What is the association between diet of lactating mothers and breast milk oxidant-antioxidant status?

By Pooja Toshniwal PahariaAug 12 2022Reviewed by Aimee Molineux

In a recent study published in the International Breastfeeding Journal, researchers assessed the association between maternal diet and the oxidant-antioxidant status in breast milk.

Background

The composition of human milk varies with time within a lactating mother and between breastfeeding mothers based on multiple factors such as the mothers’ health status, dietary patterns, and nutrition. Adequate nutrition during pregnancy and lactation is essential to improve maternal and infant health and can improve the oxidant-antioxidant status of breast milk.

About the study

In the present survey-based cross-sectional study, researchers evaluated the impact of improved maternal nutrition on the antioxidant-proxidant balance of human milk.

Lactating mothers (n=350) aged between 20 years and 35 years with infants aged between one month and six months were recruited between January and February 2021 from four healthcare centers situated in Iran, Birjand, and southern parts of Khorasan. Mothers with acute or chronic health disorders were excluded from the analysis.

Breast milk samples were obtained between 7:00 am and 10:00 am. The maternal dietary patterns were assessed with the help of food frequency questionnaires that included 65 items. The antioxidant-proxidant status of breast milk was evaluated by 2, 2′-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), thiobarbituric acid reactive substances (TBARs), and Ellman assays.

In addition, the levels of triglycerides, total protein, and calcium were measured, and demographic, psychological, and anthropometric data were obtained from the participants The dietary pattern scores were used to categorize participants into T1, T2 and T3 tertiles that denoted low, moderate and high adherence to dietary patterns, respectively.

Multinomial and multivariate logistic regression modeling was used with data adjustments for maternal age, energy/caloric intake, body mass index (BMI), and sex of the infant, principal component analysis (PCA) was performed and the adjusted odds ratios (OR) were calculated.

Results

Predominantly, two diet patterns were identified and categorized as healthy (n=181 mothers) or unhealthy (n=169) patterns. The healthy dietary pattern was characterized by higher consumption of whole grains, refined grains, legumes, non-green vegetables, eggs, and red meat. The unhealthy dietary pattern was characterized by higher consumption of carbonated beverages, honey, snacks, chicken, and seafood.

The mean age of lactating mothers was 30 years. The levels of thiol (81 μmol/L versus 74 μmol/L) and DPPH (347 μmol/L versus 321 μmol/L) were higher in the breast milk of T3 lactating mothers consuming healthy diets in comparison to T1 mothers consuming healthy diets. Thiol (74 μmol/L versus 79 μmol/L) and calcium (calcium 8.8 mg/dL versus 9.2 mg/dL) levels in breast milk were significantly lesser in T3 lactating mothers consuming unhealthy diets in comparison to T1 mothers consuming unhealthy diets.

No significant association was found between the socioeconomic and demographic characteristics of the participants in the three tertiles of dietary patterns comprising maternal age, systolic blood pressure (SBP), delivery type, BMI, death of parents, divorce of parents, level of parent education, and age, sex and hear circumference of the infants.

Logistic regression modeling showed that consumption of healthy food by lactating mothers was associated with higher thiol (OR=1.2) and DPPH levels (OR=1.3) in breast milk in T3 versus T1, whereas maternal adherence to unhealthy diets correlated with lower milk thiol levels (OR=1.3) and calcium levels (OR=1.3) in T3 versus T1.

The dietary patterns of lactating mothers can affect the macronutrient composition of breast milk and lay a strong foundation for the improved health of the infant. The antioxidant status of breast milk is based on the composition of vitamins (A, C and E), enzymes (superoxide dismutase, glutathione peroxidase), and metals (zinc, selenium and copper) that can neutralize free radicals.

Fruits and vegetables are rich in antioxidants such as phytonutrients and polyphenols, respectively, and are essential for preserving cellular homeostasis. Foods such as meat, milk, legumes, eggs, and fish meet the maternal requirements of magnesium, zinc, iron, calcium, and copper. Calcium is essential for infant growth, muscle contraction, formation of bones, coagulation of blood, and nerve conduction.

Conclusions

Overall, the study findings showed that maternal adherence to healthy diets enriched with fruits, green vegetables, and other vegetables was associated with improved oxidant-antioxidant balance in breast milk. Significant differences were found in DPPH, calcium, and thiol levels among mothers with healthy and unhealthy dietary patterns.

The authors believe that the present study is the first of its kind to determine the association between maternal dietary patterns and breast milk content conducted on lactating mothers. The infantile antioxidant status strongly depends on the maternal antioxidant status during pregnancy and continues to be preserved post-delivery by endogenous biomolecule production by the infant based on the exogenous biomolecule transmission via breast milk.