Professor Mitsuyoshi Urashima of the Division of Molecular Epidemiology at the Jikei University School of Medicine and his colleagues performed a detailed survey of the dietary habits of breastfeeding mothers and revealed that frequent maternal consumption of blue-backed and white fish was associated with high infant serum levels of docosahexaenoic acid (DHA), which is important for infant brain development. When compared to breast milk, milk formula supplemented with DHA had a reduced impact on serum DHA levels.
Urashima shared his recommendation, saying, "According to our study results, I advise mothers to breastfeed their infants as much as possible. I also recommend that breastfeeding mothers should consume blue-backed fish, including mackerel and sardine, and white fish, such as sea bream and cod as the consumption of the fish raises the infant serum level of DHA, which is important for brain development." The study results were published in Nutrients.
The World Health Organization (WHO) recommends that children be breastfed exclusively for the first 6 months of life. One reason for this is the potential positive impact of breast milk on a child's intelligence. DHA, an omega-3 unsaturated fatty acid, is essential for infant brain development because it supports nerve myelination and improves the conduction velocity of nerve cells. One study reported an association between elevated serum DHA levels and large brain volume in newborns.
In a separate study conducted by a research group in Australia, 480 premature infants born before 29 weeks of gestation were included. The infants were divided into two groups: an intervention group, which received daily DHA at a dose of 60 mg/kg of body weight from the initiation of enteral nutrition until discharge, and a control group. The participants were followed up until the age of 5 years. The intelligence quotient (IQ) of the intervention group (95.4) was significantly higher than that of the control group (91.9), which indicated that DHA supplementation during the neonatal period improved a child's cognitive function.
Urashima's group investigated an association between maternal dietary habits during breastfeeding and infant serum levels of 24 fatty acids, including DHA, before starting solid food. Gas chromatography-mass spectrometry was employed to measure 24 types of fatty acids in serum samples obtained from 268 infants aged 5−6 months who had not yet commenced solid food consumption. Concurrently, the study involved surveying the frequency of maternal consumption of 38 food items and assessing the feeding patterns of infants during the same period. The milk formula contained 0.4% DHA.
The study revealed that significant positive correlations with infant serum DHA levels were observed exclusively in relation to the consumption of 'blue-backed fish' and 'white fish.' In other words, as the frequency of fish consumption increased, so did the infant serum DHA levels. Combination of the consumption frequency of the two types of fish (composite variable 'Blue-White fish') also demonstrated an association with infant serum DHA levels. In contrast, other types of fish including salmon, tuna, and swordfish, as well as food categories including nuts, dairy products, eggs, vegetable oil, fried foods, meat, and beans did not have significant correlations with infant serum DHA levels.
Moreover, the research group investigated the impact of breastfeeding alone or in combination with milk formula on infant serum fatty acid levels. Serum levels of DHA, eicosapentaenoic acid (EPA), arachidonic acid (AA), and omega-3 fatty acids were significantly higher in infants who were predominantly breastfed than in those who received more milk formula to supplement breastfeeding. In contrast, infants who were predominantly breastfed had significantly low serum linolenic acid (LA) levels. Feeding patterns had no significant association with serum levels of α-linolenic acid (ALA) or omega-6 fatty acids.
Title: Impact of Maternal Fish Consumption on Serum Docosahexaenoic Acid (DHA) Levels in Breastfed Infants: A Cross-Sectional Study of a Randomized Clinical Trial in Japan
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