Mental performance in 8-year-old children fed reduced protein content formula during the 1st year of life: safety analysis of a randomised clinical trial

Higher versus lower protein intake in formula-fed term infants

BACKGROUND

Many infants are fed infant formulas to promote growth. Some formulas have a high protein content (≥ 2.5 g per 100 kcal) to accelerate weight gain during the first year of life. The risk-benefit balance of these formulas is unclear.

OBJECTIVES

To evaluate the benefits and harms of higher protein intake versus lower protein intake in healthy, formula-fed term infants.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, OpenGrey, clinical trial registries, and conference proceedings in October 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of healthy formula-fed infants (those fed only formula and those given formula as a complementary food). We included infants of any sex or ethnicity who were fed infant formula for at least three consecutive months at any time from birth. We excluded quasi-randomized trials, observational studies, and infants with congenital malformations or serious underlying diseases. We defined high protein content as 2.5 g or more per 100 kcal, and low protein content as less than 1.8 g per 100 kcal (for exclusive formula feeding) or less than 1.7 g per 100 kcal (for complementary formula feeding).

DATA COLLECTION AND ANALYSIS

Four review authors independently assessed the risk of bias and extracted data from trials, and a fifth review author resolved discrepancies. We performed random-effects meta-analyses, calculating risk ratios (RRs) or Peto odds ratios (Peto ORs) with 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) with 95% CIs for continuous outcomes. We used the GRADE approach to evaluate the certainty of the evidence.

MAIN RESULTS

We included 11 RCTs (1185 infants) conducted in high-income countries. Seven trials (1629 infants) compared high-protein formula against standard-protein formula, and four trials (256 infants) compared standard-protein formula against low-protein formula. The longest follow-up was 11 years. High-protein formula versus standard-protein formula We found very low-certainty evidence that feeding healthy term infants high-protein formula compared to standard-protein formula has little or no effect on underweight (MD in weight-for-age z-score 0.05 SDs, 95% CI -0.09 to 0.19; P = 0.51, I2 = 61%; 7 studies, 1629 participants), stunting (MD in height-for-age z-score 0.15 SDs, 95% CI -0.05 to 0.35; P = 0.14, I2 = 73%; 7 studies, 1629 participants), and wasting (MD in weight-for-height z-score -0.12 SDs, 95% CI -0.31 to 0.07; P = 0.20, I2 = 94%; 7 studies, 1629 participants) in the first year of life. We found very low-certainty evidence that feeding healthy infants high-protein formula compared to standard-protein formula has little or no effect on the occurrence of overweight (RR 1.26, 95% CI 0.63 to 2.51; P = 0.51; 1 study, 1090 participants) or obesity (RR 1.96, 95% CI 0.59 to 6.48; P = 0.27; 1 study, 1090 participants) at five years of follow-up. No studies reported all-cause mortality. Feeding healthy infants high-protein formula compared to standard-protein formula may have little or no effect on the occurrence of adverse events such as diarrhea, vomiting, or milk hypersensitivity (RR 0.93, 95% CI 0.76 to 1.13; P = 0.44, I2 = 0%; 4 studies, 445 participants; low-certainty evidence) in the first year of life. Standard-protein formula versus low-protein formula We found very low-certainty evidence that feeding healthy infants standard-protein formula compared to low-protein formula has little or no effect on underweight (MD in weight-for-age z-score 0.0, 95% CI -0.43 to 0.43; P = 0.99, I2 = 81%; 4 studies, 256 participants), stunting (MD in height-for-age z-score -0.01, 95% CI -0.36 to 0.35; P = 0.96, I2 = 73%; 4 studies, 256 participants), and wasting (MD in weight-for-height z-score 0.13, 95% CI -0.29 to 0.56; P = 0.54, I2 = 95%; 4 studies, 256 participants) in the first year of life. No studies reported overweight, obesity, or all-cause mortality. Feeding healthy infants standard-protein formula compared to low-protein formula may have little or no effect on the occurrence of adverse events such as diarrhea, vomiting, or milk hypersensitivity (Peto OR 1.55, 95% CI 0.70 to 3.40; P = 0.28, I2 = 0%; 2 studies, 206 participants; low-certainty evidence) in the first four months of life.

AUTHORS' CONCLUSIONS

We are unsure if feeding healthy infants high-protein formula compared to standard-protein formula has an effect on undernutrition, overweight, or obesity. There may be little or no difference in the risk of adverse effects between infants fed with high-protein formula versus those fed with standard-protein formula. We are unsure if feeding healthy infants standard-protein formula compared to low-protein formula has any effect on undernutrition. There may be little or no difference in the risk of adverse effects between infants fed with standard-protein formula versus those fed with low-protein formula. The findings of six ongoing studies and two studies awaiting classification studies may change the conclusions of this review.

Macronutrient intake during infancy and neurodevelopment in preschool children from the EDEN mother-child cohort

BACKGROUND

Although the deleterious effect of micronutrient deficiency at sensitive periods on neurodevelopment is well established, the potential influence of macronutrient intake on early life neurodevelopment of healthy term infants has been seldomly studied. We aimed to explore whether macronutrient intake at 12 months was related to neurodevelopmental scores in preschool children.

METHODS

Analyses were based on data from the EDEN mother-child cohort. Macronutrient intake was assessed by 3-day food records at 12 months of age. Neurodevelopment was assessed at 3 years using the French version of the Ages and Stages Questionnaire (ASQ) (n = 914), and at 5-6 years, using the French version of the Wechsler Preschool and Primary Scale of Intelligence-Third Edition (n = 785). An association between macronutrient intake and neurodevelopmental scores were analysed by multivariable linear regression for 3-year Full Score ASQ or 5-6-year intelligence quotient scores and multivariable logistic regression for 3-year ASQ subdomains.

RESULTS

Macronutrient intake in infancy was not associated with neurodevelopmental scores in preschool children. No association was found between PUFA intake and overall neurodevelopmental scores, after accounting for multiple testing.

CONCLUSION

In the present study, macronutrient intake at one year did not appear to influence the child's cognitive ability at 3 and 5-6 years. Further studies are needed to clarify the relationship between early fatty acid intake and neurodevelopment.

Supplementation of Infant Formula and Neurodevelopmental Outcomes: a Systematic Review

PURPOSE OF THE REVIEW

The aim is to examine data from clinical trials and prospective longitudinal studies that evaluate the effect of infant formula supplements on the cognitive function of children.

RECENT FINDINGS

A total of 300 articles from 2000 to 2021 were selected. The most researched IF supplements were initially long-chain polyunsaturated fatty acids (LC-PUFA), some proteins and, recently, milk fat globule membrane (MFGM). Supplementation of IF with LC-PUFA led to some positive effects on specific cognitive functions or no effect; however, there was no consistent benefit for cognitive function. Modifying the amount of proteins did not affect the children's neuropsychological tests. Supplementation of IF with MFGM and its components had beneficial effects on child cognitive development in the short term, but no effect was observed in the long term. Further studies are needed to confirm the safety of supplementation on the development of cognitive function in children fed with infant formula.

Infant Formula Supplemented With Milk Fat Globule Membrane, Long-Chain Polyunsaturated Fatty Acids, and Synbiotics Is Associated With Neurocognitive Function and Brain Structure of Healthy Children Aged 6 Years: The COGNIS Study

Background

Adequate nutrient intake during the first few months of life plays a critical role on brain structure and function development.

Objectives

To analyze the long-term effects of an experimental infant formula (EF) on neurocognitive function and brain structure in healthy children aged 6 years compared to those fed with a standard infant formula or breastfed.

Methods

The current study involved 108 healthy children aged 6 years and participating in the COGNIS Study. At 0-2 months, infants were randomized to receive up to 18 months of life a standard infant formula (SF) or EF enriched with milk fat globule membrane (MFGM), long-chain polyunsaturated fatty acids (LC-PUFAs) and synbiotics. Furthermore, a reference group of breastfed (BF) infants were also recruited. Children were assessed using neurocognitive tests and structural Magnetic Resonance Imaging (MRI) at 6 years old.

Results

Experimental infant formula (EF) children showed greater volumes in the left orbital cortex, higher vocabulary scores and IQ, and better performance in an attention task than BF children. EF children also presented greater volumes in parietal regions than SF kids. Additionally, greater cortical thickness in the insular, parietal, and temporal areas were found in children from the EF group than those fed with SF or BF groups. Further correlation analyses suggest that higher volumes and cortical thickness of different parietal and frontal regions are associated with better cognitive development in terms of language (verbal comprehension) and executive function (working memory). Finally, arachidonic acid (ARA), adrenic acid (AdA), docosahexaenoic acid (DHA) levels in cheek cell glycerophospholipids, ARA/DHA ratio, and protein, fatty acid, and mineral intake during the first 18 months of life seem to be associated with changes in the brain structures at 6 years old.

Conclusions

Supplemented infant formula with MFGM components, LC-PUFAs, and synbiotics seems to be associated to long-term effects on neurocognitive development and brain structure in children at 6 years old.

Clinical Trial Registration

https://www.clinicaltrials.gov/, identifier: NCT02094547.

Long-Chain Polyunsaturated Fatty Acids, Homocysteine at Birth and Fatty Acid Desaturase Gene Cluster Polymorphisms are Associated with Children's Processing Speed up to Age 9 Years

Both pre- and early postnatal supplementation with docosahexaenoic acid (DHA), arachidonic acid (AA) and folate have been related to neural development, but their long-term effects on later neural function remain unclear. We evaluated the long-term effects of maternal prenatal supplementation with fish-oil (FO), 5-methyltetrahydrofolate (5-MTHF), placebo or FO + 5-MTHF, as well as the role of fatty acid desaturase (FADS) gene cluster polymorphisms, on their offspring’s processing speed at later school age. This study was conducted in NUHEAL children at 7.5 (n = 143) and 9 years of age (n = 127). Processing speed tasks were assessed using Symbol Digit Modalities Test (SDMT), Children Color Trails Test (CCTT) and Stroop Color and Word Test (SCWT). Long-chain polyunsaturated fatty acids, folate and total homocysteine (tHcy) levels were determined at delivery from maternal and cord blood samples. FADS and methylenetetrahydrofolate reductase (MTHFR) 677 C > T genetic polymorphisms were analyzed. Mixed models (linear and logistic) were performed. There were significant differences in processing speed performance among children at different ages (p < 0.001). The type of prenatal supplementation had no effect on processing speed in children up to 9 years. Secondary exploratory analyses indicated that children born to mothers with higher AA/DHA ratio at delivery (p < 0.001) and heterozygotes for FADS1 rs174556 (p < 0.05) showed better performance in processing speed at 9 years. Negative associations between processing speed scores and maternal tHcy levels at delivery were found. Our findings suggest speed processing development in children up to 9 years could be related to maternal factors, including AA/DHA and tHcy levels, and their genetic background, mainly FADS polymorphism. These considerations support that maternal prenatal supplementation should be quantitatively adequate and individualized to obtain better brain development and mental performance in the offspring.

Effects of Maternal Fish Oil and/or 5-Methyl-Tetrahydrofolate Supplementation during Pregnancy on Offspring Brain Resting-State at 10 Years Old: A Follow-Up Study from the NUHEAL Randomized Controlled Trial

Recent studies have shown that maternal supplementation with folate and long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy may affect children's brain development. We aimed at examining the potential long-term effect of maternal supplementation with fish oil (FO) and/or 5-methyl-tetrahydrofolate (5-MTHF) on the brain functionality of offspring at the age of 9.5-10 years. The current study was conducted as a follow-up of the Spanish participants belonging to the Nutraceuticals for a Healthier Life (NUHEAL) project; 57 children were divided into groups according to mother's supplementation and assessed through functional magnetic resonance imaging (fMRI) scanning and neurodevelopment testing. Independent component analysis and double regression methods were implemented to investigate plausible associations. Children born to mothers supplemented with FO (FO and FO + 5-MTHF groups, n = 33) showed weaker functional connectivity in the default mode (DM) (angular gyrus), the sensorimotor (SM) (motor and somatosensory cortices) and the fronto-parietal (FP) (angular gyrus) networks compared to the No-FO group (placebo and 5-MTHF groups, n = 24) (PFWE < 0.05). Furthermore, no differences were found regarding the neuropsychological tests, except for a trend of better results in an object recall (memory) test. Considering the No-FO group, the aforementioned networks were associated negatively with attention and speed-processing functions. Mother's FO supplementation during pregnancy seems to be able to shape resting-state network functioning in their children at school age and appears to produce long-term effects on children´s cognitive processing.

Optimized protein intakes in term infants support physiological growth and promote long-term health

Breastfeeding is associated with a reduced later obesity risk, relative to feeding convention infant formula. Breastfeeding induces less weight gain during the first two years of life, which predicts less obesity up to adulthood. We tested the hypothesis that a high infant protein supply promotes weight gain and obesity risk, mediated by increased plasma amino acids and growth factors, insulin and insulin like growth factor 1 (IGF-1). A large multi-centre double blind trial randomized formula-fed infants to conventional bottle milk with a high protein content, or an intervention formula with a reduced protein content more similar to levels provided with human milk. Protein-reduced formula normalized weight, body mass index and body fatness up to 6 years, relative to a breastfed reference group, and reduced the adjusted odds for obesity 2.6-fold. Available data indicate potential underlying mechanisms. We conclude that infant feeding has very marked long-term programming effects on later BMI, obesity and adiposity, with major public health implications. Breastfeeding lowers the risk for later obesity and adiposity. This provides additional motivation for proactively and enthusiastically promoting, protecting and supporting breastfeeding. A high milk protein intake in infancy increases the long-term risk for obesity and adiposity. Infants not or not fully breastfed should receive infant formula delivering protein in amounts more similar to human milk contents, with high protein quality. Other sources of very high infant protein intakes, particular drinking unmodified cows' milk, should be avoided in infancy.

Breast-Feeding Friendly, but Not Formula Averse

Breast-feeding is the optimal source of newborn nutrition in term infants and is associated with multiple short- and long-term health benefits. Establishment of breast-feeding may be difficult in a small subset of mothers, which can lead to adverse consequences in the newborn. Some of the consequences of suboptimal nutritional provision to the newborn, such as severe hyperbilirubinemia and breast-feeding-associated hypernatremic dehydration, can have devastating and long-lasting sequelae. Timely identification of mothers and newborns at risk for developing these complications is necessary to avoid significant morbidity and mortality. In these cases, the judicious use of formula supplementation may be considered. However, more studies are necessary to develop comprehensive formula supplementation criteria and guidelines for pediatric medical providers. [Pediatr Ann. 2017;46(11):e402-e408.].

Advances in nutrition of the newborn infant

Nutrition of newborn infants, particularly of those born preterm, has advanced substantially in recent years. Extremely preterm infants have high nutrient demands that are challenging to meet, such that growth faltering is common. Inadequate growth is associated with poor neurodevelopmental outcomes, and although improved early growth is associated with better cognitive outcomes, there might be a trade-off in terms of worse metabolic outcomes, although the contribution of early nutrition to these associations is not established. New developments include recommendations to increase protein supply, improve formulations of parenteral lipids, and provide mineral supplements while encouraging human milk feeding. However, high quality evidence of the risks and benefits of these developments is lacking. Clinical trials are also needed to assess the effect on preterm infants of experiencing the smell and taste of milk, to determine whether boys and girls should be fed differently, and to test effects of insulin and IGF-1 supplements on growth and developmental outcomes. Moderate-to-late preterm infants have neonatal nutritional challenges that are similar to those infants born at earlier gestations, but even less high quality evidence exists upon which to base clinical decisions. The focus of research in nutrition of infants born at term is largely directed at new formula products that will improve cognitive and metabolic outcomes. Providing the most effective nutrition to preterm infants should be prioritised as an important focus of neonatal care research to improve long-term metabolic and developmental outcomes.

Early Programming by Protein Intake: The Effect of Protein on Adiposity Development and the Growth and Functionality of Vital Organs

This article reviews the role of protein intake on metabolic programming early in life. The observations that breastfeeding in infancy reduces the risk of being overweight and obese later in life and the differences in the protein content between formula milk and human milk have generated the early protein hypothesis. The present review focuses on a mechanistic approach to programmed adiposity and the growth and development of other organs by protein intake in infancy, which may be mediated by branched-chain amino acids, insulin, and insulin-like growth factor 1 via the mammalian target of rapamycin. Observational studies and clinical trials have shown that lowering the protein content in infant and follow-on formulas may reduce the risk of becoming obese later in life. The recent body of evidence is currently being translated into new policies. Therefore, the evolution of European regulatory laws and recommendations by expert panels on the protein content of infant and follow-on formulas are also reviewed. Research gaps, such as the critical window for programming adiposity by protein intake, testing formulas with modified amino acids, and the long-term consequences of differences in protein intake on organ functionality among well-nourished infants, have been identified.