human milk worldwide are 0.32% and 0.47% of total fatty acids, respectively. Prior to 2002 in the US, formula-fed infants did not receive these fatty acids and relied solely on endogenous conversion of the dietary essential omega-3 (n-3) and omega-6 (n-6) fatty acids, alpha-linolenic and linoleic acids, to DHA and ARA, respectively. Formula-fed infants were found to have significantly less accretion of DHA in brain cortex after death than breastfed infants. Numerous studies have found positive correlations between blood DHA levels and improvements in cognitive or visual function outcomes of breastfed and formula-fed infants. Results of randomized controlled clinical trials of term formula-fed infants evaluating functional benefits of dietary DHA and ARA have been mixed, likely due to study design heterogeneity. A comparison of visual and cognitive outcomes in these trials suggests that dietary DHA level is particularly relevant. Trials with formulas providing close to the worldwide human milk mean of 0.32% DHA were more likely to yield functional benefits attributable to DHA. We agree with several expert groups in recommending that infants receive at least 0.3% DHA, with at least 0.3% ARA, in infant feedings; in addition, some clinical evidence suggests that an ARA:DHA ratio greater than 1:1 is associated with improved cognitive outcomes.

Docosahexaenoic acid and lactation

Docosahexaenoic acid (DHA) is an important component of membrane phospholipids in the retina and brain and accumulates rapidly in these tissues during early infancy. DHA is present in human milk, but the amount varies considerably and is largely dependent on maternal diet. This article reviews data addressing the impact of different DHA intakes by lactating women on infant and maternal outcomes to determine if available data are sufficient to estimate optimal breast milk DHA content and estimate dietary reference intakes (DRIs) for DHA by breast-feeding mothers. Results of published observational studies and interventional trials assessing the impact of maternal DHA intake (or breast milk DHA content) on infant visual function, neurodevelopment, and immunologic status were reviewed. Studies related to the potential impact of DHA intake on depression or cognitive function of lactating women also were reviewed. Although only a limited number of studies are available in the current medical literature, and study results have not been consistent, better infant neurodevelopment and/or visual function have been reported with higher vs. lower levels of breast milk DHA. The effect of DHA intake on the incidence or severity of depression in lactating women is not clear. Increasing breast milk DHA content above that typically found in the US, by increasing maternal DHA intake, may confer neurodevelopmental benefits to the recipient breast-fed infant. However, current data are insufficient to permit determination of specific DRIs during this period.

Linoleic and arachidonic acid in perinatal asphyxia and prematurity

OBJECTIVES

Long-chain polyunsaturated fatty acids (LC-PUFA) are important for fetal and infant growth and development. The effects of prematurity and perinatal asphyxia on the levels of linoleic acid (LA) and arachidonic acid (AA) in plasma and red blood cell (RBC) membranes were investigated.

METHODS

Fifty-five neonates were studied: 18 full term neonates with perinatal asphyxia (group A), nine preterm neonates (group B), and 28 healthy term neonates (group C). Non-esterified and total levels of LA and AA in plasma and RBC membranes were estimated using gas chromatography within the first day of life. Malondialdehyde (MDA) levels were measured using the thiobarbituric acid (TBA) reactivity method.

RESULTS

Compared to group C, statistically significant lower levels of plasma free and total AA and free LA were observed in group A, whereas statistically significant higher levels of RBC total LA and AA were observed in RBC membranes of group B. A negative correlation between MDA and LC-PUFA levels was found.

CONCLUSION

Perinatal asphyxia is associated with a reduction in LC-PUFA levels, most likely as a result of increased oxidative stress. Premature infants soon after birth have higher LC-PUFA levels than term neonates, probably reflecting the overall metabolic activity and/or intrauterine transport of LC-PUFA.

Dietary Echium oil increases tissue (n-3) long-chain polyunsaturated fatty acids without elevating hepatic lipid concentrations in premature neonatal rats

Echium oil (EO) contains notable quantities of both (n-6) and (n-3) PUFA and has not, to our knowledge, been studied in neonates. We compared growth, tissue PUFA concentrations, and liver lipid profiles in premature neonatal Sprague-Dawley rats that were fed an EO diet with those that were dam-fed (DF) or fed rat milk substitute (RMS) or a fish oil (FO) diet. EO or FO comprised 10% of dietary fat. Rats were delivered prematurely at d 21 of gestation by caesarean section and then DF or fed one of the diets for 6 d. Rats were killed and the fatty acid (FA) concentrations in brain, liver, ileum, and serum and liver lipid profiles were analyzed. All diet-fed rats had similar weight gain and tissue protein concentrations. Compared with DF rats, EO-fed rats had similar brain docosahexaenoic acid (DHA) levels, similar brain and liver arachidonic acid (ARA) levels, higher liver and ileal eicosapentaenoic acid (EPA) levels (P < 0.05), and similar ARA:(EPA+DHA) ratios in brain, liver, and serum. Compared with RMS-fed rats, EO-fed rats had lower liver triglyceride FA and cholesterol ester concentrations (P < 0.05), higher EPA and DHA levels in liver, ileum, and serum, a higher DHA level in brain, and lower tissue and serum ratios of total (n-6):(n-3) PUFA and ARA:(EPA + DHA) (P < 0.05). Compared with FO-fed rats, EO-fed rats had higher ARA levels in brain, liver, ileum, and serum. In conclusion, dietary EO increases tissue EPA and DHA without reducing ARA in brain and liver and without elevating hepatic lipid concentrations of premature neonatal rats.

Effect of fortification with multiple micronutrients and n-3 fatty acids on growth and cognitive performance in Indian schoolchildren: the CHAMPION (Children's Health and Mental Performance Influenced by Optimal Nutrition) Study

BACKGROUND

Fortification with multiple micronutrients has been shown to improve growth and cognitive performance among children in developing countries, but it is unknown whether higher concentrations are more effective than lower concentrations.

OBJECTIVE

We compared the effect of 2 different concentrations of a combination of micronutrients and n-3 (omega-3) fatty acids on indicators of growth and cognitive performance in low-income, marginally nourished schoolchildren in Bangalore, India.

DESIGN

In a 2-by-2 factorial, double-blind, randomized controlled trial, 598 children aged 6-10 y were individually allocated to 1 of 4 intervention groups to receive foods fortified with either 100% or 15% of the Recommended Dietary Allowance of micronutrients in combination with either 900 mg alpha-linolenic acid plus 100 mg docosahexaenoic acid or 140 mg alpha-linolenic acid for 12 mo. Anthropometric and biochemical assessments were performed at baseline and 12 mo. Cognitive performance was measured at baseline and at 6 and 12 mo.

RESULTS

The high micronutrient treatment significantly improved linear growth at 12 mo (0.19 cm; 0.01, 0.36) and short-term memory at 6 mo (0.11 SD; 0.01, 0.20) and was less beneficial on fluid reasoning at 6 (-0.10 SD; -0.17, -0.03) and 12 (-0.12 SD; -0.20, -0.04) mo than was the low micronutrient treatment, whereas no differences were observed on weight, retrieval ability, cognitive speediness, and overall cognitive performance. No significant differences were found between the n-3 treatments.

CONCLUSIONS

The high micronutrient treatment was more beneficial for linear growth than was the low micronutrient treatment. However, with some small differential effects, higher micronutrient concentrations were as effective as lower concentrations on cognitive performance. This trial was registered at clinicaltrials.gov as NCT00467909.

n-3 Fatty acid intake from marine food products among Quebecers: comparison to worldwide recommendations

Objective

To quantify marine food product consumption and EPA + DHA intake among Quebecers, and to compare the results with the most recent recommendations.

Design

Data were obtained from a representative cross-sectional telephone survey (June 2006). Intakes of marine food product species and EPA + DHA were estimated from a validated FFQ on the consumption of marine food products during the previous month. Prevalence of fish oil consumption in the last 6 months was also assessed.

Setting

Province of Quebec (Canada).

Subjects

A representative sample (n 1001) of adults in the province of Quebec. Of these, eight were excluded from the present analysis (n 993).

Results

Mean and median EPA + DHA intakes for all participants were estimated to be 291 mg/d (sem 11) and 207 mg/d, respectively. 85·0 % (95 % CI 82·7, 87·3) of Quebecers had an EPA + DHA intake lower than 500 mg/d, which is the amount internationally recommended for the prevention of CVD. Mean and median DHA intakes among women of childbearing age (n 128, 18–34 years) were estimated to be 169 mg/d (sem 17) and 126 mg/d, respectively. Of these women, 27·7 % had a daily intake >200 mg DHA and 15·9 % had an intake >300 mg DHA. We noted that 13 % of Quebecers take ≥1 capsule of fish oil/d.

Conclusions

Consumption of marine food products and EPA + DHA among Quebecers clearly appears to be lower than international recommendations. Since EPA + DHA confer health benefits and may reduce health costs, strategies to increase their consumption should be implemented to improve public health in Quebec.

Early risk determinants and later health outcomes: implications for research prioritization and the food supply. Summary of the workshop

The International Life Sciences Institute North American Branch, in conjunction with the International Life Sciences Institute Research Foundation, on 8-9 July 2008, sponsored the workshop "Early Risk Determinants and Later Health Outcomes: Implications for Research Prioritization and the Food Supply." A primary objective was to focus on the relative influence of genetics and environmental factors, particularly in relation to specific nutrients and food components, on determinants of risk within the developmental stages of pregnancy, infancy (0-12 mo), and early childhood (</=5 y of age). A panel of experts concluded the workshop by providing their reactions to the papers presented while attempting to identify the critical time windows and the research gaps and challenges for future research. This was followed by a discussion of how the food industry might assist in the acquisition and translation of the knowledge of the determinants of disease to improve human health.

Early determinants of development: a lipid perspective

This article results from an International Life Sciences Institute workshop on early nutritional determinants of health and development. The presentation on lipids focused mainly on the longer-chain products of the essential fatty acids, particularly docosahexaenoic acid (22:6n-3), and cognitive development as among the most studied lipids and outcomes, respectively, in early human nutrition. Because there have been several recent reviews on this topic, the present review takes a broader perspective with respect to both early development and lipids: an expanded research agenda is plausible on the basis of observations from some human studies and from animal studies. Other lipids known to be provided in variable amounts to infants through human milk are cholesterol and gangliosides. Short sections address the current state of knowledge and some questions that could be pursued.

Plasman-3 fatty acids and psychological distress in aboriginal Cree Indians (Canada)

Objective

To examine the relationship between psychological distress (PD) and plasman-3 long-chain (LC) PUFA, i.e. EPA, docosapentaenoic acid (DPAn-3) and DHA.

Design

Population-based, cross-sectional Santé-Québec Health Survey (1991). Participants were categorized as high-level PD if they scored over the 80th percentile of the PD Index in the Santé-Québec Survey; non-distressed subjects were those who scored less than this cut-off. Associations between tertiles ofn-3 fatty acids (FA) and the risk of high-level PD were expressed as odds ratios, with the lowest tertile as the reference group.

Setting

Québec, Canada.

Subjects

Data were analysed from a representative sample of 852 James Bay Cree Indian adults aged 18 years and over.

Results

Proportions ofn-3 FA were statistically significantly lower in the PD than in the non-distressed group. After adjustment for confounders, EPA was the only individualn-3 FA significantly associated with the risk of high-level PD. Combinations of EPA + DHA or EPA + DPAn-3 + DHA or the sum ofn-3 were also associated with the risk of high-level PD. Compared with the lowest tertile of EPA + DHA, the OR for high-level PD was 0·89 (95 % CI 0·59, 1·36) for the second and 0·56 (95 % CI 0·32, 0·98) for the third tertile, after controlling for confounders.

Conclusions

In the present retrospective, cross-sectional study, we found that proportions ofn-3 LC PUFA in plasma phospholipids, markers ofn-3 LC PUFA consumption from fish, were inversely associated with PD.

Docosahexaenoic acid supplementation in pregnancy and lactation

The goal of the Experimental Biology symposium on maternal supplementation was to review all available lines of evidence, delineate unanswered questions, and develop, if it seemed reasonable, a research agenda to determine whether maternal supplementation with specific nutrients might be beneficial. In the case of maternal docosahexaenoic acid (DHA) status, the topic addressed in this article, few clinical studies show benefits of maternal DHA supplementation during pregnancy or lactation for the infant or child. However, quite a large number of observational studies link higher intrauterine DHA exposure to a number of positive developmental outcomes. This article reviews the factors known to contribute to DHA status of women and their offspring during the reproductive cycle, relates maternal DHA status to that of the developing fetus and newborn, and reviews the evidence for functional differences in behavior related to DHA status, including the available evidence related to DHA supplementation of women pregnant and lactating and their offspring. Other outcomes for infants and children and for women themselves appear plausible and are also addressed as part of a research agenda for future work.

Uncoupling of interleukin-6 from its signalling pathway by dietary n-3-polyunsaturated fatty acid deprivation alters sickness behaviour in mice

Sickness behaviour is an adaptive behavioural response to the activation of the innate immune system. It is mediated by brain cytokine production and action, especially interleukin-6 (IL-6). Polyunsaturated fatty acids (PUFA) are essential fatty acids that are highly incorporated in brain cell membranes and display immunomodulating properties. We hypothesized that a decrease in n-3 (also known as omega3) PUFA brain level by dietary means impacts on lipopolysaccharide (LPS)-induced IL-6 production and sickness behaviour. Our results show that mice exposed throughout life to a diet containing n-3 PUFA (n-3/n-6 diet) display a decrease in social interaction that does not occur in mice submitted to a diet devoid of n-3 PUFA (n-6 diet). LPS induced high IL-6 plasma levels as well as expression of IL-6 mRNA in the hippocampus and cFos mRNA in the brainstem of mice fed either diet, indicating intact immune-to-brain communication. However, STAT3 and STAT1 activation, a hallmark of the IL-6 signalling pathway, was lower in the hippocampus of LPS-treated n-6 mice than n-3/n-6 mice. In addition, LPS did not reduce social interaction in IL-6-knockout (IL-6-KO) mice and failed to induce STAT3 activation in the brain of IL-6-KO mice. Altogether, these findings point to alteration in brain STAT3 as a key mechanism for the lack of effect of LPS on social interaction in mice fed with the n-6 PUFA diet. The relative deficiency of Western diets in n-3 PUFA could impact on behavioural aspects of the host response to infection.

Docosahexaenoic acid supplementation and time at achievement of gross motor milestones in healthy infants: a randomized, prospective, double-blind, placebo-controlled trial

BACKGROUND

Docosahexaenoic acid (DHA) intake throughout the first year of life is associated with neurodevelopmental and neuropsychological benefits. Few studies have evaluated the role of DHA intakes on age at achievement of gross motor milestones.

OBJECTIVE

The objective was to assess the effects of DHA supplementation throughout the first year of life on the achievement of four gross motor milestones in healthy infants.

DESIGN

In this multicenter prospective, randomized, double-blind, placebo-controlled trial, 1160 healthy neonates were assigned to receive supplementation with either 20 mg liquid DHA (n = 580) or placebo (n = 580) orally once daily throughout the first year of life. The primary endpoint was the time at achievement of 4 gross motor milestones (sitting without support, hands-and-knees crawling, standing alone, and walking alone). All analyses were performed on an intention-to-treat basis.

RESULTS

The time to achievement of sitting without support was shorter (P < 0.001) in infants who received DHA [median: 26 wk; interquartile range (IQR): 24-29 wk] than in those who received placebo (27 wk; 26-31 wk). No significant difference between infants who received DHA or placebo was found for hands-and-knees crawling [39 wk (34-44 wk) compared with 40 wk (35-44 wk), respectively], standing alone [49 wk (43-55 wk) compared with 49 wk (44-57 wk), respectively], and walking alone [55 wk (50-60 wk) compared with 56 wk (52-61 wk), respectively].

CONCLUSIONS

Despite the 1-wk advance in sitting without support associated with DHA supplementation, no demonstrable persistent effects of DHA supplementation on later motor development milestones were found. Thus, the long-term clinical significance of the 1-wk change in sitting without support, if any, remains unknown. This trial is registered at (clinicaltrials.gov) as NCT00610922.

Maternal DHA levels and toddler free-play attention

We investigated the relationship between maternal docosahexaenoic acid (DHA) levels at birth and toddler free-play attention in the second year. Toddler free-play attention was assessed at 12 and 18 months, and maternal erythrocyte (red-blood cell; RBC) phospholipid DHA (percentage of total fatty acids) was measured from mothers at delivery. Overall, higher maternal DHA status at birth was associated with enhanced attentional functioning during the second year. Toddlers whose mothers had high DHA at birth exhibited more total looking and fewer episodes of inattention during free-play than did toddlers whose mothers had low DHA at birth. Analyses also provided further information on changes in attention during toddlerhood. These findings are consistent with evidence suggesting a link between DHA and cognitive development in infancy and early childhood.

Dietary arachidonic acid dose-dependently increases the arachidonic acid concentration in human milk

Lactation hampers normalization of the maternal arachidonic acid (AA) status, which is reduced after pregnancy and can further decline by the presently recommended increased consumption of (n-3) long-chain PUFA [(n-3) LCPUFA]. This may be unfavorable for breast-fed infants, because they also require an optimum supply of (n-6) LCPUFA. We therefore investigated the LCPUFA responses in nursing mothers upon increased consumption of AA and (n-3) LCPUFA. In a parallel, double-blind, controlled trial, lactating women received for 8 wk no extra LCPUFA (control group, n = 8), 200 (low AA group, n = 9), or 400 (high AA group, n = 8) mg/d AA in combination with (n-3) LCPUFA [320 mg/d docosahexaenoic acid (DHA), 80 mg/d eicosapentaenoic acid, and 80 mg/d other (n-3) fatty acids], or this dose of (n-3) LCPUFA alone [DHA + eicosapentaenoic acid group, n = 8]. Relative concentrations of AA, DHA, and sums of (n-6) and (n-3) LCPUFA were measured in milk total lipids (TL) and erythrocyte phospholipids (PL) after 2 and 8 wk and changes were compared by ANCOVA. The combined consumption of AA and (n-3) LCPUFA caused dose-dependent elevations of AA and total (n-6) LCPUFA concentrations in milk TL and did not significantly affect the DHA and total (n-3) LCPUFA increases caused by (n-3) LCPUFA supplementation only. This latter treatment did not significantly affect breast milk AA and total (n-6) LCPUFA concentrations. AA and DHA concentrations in milk TL and their changes were strongly and positively correlated with their corresponding values in erythrocyte PL (r(2) = 0.27-0.50; P </= 0.002). We thus concluded that the consumption by lactating women of AA in addition to extra (n-3) LCPUFA dose dependently increased the AA concentration of their milk TL.

Role of long-chain polyunsaturated fatty acids in the first year of life

The 2 most abundant long-chain polyunsaturated fatty acids (LCPUFAs) in the brain are docosahexaenoic acid (DHA) and arachidonic acid (ARA), where they have a functional and structural role in infant development. DHA is concentrated in the prefrontal cortex, which is important for association and short-term memory, and in some retinal cells. Concentrations of PUFAs in human breast milk are relatively consistent during the first year of life, and studies have shown that breast-fed infants have a greater mean weight percentage of DHA and a greater proportion of DHA in their red blood cells and brain cortex than formula-fed infants. Furthermore, cortex DHA in breast-fed infants increases with age, probably due to the length of feeding. Maternal supplementation with cod liver oil, which is rich in DHA and eicosapentaenoic acid, improved children's intelligence quotient compared with corn-oil supplementation by 4 years of age. The LCPUFA content of human breast milk is affected by a number of factors, including diet, gestational age, parity, and smoking. Supplementation of formula feed with DHA and ARA results in infant development that is similar to breast-feeding, and may have benefits on blood pressure in later childhood. The beneficial effects of LCPUFA supplementation on visual acuity continue after weaning irrespective of the type of diet. The long-term effects and duration of supplementation of breast- and formula-fed infants requires further investigation.

Dietary supplementation with cholesterol and docosahexaenoic acid increases the activity of the arginine-nitric oxide pathway in tissues of young pigs

Nitric oxide (NO), synthesized from l-arginine by tetrahydrobiopterin (BH4)-dependent NO synthase (NOS), is critical for neurological and muscular development and function. This study was designed to test the hypothesis that cholesterol and docosahexaenoic acid (DHA) may modulate the arginine-NO pathway in tissues of the young pig. Sixteen newborn pigs were nursed by sows for 24h and then assigned to one of four treatment groups, representing supplementation with 0.0%, 0.2% cholesterol, 0.2% DHA, or cholesterol plus DHA to the basal milk-formula. All piglets were euthanized at 49 days of age. Brain, liver and gastrocnemius muscle were analyzed for BH4, NADPH and arginine, GTP cyclohydrolase-I (GTP-CH) and NOS activities, and NOS protein isoforms. Hepatic NOS activity was below the detection limit in all pigs. DHA supplementation (P<0.01) increased GTP-CH activities, as well as BH4 and NADPH concentrations in brain, liver, and muscle by 24-46%, while enhancing (P<0.05) NOS activities by 45-48% in brain and muscle. Dietary cholesterol supplementation increased (P<0.05) NOS and GTP-CH activities by 17-26% in brain but had no effect in liver or muscle. The enhanced NOS activity in the brain or muscle of cholesterol- or DHA-supplemented piglets was attributable to the combined effects of increased eNOS and nNOS activation (changes in phosphorylation levels) and total iNOS protein. Additionally, DHA and cholesterol enhanced (P<0.05) arginine concentrations in brain (35-42%), but not in liver or muscle. These tissue-specific effects of cholesterol and DHA on NO synthesis may play an important role in postnatal growth and development.

Maturation of rod function in preterm infants with and without retinopathy of prematurity

OBJECTIVES

To establish normal development of rod electroretinograms in preterm infants and to assess the effects of retinopathy of prematurity (ROP).

STUDY DESIGN

We measured 88 Naka-Rushton functions from 41 preterm infants at maturities from 30 to 72 weeks postmenstrual age (PMA). Outcomes (log sigma, retinal sensitivity and V(max), retinal responsivity) were compared between control (no ROP), untreated ROP, and treated ROP.

RESULTS

In control infants, sensitivity increased by 1.5 log units from 30 to 40 weeks PMA and by a further 0.5 log units by 50 weeks PMA but was 0.5 log units less than in similarly-mature, healthy, term-born infants. Average retinal responsivity increased from 23 microV to 90 microV between 30 and 40 weeks PMA and was 35 muV greater at 40 weeks PMA than in similarly-mature term-born infants. At around 36 weeks PMA, (when onset of ROP peaks), infants with untreated ROP had average retinal sensitivity 0.2 log units lower than control infants; sensitivity was reduced further in infants treated for ROP. Retinal responsiveness did not differ between control subjects and untreated infants with ROP but was greatly reduced in infants treated for ROP.

CONCLUSIONS

Maturation of rod sensitivity appears to be slowed by preterm birth whereas maturation of rod responsivity is accelerated. ROP reduces retinal sensitivity, and treated ROP reduces both sensitivity and responsivity.

Dietary supplementation with cholesterol and docosahexaenoic acid affects concentrations of amino acids in tissues of young pigs

Cholesterol and docosahexaenoic acid (DHA) are important nutrients for neural development of infants. However, little is known about the effect of cholesterol or DHA on concentrations of amino acids (AA) in neonatal tissues. This study was conducted with the piglet (an established model for studying human infant nutrition) to test the hypothesis that dietary supplementation with the lipids may modulate AA availability in tissues. Sixteen newborn pigs were nursed by sows for 24 h and then assigned to one of four treatment groups, representing supplementation with 0.0% (control), 0.2% cholesterol, 0.2% DHA, or cholesterol plus DHA to the basal milk-formula. All piglets were euthanized at 49 days of age. In brain, cholesterol supplementation reduced (P < 0.05) concentrations of glutamate, serine, glutamine, threonine, beta-alanine, alanine, methionine, isoleucine, leucine, and gamma-aminobutyrate but increased (P < 0.05) concentrations of glycine and lysine, whereas DHA supplementation similarly affected (P < 0.05) concentrations of the same AA (except for isoleucine and lysine) and taurine. In addition, concentrations of most AA in liver, muscle and plasma were substantially altered by dietary supplementation of cholesterol and DHA in a tissue-dependent manner. Further, DHA reduced concentrations of carnosine in skeletal muscle, as well as ammonia in both plasma and brain. The results reveal that cholesterol and DHA can regulate AA metabolism and availability in various tissues of piglets. These novel findings have important implications for designing the next generation of infant formula to optimize neonatal growth and development.

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.

Effect of supplementing pregnant and lactating mothers with n-3 very-long-chain fatty acids on children's IQ and body mass index at 7 years of age

OBJECTIVES

Arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3) are essential for brain growth and cognitive development. We have reported that supplementing pregnant and lactating women with n-3 very-long-chain polyunsaturated fatty acids promotes higher IQ scores at 4 years of age as compared with maternal supplementation with n-6 polyunsaturated fatty acids. In our present study, the children were examined at 7 years of age with the same cognitive tests as at 4 years of age. We also examined the relation between plasma fatty acid pattern and BMI in children, because an association between arachidonic acid and adipose tissue size has been suggested.

METHODS

The study was randomized and double-blinded. The mothers took 10 mL of cod liver oil or corn oil from week 18 of pregnancy until 3 months after delivery. Their children were tested with the Kaufman Assessment Battery for Children at 7 years of age, and their height and weight were measured.

RESULTS

We did not find any significant differences in scores on the Kaufman Assessment Battery for Children test at 7 years of age between children whose mothers had taken cod liver oil (n = 82) or corn oil (n = 61). We observed, however, that maternal plasma phospholipid concentrations of alpha-linolenic acid (18:3n-3) and docosahexaenoic acid during pregnancy were correlated to sequential processing at 7 years of age. We observed no correlation between fatty acid status at birth or during the first 3 months of life and BMI at 7 years of age.

CONCLUSION

This study suggests that maternal concentration of n-3 very-long-chain polyunsaturated fatty acids during pregnancy might be of importance for later cognitive function, such as sequential processing, although we observed no significant effect of n-3 fatty acid intervention on global IQs. Neonatal fatty acid status had no influence on BMI at 7 years of age.

Fish oil supplementation of control and (n-3) fatty acid-deficient male rats enhances reference and working memory performance and increases brain regional docosahexaenoic acid levels

Most previous studies have focused on improved reference memory and recovery of whole brain docosahexaenoic acid [DHA, 22:6(n-3)] levels in DHA-deficient animals supplemented with fish oil (FO) or switched to an adequate DHA-enriched diet. The aims of this study were to determine whether reference and working memory performance can be enhanced in control male rats and improved in (n-3) fatty acid-deficient male rats given an FO supplement and whether brain DHA accumulation, deficiency, and recovery are region specific. From the embryo to postnatal d 140, 4 groups of rats were fed a nonpurified or sunflower oil-based (n-3) fatty acid-deficient diet alone or supplemented with (n-3) fatty acids from FO representing approximately 0.3% of the energy source. The male rats were tested at postnatal d 102-130 for spatial learning memory performance in the Morris water maze. The fatty acid composition of different brain regions was analyzed by GC. Rats fed the (n-3) fatty acid-deficient diet showed significantly poorer reference and working memory, and FO supplementation partially rescued both memory performances. Furthermore, FO supplementation during brain development and adulthood in normal rats resulted in significant enhancement of both memories. Following dietary DHA repletion, the hippocampus and olfactory bulbs accumulated more DHA, were more resistant to dietary DHA deprivation, and showed better DHA recovery than the visual cortex, frontal cortex, and cerebellum. These results suggest that DHA is critical for the development and maintenance of learning memory performance.

Effect of long-chain polyunsaturated fatty acid supplementation of preterm infants on disease risk and neurodevelopment: a systematic review of randomized controlled trials

BACKGROUND

Supplementation of preterm formulas with long-chain polyunsaturated fatty acids (LCPUFAs) is based on their effectiveness to increase blood status and improve visual outcomes. Dispute remains over their efficacy on global development.

OBJECTIVE

The objective was to compare the effects of LCPUFA-supplemented with those of control formulas on neurodevelopment and diseases associated with prematurity.

DESIGN

We systematically reviewed randomized controlled trials involving preterm infants that tested LCPUFA-supplemented formulas. The weighted mean differences (WMDs) in neurodevelopmental scores and relative risk (RR) of disease were calculated to compare infants fed LCPUFA-supplemented formula with those fed control formula.

RESULTS

No clear differences in Bayley Scales of Infant Development (BSID) scores were observed between groups. Mental development of LCPUFA-supplemented infants was 3.4 points higher than that of control infants with BSID version II (WMD: 3.44; 95% CI: 0.56, 6.31; P = 0.02; n = 879), although it was driven by 2 trials with large effect sizes and wide CIs. Psychomotor development was lower in supplemented infants tested with BSID version I (WMD: -7.99; 95% CI: -14.00, -1.99; P = 0.009; n = 87); however, it was limited by small sample sizes. No differences in the RR of sepsis (1.08; 95% CI: 0.79, 1.46; P = 0.63; n = 1333) or in the RR of necrotizing enterocolitis (1.13; 95% CI: 0.62, 2.04; P = 0.69; n = 1333) were found. Similarly, the risks of retinopathy of prematurity, intraventricular hemorrhage, and bronchopulmonary dysplasia were not different between groups, but data were limited by small sample sizes and trials with an increased risk of bias.

CONCLUSIONS

LCPUFA-supplemented formula does not alter the risk of NEC or sepsis. Further work is needed to determine the extent of benefit of LCPUFA-supplemented formula on the mental development of preterm infants.

Differences in fatty acid composition between cerebral brain lobes in juvenile pigs after fish oil feeding

Very long-chain n-3 PUFA from fish are suggested to play a role in the development of the brain. Fish oil feeding results in higher proportions of n-3 PUFA in the brains of newborn piglets. However, the effect of fish oil on the fatty acid composition of specific cerebral brain lobes in juvenile pigs is largely uninvestigated. This study examined the effect of a fish oil diet on the fatty acid composition of the frontal, parietal, temporal and occipital brain lobes in juvenile pigs (7 weeks old). Pigs were randomly allocated to a semipurified pig diet containing either 4% (w/w) fish oil (n 19) or 4% (w/w) high-oleic acid sunflower oil (HOSF diet, n 18) for a period of 8 weeks. The fish oil diet resulted in significantly higher proportions (%) of DHA in the frontal (10.6 (SD1.2)), parietal (10.2 (SD1.5)) and occipital brain lobes (9.9 (SD 1.3)), but not in the temporal lobe (7.7 (SD1.6)), compared with pigs fed the HOSF diet (frontal lobe, 7.5 (SD1.0); parietal lobe, 8.1 (SD 1.3); occipital lobe, 7.3 (SD1.2), temporal lobe, 6.6 (SD1.2). Moreover, the proportion of DHA was significantly lower in the temporal lobe compared with the frontal, parietal and occipital brain lobes in pigs fed a fish oil diet. In conclusion, the brains of juvenile pigs appear to be responsive to dietary fish oil, although the temporal brain lobe is less responsive compared with the other three brain lobes. The functional consequences of these differences are a challenging focus for future investigation.

Beneficial effects of a polyunsaturated fatty acid on infant development: evidence from the inuit of arctic Quebec

OBJECTIVES

To examine the relation of cord plasma docosahexaenoic acid (DHA) concentration to gestation length, birth size, growth, and infant visual acuity, cognitive, and motor development and the effects on growth and development associated with DHA intake from breast-feeding.

STUDY DESIGN

DHA, other polyunsaturated fatty acids, and 3 environmental contaminants (polychlorinated biphenyls, mercury, and lead) were assessed in cord plasma and maternal plasma and milk in 109 Inuit infants in Arctic Quebec. Multiple regression was used to examine the relation of cord DHA and DHA from breast-feeding on growth and development at 6 and 11 months, after controlling for contaminant exposure and other potential confounders.

RESULTS

Higher cord DHA concentration was associated with longer gestation, better visual acuity and novelty preference on the Fagan Test at 6 months, and better Bayley Scale mental and psychomotor performance at 11 months. By contrast, DHA from breast-feeding was not related to any indicator of cognitive or motor development in this full-term sample.

CONCLUSIONS

The association of higher cord DHA concentration with more optimal visual, cognitive, and motor development is consistent with the need for substantial increases in this critically important fatty acid during the third trimester spurt of synaptogenesis in brain and photoreceptor development.

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.

Folic acid and polyunsaturated fatty acids improve cognitive function and prevent depression, dementia, and Alzheimer's disease--but how and why?

Low blood folate and raised homocysteine concentrations are associated with poor cognitive function. Folic acid supplementation improves cognitive function. Folic acid enhances the plasma concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). EPA, DHA, and arachidonic acid (AA) are of benefit in dementia and Alzheimer's disease by up-regulating gene expression concerned with neurogenesis, neurotransmission and connectivity, improving endothelial nitric oxide (eNO) generation, enhancing brain acetylcholine levels, and suppressing the production of pro-inflammatory cytokines. EPA, DHA, and AA also form precursors to anti-inflammatory compounds such as lipoxins, resolvins, and neuroprotectin D1 (NPD1) that protect neurons from the cytotoxic action of various noxious stimuli. Furthermore, various neurotrophins and statins enhance the formation of NPD1 and thus, protect neurons from oxidative stress and prevent neuronal apoptosis Folic acid improves eNO generation, enhances plasma levels of EPA/DHA and thus, could augment the formation of NPD1. These results suggest that a combination of EPA, DHA, AA and folic acid could be of significant benefit in dementia, depression, and Alzheimer's disease and improve cognitive function.

Soy-based infant formula supplemented with DHA and ARA supports growth and increases circulating levels of these fatty acids in infants

Healthy term infants (n = 244) were randomized to receive: (1) control, soy-based formula without supplementation or (2) docosahexaenoic acid-arachidonic acid (DHA + ARA), soy-based formula supplemented with at least 17 mg DHA/100 kcal (from algal oil) and 34 mg ARA/100 kcal (from fungal oil) in a double-blind, parallel group trial to evaluate safety, benefits, and growth from 14 to 120 days of age. Anthropometric measurements were taken at 14, 30, 60, 90, and 120 days of age and 24-h dietary and tolerance recall were recorded at 30, 60, 90, and 120 days of age. Adverse events were recorded throughout the study. Blood samples were drawn from subsets of 25 infants in each group. Capillary column gas chromatography was used to analyze the percentages of fatty acids in red blood cell (RBC) lipids and plasma phospholipids. Compared with the control group, percentages of fatty acids such as DHA and ARA in total RBC and plasma phospholipids were significantly higher in infants in the DHA + ARA group at 120 days of age (P < 0.001). Growth rates did not differ significantly between feeding groups at any assessed time point. Supplementation did not affect the tolerance of formula or the incidence of adverse events. Feeding healthy term infants soy-based formula supplemented with DHA and ARA from single cell oil sources at concentrations similar to human milk significantly increased circulating levels of DHA and ARA when compared with the control group. Both formulas supported normal growth and were well tolerated.

Fatty acids and early human development

Fatty acids play central roles in growth and development through their roles in membrane lipids, as ligands for receptors and transcription factors that regulate gene expression, precursor for eicosanoids, in cellular communication, and through direct interactions with proteins. Adverse fatty acid supplies during fetal and child development alter the fatty acid composition of membrane phospholipids and storage triglycerides with the potential to disrupt cellular environments, and program structure and function. Maternal fatty acid nutrition during pregnancy and lactation determines the transfer of essential n-6 and n-3, and non-essential trans fatty acids via the placenta and through human milk. Poor maternal docosahexaenoic acid (DHA) status increases risk of inadequate DHA to support brain and retinal development, delaying or limiting neural and visual system development. The implications of recent changes in the dietary fatty acids on maternal to infant fatty acid transfer, including the composition of human milk has been insufficiently studied.

The influence of dietary docosahexaenoic acid and arachidonic acid on central nervous system polyunsaturated fatty acid composition

Numerous studies on perinatal long-chain polyunsaturated fatty acid nutrition have clarified the influence of dietary docosahexaenoic acid (DHA) and arachidonic acid (ARA) on central nervous system PUFA concentrations. In humans, omnivorous primates, and piglets, DHA and ARA plasma and red blood cells concentrations rise with dietary preformed DHA and ARA. Brain and retina DHA are responsive to diet while ARA is not. DHA is at highest concentration in cells and tissues associated with high energy consumption, consistent with high DHA levels in mitochondria and synaptosomes. DHA is a substrate for docosanoids, signaling compounds of intense current interest. The high concentration in tissues with high rates of oxidative metabolism may be explained by a critical role related to oxidative metabolism.

Human milk: maternal dietary lipids and infant development

Human milk provides all the dietary essential fatty acids, linoleic acid (LA; 18:2n-6) and alpha-linolenic acid (18:3n-3), as well as their longer-chain more-unsaturated metabolites, including arachidonic acid (20:4n-6) and DHA (22:6n-3) to support the growth and development of the breast-fed infant. Human milk levels of LA have increased in Westernized nations from mean levels (g/100 g total fatty acids) of 6 to 12-16 over the last century, paralleling the increase in dietary intake of LA-rich vegetable oils. DHA levels (g/100 g total milk fatty acids) vary from 1% and are lowest in countries in which the intake of DHA from fish and other animal tissue lipids is low. The role of DHA in infant nutrition is of particular importance because DHA is accumulated specifically in the membrane lipids of the brain and retina, where it is important to visual and neural function. An important question is the extent to which many human diets that contain low amounts of n-3 fatty acids may compromise human development. The present paper reviews current knowledge on maternal diet and human milk fatty acids, the implications of maternal diet as the only source of essential fatty acids for infant development both before and after birth, and recent studies addressing the maternal intakes and milk DHA levels associated with risk of low infant neural system maturation.

Metabolic and molecular aspects of ethanolamine phospholipid biosynthesis: the role of CTP:phosphoethanolamine cytidylyltransferase (Pcyt2)

The CDP-ethanolamine branch of the Kennedy pathway is the major route for the formation of ethanolamine-derived phospholipids, including diacyl phosphatidylethanolamine and alkenylacyl phosphatidylethanolamine derivatives, known as plasmalogens. Ethanolamine phospholipids are essential structural components of the cell membranes and play regulatory roles in cell division, cell signaling, activation, autophagy, and phagocytosis. The physiological importance of plasmalogens has not been not fully elucidated, although they are known for their antioxidant properties and deficiencies in a number of inherited peroxisomal disorders. This review highlights important aspects of ethanolamine phospholipid metabolism and reports current molecular information on 1 of the regulatory enzymes in their synthesis, CTP:phosphoethanolamine cytidylyltransferase (Pcyt2). Pcyt2 is encoded by a single, nonredundant gene in animal species that could be alternatively spliced into 2 potential protein products. We describe properties of the mouse and human Pcyt2 genes and their regulatory promoters and provide molecular evidence for the existence of 2 distinct Pcyt2 proteins. The goal is to obtain more insight into Pcyt2 catalytic function and regulation to facilitate a better understanding of the production of ethanolamine phospholipids via the CDP-ethanolamine branch of the Kennedy pathway.

Differential tissue dose responses of (n-3) and (n-6) PUFA in neonatal piglets fed docosahexaenoate and arachidonoate

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are commonly added to infant formula worldwide; however, dietary concentrations needed to obtain optimal tissue levels have not been established. Hence, we studied tissue responses in piglets fed various doses of DHA and ARA. Doses were 0, 1, 2, and 5 times those used in U.S. infant formulas and DHA/ARA in Diet 0, Diet 1, Diet 2, and Diet 5 were 0, 4.1/8.1, 8.1/16.2, and 20.3/40.6 mg/100 kJ formula, respectively. Supplementation of dietary DHA and ARA increased DHA in brain, retina, liver, adipose tissue, plasma, and erythrocyte by 1.1- to 25.8-fold of Diet 0 (P-trend < 0.01). Tissue ARA (1.1- to 6.0-fold of Diet 0) responded to dietary ARA in liver, adipose tissue, plasma, and erythrocytes (P-trend < 0.05); brain and retina ARA was, however, unresponsive to dietary DHA and ARA. Plasma and erythrocyte DHA were positively associated with DHA in neural (brain and retina) and visceral (liver and adipose) tissues (r(2) = 0.11-0.56; P < 0.001-P = 0.042). Plasma and erythrocyte ARA did not correlate with neural ARA. Only plasma ARA was associated with liver ARA (r(2) = 0.222; P = 0.02) and adipose ARA (r(2) = 0.867; P < 0.001) and erythrocyte ARA correlated with adipose ARA (r(2) = 0.470; P < 0.001). We conclude that dietary DHA supplementation affords an effective strategy for enhancing tissue DHA, ARA in visceral but not neural tissues is sensitive to dietary ARA, and erythrocyte and plasma DHA can be used as proxies for tissue DHA, although blood-borne ARA is not an indicator of neural ARA.

Changes in the lipid composition of powdered infant formulas during long-term storage

Changes in the lipid composition of two standard infant formulas induced by 4 years of storage were determined. Lipids were thoroughly analyzed using different gas-liquid and liquid-liquid chromatographic techniques. Oleic acid and linoleic acid, which accounted for almost the total monounsaturated and polyunsaturated fatty acids, respectively, showed slight but significant decreases (P < 0.05) during the 4 years of storage (from 41.52 to 39.83% for oleic acid and from 17.35 to 15.99% for linoleic acid). Total trans fatty acid isomers showed low initial level (0.22% of total fatty acids), and such level remained unchanged during the storage period. Nonvolatile oxidation compounds including oxidized, dimeric, and polymeric triglycerides did not significantly increase during the storage period, although a significant loss of tocopherols was found in the surface oil fraction (10-15%). In general, the results obtained indicate that, although small losses of oleic and linolenic acid as well as tocopherols were found, the 4 year storage period did not lead to relevant changes in the lipid fraction of infant formulas.

Dietary long-chain polyunsaturated fatty acid supplementation in infants with phenylketonuria: a randomized controlled trial

BACKGROUND

Pre- and postnatal tissue accretion of long-chain polyunsaturated fatty acids (LCPUFA) has been related to visual and cognitive development in healthy children in several studies. Children with phenylketonuria (PKU) consume diets with very low contents of preformed LCPUFA. We studied prospectively the LCPUFA status in infants with PKU without or with LCPUFA supplementation during the first year of life.

SUBJECTS AND METHODS

Infants with PKU were enrolled at diagnosis (<4 weeks of age) and randomized double blind to phenylalanine-free amino acid supplements without LCPUFA (n = 11) or with both arachidonic (AA, 0.46 wt%) and docosahexaenoic acids (DHA, 0.27 wt%) (n = 10). At enrolment and again at 1, 2, 3, 4, 6, 9 and 12 months, plasma phospholipid fatty acids were measured and dietary intakes were calculated from dietary protocols.

RESULTS

Unsupplemented patients showed a marked LCPUFA depletion to levels clearly below those observed in healthy breast-fed infants. In contrast, supplemented infants had stable and higher LCPUFA levels than unsupplemented infants, reaching significant differences for AA values at 3, 4 and 6 months, and for DHA values at 1, 3, 4, 6, 9 and 12 months. Plasma phospholipid levels correlated closely with estimated dietary intakes of preformed LCPUFA.

CONCLUSION

Low LCPUFA intakes with PKU diets induce marked depletion of AA and particularly of DHA in the first year of life. Thus endogenous synthesis of LCPUFA from precursors supplied by diet seems unable to compensate for low LCPUFA intakes. LCPUFA supplementation of PKU diets during the first year of life effectively enhances LCPUFA status to levels comparable to those of healthy breast-fed infants.

The influence of moderate and high dietary long chain polyunsaturated fatty acids (LCPUFA) on baboon neonate tissue fatty acids

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are now common ingredients in commercial infant formulas, however, the optimal levels have not been established. Our previous data showed that the current amount of DHA in U.S. term formulas, 0.3%w/w, is insufficient to normalize cerebral cortex DHA to levels in breastfed baboon neonate controls (Diau et al.: BMC Medicine 3: 11, 2005). Here, we report on the influence of higher formula DHA levels on 12-wk-old full-term baboon CNS and visceral organs. Fourteen nursery-reared baboons were randomized to one of three diets: control (C, no DHA-ARA); moderate LCPUFA (L, 0.33%DHA-0.67%ARA); high LCPUFA (L3, 1.00%DHA-0.67%ARA). DHA increased significantly in liver, heart, and plasma (all C < L < L3), RBC (C < L, L3), and CNS regions: precentral gyrus (C < L < L3), frontal cortex, inferior and superior colliculi, globus pallidus, and caudate (all C < L, L3). These data extend previous observations indicating that 1) tissue DHA is more sensitive to diet than ARA; 2) cerebral cortex DHA increases with higher levels of DHA than in present commercial formulas; and 3) basal ganglia and limbic system DHA saturate with levels of DHA currently available in formulas. These results imply that higher levels of DHA are necessary to normalize cortex DHA to those found in breastfed animals.

Visual acuity and cognitive outcomes at 4 years of age in a double-blind, randomized trial of long-chain polyunsaturated fatty acid-supplemented infant formula

BACKGROUND

While there is a large body of data on the effects of long-chain polyunsaturated fatty acid supplementation of infant formula on visual and cognitive maturation during infancy, longterm visual and cognitive outcome data from randomized trials are scarce.

AIM

To evaluate docosahexaenoic acid (DHA) and arachidonic acid (ARA)-supplementation of infant formula on visual and cognitive outcomes at 4 years of age.

METHODS

Fifty-two of 79 healthy term infants who were enrolled in a single-center, double-blind, randomized clinical trial of DHA and ARA supplementation of infant formula were available for follow-up at 4 years of age. In addition, 32 breast-fed infants served as a "gold standard". Outcome measures were visual acuity and the Wechsler Preschool and Primary Scale of Intelligence--Revised.

RESULTS

At 4 years, the control formula group had poorer visual acuity than the breast-fed group; the DHA- and DHA+ARA-supplemented groups did not differ significantly from the breast-fed group. The control formula and DHA-supplemented groups had Verbal IQ scores poorer than the breast-fed group.

CONCLUSION

DHA and ARA-supplementation of infant formula supports visual acuity and IQ maturation similar to that of breast-fed infants.

Differential cerebral cortex transcriptomes of baboon neonates consuming moderate and high docosahexaenoic acid formulas

BACKGROUND

Docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6) are the major long chain polyunsaturated fatty acids (LCPUFA) of the central nervous system (CNS). These nutrients are present in most infant formulas at modest levels, intended to support visual and neural development. There are no investigations in primates of the biological consequences of dietary DHA at levels above those present in formulas but within normal breastmilk levels.

METHODS AND FINDINGS

Twelve baboons were divided into three formula groups: Control, with no DHA-ARA; "L", LCPUFA, with 0.33%DHA-0.67%ARA; "L3", LCPUFA, with 1.00%DHA-0.67%ARA. All the samples are from the precentral gyrus of cerebral cortex brain regions. At 12 weeks of age, changes in gene expression were detected in 1,108 of 54,000 probe sets (2.05%), with most showing <2-fold change. Gene ontology analysis assigns them to diverse biological functions, notably lipid metabolism and transport, G-protein and signal transduction, development, visual perception, cytoskeleton, peptidases, stress response, transcription regulation, and 400 transcripts having no defined function. PLA2G6, a phospholipase recently associated with infantile neuroaxonal dystrophy, was downregulated in both LCPUFA groups. ELOVL5, a PUFA elongase, was the only LCPUFA biosynthetic enzyme that was differentially expressed. Mitochondrial fatty acid carrier, CPT2, was among several genes associated with mitochondrial fatty acid oxidation to be downregulated by high DHA, while the mitochondrial proton carrier, UCP2, was upregulated. TIMM8A, also known as deafness/dystonia peptide 1, was among several differentially expressed neural development genes. LUM and TIMP3, associated with corneal structure and age-related macular degeneration, respectively, were among visual perception genes influenced by LCPUFA. TIA1, a silencer of COX2 gene translation, is upregulated by high DHA. Ingenuity pathway analysis identified a highly significant nervous system network, with epidermal growth factor receptor (EGFR) as the outstanding interaction partner.

CONCLUSIONS

These data indicate that LCPUFA concentrations within the normal range of human breastmilk induce global changes in gene expression across a wide array of processes, in addition to changes in visual and neural function normally associated with formula LCPUFA.

Effects of n-3 long chain polyunsaturated fatty acid supplementation on visual and cognitive development throughout childhood: a review of human studies

The present paper evaluates the most recent randomized controlled trials assessing the efficacy of n-3 LCPUFA supplementation (with or without n-6 LCPUFA) during pregnancy, lactation, infancy and childhood on visual and cognitive development. Available evidence suggests a beneficial effect of maternal n-3 LCPUFA supplementation during pregnancy and lactation on cognitive development of infants and children, but not for visual development. Evidence for an effect of LCPUFA supplementation of preterm and term infants on cognitive development of infants remains inconclusive. However, supplementing term infants with daily doses of 100 mg docosahexaenoic acid plus 200 mg arachidonic acid improves visual development as measured by electrophysiological tests. Evidence for benefits of n-3 LCPUFA on cognitive development in healthy children older than 2 years of age is too limited to allow a clear conclusion. Taken together, the evidence for potential benefits of LCPUFA supplementation is promising but yet inconclusive.

Has an aquatic diet been necessary for hominin brain evolution and functional development?

A number of authors have argued that only an aquatic-based diet can provide the necessary quantity of DHA to support the human brain, and that a switch to such a diet early in hominin evolution was critical to human brain evolution. This paper identifies the premises behind this hypothesis and critiques them on the basis of clinical literature. Both tissue levels and certain functions of the developing infant brain are sensitive to extreme variations in the supply of DHA in artificial feeding, and it can be shown that levels in human milk reflect maternal diet. However, both the maternal and infant bodies have mechanisms to store and buffer the supply of DHA, so that functional deficits are generally resolved without compensatory diets. There is no evidence that human diets based on terrestrial food chains with traditional nursing practices fail to provide adequate levels of DHA or other n-3 fatty acids. Consequently, the hypothesis that DHA has been a limiting resource in human brain evolution must be considered to be unsupported.

Biochemical homeostasis and body growth are reliable end points in clinical nutrition trials

Studies of biochemical homeostasis and/or body growth have been included as outcome variables in most nutrition trials in paediatric patients. Moreover, these outcome variables have provided important insights into the nutrient requirements of infants and children, and continue to do so. Examples of the value of such studies in improving parenteral nutrition, in defining essential fatty acid metabolism and requirements of infants and in defining the protein and energy needs of low-birth-weight infants are discussed. Data from such studies have helped to define the mechanism of metabolic acidosis and hyperammonaemia associated with the use of early crystalline amino acid mixture and, hence, how to prevent these disorders. Such studies have allowed the development of parenteral amino acid mixtures that circumvent grossly abnormal plasma concentrations of most amino acids and appear to be utilized more efficiently. These studies have also helped define micronutrient requirements, including requirements for several such nutrients that had not been previously recognized as essential (e.g. Cr, Se, Mo, α-linolenic acid). Studies of body growth have been particularly valuable in defining the nutritional requirements of low-birth-weight infants. Finally, studies of metabolic homeostasis coupled with more sophisticated metabolic studies have provided considerable insight into the metabolism of the essential fatty acids, linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3). Although such studies have not defined the amount of the longer-chain PUFA synthesized from each of these essential fatty acids, i.e. arachidonic acid (20:4n-6) and DHA (22:6n-3), they have shown that the rates of conversion are extremely variable from infant to infant, suggesting a possible explanation of why some studies show developmental advantages from intake of these fatty acids while others do not.

Infants fed docosahexaenoic acid- and arachidonic acid-supplemented formula have decreased incidence of bronchiolitis/bronchitis the first year of life

To assess the effect of docosahexaenoic acid and arachidonic acid supplementation in infant formula on the incidence of respiratory illnesses, pediatricians assigned infants to receive docosahexaenoic acid/arachidonic acid-supplemented formula or control formula. Anthropometrics, medical history, and illnesses were reported. Among 1342 infants, there was a higher incidence of bronchiolitis in control versus docosahexaenoic acid/arachidonic acid-supplemented groups at 5, 7, and 9 months (P < .01). Weight, length, and head circumference were similar for both groups. Infants fed formula supplemented with 0.32% docosahexaenoic acid and 0.64% arachidonic acid experienced a lower incidence of bronchiolitis compared with infants fed formula supplemented with no docosahexaenoic acid/arachidonic acid or lower levels of docosahexaenoic acid/arachidonic acid in the first year of life.

Supplementation of n-3 fatty acids during pregnancy and lactation reduces maternal plasma lipid levels and provides DHA to the infants

OBJECTIVE

Docosahexaenoic acid (DHA, 22:6 n-3) is considered an essential fatty acid for the fetus and newborn infant, but the optimal level of supply is not known. We studied the effect of supplementing pregnant and lactating women with marine n-3 polyunsaturated fatty acids (PUFAs) as compared to n-6 PUFAs related to maternal and infant lipid levels.

STUDY DESIGN

Five hundred and ninety pregnant women in weeks 17-19 of pregnancy were recruited. They were given either 10 mL cod liver oil (n-3 PUFAs) or corn oil (n-6 PUFAs) daily until three months after delivery, and 341 women took part in the study until giving birth.

RESULTS

Maternal supplementation with cod liver oil increased the concentration of DHA in maternal as well as infant plasma and umbilical tissue phospholipids, as compared to corn oil. The maternal plasma triacylglycerol increase during pregnancy was less pronounced in women supplemented with cod liver oil as compared to corn oil. The concentration of high-density lipoprotein (HDL)-cholesterol was unchanged during pregnancy in the cod liver oil group, whereas it decreased in the corn oil group, promoting a greater increase in the ratio of total cholesterol/HDL-cholesterol in the corn oil group.

CONCLUSION

Maternal supplementation with n-3 fatty acids during pregnancy and lactation provides more DHA to the infant and reduces maternal plasma lipid levels compared to supplementation with n-6 fatty acids.