Maternal fish oil supplementation in lactation: Effect on visual acuity and n−3 fatty acid content of infant erythrocytes

Studies on formula-fed infants indicate a beneficial effect of dietary DHA on visual acuity. Cross-sectional studies have shown an association between breast-milk DHA levels and visual acuity in breast-fed infants. The objective in this study was to evaluate the biochemical and functional effects of fish oil (FO) supplements in lactating mothers. In this double-blinded randomized trial, Danish mothers with habitual fish intake below the 50th percentile of the Danish National Birth Cohort were randomized to microencapsulated FO [1.3 g/d long-chain n−3 FA (n−3 LCPUFA)] or olive oil (OO). The intervention started within a week after delivery and lasted 4 mon. Mothers with habitual high fish intake and their infants were included as a reference group. Ninety-seven infants completed the trial (44 OO-group, 53 FO-group) and 47 reference infants were followed up. The primary outcome measures were: DHA content of milk samples (0, 2, and 4 mon postnatal) and of infant red blood cell (RBC) membranes (4 mon postnatal), and infant visual acuity (measured by swept visual evoked potential at 2 and 4 mon of age). FO supplementation gave rise to a threefold increase in the DHA content of the 4-mon milk samples (P<0.001). DHA in infant RBC reflected milk contents (r=0.564, P<0.001) and was increased by almost 50% (P<0.001). Infant visual acuity was not significantly different in the randomized groups but was positively associated at 4 mon with infant RBC-DHA (P=0.004, multiple regression). We concluded that maternal FO supplementation during lactation did not enhance visual acuity of the infants who completed the intervention. However, the results showed that infants with higher RBC levels of n−3 LCPUFA had a better visual acuity at 4 mon of age, suggesting that n−3 LCPUFA may influence visual maturation.     

Dietary nucleotides do not alter erythrocyte long-chain polyunsaturated fatty acids in formula-fed term infants

There have been conflicting reports regarding the effectiveness of dietary nucleotides (NT) to regulate tissue desaturases and hence stimulate accumulation of both n−6 and n−3 long-chain polyunsaturated fatty acids (LCPUFA). The aim of this study was to examine the effect of NT-supplemented cow's milk-based formula on erythrocyte phospholipid FA status in a large randomized controlled trial involving a well-nourished infant population born at term. Formula-fed infants were allocated to control formula with an innate level of NT at 10 mg/L (n=102), or formula fortified with NT at 34 mg/L (n=98). A parallel group of breastfed infants was included as a reference. Peripheral blood samples were collected by venipuncture at 7 mon of age and erythrocyte phospholipid FA determined by capillary GC. Erythrocyte LCPUFA levels did not differe between the NT-supplemented and control formula groups and were reduced in both groups compared with breastfed infants. We conclude that there is no induction of LCPUFa accumulation in erythrocyte phospholipids of term, formula-fed infants following 7 mon of NT supplementation.     

Maternal and Neonatal Polyunsaturated Fatty Acid Intake and Risk of Neurodevelopmental Impairment in Premature Infants

The N3 and N6 long chain polyunsaturated fatty acids (LCPUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are essential for proper neurodevelopment in early life. These fatty acids are passed from mother to infant via the placenta, accreting into fetal tissues such as brain and adipose tissue. Placental transfer of LCPUFA is highest in the final trimester, but this transfer is abruptly severed with premature birth. As such, efforts have been made to supplement the post-natal feed of premature infants with LCPUFA to improve neurodevelopmental outcomes. This narrative review analyzes the current body of evidence pertinent to neurodevelopmental outcomes after LCPUFA supplementation in prematurely born infants, which was identified via the reference lists of systematic and narrative reviews and PubMed search engine results. This review finds that, while the evidence is weakened by heterogeneity, it may be seen that feed comprising 0.3% DHA and 0.6% AA is associated with more positive neurodevelopmental outcomes than LCPUFA-deplete feed. While no new RCTs have been performed since the most recent Cochrane meta-analysis in 2016, this narrative review provides a wider commentary; the wider effects of LCPUFA supplementation in prematurely born infants, the physiology of LCPUFA accretion into preterm tissues, and the physiological effects of LCPUFA that affect neurodevelopment. We also discuss the roles of maternal LCPUFA status as a modifiable factor affecting the risk of preterm birth and infant neurodevelopmental outcomes. To better understand the role of LCPUFAs in infant neurodevelopment, future study designs must consider absolute and relative availabilities of all LCPUFA species and incorporate the LCPUFA status of both mother and infant in pre- and postnatal periods.     

Long-chain polyunsaturated fatty acids and eicosanoids in infants-physiological and pathophysiological aspects and open questions

Eicosanoids are highly active lipid mediators in physiologic and pathologic processes, with their effects ranging from cytoprotection and vasoactivity to modulation of inflammatory and proliferative reactions. Generation of eicosanoids can be affected by changes in the pools of their precursors, the long-chain polyunsaturated fatty acids (LCPUFA). Thus, dietary interventions such as supplementation of infant formula with specific n−3 and n−6 LCPUFA will alter formation as well as activity of the eicosanoids produced. This report summarizes the results and discussion of the workshop on “Eicosanoids and Polyunsaturated Fatty Acids in Infants”. The intention of the workshop organizers was to give an overview of the role of eicosanoids in physiological and pathophysiological processes in infants, to discuss the implications that an increased n−3 and n−6 LCPUFA intake may have on eicosanoid genration, and to point out open questions and controversies for future research.     

Noninvasive characterization of neonatal adipose tissue by 13C magnetic resonance spectroscopy

In vivo ¹³C magnetic resonance spectroscopy (MRS) was applied noninvasively to analyze the fatty acid composition of adipose tissue in 21 full-term newborn infants and 6 mothers. In order to assess the effects of gestational and postnatal age on adipose tissue composition, we studied preterm infants at birth, term infants at the ages of 6 wk and at 6 mon. We also investigated the influence of maternal diet on infant adipose tissue composition by studying the breast-fed infants of women who maintained either an omnivore or a vegan diet. Significant differences were observed in adipose tissue composition of neonates compared with their mothers. Neonates had more saturated and less unsaturated fatty acids than their mothers (P<0.01). We also observed changes in adipose tissue composition with maturity. From birth to 6 wk of age ¹³C MR spectra showed a significant increase in the amount of unsaturated fatty acids, particularly polyunsaturated fatty acids (P<0.01). Similarly, differences were seen as a result of gestational age. Preterm infants had relatively fewer unsaturated fatty acids than full-term infants. A greater proportion of these unsaturated fatty acids were polyunsaturated. Our results demonstrate that ¹³C MRS can be utilized to assess noninvasively neonatal adipose tissue lipid composition and to monitor the effects of developmental changes due to gestational age and oral feeding.     

Fish Oil Supplementation During Lactation: Effects on Cognition and Behavior at 7 Years of Age

Early accumulation of n-3 long-chain PUFA (LCPUFA) in the brain may contribute to differences in later cognitive abilities. In this study, our objective was to examine whether fish oil (FO) supplementation during lactation affects processing speed, working memory, inhibitory control, and socioemotional development at 7 years. Danish mothers (n = 122) were randomized to FO [1.5 g/d n-3 LCPUFA] or olive oil (OO) supplementation during the first 4 months of lactation. The trial also included a high-fish intake (HFI) reference group (n = 53). Ninety-eight children were followed-up with an assessment of processing speed, an age-appropriate Stroop task, and the Strength and Difficulties Questionnaire at 7 year. A group effect of the intervention (FO vs. OO) was found in prosocial behavior scores; this negative effect was carried by the boys. Exploratory analyses including all participants revealed the speed of processing scores were predicted by maternal n-3 LCPUFA intake during the intervention period (negative relation) and maternal education (positive relation). Stroop scores indicative of working memory and inhibitory control were predicted by infant erythrocyte DHA status at 4 months of age (negative relation). Early fish oil supplementation may have a negative effect on later cognitive abilities. Speed of processing and inhibitory control/working memory are differentially affected, with speed of processing showing effects of fish oil intake as a whole, whereas inhibitory control/working memory was related more specifically to DHA status.     

Polyunsaturated fatty acid status and neurodevelopment: A summary and critical analysis of the literature

The rationale for randomized trials designed to measure the effects of variable docosahexaenoic acid (DHA) status on neurodevelopment in human infants came from earlier studies of neurodevelopment in animals that were deficient in DHA owing to diets low in alpha-linolenic acid. The session on neurodevelopment looked at the results of these animal studies and discussed outcomes that appear to be analogous in human infants with variable DHA status. Presentations focused mainly on measures of development that may be attributed to more specific developmental domains (e.g., visual attention, recognition memory, problem-solving), some of which have been shown to be affected by long-chain polyunsaturated fatty acid (LCPUFA) status. This paper derives from discussions that took place during the session and reviews subsequent developments in this area. Although more difficult to interpret, global measures of infant development (e.g., the Bayley Scales of Infant Development, and Brunet-Lezine) can only suggest a relationship to specific developmental domains, but they have been applied in some randomized trials of LCPUFA and infant development. Those results are also summarized here.     

Visual acuity and erythrocyte docosahexaenoic acid status in breast-fed and formula-fed term infants during the first four months of life

It has been recognized that preterm infants have a more rapid development of visual acuity if fed human milk or a formula enriched with the long-chain polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) compared to a standard formula devoid of LCPUFA. Few studies have addressed whether the same is also true in term infants. The aim of the present study was to follow visual acuity and fatty acid composition in red blood cells (RBC) for the first 4 mon of life in 17 breast-fed and 16 formula-fed term infants. The formula used did not contain LCPUFA, but contained 1.7 wt% α-linolenic acid, and the linoleic/α-linolenic acid ratio was 8.5. The increase in visual acuity measured by Teller acuity cards developed more rapidly in breast-fed infants compared to formula-fed infants (P<0.001). This was parallelled by a decrease in DHA of RBC in formulafed infants, and with a significantly lower level at two and four months as compared to breast-fed infants. The content of DHA in milk from the breast-feeding mothers was high compared to other Western countries. The difference in visual acuity between the two feeding groups could be due to differences in DHA status as reflected by the RBC levels, but other explanations are possible. Intervention studies are required to verify if development of visual acuity in term formula-fed infants is dependent on the DHA level of formula. Based on a presentation at the AOCS Annual Meeting & Expo in San Antonio, Texas, May 7–11, 1995.     

Daily Enteral DHA Supplementation Alleviates Deficiency in Premature Infants

Docosahexaenoic acid (DHA) is an essential fatty acid (FA) important for health and neurodevelopment. Premature infants are at risk of DHA deficiency and circulating levels directly correlate with health outcomes. Most supplementation strategies have focused on increasing DHA content in mother's milk or infant formula. However, extremely premature infants may not reach full feedings for weeks and commercially available parenteral lipid emulsions do not contain preformed DHA, so blood levels decline rapidly after birth. Our objective was to develop a DHA supplementation strategy to overcome these barriers. This double‐blind, randomized, controlled trial determined feasibility, tolerability and efficacy of daily enteral DHA supplementation (50 mg/day) in addition to standard nutrition for preterm infants (24–34 weeks gestational age) beginning in the first week of life. Blood FA levels were analyzed at baseline, full feedings and near discharge in DHA (n = 31) or placebo supplemented (n = 29) preterm infants. Term peers (n = 30) were analyzed for comparison. Preterm infants had lower baseline DHA levels (p < 0.0001). Those receiving DHA had a progressive increase in circulating DHA over time (from 3.33 to 4.09 wt% or 2.88 to 3.55 mol%, p < 0.0001) while placebo‐supplemented infants (receiving standard neonatal nutrition) had no increase over time (from 3.35 to 3.32 wt% or 2.91 to 2.87 mol%). Although levels increased with additional DHA supplementation, preterm infants still had lower blood DHA levels than term peers (4.97 wt% or 4.31 mol%) at discharge (p = 0.0002). No differences in adverse events were observed between the groups. Overall, daily enteral DHA supplementation is feasible and alleviates deficiency in premature infants.     

The effect of α-linolenic acid and linoleic acid on the growth and development of formula-fed infants: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis aimed to evaluate the effect of modifying 18-carbon PUFA [18-C PUFA: α-linolenic acid (ALA, 18∶3n−3) and linoleic acid (LA, 18∶2n−6)] in the diets of term and preterm infants on DHA (22∶6n−3) status, growth, and developmental outcomes. Only randomized controlled trials (RCT) involving formula-fed term and preterm infants, in which the 18-C PUFA composition of the formula was changed and growth or developmental outcomes were measured, were included. Differences were presented as control (standard formula) and treatment (18-C PUFA-supplemented formula). Primary analyses for term infants were 4 and 12 mon and for preterm infants 37–42 and 57 wk postmenstrual age. Five RCT involving term infants and three RCT involving preterm infants were included in the systematic review. Infants fed ALA-supplemented formula had significantly higher plasma and erythrocyte phospholipid DHA levels than control infants. There was no effect of ALA supplementation on the growth of preterm infants. In term infants, ALA supplementation was associated with increased weight and length at 12 mon, which was at least 4 mon after the end of dietary intervention. Developmental indices of term infants did not differ between groups. There was a transient improvement in the retinal function of preterm infants fed ALA-supplemented diets compared with controls. The findings suggest that ALA-supplemented diets improve the DHA status of infants. Further studies are needed to provide convincing evidence regarding the effects of ALA supplementation of formula on infant growth and development.     

Infant cerebellar gray and white matter fatty acids in relation to age and diet

There is little evidence as to the fatty acid composition of the cerebellum in infancy and it remains uncertain whether milk diet can influence its composition. We therefore examined cerebellar gray and white matter of infants less than 6 mon old who had died unexpectedly. The fatty acid content of 33 gray and 21 white matter specimens from infants born at term and 6 gray and 5 white matter specimens from pretern infants was assessed by gas chromatographic/mass spectrometric analysis. Infants were grouped according to whether they had received human or manufactured formula milk. Whereas cerebellar cortex docosahexaenoic acid (DHA, 22∶6n−3) concentrations were significantly lower (P<0.01) in the formula-fed than breast-fed infants, no differences existed between the term (n=10) and preterm (n=5) Scientific Milk Adaptation (SMA) formula-fed infants. Cerebellar white matter DHA concentrations were similarly lower (P<0.01) in the SMA formula-fed infants (n=8) than in an age-matched breast-fed group. Low concentrations of cerebellar white matter lignoceric (24∶0) and nervonic acid (24∶1n−9) in two 7-wk-old preterm infants appeared to correlated with postgestational rather than chronological age. Dietary long-chain polyunsaturated fatty acids particularly DHA, are probably essential for normal development of the infant cerebellum.     

Prenatal Fatty Acid Status and Immune Development: The Pathways and the Evidence

This review explores the effects of dietary long chain polyunsaturated fatty acids (LCPUFA) on various aspects of early immune development and their potential role in the development or the prevention of immune disease. Modern diets have become increasingly rich in n-6 LCPUFA and relatively n-3 LCPUFA deficient. These potentially “pro-inflammatory” dietary changes have clear implications for the immature and developing fetal immune system. It is now well known that immunological abnormalities precede the development of allergic disease and are frequently evident at birth or in the first months of life. This has lead to the hypothesis that potential effects of LCPUFA could be greatest in very early life before immune responses and clinical phenotype are established. Here we summarise the evidence that patterns of LCPUFA exposure in pregnancy can influence aspects of fetal immune in ways that are consistent with the immunological properties of these nutrients in adults. Specifically, human studies have shown that higher levels of n-3 LCPUFA are associated with reduction in neonatal oxidative stress, reduced production of inflammatory leukotienne B4 (LTB4) and altered T cell function. Inverse correlations between n-3 LCPUFA levels and neonatal T cell cytokine production, are consistent with adult studies showing reduction in T cell cytokine production with fish oil supplementation. At this stage the relevance of these effects in the prevention of disease is unclear. Although there have been no effects of postnatal fish oil supplementation (from 6 months of age) on allergy prevention, preliminary studies suggest possible merits in pregnancy and there are ongoing pregnancy intervention studies to address this more definitively.     

Visual acuity and blood lipids in term infants fed human milk or formulae

This multicenter, parallel group study determined plasma phospholipid and red blood cell (RBC) phosphatidylcholine and phosphatidylethanolamine fatty acids, plasma cholesterol, apo A-1 and B, growth and visual acuity (using the acuity card procedure) in term infants fed from birth to 90 d of age with formula containing palm-olein, high oleic sunflower, coconut and soy oil (22.2% 16∶0, 36.2% 18∶1, 18% 18∶2n−6, 1.9% 18∶3n−3) (n=59) or coconut and soy oil (10.3% 16∶0 18∶6% 18∶1, 34.2% 18∶2n−6, 4.7% 18∶3n−3) (n=57) or breast-fed (n=56) with no formula supplementation. Different centers in North America were included to overcome potential bias due to differences in n−6 or n−3 fatty acids at birth or in breast-fed infants that might occur in a single-site study. Plasma and RBC phospholipid docosahexaenoic acid (DHA, 22∶6n−3) and arachidonic acid (AA, 20∶4n−6), cholesterol and apo B were significantly lower in the formula- than breast-fed infants. There were no differences in looking acuity or growth among the breast-fed and formula-fed infants. No significant relations were found between DHA and looking acuity, or AA and growth within or among any of the infant groups. This study provides no evidence to suggest the formula provided inadequate n−6 or n−3 fatty acids for growth and looking acuity for the first 3 mon after birth.     

A multilevel,multicomponent childhood obesity prevention group-randomized controlled trial improves healthier food purchasing and reduces sweet-snack consumption among low-income African-American youth

Long chain polyunsaturated fatty acids (LCPUFA) especially docosahexaenoic acid (DHA) and arachidonic acid (AA) are crucial for normal brain development in utero and in early infancy. Data on fatty acid status and cognitive development in infants and children from low-income countries are scarce. We examined the association between the DHA and AA status in infancy (n = 320) and developmental status and cognitive functioning five years later. At five years of age, we measured development by the Ages and Stages Questionnaire 3rd. ed. (ASQ-3) and cognitive functioning by subtests from the neuropsychological test battery NEPSY II. In addition, infant fatty acid composition in red blood cells (RBC) was analyzed. In multiple linear and logistic regression models, we estimated the associations between DHA and AA status in infancy and scores on the ASQ-3 and the NEPSY II subtests. There were no notable associations between infant AA and DHA status, and the scores on the ASQ-3 and the NEPSY II subtests five years later. It should be noted that we found better than expected concentrations of erythrocyte DHA and AA among the infants, and the ASQ scores were left-skewed, which limited the ability to identify associations. DHA and AA status in infancy is seemingly not related to neurodevelopment measured 5 years later in this peri-urban population from Nepal.     

Modification of milk formula to enhance accretion of long-chain n−6 and n−3 polyunsaturated fatty acids in artificially reared infant rats

Artificially reared infant rats were used to determine the effects of long-chain polyunsaturated fatty acid (LCP-UFA) supplementation on blood and tissue concentrations of arachidonic acid (AA) and docosahexaenoic acid (DHA). Beginning at 7 d of age, infant rats were fed for 10 d with rat milk formulas supplemented with AA at 0,0.5 and 1.0%, or supplemented with DHA at 0,0.5 and 1.0% of total fatty acid. The supplementation of AA increased accretion of the fatty acid in tissue and blood phospholipids with a maximum increase of 9% in brain, 15% in liver, 25% in erythrocytes, and 43% in plasma above the values of unsupplemented infant rats. Rat milk formula containing 1.0% of AA had no added benefits over that containing 0.5% of AA. The supplementation of DHA increased phospholipid DHA by a maximum of 24% in brain, 87% in liver, 54% in erythrocytes, and 360% in plasma above the unsupplemented control. The increase in tissue and blood DHA was concentration-dependent on formula fatty acid. Brain phosphatidylcholine and phosphatidylethanolamine were similarly enriched with AA and DHA by supplementation of the corresponding fatty acids. In general the observed increase of AA was accompanied by a decrease in 16:0, 18:1n−9, and/or 18:2n−6, whereas the increased DHA was associated with a reduction of 18:1n−9, 18:2n−6, and/or 20:4n−6. Clearly, infant rats were more responsive to DHA than AA supplementation, suggesting a great potential of dietary manipulation to alter tissue DHA concentrations. However, the supplementation of DHA significantly decreased tissue and blood AA/DHA ratios (wt%/wt%), whereas there was little or no change in the ratio by AA supplementation. Although the physiological implications of the levels of AA and DHA, and AA/DHA ratios achieved under the present experimental conditions are not readily known, the findings suggest that artificial rearing could provide a suitable model to investigate LCPUFA requirements using various sources of AA and DHA in rats.     

A randomized controlled trial of the effect of fish oil supplementation in late pregnancy and early lactation on the n−3 fatty acid content in human breast milk

The aim of this research was to investigate the effect of fish oil supplementation, in the third trimester of pregnancy and early lactation period of healthy pregnant Danish women. Forty-four pregnant women were randomly allocated to fish oil supplementation (1.3 g EPA and 0.9 g DHA per day) from week 30 of gestation (FO-group) or to a control regimen (olive oil or no oil; controls). The FO-group was randomly subdivided into women stopping fish oil supplementation at delivery [FO(pregn)], and women continuing supplementation for an, additional 30 d [FO(pregn/lact)]. Thirty-six women agreed to collect milk samples at days 4, 16, and 30 postpartum. The FA composition of the milk samples was determined by GLC. At days 4, 16, and 30 in lactation, FO(pregn/lact) women (n=12) had, respectively 2.3 (P=0.001), 4.1 (P=0.001), and 3.3 (P=0.001) times higher mean contents of LCPUFA(n−3) in their breast milk compared with controls (n=13), and 1.7 (P=0.005), 2.8 (P=0.001), and 2.8 (P=0.001), times higher LCPUFA(n−3) contents, respectively, at these days compared with FO(pregn) women (n=11). The latter group did not differ significantly from controls with regard to LCPUFA(n−3) content in the breast milk. Similar results were obtained when analyzing separately for effects on the milk content of DHA. Dietary supplementation with 2.7 g LCPUFA(n−3) per day from week 30 of gestation and onward more than tripled the LCPUFA(n−3) content in early breast milk; supplementation limited to pregnancy only was much less effective.     

A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until nine months

This randomized, double-blind trial tested the hypothesis that the addition of 0.2% docosahexaenoic acid (DHA, 22∶6n−3) from marine oil to commercially-available preterm and term formulas with ≥3% linolenic acid (18∶3n−3) would enhance novelty preference and visual attention of preterm infants. Among preterm infants cared for in our center, study infants were a select group considered to be at lower risk for developmental delay. Study infants received their assigned diet (control, DHA-supplemented) from a mean postnatal age of 25 d until 9 mon past term. At 6.5, 9, and 12 mon past term, they were tested for visual recognition memory (novelty preference) and attention with the Fagan Test of Infant Intelligence. The effects of DHA supplementation were analyzed by repeated measures analysis of variance. In paired comparisons of novel and familiar stimuli, DHA-supplemented and control infants had the same novelty preference, but supplemented infants had more discrete looks to both novel (P<0.03) and familiar (P<0.02) stimuli and a shorter overall look duration (P<0.03). These data are analogous to those from n−3-deficient and n−3-fed monkeys in that the group with better DHA status had shorter overall look duration. Because shorter look duration has been associated with more rapid information processing, preterm infants fed formulas with only linolenic acid may have had slower information processing than those fed DHA. Based on a presentation at the AOCS Annual Meeting & Expo in San Antonio, Texas, May 7–11, 1995.     

Breast-fed infants achieve a higher rate of brain and whole body docosahexaenoate accumulation than formula-fed infants not consuming dietary docosahexaenoate

Docosahexaenoate (DHA) has been increasingly recognized as an important fatty acid for neural and visual development during the first 6 mon of life. One important point of controversy that remains is the degree to which adequate levels of DHA can be acquired from endogenous synthesis in infants vs. what should be provided as dietary DHA. We have approached this problem by a retrospective analysis of published body composition data to estimate the actual accumulation of DHA in the human infant brain, liver, adipose tissue, remaining lean tissue, and whole body. Estimating whether infants can synthesize sufficient DHA required comparison to and extrapolation from animal data. Over the first 6 mon of life, DHA accumulates at about 10 mg/d in the whole body of breast-fed infants, with 48% of that amount appearing in the brain. To achieve that rate of accumulation, breast-fed infants need to consume a minimum of 20 mg DHA/d. Virtually all breast milk provides a DHA intake of at least 60 mg/d. Despite a store of about 1,050 mg of DHA in body fat at term birth and an intake of about 390 mg/d α-linolenate (α-LnA), the brain of formula-fed infants not consuming DHA accumulates half the DHA of the brain of breast-fed infants while the rest of the body actually loses DHA over the first 6 mon of life. No experimental data indicate that formula-fed infants not consuming DHA are able to convert the necessary 5.2% of α-LnA intake to DHA to match the DHA accumulation of breast-fed infants. We conclude that dietary DHA should likely be provided during at least the first 6 mon of life.     

Dietary supplementation with arachidonic and docosahexaenoic acids has no effect on pulmonary surfactant in artificially reared infant rats

Despite the potential use of long-chain polyunsaturated fatty acid (LCPUFA) supplementation to promote growth and neural development of the infant, little is known about potential harmful effects of the supplementation. The present study determined whether supplementation with arachidonic acid (AA) and/or docosahexaenoic acid (DHA) in rat milk formula (RMF) affects saturation of pulmonary surfactant phospholipids (PL). Beginning at 7 d of age, infant rats were artificially fed for 10 d with RMF supplemented with AA at 0, 0.5, and 1.0% of total fatty acid, or supplemented with DHA at 0, 0.5, and 1.0%, or cosupplemented with AA and DHA at levels of 0∶0, 0.5∶0.3, and 1.0∶0.6% of the fat blend. Lung tissue PL contained 43 weight percent palmitate (16∶0) of total fatty acids in infant rats fed the unsupplemented RMF. The supplementation with AA at both 0.5 and 1.0% decreased the weight percentage of 16∶0 and stearate (18∶0), indicating a decrease in saturation of PL. The observed decreases were accompanied by increases in AA and linoleic acid (18∶2n−6). Surfactant phosphatidylcholine (PC) consisted of 71 weight percent 16∶0 in the unsupplemented group, and this highly saturated PC was not altered by the cosupplementation with AA and DHA although there was a slight increase in DHA. Similarly, the cosupplementation did not change fatty acid composition of surfactant PL when compared with the unsupplemented group. The cosupplementation slightly decreased the weight percentage of 16∶0 with a proportional increase in 18∶0 leading to an unchanged weight percentage of total saturated fatty acids. These results suggest that, unlike lung tissue PL, the composition of saturated fatty acids in surfactant PL, particularly PC, is resistant to change by dietary AA and DHA supplementation. This, together with the unchanged concentration of total fatty acids in surfactant PC, indicates that LCPUFA cosupplementation causes no effect on pulmonary surfactant.