Essential fat requirements of preterm infants

A Narrative Review of Strategies to Optimize Nutrition, Feeding, and Growth among Preterm-Born Infants: Implications for Practice

Preterm birth is the leading cause of neonatal and under-5 mortality globally, and healthcare-related burden and nutrition-related morbidities are unsustainable, particularly in resource-limited regions. Additionally, preterm infants are susceptible to multiple adverse outcomes including growth faltering, suboptimal neurodevelopment, and multisystemic morbidities. Maturation, healing, repair, and restoration to normalcy in preterm-born infants require optimizing nutrition; only then, prognosis, growth, neurodevelopment, and overall quality of life can improve. In this article, we discuss the various evidence-based feeding and nutritional strategies that can be applicable even in resource-limited settings, where resources and infrastructure for advanced neonatal care are limited. This article addresses nutrition, feeding strategies, and growth monitoring in the neonatal intensive care unit and at discharge to optimize nutrition, growth, and development.

Metabolic, structure-activity characteristics of conjugated linolenic acids and their mediated health benefits

Conjugated linolenic acid (CLnA) is a mixture of octadecenoic acid with multiple positional and geometric isomers (including four 9, 11, 13-C18:3 isomers and three 8, 10, 12-C18:3 isomers) that is mainly present in plant seeds. In recent years, CLnA has shown many promising health benefits with the deepening of research, but the metabolic characteristics, physiological function differences and mechanisms of different isomers are relatively complex. In this article, the metabolic characteristics of CLnA were firstly reviewed, with focus on its conversion, catabolism and anabolism. Then the possible mechanisms of CLnA exerting biological effects were summarized and analyzed from its own chemical and physical characteristics, as well as biological receptor targeting characteristics. In addition, the differences and mechanisms of different isomers of CLnA in anticancer, lipid-lowering, anti-diabetic and anti-inflammatory physiological functions were compared and summarized. The current results show that the position and cis-trans conformation of conjugated structure endow CLnA with unique physical and chemical properties, which also makes different isomers have commonalities and particularities in the regulation of metabolism and physiological functions. Corresponding the metabolic characteristics of different isomers with precise nutrition strategy will help them to play a better role in disease prevention and treatment. CLnA has the potential to be developed into food functional components and dietary nutritional supplements. The advantages and mechanisms of different CLnA isomers in the clinical management of specific diseases need further study.

Association of fish oil containing lipid emulsions with retinopathy of prematurity: a retrospective observational study

Background

Retinopathy of prematurity (ROP) remains a leading cause of childhood blindness worldwide. This study aimed to investigate whether supplementation of n-3 polyunsaturated fatty acids (n-3 PUFAs) in parenteral nutrition may have beneficial effects on ROP in preterm infants.

Methods

A total of 89 preterm infants, admitted to Neonatal Intensive Care Unit (NICU) in Anhui Provincial Children’s Hospital from September 2017 to August 2020, were recruited in the study. Based on the medical documents, the subjects were categorised into two groups: administration of the fish oil emulsion (n=43) containing soy oil, medium-chain-triglycerides (MCT), olive oil and fish oil (6g/dL, 6g/dL, 5g/dL and 3g/dL respectively), and the soy oil emulsion (n=46) containing 10g/dL of soy oil and MCT each. At 4 weeks of hospitalization, ROP was screened and diagnosed. Fatty acids in erythrocytes were determined using gas chromatography.

Results

The averaged birth weight and gestational age were 1594±296 g and 31.9±2.3 wk, 1596±263 g and 31.6±2.3 wk respectively for preterm infants in the fish oil group and soy oil group. After 4 to 6 weeks of hospitalization, among all the preterm infants, 52 developed ROP (all stages) indicating an incidence of ROP at 58.43%. Although the incidence of ROP with any stages showed no differences between the two groups, the severe ROP incidence in the group with fish oil emulsions (2.33%) was significantly lower than that in the group with soy oil emulsions (23.91%) (P<0.05). After 14 days of nutrition support, the preterm infants administered fish oil emulsions had an increase in erythrocyte DHA content, with a reduction in ratio of arachidonic acid (AA) to DHA and an increase of n-3 index.

Conclusion

Supplementation of n-3 PUFAs through parenteral fish oil containing lipid emulsions resulted in an increase in erythrocyte DHA, and this might have beneficial effects on prevention of severe ROP in preterm infants.

Maternal Fatty Acid Metabolism in Pregnancy and Its Consequences in the Feto-Placental Development

During pregnancy, maternal plasma fatty acids are critically required for cell growth and development, cell signaling, and the development of critical structural and functional aspects of the feto-placental unit. In addition, the fatty acids modulate the early stages of placental development by regulating angiogenesis in the first-trimester human placenta. Preferential transport of maternal plasma long-chain polyunsaturated fatty acids during the third trimester is critical for optimal fetal brain development. Maternal status such as obesity, diabetes, and dietary intakes may affect the functional changes in lipid metabolic processes in maternal-fetal lipid transport and metabolism. Fatty acids traverse the placental membranes via several plasma membrane fatty acid transport/binding proteins (FAT, FATP, p-FABPpm, and FFARs) and cytoplasmic fatty acid-binding proteins (FABPs). This review discusses the maternal metabolism of fatty acids and their effects on early placentation, placental fatty acid transport and metabolism, and their roles in feto-placental growth and development. The review also highlights how maternal fat metabolism modulates lipid processing, including transportation, esterification, and oxidation of fatty acids.

Transition to a Safe Home Sleep Environment for the NICU Patient

Of the nearly 3.8 million infants born in the United States in 2018, 8.3% had low birth weight (<2500 g [5.5 lb]) and 10% were born preterm (gestational age of <37 completed weeks). Many of these infants and others with congenital anomalies, perinatally acquired infections, and other disease require admission to a NICU. In the past decade, admission rates to NICUs have been increasing; it is estimated that between 10% and 15% of infants will spend time in a NICU, representing approximately 500 000 neonates annually. Approximately 3600 infants die annually in the United States from sleep-related deaths, including sudden infant death syndrome International Classification of Diseases, 10th Revision (R95), ill-defined deaths (R99), and accidental suffocation and strangulation in bed (W75). Preterm and low birth weight infants are particularly vulnerable, with an incidence of death 2 to 3 times greater than healthy term infants. Thus, it is important for health care professionals to prepare families to maintain their infant in a safe sleep environment, as per the recommendations of the American Academy of Pediatrics. However, infants in the NICU setting commonly require care that is inconsistent with infant sleep safety recommendations. The conflicting needs of the NICU infant with the necessity to provide a safe sleep environment before hospital discharge can create confusion for providers and distress for families. This technical report is intended to assist in the establishment of appropriate NICU protocols to achieve a consistent approach to transitioning NICU infants to a safe sleep environment as soon as medically possible, well before hospital discharge.

Reproducibility of the creamatocrit technique for the measurement of fat content in human milk

Quantification of human milk (HM) fat is important for determining the energy intake of infants. The simplest and most rapid method is the creamatocrit method. However, the reliability of the creamatocrit has not been comprehensively investigated. The aims of this study were to test the inter- and-intra-rater reliability of: 1) HM sampling after hand- or-machine mixing methods and 2) HM fat measurement by the creamatocrit method. Inter-and-intra rater HM sampling after hand- or-machine mixing methods had high intraclass correlation coefficient (>0.91). Inter-rater reliability of measurement of HM with low fat (<2%) resulted in high variability (median coefficient of variations (CVs) > 15%). Intra- and inter-rater reliability of measurement of HM with higher fat (>3.5%) had low variability (median CVs < 10%). As the greatest variation in the creamatocrit method occurred during the measurement of HM samples with low fat, duplicate readings are necessary to reduce discrepancies in every HM fat determination.

Docosahexaenoic Acid (DHA) Bioavailability in Humans after Oral Intake of DHA-Containing Triacylglycerol or the Structured Phospholipid AceDoPC®

AceDoPC^® is a structured glycerophospholipid that targets the brain with docosahexaenoic acid (DHA) and is neuroprotective in the experimental ischemic stroke. AceDoPC^® is a stabilized form of the physiological 2-DHA-LysoPC with an acetyl group at the sn1 position; preventing the migration of DHA from the sn2 to sn1 position. In this study we aimed to know the bioavailability of ¹³C-labeled DHA after oral intake of a single dose of ¹³C-AceDoPC^®, in comparison with ¹³C-DHA in triglycerides (TAG), using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to assess the ¹³C enrichment of DHA-containing lipids. ¹³C-DHA enrichment in plasma phospholipids was significantly higher after intake of AceDoPC^® compared with TAG-DHA, peaking after 24 h in both cases. In red cells, ¹³C-DHA enrichment in choline phospholipids was comparable from both sources of DHA, with a maximum after 72 h, whereas the ¹³C-DHA enrichment in ethanolamine phospholipids was higher from AceDoPC^® compared to TAG-DHA, and continued to increase after 144 h. Overall, our study indicates that DHA from AceDoPC^® is more efficient than from TAG-DHA for a sustained accumulation in red cell ethanolamine phospholipids, which has been associated with increased brain accretion.

Nutrition, Growth, Brain Volume, and Neurodevelopment in Very Preterm Children

OBJECTIVE

To explore the associations between nutrition in the first 28 days after birth with somatic growth from birth to term-equivalent age, brain volumes at term-equivalent age, and neurodevelopment at 24 months of corrected age.

STUDY DESIGN

Prospective cohort study of 149 infants born from 2011 to 2014 at <30 weeks of gestation in a tertiary neonatal nursery in Australia. The following data were collected: average daily energy, protein, fat, and carbohydrate intakes from birth until 28 days, and the difference in weight and head circumference z scores between birth and term-equivalent. Total brain tissue volumes were calculated from brain magnetic resonance imaging at term-equivalent age. Children were assessed at 2 years of corrected age with the Bayley Scales of Infant and Toddler Development-Third Edition. Relationships of nutritional variables with growth, brain volumes, and cognitive, language, and motor development were explored using linear regression.

RESULTS

Complete nutritional data were available for 116 (78%) of the cohort. A 1 g/kg/day higher mean protein intake was associated with a mean increase in weight z score per week of 0.05 (95% CI 0.05, 0.10; P = .04). There was a lack of evidence for associations of any nutritional variables with head circumference growth, with brain volumes at term-equivalent age, or with 2-year neurodevelopment.

CONCLUSIONS

Only higher protein intakes in the first 28 days after birth were associated with better weight growth between birth and term-equivalent age in very preterm infants. Nutrition in the first 28 days was otherwise not substantially related to brain size or to neurodevelopmental outcomes.

Inpatient outcomes of preterm infants receiving ω-3 enriched lipid emulsion (SMOFlipid): an observational study

Neonatal units have started to switch from using conventional soy-based to alternate lipid emulsions, like SMOFlipid. SMOFlipid has been associated with an improvement in biochemical parameters and delays progression of parenteral nutrition-associated liver disease (PNALD). This retrospective epoch study aimed to compare clinically relevant neonatal outcomes in preterm infants (< 32 weeks), receiving SMOFlipid versus Intralipid. We compared clinical outcomes in two epochs-epoch 1 (Intralipid, October 2013-June 2015) versus epoch 2 (SMOFlipid, July 2015-March 2017). Primary outcome studied was mortality and rates of severe neonatal morbidities. Univariate and multivariate regression was conducted to determine risk for mortality and PNALD. A total of 222 infants (epoch 1, 123 versus epoch 2, 99) were included in the study. A higher incidence of late onset sepsis (56 versus 30%, p < 0.005) was observed in epoch 1. There was no significant difference in mortality or rates of any other severe neonatal morbidity. The type of lipid emulsion did not have a significant effect on mortality or PNALD on regression analysis.

CONCLUSION

Use of SMOFlipid as the primary lipid emulsion seems to have minimal effect on rates of clinically important neonatal outcomes; however, long-term effects need to be further evaluated. What is Known: • Many neonatal units have started replacing traditional soy-based lipid formulations with SMOFlipid (ω-3 enriched lipid emulsion), as the primary lipid component in parenteral nutrition for preterm infants. • While there is evidence associating improved liver function and balanced essential fatty acid levels in infants receiving SMOFlipid, there is a lack of evidence evaluating relevant clinical outcomes in infants receiving SMOFlipid versus traditional lipid formulations. What is New: • The influence of SMOFlipid on a series of clinical outcomes in an at-risk preterm population is presented. • SMOFlipid appears to be well tolerated in preterm infants with minimal side effects, and some growth benefits seen.

Of Meat and Men: Sex Differences in Implicit and Explicit Attitudes Toward Meat

Modern attitudes to meat in both men and women reflect a strong meat-masculinity association. Sex differences in the relationship between meat and masculinity have not been previously explored. In the current study we used two IATs (implicit association tasks), a visual search task, and a questionnaire to measure implicit and explicit attitudes toward meat in men and women. Men exhibited stronger implicit associations between meat and healthiness than did women, but both sexes associated meat more strongly with 'healthy' than 'unhealthy' concepts. As 'healthy' was operationalized in the current study using terms such as "virile" and "powerful," this suggests that a meat-strength/power association may mediate the meat-masculinity link readily observed across western cultures. The sex difference was not related to explicit attitudes to meat, nor was it attributable to a variety of other factors, such as a generally more positive disposition toward meat in men than women. Men also exhibited an attention bias toward meats, compared to non-meat foods, while females exhibited more caution when searching for non-meat foods, compared to meat. These biases were not related to implicit attitudes, but did tend to increase with increasing hunger levels. Potential ultimate explanations for these differences, including sex differences in bio-physiological needs and receptivity to social signals are discussed.

Prenatal mercury exposure, fish intake and neurocognitive development during first three years of life: Prospective cohort mothers and Children's environmental health (MOCEH) study

OBJECTIVES

In this prospective cohort study, the effects of prenatal Hg exposure on neurocognitive development during the first 3years of life were investigated.

METHODS

The maternal blood levels of Hg were assessed during pregnancy and in cord blood. Maternal fish intake was assessed by interviewing the weekly frequency of fish intake during pregnancy. Maternal n-3 and n-6 fatty acid intake was estimated based on 24h recall food intake interview. The mental (MDI) and psychomotor (PDI) development index scores were assessed using the Bayley Scales of Infant Development at 6, 12, 24, 36months of age.

RESULTS

The geometric mean of the maternal blood Hg concentration was 3.3μg/L (10th percentile=1.81; 90th=5.91) during the early pregnancy, 3.0μg/L (10th=1.68; 90th=5.57) during late pregnancy, and 5.1μg/L (10th=2.94; 90th=8.93) in cord blood. After adjusting for weekly frequency of fish intake, the blood Hg concentrations during early pregnancy showed association with the adjusted MDI (β=-0.408, p=0.048) and PDI scores (β=-0.550, p=0.031) at 6months. After further adjusting for n-3 and n-6 fatty acids estimated based on 24h recall of food intake, the blood Hg concentrations during early pregnancy showed association with the MDI (β=-0.489, p=0.026) and PDI (β=-0.664, p=0.015) at 6months.

CONCLUSION

These results show that prenatal Hg exposure during early pregnancy adversely associated with early neurodevelopment during infancy, after adjusting for fish and n-3, n-6 fatty acid intake. Consuming fish high in fatty acids and low in Hg during early pregnancy may be important to neurocognitive development at early infancy.

Flaxseed used since pregnancy by the mother and after weaning by the offspring benefits the retina and optic nerve development in rats

OBJECTIVE

This study aimed to evaluate the influence of a diet based on flaxseed upon the development of the nervous system, more specifically, the optic nerve and retina.

METHODS

Rats were divided into three groups: Control (CG), Flaxseed (FG), and Modified Control (MCG). The analyses were performed in the offspring (n = 6/group) at the immediate postnatal period (P0), 14 d of life (P14) and 30 d of life (P30). Descriptive analysis and histomorphometry of optic nerve and retina were performed.

RESULTS

There was a great evolution in the development of the nervous fascicles, connective trabeculae, and blood vessels, when comparing the three ages studied, and these characteristics were more evident in FG at all three ages. The P0, P14, and P30 retina showed similar morphology to that described in the literature. In histomorphometry, at P14, the FG presented the retina and its layers with significant increase in thickness, except for internal granular and ganglionar, whereas MCG had greater retina and photoreceptor layers thickness, inner plexiform and external granular when compared with CG (p < .05).

CONCLUSION

The use of flaxseed in the pre-and postnatal period displays favourable influence on the development of rat optic nerve and retina, probably leading to myelination.

Effects of different arachidonic acid supplementation on psychomotor development in very preterm infants; a randomized controlled trial

Background & aims

Nutritional supplementation with polyunsaturated fatty acids is important in preterm infants neurodevelopment, but it is not known if the omega-6/omega-3 ratio affects this process. This study was designed to determine the effects of a balanced contribution of arachidonic acid in very preterm newborns fed with formula milk.

Methods

This was a randomized trial, in which newborns <1500 g and/or <32 weeks gestational age were assigned to one of two groups, based on the milk formula they would receive during the first year of life. Initially, 60 newborns entered the study, but ultimately, group A was composed of 24 newborns, who were given formula milk with an ω-6/ω-3 ratio of 2/1, and Group B was composed of 21 newborns, given formula milk with an ω-6/ω-3 ratio of 1/1. The infants were followed up for two years: growth, visual-evoked potentials, brainstem auditory-evoked potentials, and plasma fatty acids were periodically measured, and psychomotor development was assessed using the Brunet Lézine scale at 24 months corrected age. A control group, for comparison of Brunet Lézine score, was made up of 25 newborns from the SEN1500 project, who were fed exclusively with breast milk.

Results

At 12 months, arachidonic acid values were significantly higher in group A than in group B (6.95 ± 1.55 % vs. 4.55 ± 0.78 %), as were polyunsaturated fatty acids (41.02 ± 2.09 % vs. 38.08 ± 2.32 %) achieved a higher average. Group A achieved a higher average Brunet Lézine score at 24 months than group B (99.9 ± 9 vs. 90.8 ± 11, p =0.028). The Brunet Lézine results from group A were compared with the control group results, with very similar scores registered between the two groups (99.9 ± 9 vs. 100.5 ± 7). There were no significant differences in growth or evoked potentials between the two formula groups.

Conclusions

Very preterm infants who received formula with an ω-6/ω-3 ratio of 2/1 had higher blood levels of essential fatty acids during the first year of life, and better psychomotor development, compared with very preterm newborns who consumed formula with an ω-6/ω-3 of 1/1. Therefore, formula milk with an arachidonic acid quantity double that of docosahexaenoic acid should be considered for feeding very preterm infants.

Trial registration

ClinicalTrials.gov Identifier NCT02503020.

Omega 3 fatty acids and inborn errors of metabolism

A number of studies are investigating the role of n-3 polyunsaturated fatty acids in children with metabolic inborn errors, while the effects on visual and brain development in premature infants and neonates are well known. However, their function incertain chronic neurological, inflammatory and metabolic disorders is still under study. Standards should be established to help identify the need of docosahexaenoic acid supplementation in conditions requiring a restricted diet resulting in an altered metabolism system, and find scientific evidence on the effects of such supplementation. This study reviews relevant published literature to propose adequate n-3 intake or supplementation doses for different ages and pathologies. The aim of this review is to examine the effects of long chain polyunsaturated fatty acids supplementation in preventing cognitive impairment or in retarding its progress, and to identify nutritional deficiencies, in children with inborn errors of metabolism. Trials were identified from a search of the Cochrane and MEDLINE databases in 2011. These databases include all major completed and ongoing double-blind, placebo-controlled, randomized trials, as well as all studies in which omega-3 supplementation was administered to children with inborn errors, and studies assessing omega-3 fatty acids status in plasma in these pathologies. Although few randomized controlled trials met the inclusion criteria of this review, some evidenced that most of children with inborn errors are deficient in omega-3 fatty acids, and demonstrated that supplementation might improve their neural function, or prevent the progression of neurological impairment. Nontheless, further investigations are needed on this issue.

Dietary long-chain PUFA enhance acute repair of ischemia-injured intestine of suckling pigs

Infant formula companies have been fortifying formulas with long-chain PUFA for 10 y. Long-chain PUFA are precursors of prostanoids, which stimulate recovery of intestinal barrier function. Supplementation of milk with PUFA increases the content of arachidonic acid (ARA) in enterocyte membranes; however, the effect of this enrichment on intestinal repair is not known. The objective of these experiments was to investigate the effect of supplemental ARA on intestinal barrier repair in ischemia-injured porcine ileum. One-day-old pigs (n = 24) were fed a milk-based formula for 10 d. Diets contained no PUFA (0% ARA), 0.5% ARA, 5% ARA, or 5% EPA of total fatty acids. Following dietary enrichment, ilea were subjected to in vivo ischemic injury by clamping the local mesenteric blood supply for 45 min. Following the ischemic period, control (nonischemic) and ischemic loops were mounted on Ussing chambers. Transepithelial electrical resistance (TER) was measured over a 240-min recovery period. Ischemia-injured ileum from piglets fed 5% ARA (61.0 ± 14%) exhibited enhanced recovery compared with 0% ARA (16 ± 14) and 0.5% ARA (22.1 ± 14)-fed pigs. Additionally, ischemia-injured ileum from 5% EPA (51.3 ± 14)-fed pigs had enhanced recovery compared with 0% ARA-fed pigs (P < 0.05). The enhanced TER recovery response observed with ischemia-injured 5% ARA supplementation was supported by a significant reduction in mucosal-to-serosal flux of (3)H-mannitol and (14)C-inulin compared with all other ischemia-injured dietary groups (P < 0.05). A histological evaluation of ischemic ilea from piglets fed the 5% ARA showed reduced histological lesions after ischemia compared with the other dietary groups (P < 0.05). These data demonstrate that feeding elevated levels of long-chain PUFA enhances acute recovery of ischemia-injured porcine ileum.

Eating the right amount of fish: inverted U-shape association between fish consumption and cognitive performance and academic achievement in Dutch adolescents

Fish consumption has shown its benefits for cognitive functioning in the elderly or children with disorders (e.g., autism, ADHD), but has rarely been investigated in relation to cognitive performance and school performance of healthy adolescents. We executed an observational study in 700 Dutch high school students aged 12-18 years. Fish consumption data, end term grades, scores on the Amsterdam Vocabulary Test, and scores on the Youth Self-Report were collected. Results revealed that 13.6% of the Dutch adolescents never ate fish, 6.4% met national guidelines, 16.9% reached half of the norm, and 63.1% did eat fish but too little to meet at least half of the norm. Analysis of variance, controlled for relevant covariates, showed significant differences between the four fish consumption groups in vocabulary (p=.05). A trend for significance was found for end term grades (p=.07). Contrast analyses demonstrated significant quadratic associations between fish consumption and vocabulary (p=.01) and end term grades (p=.01). Thus higher fish intake was associated with more advanced vocabulary and higher end term grades. However, eating more fish than the described norm seemed no longer beneficial.

A double-blind, randomized clinical trial of the effect of omega-3 fatty acids on the oxidative stress of preterm neonates fed through parenteral nutrition

BACKGROUND/OBJECTIVES

The aim of this study was to research and draw conclusions about the effect of a parenteral nutrition (PN) fat emulsion, rich in omega-3 fatty acids, on the antioxidant markers of preterm infants, when compared with a standard fat emulsion. This was a double-blind, parallel-group study conducted in Athens, Greece, using an equal randomization method.

SUBJECTS/METHODS

Thirty-eight infants were selected using a double-blind method and a computer-generated randomization list. Both groups received PN, based on the same protocols. Group A received SMOFlipid fat emulsion, while group B received the standard fat emulsion (Intralipid). Serum levels of vitamin A, E and total antioxidant potential (TAP) were measured on days 0, 7 and 14 of PN support. Clinical and biochemical data were collected on days 0, 14 and on the day of discharge.

RESULTS

Serum levels of vitamin E and A were significantly increased in group A, while only vitamin A serum level was increased in group B on the fourteenth day (group A: vitamin E: P-value=0.002, vitamin A: P-value=0.000, group B: vitamin E: P-value=0.065, vitamin A: P-value=0.000). TAP was increased only in the intervention group (group A: P-value=0.000, group B: P-value=0.287). Mild anemia was developed in both groups, while no differences were detected in the infection rate, days of hospitalization, days of ventilator support and days of phototherapy.

CONCLUSIONS

Oxidative stress was significantly reduced in those neonates fed with omega-3 fatty acids, whereas no effect was observed in the neonates fed with standard lipids. Intervention had no effect on infants' growth and clinical outcome.

Maternal nutrition and birth outcomes

In this review, the authors summarize current knowledge on maternal nutritional requirements during pregnancy, with a focus on the nutrients that have been most commonly investigated in association with birth outcomes. Data sourcing and extraction included searches of the primary resources establishing maternal nutrient requirements during pregnancy (e.g., Dietary Reference Intakes), and searches of Medline for "maternal nutrition"/[specific nutrient of interest] and "birth/pregnancy outcomes," focusing mainly on the less extensively reviewed evidence from observational studies of maternal dietary intake and birth outcomes. The authors used a conceptual framework which took both primary and secondary factors (e.g., baseline maternal nutritional status, socioeconomic status of the study populations, timing and methods of assessing maternal nutritional variables) into account when interpreting study findings. The authors conclude that maternal nutrition is a modifiable risk factor of public health importance that can be integrated into efforts to prevent adverse birth outcomes, particularly among economically developing/low-income populations.

Neonatal dietary cholesterol and alleles of cholesterol 7-alpha hydroxylase affect piglet cerebrum weight, cholesterol concentration, and behavior

This experiment was designed to test the effect of polymorphism in the cholesterol 7-alpha hydroxylase (CYP7) gene locus and dietary cholesterol (C) on cerebrum C in neonatal pigs fed sow's milk formulas. Thirty-six pigs (18 male and 18 female) genetically selected for high (HG) or low (LG) plasma total C were weaned at 24-36 h after birth and assigned in a 2 x 2 x 2 factorial arrangement of treatments with 2 diets (0 or 0.5% C), 2 sexes, and 2 genotypes (HG and LG). Individually housed pigs consumed diets ad libitum for 42 d. Open-field behavior was tested at wk 2 and 4. All pigs were killed at 42 d of age, the cerebrum was weighed, and C content and concentration measured. All data were analyzed by general linear model ANOVA. Cerebrum weight was greater in HG than LG pigs (P < 0.03) but was not affected by diet or sex. Pigs fed C tended to have a higher cerebrum C concentration than those deprived (P = 0.12). At 2 wk, LG pigs explored a novel open-field environment less often (P < 0.001) than did HG pigs. At 4 wk, some LG pigs explored the open field but fewer (P < 0.001) vs. HG pigs retreated back to the safe area. There were no genotype x diet, genotype x sex, or diet x sex interactions affecting cerebrum weight, or C content or concentration. Polymorphism in the CYP7 gene locus affected cerebrum weight and behavior and dietary C tended to increase cerebrum C concentration in neonatal pigs. These findings in neonatal pigs have considerable potential importance in human infant nutrition and behavioral development.

Fluidity and oxidative stress in erythrocytes from very low birth weight infants during their first 7 days of life

OBJECTIVE

To study the evolution of lipid peroxidation, enzymatic antioxidants response, lipid profile and membrane fluidity in erythrocytes from very low birth weight (VLBW) infants during their first 7 days of extra-uterine life.

STUDY DESIGN

One hundred and twenty infants were selected and divided in two groups according to their weight and gestational age. Hydroperoxides, fatty-acid profile, fluidity (DPH and TMA-DPH) and catalase, SOD and GPx activities were measured in erythrocytes.

RESULTS

VLBW group showed higher concentration of hydroperoxides and lower membrane fluidity during the first 72 h, lower SOD activity during the first 3 h and higher GPx activity during the first 7 days of life. Also, this group showed lower n-3 polyunsaturated fatty-acids percentage with respect to the term group.

CONCLUSION

Erythrocytes from VLBW infants showed higher oxidative damage and lower fluidity in their membranes, at least during the first 3 days of extra-uterine life, which may cause alterations in their functions and flexibility.

Effect of Placental Fatty Acid Metabolism and Regulation by Peroxisome Proliferator Activated Receptor on Pregnancy and Fetal Outcomes

Fatty acids, particularly the omega-3 and omega-6 essential fatty acids (EFAs), are considered critical nutritional sources for the developing fetus. The placenta governs the fetal supply of fatty acids via two processes: transport and metabolism. Placental fatty acid metabolism can play a critical role in guiding pregnancy and fetal outcome. EFAs can be metabolized to important cell signaling molecules in placenta by several major isoform families including: the Cytochrome P450 subfamily 4A (CYP4A); Cyclooxygenases (COXs); and Lipoxygenases (LOXs). Peroxisome proliferator-activated nuclear receptors (PPARs) have been demonstrated to regulate a number of placental fatty acid/lipid homeostasis-related proteins (e.g., metabolizing enzymes and transporters). The present review summarizes research on the molecular and functional relevance of fatty acid metabolizing enzymes and the role of PPARs in regulating their expression in the mammalian placenta. Elucidating the pathways of placental fatty acid metabolism and the regulatory processes governing these pathways is critical for advancing our understanding of the role of placenta in supplying EFAs to the developing fetus and the potential implications on pregnancy and fetal outcome. A more complete understanding of placental fatty acid disposition may also provide a basis for nutritional/pharmacological interventions to ameliorate the risk of adverse pregnancy and/or fetal outcomes.

Fish oil: what the prescriber needs to know

There is a general belief among doctors, in part grounded in experience, that patients with arthritis need nonsteroidal anti-inflammatory drugs (NSAIDs). Implicit in this view is that these patients require the symptomatic relief provided by inhibiting synthesis of nociceptive prostaglandin E₂, a downstream product of the enzyme cyclo-oxygenase (COX), which is inhibited by NSAIDs. However, the concept of 'safe' NSAIDs has collapsed following a multiplicity of observations establishing increased risk for cardiovascular events associated with NSAID use, especially but not uniquely with the new COX-2-selective NSAIDs. This mandates greater parsimony in the use of these agents. Fish oils contain a natural inhibitor of COX, reduce reliance on NSAIDs, and reduce cardiovascular risk through multiple mechanisms. Fish oil thus warrants consideration as a component of therapy for arthritis, especially rheumatoid arthritis, in which its symptomatic benefits are well established. A major barrier to the therapeutic use of fish oil in inflammatory diseases is ignorance of its mechanism, range of beneficial effects, safety profile, availability of suitable products, effective dose, latency of effects and instructions for administration. This review provides an evidence-based resource for doctors and patients who may choose to prescribe or take fish oil.

Arachidonic acid predominates in the membrane phosphoglycerides of the early and term human placenta

The aim of this study was to determine whether the high concentration of arachidonic acid (AA) in term placentae accumulates during pregnancy or is an inherent characteristic of placental lipids. We investigated the lipid content and fatty acid composition of the human placental phospholipids at 2 gestational periods, early in pregnancy (8-14 wk, n = 48) and at term (38-41 wk of gestation, n = 19). The subjects were healthy, normotensive, and free of medical and obstetric complications. The lipid concentration of placentae increased from 0.8% in early gestation to 1.4% at term (P < 0.0001). The mean proportions of AA were lower in the choline (P < 0.05), inositol (P < 0.0001), and ethanolamine (P < 0.0001) phosphoglycerides of the term compared with the early placenta. In contrast, the proportions of the immediate precursor of AA, dihomo-gamma-linolenic acid (DGLA), were higher in the term placenta, particularly in the inositol and serine phosphoglycerides (P < 0.0001). In sphingomyelin, the percentage of lignoceric acid was increased and that of nervonic acid was reduced at term (P < 0.01). The dominance of AA, particularly in the early placenta, suggests that it has an important role for placental development, i.e., organogenesis and vascularization. There was no evidence of an accumulation of AA in the placenta toward term, which might be a trigger for parturition. In contrast, the increased proportion of DGLA (precursor of the vasorelaxant and anticoagulant prostaglandin E(1)) at term is more consistent with a profile favoring optimal blood flow to nourish the fetal growth spurt.

Expression of CYP4A isoforms in developing rat placental tissue and rat trophoblastic cell models

Maintaining fatty acid homeostasis during pregnancy is critical for normal fetal development. As an organ that controls nutrient supply from the mother to the fetus, the placenta plays a significant role in guiding fatty acid transfer to the developing fetus. The cytochrome P450 4A (CYP4A) subfamily of metabolizing enzymes is a group of structurally and functionally conserved proteins that are specialized in the omega/omega-1 hydroxylation of saturated and unsaturated fatty acids and their derivatives. To understand the function of the CYP4A system in the placenta and its significance in maintaining fetal fatty acid homeostasis, information about the placental expression of individual CYP4A isoforms is required. In the present study, we have elucidated the temporal and spatial patterns of expression of the four known rat CYP4A isoforms (CYP4A1, CYP4A2, CYP4A3, and CYP4A8) in the junctional and labyrinthine zones of the developing rat chorioallantoic placenta as well as two rat trophoblastic cell lines, HRP-1 and Rcho-1, using semi-quantitative RT-PCR and immunohistochemical analyses. The mRNA from the four rat CYP4A isoforms was detected in the developing rat placenta with CYP4A1 exhibiting the strongest expression (4A1 > 4A2 >> 4A3 approximately equal to 4A8). CYP4A1 was also detected by immunohistochemical staining in the developing rat placenta. We also observed CYP4A1 in both HRP-1 and Rcho-1 cells by RT-PCR, suggesting the utility of these cells as in vitro tools to study the effects of xenobiotics on placental fatty acid metabolism. Establishing the expression of CYP4A isoforms in these tissues and cell models provides a framework for further investigation of their functional and physiological significance in guiding proper fetal development.

An integrative metabolism approach identifies stearoyl‐CoA desaturase as a target for an arachidonate‐enriched diet

Epidemiological studies have correlated diets containing higher intakes of PUFA with lower rates of chronic metabolic diseases. The molecular mechanisms regulated by the consumption of PUFA were examined by using an integrative metabolism approach assaying the liver transcriptome and lipid-metabolome of mice fed a control diet, an arachidonate (AA)-enriched fungal oil, an eicosapentaenoic (EPA)/docosahexaenoic (DHA)-enriched fish oil, or a combination of the two oils. Hepatic gene transcription and fatty acid (FA) metabolism were significantly altered by diets enriched with AA, as revealed by global error assessment and singular value decomposition (SVD) analysis, respectively. SVD analysis of the lipid data, reinforced with transcriptomics, suggests that the chronic feeding of AA modulates molecular endpoints similar to those previously reported in the obesity-resistant SCD1-/- mouse, namely, genes involved in lipid oxidation/synthesis and the significant changes in FA metabolism stemming from a repressed SCD1 activity. Specifically, the total levels and FA composition of several phospholipid (PL) species were significantly changed, with phosphatidylcholine (PC) demonstrating the greatest alterations. Reduced PC levels were linked to decreased expression of enzymes in PC biosynthesis (choline kinase, -2.2-fold; glycerol-3-phosphate acyltransferase, -2.0-fold). Alterations in PL-FA composition were related to decreased expression of FA biosynthetic genes [fatty acid synthetase, -3.7-fold; stearoyl-CoA desaturase-1 (SCD1), -1.8-fold]. Lower hepatic SCD1 gene expression levels were reflected in various aspects of FA metabolism through increased concentrations of palmitic (fungal oil, +45%; combination, +106%) and stearic acids (fungal oil, +60%; combination, +63%) in PC. Importantly, an integrated approach showed that these effects were not attenuated by the addition of an EPA/DHA-enriched fish oil, thereby identifying a previously unrecognized and distinct role for AA in the regulation of hepatic lipid metabolism.

Formula feeding potentiates docosahexaenoic and arachidonic acid biosynthesis in term and preterm baboon neonates

Infant formulas supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) are now available in the United States; however, little is known about the factors that affect biosynthesis. Baboon neonates were assigned to one of four treatments: term, breast-fed; term, formula-fed; preterm (155 of 182 days gestation), formula-fed; and preterm, formula+DHA/ARA-fed. Standard formula had no DHA/ARA; supplemented formula had 0.61%wt DHA (0.3% of calories) and 1.21%wt ARA (0.6% of calories), and baboon breast milk contained 0.68 +/- 0.22%wt DHA and 0.62 +/- 0.12%wt ARA. At 14 days adjusted age, neonates received a combined oral dose of [U-13C]alpha-linolenic acid (LNA*) and [U-13C]linoleic acid (LA*), and tissues were analyzed 14 days after dose. Brain accretion of linolenic acid-derived DHA was approximately 3-fold greater for the formula groups than for the breast-fed group, and dietary DHA partially attenuated excess DHA synthesis among preterms. A similar, significant pattern was found in other organs. Brain linoleic acid-derived ARA accretion was significantly greater in the unsupplemented term group but not in the preterm groups compared with the breast-fed group. These data show that formula potentiates the biosynthesis/accretion of DHA/ARA in term and preterm neonates compared with breast-fed neonates and that the inclusion of DHA/ARA in preterm formula partially restores DHA/ARA biosynthesis to lower, breast-fed levels. Current formula DHA concentrations are inadequate to normalize long-chain polyunsaturated fatty acids synthesis to that of breast-fed levels.

Lipid requirements of infants: implications for nutrient composition of fortified complementary foods

Dietary lipids have traditionally been considered as solely part of the exchangeable energy supply. The main consideration in infant nutrition has been the amount of fat that can be tolerated and digested by infants and young children. The significance of the composition of dietary fat has received little attention. Presently, there is a growing interest in the quality of dietary lipid supply in early childhood as a major determinant of growth, infant development and long-term health. Thus, the selection of dietary lipids during the first years of life is now considered to be critically important for health and good nutrition throughout the life course. Over the past decades interest has focused on the role of essential lipids in central nervous system development and of fatty acids and cholesterol in lipoprotein metabolism throughout life. Lipids are structural components of all tissues and are indispensable for cell and plasma membrane synthesis. The brain, retina and other neural tissues are particularly rich in long-chain PUFA. Some (n-6) and (n-3) fatty acids are precursors for eicosanoid formation; these are powerful mediators of numerous cell and tissue functions. Recommendations for infant nutrition and implications of these for the nutrient composition of complementary foods are presented and discussed. There is more to fat than its role as a key fuel in energy metabolism and body energy storage; lipids are essential for tissue growth, cardiovascular health, brain development and function throughout the life course.

Breastfeeding: making the difference in the development, health and nutrition of term and preterm newborns

Breastfeeding is the natural and safe way of feeding small infants, providing nutritional, immunological, psychological and economic recognized and unquestionable advantages. These qualities are especially important in premature infants, because of their vulnerability. Despite highly desirable, there is, in general, little success in breastfeeding preterm infants, especially in special care neonatal units. There are evidences that a high supportive hospital environment, with an interdisciplinary team, makes possible to these infants to be breastfed. In this article, the authors present an up-to-date review about the components of human milk and its unique characteristics, as well as describes aspects that make the breast milk particularly suitable for feeding the premature newborn.

Expression of PPAR and RXR isoforms in the developing rat and human term placentas

Placental fatty acid transfer is critical to meet the foetal requirements necessary for the biosynthesis of biological membranes, myelin, and various signaling molecules. The primary objective of this research was to elucidate the placental expression patterns of genes that may potentially regulate placental fatty acid transfer and homeostasis. In this study, we have elucidated the temporal and spatial patterns of expression of peroxisome proliferator-activated receptor (PPAR) and 9-cis retinoic acid receptor (RXR) isoforms in the junctional and labyrinth zones of the developing rat chorioallantoic placenta and in human term placenta. PPAR (alpha, beta, and gamma) and RXR (alpha, beta, and gamma) isoforms are nuclear hormone receptors that are known to regulate gene transcription and protein expression levels of fatty acid transport and metabolism mediating proteins through the formation of a DNA binding heterodimer complex. In the present study, the expression patterns of PPAR and RXR isoforms were determined in developing rat placenta and human term placenta using RT-PCR and immunohistochemical analyses. PPARalpha, beta, gamma, RXRalpha, beta and gamma were expressed in both junctional (invasive/endocrine function) and labyrinth (transport barrier) zones of the rat placenta, from day 13 to day 21 of gestation. In the human term placenta, PPARalpha, beta, gamma, RXRalpha and gamma were observed, while RXRbeta was not detected. Immunocytochemistry staining results determined the presence of PPARalpha, beta, gamma, RXRalpha and gamma to be specific to the syncytial trophoblast layer of the human chorionic villi. The presence of PPAR and RXR isoforms in both the rat and human placentas suggest that PPAR and RXR isoforms are potential regulators of placental lipid transfer and homeostasis. Our work provides a framework for the further investigation of PPAR and RXR isoform specific regulation of placental fatty acid uptake, transport and metabolism.

Negligible changes in piglet serum clinical indicators or organ weights due to dietary single-cell long-chain polyunsaturated oils

Single-cell oils are currently included in human infant formula as sources of the long-chain polyunsaturates (LCP) docosahexaenoic acid (DHA) and arachidonic acid (AA) in many countries, but have not yet been approved for use in the USA. We prepared four bovine-milk-based formulas with AA/DHA=0, 34/17, 68/34 and 170/85 (mg per 100 kcal formula) provided by two commercial single-cell oils. These levels correspond approximately to 0, 1, 2 and 5 times the concentrations used in infant formulas and, due to greater consumption of formula per unit body weight, resulted in daily consumption of approximately 0, 3, 6 and 16 times those anticipated for human infants. All other dietary fat (47% of calories) was provided by a vegetable oil blend used in commercial human infant formulas. Domestic piglets were allowed to nurse with the sow for 24 h after parturition, then removed to individual cages and maintained on one of the four diets. At 30 days of age the piglets were sacrificed, and serum collected and organs weighed. With litters treated as a blocked variable, no significant differences among groups were found by analysis of variance for the following serum assays: alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine, albumin, glucose, cholesterol, triglycerides, and total protein. No significant differences were found for hematocrit or body weight. No significant differences were found among groups for weights of liver, brain, heart, lung, spleen, kidneys or lung, analyzed as absolute weight and as a fraction of body weight. Hematoxylin/eosin liver sections examined by light microscopy showed no abnormalities as evaluated by an independent pathologist. DHA content in liver and heart and AA content in heart showed significant dose-related accumulation (P<0.05) and confirmed enhanced tissue accretion of DHA and AA from both oils. We conclude that single-cell oils in formula consumed for 1 month in amounts up to 16-fold greater than proposed for human infants in the USA did not result in clinical chemistry or histopathologic indications of toxic effects in neonatal pigs.

Efficacy of dietary arachidonic acid provided as triglyceride or phospholipid as substrates for brain arachidonic acid accretion in baboon neonates

Arachidonic acid (AA) is a long-chain polyunsaturate (LCP) present in human breast milk as both triglyceride (TG) and as phospholipid (PL). There has been little attention to the metabolic consequences of lipid form of AA in infant formulas. Our objective was to investigate the efficacy of dietary TG and PL as carriers of AA for accretion in the brain and associated organs of term baboon neonates consuming a formula with LCP composition typical of human milk. TG and phosphatidylcholine (PC) with [U-(13)C]-AA in the sn-2 position and with unlabeled 16:0 in the remaining positions (TG-AA* or PL-AA*, respectively) were used as tracers to study the tissue AA* incorporation. Baboon neonates received a single oral dose of either TG-AA* (n = 3) or PL-AA* (n = 4) at 18-19 d of life. Tissues were obtained 10 d later (28-29 d of life) and isotopic enrichment was measured. In the brain, 4.5% of the PL-AA* dose and 2.1% of the TG-AA* dose were recovered as brain AA*, respectively, indicating that PL was about 2.1-fold more effective than TG as a substrate for brain AA accretion. Preferential incorporation of PL-derived AA* over TG source of AA* was also observed in the liver, lung, plasma, and erythrocytes. Because of the quantitative predominance of TG-AA in formula, total brain AA accretion, expressed as absolute weight, was 5.0-fold greater from TG-AA than from PL-AA. We estimate that about half of postnatal brain AA accretion is derived from dietary preformed AA in term baboon neonates consuming a formula with lipid composition similar to that of human milk.

Dietary long-chain polyunsaturated fatty acids from different sources affect fat and fatty acid excretions in rats

Several sources of long-chain polyunsaturated fatty acids (LCP) have been evaluated for infant-formula supplementation. These sources differ in their chemical structure [triglyceride (TG) or phospholipid (PL)], arrangement of fatty acids on the TG or PL backbone, fatty acid composition and presence of other lipid components. All of these characteristics influence fat digestion, may affect fat and fatty acid absorption, and hence, LCP bioavailability and metabolism in infancy. The main objective of this work was to establish the influence of different dietary LCP sources on overall fat and LCP absorption in early life. We compared fat and fatty acid excretions at weaning in rats fed control diets or diets supplemented with LCP as TG or PL. Two separate experiments were conducted. In Experiment 1, weanling rats were fed for 3 wk a control diet (C1), a diet with TG from tuna and fungal oils (TF-TG) or a diet with PL from pig brain concentrate (PB-PL). In Experiment 2, weanling rats were fed for 3 wk a control diet (C2), a diet containing egg-TG (EG-TG) or a diet containing egg-PL (EG-PL). Fat, mineral and saturated fatty acid excretions in feces were higher in rats fed PB-PL compared with those fed TF-TG diet. In Experiment 2, groups did not differ in fat and mineral excretions. However, the EG-PL group had lower fecal excretions of saturated fatty acids than the C2 and EG-TG groups. The 16:1(n-7), 18:1(n-9), 18:2(n-6) and 22:6(n-3) levels in feces were higher in the EG-TG group than in the EG-PL group. In summary, total fat and LCP excretions differed among rats fed diets supplemented with LCP from different sources.

Maternal dietary PUFAs intake and human milk content relationships during the first month of lactation

Maternal dietary fatty acids (FFAs) intake and corresponding human milk composition relationships have been assessed throughout the first month of lactation in 34 lactating women consecutively enrolled. All mothers were on their habitual diet. Food records (95 items) were administered to the mothers, six-times during the first month of lactation (1 day after delivery, 4, 7, 14, 21, and 28 days after colostrum appearance) and referred to maternal dietary intake of the day before. Milk collected on day 1 was considered as colostrum, day 4 and 7 samples as transitional milk, and day 14, 21 and 28 samples as mature milk. Five gas chromatographic analyses were performed on each sample. Statistics were made using Friedman's and Pearson's test. Maternal dietary saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were significantly related to the corresponding milk pattern in the phase of transitional milk (P<0.01), while total polyunsaturated (PUFAs) content was significantly related only to the mature milk (P<0.01); in this phase about 42% of the variations occurring in PUFAs milk content can be related to variation of maternal PUFAs dietary intake. The results in the present study provide evidence of the relationships between maternal diet and milk composition. The degree of correlation between maternal diet and PUFAs milk content increases throughout milk maturational process and reaches significance only in mature milk. This would imply that advancing lactation, milk PUFAs provision sources gradually shift from adipose tissue catabolism to maternal diet.

The role of polyunsaturated fatty acid supplementation in intestinal inflammation and neonatal necrotizing enterocolitis

Dietary polyunsaturated fatty acid (PUFA) supplementation has been shown to reduce the incidence of necrotizing enterocolitis (NEC) in a recent randomized, controlled trial. These compounds are known to modulate the inflammatory cascade and to influence intestinal health in a variety of ways. Although the pathophysiology of NEC is not well understood, recent evidence suggests that platelet-activating factor (PAF) is a key endogenous mediator of intestinal necrosis in animals. Using a neonatal rat model of NEC that includes the key risk factors of asphyxia and formula feeding, we investigated the role of dietary PUFA supplementation on the incidence and pathophysiology of NEC. Our findings suggest that PUFA reduce the incidence of NEC by modulating PAF metabolism and endotoxin translocation.

Effect of polyunsaturated fatty acid (PUFA) supplementation on intestinal inflammation and necrotizing enterocolitis (NEC) in a neonatal rat model

Inasmuch as long-chain polyunsaturated fatty acids (PUFA, metabolites of the essential n-3 and n-6 fatty acids) are known to modulate inflammation, we hypothesized that supplementation of formula with these compounds would prevent necrotizing enterocolitis (NEC) and intestinal inflammation in our neonatal rat model. Newborn rats were stressed with asphyxia and formula feeding, and randomly assigned to control formula, control with PUFA supplementation, and PUFA with nucleotides. Animals were followed for 72--96 h and assessed for death, gross and histologic NEC, intestinal apoptosis, endotoxemia, and intestinal mRNA synthesis of phospholipase A(2)-II (rate-limiting enzyme for platelet activating factor production), platelet activating factor receptor, and inducible nitric oxide synthase. We found that PUFA reduced the incidence of death and NEC compared with the other groups (NEC 8 of 24 versus 17 of 24 control and 13 of 23 PUFA + nucleotides, p < 0.05). Furthermore, PUFA reduced plasma endotoxemia at 48 h (25 +/- 4 EU/mL versus 276 +/- 39 EU/mL in control and 170 +/- 28 EU/mL in PUFA + nucleotide), intestinal phospholipase A(2)-II expression at 24 h, and platelet activating factor receptor expression at 48 h. Formula supplementation had no effect on apoptosis of intestinal epithelium or intestinal inducible nitric oxide synthase expression. Addition of nucleotides with PUFA abrogated the beneficial effects of PUFA on intestinal inflammation. We conclude that PUFA reduces the incidence of NEC and intestinal inflammation in a neonatal rat model.

Infant feeding: a critical look at infant formulas

Commercially available infant formulas serve as the best alternative to human milk when breastfeeding is not possible. Infant formulas are designed specifically to mimic the composition of human milk or the functional aspects of human milk feeding. This review highlights the issues related to the composition of infant formulas. The most hotly debated issue currently is whether to add long-chain polyunsaturated fatty acids to infant formulas. Other controversial topics include the safety and efficacy of soy-based protein formulas, protein quantity and quality as they relate to the infant's nutritional needs and feeding tolerance, and the replacement of lactose with other carbohydrate sources for specialized infant formulas. Recent modifications in the fat blend of infant formulas have led to improved fat digestibility. However, the full spectrum of benefits associated with the addition of nucleotides awaits further study. Modifications to infant formulas are made when the preponderance of scientific evidence suggests that the compositional change will better meet the nutritional needs of the infant.