Maternal milk DHA content predicts cognitive performance in a sample of 28 nations

Nutritional Status of Breastfeeding Mothers and Impact of Diet and Dietary Supplementation: A Narrative Review

Adequate nutrition during breastfeeding is crucial for ensuring the good health of mothers and babies. Despite the high energy and nutrient demands of breastfeeding, lactating women are often vulnerable from a nutritional perspective. The nutritional focus during breastfeeding tends to be on the newborn, often neglecting the mother's diet. Therefore, in the present narrative review, nutrient intakes were compared with the dietary reference values (DRVs) proposed by the European Food Safety Authority (EFSA) as well as by the World Health Organization/Food and Agriculture Organization (WHO/FAO). In the diets of lactating mothers, dietary inadequacies were observed in the intake of some vitamins, such as folic acid, vitamin B12, vitamin A, and vitamin D, and in the intake of certain minerals like calcium, iron, and iodine; polyunsaturated omega-3 fatty acid deficiencies, primarily in eicosapentaenoic acid and docosahexaenoic acid, were also observed. On the other hand, the debate on the necessity of supplementation during lactation continues; the need for nutritional supplementation during lactation depends on many factors, such us mothers' eating habits. There seems to be a positive association between nutritional supplementation of the lactating mother and the concentration of certain nutrients in human milk. The present narrative review provides an update on the nutritional status (fatty acids and micronutrients) of breastfeeding mothers and the impact of diet and dietary supplementation on human milk composition.

Association of breastfeeding with mental disorders in mother and child: a systematic review and meta-analysis

BACKGROUND

Breastfeeding has long been associated with numerous benefits for both mothers and infants. While some observational studies have explored the relationship between breastfeeding and mental health outcomes in mothers and children, a systematic review of the available evidence is lacking. The purpose of this study is to systematically evaluate the association between breastfeeding and mental health disorders in mothers and children.

METHODS

We systematically searched MEDLINE and EMBASE from inception to June 2, 2023. The inclusion criteria consisted of all studies evaluating links between breastfeeding and development of mental health disorders in children and mothers. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) while grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess the certainty of evidence. A random-effects meta-analysis was used if possible, to estimate the odds ratio for the association between breastfeeding and mental health outcomes. The Mantel-Haenszel method was utilised for pooling ORs across studies. Study heterogeneity was assessed using the I2 statistic.

RESULTS

Our review identified twenty-one original study. Of these, 18 focused on the association between breastfeeding and child health, assessing depressive disorders, schizophrenia, anxiety disorders, eating disorders and borderline personality disorder. Three studies evaluated the associations between breastfeeding and maternal mental health disorders. Three studies looking at outcomes in children showed no significant association between breastfeeding and occurrence of schizophrenia later in life (OR 0.98; 95% CI 0.57-1.71; I2 = 29%). For depressive disorders (5 studies) and anxiety disorders (3 studies), we found conflicting evidence with some studies showing a small protective effect while others found no effect. The GRADE certainty for all these findings was very low due to multiple limitations. Three studies looking at association between breastfeeding and maternal mental health, were too heterogeneous to draw any firm conclusions.

CONCLUSIONS

We found limited evidence to support a protective association between breastfeeding and the development of mental health disorders in children later in life. The data regarding the association between breastfeeding and maternal mental health beyond the postnatal period is also limited. The methodological limitations of the published literature prevent definitive conclusions, and further research is needed to better understand the relationship between breastfeeding and mental health in mothers and children.

Weight Location Moderates Weight-Based Self-Devaluation and Perceived Social Devaluation in Women

Overweight and obese (“heavyweight”) people devalue themselves because, it has been proposed, they are socially devalued. However, for women, social valuation depends not only on how much weight they carry but also on where on their bodies they carry it. Here, we investigated whether weight-based self-valuation and perceived social valuation similarly depend on body shape. Study 1, using a nationally representative sample from National Health and Nutrition Examination Survey (NHANES; N = 1,093 reproductive-aged women), showed that, controlling for body fat, weight labeling (by self and others) and wanting to lose weight depended on body shape. Study 2, in a direct test of predictions using an undergraduate sample of women ( N = 215), showed that with increased body fat, women with an abdominal weight distribution reported more self-devaluation (e.g., lower self-esteem) and perceived social devaluation (e.g., higher perceived weight discrimination); women with a gluteofemoral weight distribution, however, were shielded—partially or fully—from these adverse effects of increased body fat.

Breastfeeding Duration Is Associated With Domain-Specific Improvements in Cognitive Performance in 9-10-Year-Old Children

Significant immunological, physical and neurological benefits of breastfeeding in infancy are well-established, but to what extent these gains persist into later childhood remain uncertain. This study examines the association between breastfeeding duration and subsequent domain-specific cognitive performance in a diverse sample of 9-10-year-olds enrolled in the Adolescent Brain Cognitive Development (ABCD) Study®. The analyses included 9,116 children that attended baseline with their biological mother and had complete neurocognitive and breastfeeding data. Principal component analysis was conducted on data from an extensive battery of neurocognitive tests using varimax-rotation to extract a three-component model encompassing General Ability, Executive Functioning, and Memory. Propensity score weighting using generalized boosted modeling was applied to balance the distribution of observed covariates for children breastfed for 0, 1-6, 7-12, and more than 12 months. Propensity score-adjusted linear regression models revealed significant association between breastfeeding duration and performance on neurocognitive tests representing General Ability, but no evidence of a strong association with Executive Function or Memory. Benefits on General Ability ranged from a 0.109 (1-6 months) to 0.301 (>12 months) standardized beta coefficient difference compared to those not breastfed. Results indicate clear cognitive benefits of breastfeeding but that these do not generalize to all measured domains, with implications for public health policy as it pertains to nutrition during infancy.

Adolescent Cranial Volume as a Sensitive Marker of Parental Investment: The Role of Non-material Resources?

Growth of different body parts in humans is sensitive to different resource constraints that are mediated by parental investment. Parental investment can involve the expenditure of material, cognitive, and emotional resources on offspring. Cranial volume, an important predictor of cognitive ability, appears understudied in this context. We asked (1) whether there are associations between growth and family structure, self-reported estimates for resource availability, and sibling number; and (2) whether these constraints relate to head and body growth in a similar manner. We assessed the associations between parental investment, height, and cranial volume in a cross-sectional study of Estonian children (born 1980-87, aged 11-17). Height correlated negatively with the number of siblings but this association became negligible in a model controlling for birthweight, parental heights, and mother's age at birth. Unlike height, cranial volume was unrelated to sibling number, but it was negatively associated with self-reported meat and general resource shortage. Cranial volume was related to family structure and paternal education. Children living with both birth-parents had larger heads than those living in families containing a step-parent. Since these family types did not differ with respect to meat or general resource shortage, our findings suggest that families including both genetic parents provide non-material benefits that stimulate predominantly cranial growth. For the studied developmental period, cranial volume appeared a more sensitive marker of growth constraints than height. The potential of using cranial volume for quantifying physical impact of non-material parental investment deserves further attention.

Human milk fatty acid composition is associated with dietary, genetic, sociodemographic, and environmental factors in the CHILD Cohort Study

BACKGROUND

Fatty acids are a vital component of human milk. They influence infant neurodevelopment and immune function, and they provide ∼50% of milk's energy content.

OBJECTIVES

The objectives of this study were to characterize the composition of human milk fatty acids in a large Canadian birth cohort and identify factors influencing their variability.

METHODS

In a subset of the CHILD cohort (n = 1094), we analyzed milk fatty acids at 3-4 mo postpartum using GLC. Individual and total SFAs, MUFAs, and n-3 and n-6 PUFAs were analyzed using SD scores and principal component analysis (PCA). Maternal diet, sociodemographic, health, and environmental factors were self-reported. Single-nucleotide polymorphisms were assessed in the fatty acid desaturase 1 (FADS1-rs174556) and 2 (FADS2-rs174575) genes.

RESULTS

Fatty acid profiles were variable, with individual fatty acid proportions varying from 2- to >30-fold between women. Using PCA, we identified 4 milk fatty acid patterns: "MUFA and low SFA," "high n-6 PUFA," "high n-3 PUFA," and "high medium-chain fatty acids." In multivariable-adjusted analyses, fish oil supplementation and fatty cold water fish intake were positively associated with DHA and the "high n-3 PUFA" pattern. Mothers carrying the minor allele of FADS1-rs174556 had lower proportions of arachidonic acid (ARA; 20:4n-6). Independent of selected dietary variables and genetic variants, Asian ethnicity was associated with higher linoleic acid (18:2n-6) and total n-3 PUFAs. Ethnic differences in ARA were explained by FADS1 genotype. Maternal obesity was independently associated with higher total SFAs, the "high medium-chain fatty acid" pattern, and lower total MUFAs. Lactation stage, season, study site, and maternal education were also independently associated with some milk fatty acids. No associations were observed for maternal age, parity, delivery mode, or infant sex.

CONCLUSIONS

This study provides unique insights about the "normal" variation in the composition of human milk fatty acids and the contributing dietary, genetic, sociodemographic, health, and environmental factors. Further research is required to assess implications for infant health.

The Effect of Maternal Obesity on Breast Milk Fatty Acids and Its Association with Infant Growth and Cognition-The PREOBE Follow-Up

This study analyzed how maternal obesity affected fatty acids (FAs) in breast milk and their association with infant growth and cognition to raise awareness about the programming effect of maternal health and to promote a healthy prenatal weight. Mother–child pairs (n = 78) were grouped per maternal pre-pregnancy body mass index (BMI): normal-weight (BMI = 18.5–24.99), overweight (BMI = 25–29.99) and obese (BMI > 30). Colostrum and mature milk FAs were determined. Infant anthropometry at 6, 18 and 36 months of age and cognition at 18 were analyzed. Mature milk exhibited lower arachidonic acid (AA) and docosahexaenoic acid (DHA), among others, than colostrum. Breast milk of non-normal weight mothers presented increased saturated FAs and n6:n3 ratio and decreased α-linolenic acid (ALA), DHA and monounsaturated FAs. Infant BMI-for-age at 6 months of age was inversely associated with colostrum n6 (e.g., AA) and n3 (e.g., DHA) FAs and positively associated with n6:n3 ratio. Depending on the maternal weight, infant cognition was positively influenced by breast milk linoleic acid, n6 PUFAs, ALA, DHA and n3 LC-PUFAs, and negatively affected by n6:n3 ratio. In conclusion, this study shows that maternal pre-pregnancy BMI can influence breast milk FAs and infant growth and cognition, endorsing the importance of a healthy weight in future generations.

The Concentration of Omega-3 Fatty Acids in Human Milk Is Related to Their Habitual but Not Current Intake

This study determined fatty acid (FA) concentrations in maternal milk and investigated the association between omega-3 fatty acid levels and their maternal current dietary intake (based on three-day dietary records) and habitual dietary intake (based on intake frequency of food products). Tested material comprised 32 samples of human milk, coming from exclusively breastfeeding women during their first month of lactation. Milk fatty acids were analyzed as fatty acid methyl ester (FAME) by gas chromatography using a Hewlett-Packard 6890 gas chromatograph with MS detector 5972A. We did not observe any correlation between current dietary intake of omega-3 FAs and their concentrations in human milk. However, we observed that the habitual intake of fatty fish affected omega-3 FA concentrations in human milk. Kendall’s rank correlation coefficients were 0.25 (p = 0.049) for DHA, 0.27 (p = 0.03) for EPA, and 0.28 (p = 0.02) for ALA. Beef consumption was negatively correlated with DHA concentrations in human milk (r = −0.25; p = 0.046). These findings suggest that current omega-3 FA intake does not translate directly into their concentration in human milk. On the contrary, their habitual intake seems to markedly influence their milk concentration.

[A review on the relationship between breast milk nutrients and brain development in preterm infants]

Breast milk is the preferred food for preterm infants. In recent years, the role of breast milk in the brain development of preterm infants has attracted more and more attention. Studies have shown that the effect of breastfeeding on neurodevelopment and long-term cognitive outcome of preterm infants may persist into childhood, adolescence, and even adulthood. The nutrients in breast milk, such as oligosaccharides, polyunsaturated fatty acids, and lactoferrin, play an important role in this process. This article reviews the latest research advances in the role of breast milk nutrients in the brain development of preterm infants and elaborates on the concept and function of each nutrient.

Docosahexaenoic acid levels in erythrocytes and their association with the University Selection Test Outcomes in Chile

The aim of this study was to quantitate the relative impact of DHA and AA levels in erythrocytes, anthropometric parameters and socio-economic status of school-age children, of both genders, graduated from high school in Chile, on the scholastic achievement in the University Selection Test (Prueba de Selección Universitaria, PSU) both language scholastic achievement (LSA) and mathematics scholastic achievement (MSA). A representative sample of 671 school-age young graduated from high school in 2013, 550 and 548 of them took the PSU for LSA and MSA, respectively. Only school-age young with high (n = 91) and low (n = 69) SA in both tests were considered. A total of 122 school-age children agreed to participate in the study and were divided as follows: Group 1: high PSU outcome (n = 70; males n = 48) and Group 2: low PSU outcome (n = 52; males n = 23). Data were analyzed by means of SAS software. Independently of gender, DHA, socio-economic status and head circumference-for-age Z-score were the most relevant parameters explaining both LSA (R²= 0.650; p < 0.0001) and MSA outcomes (R²= 0.700; p < 0.0001). These results can be useful for nutrition, health and education planning, in order to protect children starting from an early age and thus increase their school outcomes.

Fish intake reflects on DHA level in breast milk among lactating women in Latvia

Background

Docosahexaenoic acid (DHA) is an essential fatty acid required for proper growth and development. DHA levels in breast milk vary worldwide. Higher levels are observed among coastal populations and are associated with marine food consumption. Latvia is located in Northern Europe, on the eastern shore of the Baltic Sea. Nevertheless, fish consumption among women of reproductive age is low. The aim of this study was to determine DHA levels in breast milk among lactating women in Latvia.

Methods

Invitation to participate in the study was posted on a social media member group for breastfeeding mothers. In total, 71 women were enrolled from November 2016 until December 2017. DHA levels (% of total fatty acids) in breast milk were measured by gas chromatography. Information about food consumed during the three consecutive days prior to the milk sampling was obtained and a food frequency questionnaire (FFQ) was completed. Information about maternal and infant characteristics, current breastfeeding pattern and milk expression method was also collected.

Results

The mean age of participants was 31 ± 4 years and the mean BMI was 22.1 ± 3.2. 27 participants were primiparas. The average age and birth weight for infants (34 males, 33 females) was 6 ± 4 months and 3.46 ± 0.55 kg, respectively. The median DHA level in breast milk (n = 60) was 0.30 ± 0.18% of total fatty acids and it was not influenced by any of the maternal or infant’s characteristics nor current breastfeeding pattern or milk expression manner (p > 0.05). Fish intake was a positive predictor for DHA levels in breast milk (r = 0.318, p = 0.013). Average maternal DHA intake was 136 ± 26, 137 ± 33 and 178 ± 49 (SEM – standard error of the mean) mg, for the third, second and last day prior to sampling day, respectively.

Conclusions

DHA levels in breast milk among lactating women in Latvia correspond to the suggested target DHA value in breast milk (0.30%). Fish consumption is a significant positive predictor for DHA levels in breast milk, however, daily DHA intake among the participants was lower than recommended (200 mg).

The Impact of Maternal Diet during Pregnancy and Lactation on the Fatty Acid Composition of Erythrocytes and Breast Milk of Chilean Women

Maternal diet during pregnancy is relevant for fatty acid supply during fetal life and lactation. Arachidonic (AA) and docosahexaenoic (DHA) acids are also relevant for the normal growth and development of brain and visual system. AA and DHA provided by the mother to the fetus and infant are directly associated with maternal dietary intake and body stores. Our aim was to evaluate the impact of maternal diet, specially referring to the quality of fatty acid intake, in a sample of Chilean women during last stage of pregnancy and across the lactation period. Fifty healthy pregnant women (age range 20–33 years) were studied from the 6th month of pregnancy and followed until 6th month of lactation period. Diet characteristics were evaluated through food frequency questionnaires. Fatty acids composition of erythrocyte phospholipids and breast milk samples was assessed by gas-liquid chromatography. Overall, women had high saturated fatty acids intake with sufficient intake of mono- and polyunsaturated fatty acids (PUFA). Diet was high in n-6 PUFA and low in n-3 PUFA (mainly DHA), with imbalanced n-6/n-3 PUFA ratio. Erythrocytes and breast milk DHA concentration was significantly reduced during lactation compared to pregnancy, a pattern not observed for AA. We concluded that is necessary to increase the intake of n-3 PUFA during pregnancy and lactation by improving the quality of consumed foods with particular emphasis on its DHA content.

Dietary Docosahexaenoic Acid and Arachidonic Acid in Early Life: What Is the Best Evidence for Policymakers?

BACKGROUND

A wealth of information on the functional roles of docosahexaenoic acid (DHA) and arachidonic acid (ARA) from cellular, animal, and human studies is available. Yet, there remains a lack of cohesion in policymaking for recommended dietary intakes of DHA and ARA in early life. This is predominantly driven by inconsistent findings from a relatively small number of randomised clinical trials (RCTs), which vary in design, methodology, and outcome measures, all of which were conducted in high-income countries. It is proposed that this selective evidence base may not fully represent the biological importance of DHA and ARA during early and later life and the aim of this paper is to consider a more inclusive and pragmatic approach to evidence assessment of DHA and ARA requirements in infants and young children, which will allow policymaking to reflect the marked diversity of need worldwide.

SUMMARY

Data from clinical RCTs is considered in the context of the extensive evidence from experimental, animal and human observational studies. Although the RCT data shows evidence of beneficial effects on visual function and in specific cognitive domains, early methodological approaches do not reflect current thinking and this undermines the strength of evidence. An outline of a framework for an inclusive and pragmatic approach to policy development on dietary DHA and ARA in early life is described.

CONCLUSION

High-quality RCTs that will determine long-term health outcomes in appropriate real-world settings need to be undertaken. In the meantime, a collective pragmatic approach to evidence assessment, may allow public health policymakers to make comprehensive reasoned judgements on the merits, costs, and expediency of dietary DHA and ARA interventions.

Modification of Docosahexaenoic Acid Composition of Milk from Nursing Women Who Received Alpha Linolenic Acid from Chia Oil during Gestation and Nursing

α-Linolenic acid (ALA) is the precursor of docosahexaenoic acid (DHA) in humans, which is fundamental for brain and visual function. Western diet provides low ALA and DHA, which is reflected in low DHA in maternal milk. Chia oil extracted from chia (Salvia hispanica L.), a plant native to some Latin American countries, is high in ALA (up to 60%) and thereby is an alternative to provide ALA with the aim to reduce DHA deficits. We evaluated the modification of the fatty acid profile of milk obtained from Chilean mothers who received chia oil during gestation and nursing. Forty healthy pregnant women (22–35 years old) tabulated for food consumption, were randomly separated into two groups: a control group with normal feeding (n = 21) and a chia group (n = 19), which received 16 mL chia oil daily from the third trimester of pregnancy until the first six months of nursing. The fatty acid profile of erythrocyte phospholipids, measured at six months of pregnancy, at time of delivery and at six months of nursing, and the fatty acid profile of the milk collected during the first six months of nursing were assessed by gas-chromatography. The chia group, compared to the control group, showed (i) a significant increase in ALA ingestion and a significant reduction of linoleic acid (LA) ingestion, no showing modification of arachidonic acid (AA), eicosapentaenoic acid (EPA) and DHA; (ii) a significant increase of erythrocyte ALA and EPA and a reduction of LA. AA and DHA were not modified; (iii) a increased milk content of ALA during the six months of nursing, whereas LA showed a decrease. AA and EPA were not modified, however DHA increased only during the first three months of nursing. Consumption of chia oil during the last trimester of pregnancy and the first three months of nursing transiently increases the milk content of DHA.

Does Circadian Disruption Play a Role in the Metabolic-Hormonal Link to Delayed Lactogenesis II?

Breastfeeding improves maternal and child health. The American Academy of Pediatrics recommends exclusive breastfeeding for 6 months, with continued breastfeeding for at least 1 year. However, in the US, only 18.8% of infants are exclusively breastfed until 6 months of age. For mothers who initiate breastfeeding, the early post-partum period sets the stage for sustained breastfeeding. Mothers who experience breastfeeding problems in the early post-partum period are more likely to discontinue breastfeeding within 2 weeks. A major risk factor for shorter breastfeeding duration is delayed lactogenesis II (DLII; i.e., onset of milk "coming in" more than 72 h post-partum). Recent studies report a metabolic-hormonal link to DLII. This is not surprising because around the time of birth the mother's entire metabolism changes to direct nutrients to mammary glands. Circadian and metabolic systems are closely linked, and our rodent studies suggest circadian clocks coordinate hormonal and metabolic changes to support lactation. Molecular and environmental disruption of the circadian system decreases a dam's ability to initiate lactation and negatively impacts milk production. Circadian and metabolic systems evolved to be functional and adaptive when lifestyles and environmental exposures were quite different from modern times. We now have artificial lights, longer work days, and increases in shift work. Disruption in the circadian system due to shift work, jet-lag, sleep disorders, and other modern life style choices are associated with metabolic disorders, obesity, and impaired reproduction. We hypothesize that DLII is related to disruption of the mother's circadian system. Here, we review literature that supports this hypothesis, and describe interventions that may help to increase breastfeeding success.

Maternal milk DHA content predicts cognitive performance in a sample of 28 nations

Convergent evidence from neuronal biology and hominin brain hypertrophy suggests that omega-3 fatty acids are a limiting resource for neural and cognitive development in Homo sapiens, and therefore that children from populations with higher omega-3 availability should display superior cognitive performance. Using multiple regression, we tested this prediction in a sample of 28 countries, with Programme for International Student Assessment (PISA) math scores in 2009 as an index of cognitive performance, and country-specific breast milk levels of omega-3 docosahexaenoic acid (DHA) as an index of omega-3 availability. Breast milk DHA makes a highly significant contribution to math scores (β = 0.462, P = 0.006), greater in magnitude than the control variables of per capita Gross Domestic Product (PCGDP) and educational expenditures per pupil. Together, dietary fish (positively) and total fat (negatively) explain 61% of the variance in maternal milk DHA in a larger sample of 39 countries.