Effects of long-chain PUFA supplementation in infant formula on cognitive function in later childhood

Effect of n-3 PUFA supplementation on cognitive function throughout the life span from infancy to old age: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

n-3 PUFAs play an important role in cognitive function.

OBJECTIVE

The objective was to investigate the effect of n-3 PUFA supplements on cognitive development, function, and decline throughout the life span.

DESIGN

The study included randomized controlled trials and provided ≥3 mo of treatment. Potential studies were independently screened in duplicate, and study characteristics and outcomes were extracted. A meta-analysis was performed by using fixed- or random-effects models. The results are presented as standardized mean differences (SMDs) with 95% CIs.

RESULTS

Of the 3692 citations retrieved, 34 studies of a total of 12,999 participants (1031 infants, 1517 children, 3657 adults, and 6794 elderly individuals) were included. Compared with placebo, n-3 PUFA supplements significantly improved cognitive development in infants, including the Mental Development Index (SMD: 0.33; 95% CI: 0.15, 0.52), the Psychomotor Development Index (0.27; 95% CI: 0.09, 0.45), and language (0.27; 95% CI: 0.13, 0.42), motor (0.29; 95% CI: 0.14, 0.43), and cognitive (0.31; 95% CI: 0.16, 0.45) abilities. However, n-3 PUFAs did not promote cognitive function in terms of composite memory, executive function, and processing speed domains in children, adults, or the elderly, except for the attention domain. No association was found between n-3 PUFA intake and improvements in cognitive performance in terms of recognition, immediate and delayed word recall, digit span backward and forward tests, rapid visual information processing, verbal fluency, and simple and choice reaction times. In addition, n-3 PUFA supplements were not associated with improvements in cognitive decline or with any effects on Alzheimer disease in elderly people.

CONCLUSIONS

n-3 PUFA supplements may significantly improve cognitive development in infants but do not improve cognitive performance in children, adults, or the elderly. n-3 PUFA intake, especially that of DHA supplements, may benefit cognitive development during infancy.

Parenteral nutrition compromises neurodevelopment of preterm pigs

BACKGROUND

Despite advances in nutritional support and intensive care, preterm infants are at higher risk of compromised neurodevelopment.

OBJECTIVE

This study evaluated the contribution of total parenteral nutrition (PN) to compromised neurodevelopment after preterm birth.

METHODS

Preterm pigs were provided PN or enteral nutrition (EN) for 10 d. Neurodevelopment was assessed by observations of motor activity and evaluation of sensory/motor reflexes, brain weight, MRI, and cerebellar histology.

RESULTS

Despite similar gains in body weight, PN pigs had smaller brains (32 ± 0.4 vs. 35 ± 0.6 g; P = 0.0002) including the cerebellum, as well as reduced motor activity (P = 0.005), which corresponded to underdeveloped myelination (P = 0.004) measured by diffusion tensor imaging. PN resulted in lower serum triglycerides (17 ± 5.9 vs. 27 ± 3.1 mg/dL; P = 0.05), total cholesterol (31 ± 9.6 vs. 85 ± 8.1 mg/dL; P = 0.04), VLDL cholesterol (3.7 ± 1.2 vs. 5.7 ± 0.7 mg/dL; P = 0.04), and HDL cholesterol (16 ± 4.6 vs. 57 ± 7.3 mg/dL; P = 0.03) and nonsignificantly lower LDL cholesterol (10.7 ± 4.4 vs. 22.7 ± 2.9 mg/dL; P = 0.09).

CONCLUSIONS

The compromised neurodevelopment caused by total PN is a novel finding, was independent of confounding variables (disease, inconsistent gestational ages, diverse genetics, extrauterine growth retardation, and inconsistent neonatal intensive care unit protocols), and highlights a need to improve current PN solutions. The preterm pig is a translational animal model for improving nutrition support to enhance neurodevelopment of preterm infants requiring PN.

Current information and Asian perspectives on long-chain polyunsaturated fatty acids in pregnancy, lactation, and infancy: systematic review and practice recommendations from an early nutrition academy workshop

The Early Nutrition Academy supported a systematic review of human studies on the roles of pre- and postnatal long-chain polyunsaturated fatty acids (LC-PUFA) published from 2008 to 2013 and an expert workshop that reviewed the information and developed recommendations, considering particularly Asian populations. An increased supply of n-3 LC-PUFA during pregnancy reduces the risk of preterm birth before 34 weeks of gestation. Pregnant women should achieve an additional supply ≥200 mg docosahexaenic acid (DHA)/day, usually achieving a total intake ≥300 mg DHA/day. Higher intakes (600-800 mg DHA/day) may provide greater protection against early preterm birth. Some studies indicate beneficial effects of pre- and postnatal DHA supply on child neurodevelopment and allergy risk. Breast-feeding is the best choice for infants. Breast-feeding women should get ≥200 mg DHA/day to achieve a human milk DHA content of ∼0.3% fatty acids. Infant formula for term infants should contain DHA and arachidonic acid (AA) to provide 100 mg DHA/day and 140 mg AA/day. A supply of 100 mg DHA/day should continue during the second half of infancy. We do not provide quantitative advice on AA levels in follow-on formula fed after the introduction of complimentary feeding due to a lack of sufficient data and considerable variation in the AA amounts provided by complimentary foods. Reasonable intakes for very-low-birth weight infants are 18-60 mg/kg/day DHA and 18-45 mg/kg/day AA, while higher intakes (55-60 mg/kg/day DHA, ∼1% fatty acids; 35-45 mg/kg/day AA, ∼0.6-0.75%) appear preferable. Research on the requirements and effects of LC-PUFA during pregnancy, lactation, and early childhood should continue. © 2014 S. Karger AG, Basel.

Cognitive and neurodevelopmental benefits of extended formula-feeding in infants: re: Deoni et al. 2013

The recent Deoni et al. (2013) manuscript proposed that breastfeeding was associated with increased cognitive ability and white-matter in older children (over 26 months), using ms-DESPOT MRI imaging to indirectly measure white matter in children who were either breastfed, formula fed, or combined breast+formula fed. In this response, we identify limitations in drawing causal inference among white matter, cognitive ability, and breastfeeding. We propose that the observed cognitive and neurodevelopmental differences between breastfed and formula-fed infants might actually be caused by the premature introduction of cow's milk in the second year of life, among other contributing factors. The implication of a causal relationship between intelligence and white matter metrics, especially in a developmentally young population, is premature given the recency of this field. The original analyses did not control for important covariates; when comparing both white matter and test scores, mothers were not controlled for age and socio-economic status (SES) and their children were not controlled for gender. Raw test scores, instead of age-adjusted test scores, were used even though the children were of different ages. Mothers were not controlled for reason(s) not to breastfeed, even though many prenatal factors are known to predict this such as stress, parity, obesity, and smoking habits. The observed cognitive ability and white matter benefits identified primarily within the long-term breastfed children are at least partially attributable to other factors such as age, gender, and SES. We suggest methodological approaches to removing such ambiguity, and ways to dissociate cause from effect. The formula and breastfeeding groups didn't show differences until the "formula fed" children likely had been fed cow's milk for longer than they had been fed formula, at 2.2 years. The greatest cognitive differences however were observed within the high SES breastfed infants depending on breastfeeding duration; infants who were breastfed over 15 months showed increased cognitive ability compared to those breastfed less than months. This implicates the source of dairy during the second year of life, and not other SES factors or infant formula, as the most likely nutritional factor responsible for the observed differences within the breastfed children. Given the known nutritional deficiencies of cow's milk, these findings imply infants who received cow's milk during the second year of life were at a disadvantage compared to those who were breastfed, independent of whether they were fed formula or breast milk during the first year of life. This evidence suggests that infants should receive formula in lieu of cow's milk when breast milk is unavailable as a dairy source, until roughly 2 years of age.

Higher efficacy of dietary DHA provided as a phospholipid than as a triglyceride for brain DHA accretion in neonatal piglets

Long-chain PUFAs (LCPUFAs) occur in foods primarily in the natural lipid classes, triacylglycerols (TAGs) or phospholipids (PLs). We studied the relative efficacy of the neural omega-3 DHA provided in formula to growing piglets as a dose of (13)C-DHA bound to either TAG or phosphatidylcholine (PC). Piglets were assigned to identical formula-based diets from early life and provided with TAG-(13)C-DHA or PC-(13)C-DHA orally at 16 days. Days later, piglet organs were analyzed for (13)C-DHA and other FA metabolites. PC-(13)C-DHA was 1.9-fold more efficacious for brain gray matter DHA accretion than TAG-(13)C-DHA, and was similarly more efficacious in gray matter synaptosomes, retina, liver, and red blood cells (RBCs). Liver labeling was greatest, implying initial processing in that organ followed by export to other organs, and suggesting that transfer from gut to bloodstream to liver in part drove the difference in relative efficacy for tissue accretion. Apparent retroconversion to 22:5n-3 was more than double for PC-(13)C-DHA and was more prominent in neural tissue than in liver or RBCs. These data directly support greater efficacy for PC as a carrier for LCPUFAs compared with TAG, consistent with previous studies of arachidonic acid and DHA measured in other species.

An update on adding docosahexaenoic acid (DHA) and arachidonic acid (AA) to baby formula

Human milk is the ideal food providing optimal nutrition for healthy term infants. Its complex lipid composition is critical for infant growth and serves as a golden standard for baby formula development. Docosahexaenoic acid (C22:6 n- 3, DHA) and arachidonic acid (C20:4 n- 6, AA) are the two major long chain polyunsaturated fatty acids (PUFAs) in human milk. In humans, they are fundamental components of the cell membrane and play an important role in neurite growth and signal transmission. Their importance for both preterm and term infants has been demonstrated by various clinical trials. DHA and AA supplementation shows desirable influences on visual and cognitive development in early life and is additionally associated with potential benefits on later health. Further clinical data revealed that supplementing both DHA and AA instead of DHA alone during infancy is important to deliver the optimal outcome. In this review, we summarize current research and scientific evidence of DHA and AA on baby development.

Use of published research in paediatric nutrition for the scientific substantiation of health claims referring to children's development and health

The European Food Safety Authority (EFSA) provides policy makers with scientific and technical advice in relation to food safety and human nutrition in an independent and transparent way, and communicates such advice to the general public. Requirements for the scientific substantiation of health claims referring to children's development and health are the same as for other health claims. However, children (particularly infants) have peculiarities which should be taken into account, because these may impair the extrapolation of results to other groups.

CONCLUSION

Health claims used in commercial communications should be authorized only after a scientific assessment of the highest possible standard by EFSA. EFSA's negative opinions on rejected claims should not be read as a criticism to research studies published in paediatric nutrition but rather highlight their limitations in relation to the substantiation of specific health claims made on foods.