Research from the Netherlands shows that what mothers eat during breastfeeding influences the fat profile in their milk, with omega-3 and omega-6 intake having the most notable effects, highlighting the importance of maternal diet for infant development.
A new study suggests that what mothers eat while breastfeeding may shape the mix of fats in human milk, with omega-3 and omega-6 intake showing the clearest links. Researchers in the Netherlands found that higher intakes of these polyunsaturated fats were associated with higher levels of the same fats in milk, while trans-fat intake tracked closely with trans fats in breast milk, according to findings published in the European Journal of Nutrition.
The study looked at 109 healthy women who were exclusively breastfeeding six to eight weeks after giving birth. Their diets were recorded using food diaries and a food frequency questionnaire, and two standard morning milk samples were collected from each participant. The mothers consumed an average of 2,277 calories and 97 grams of fat a day, and the milk contained about 4.03 grams of fat per 100 millilitres, with saturated fats making up the largest share.
One of the strongest findings was the link between omega-3 intake and milk composition. For every extra gram a day of omega-3 consumed by the mother, the proportion of omega-3 in milk rose by 0.63 percentage points, even after accounting for supplements. Higher omega-3 intake was also tied to more total polyunsaturated fats and to lower levels of saturated and trans fats in milk. Omega-6 intake showed a similar, though smaller, positive association with milk omega-6 levels.
The study also found associations beyond fat intake alone. Higher intakes of vitamin B1, copper, vitamin E and magnesium were linked with lower proportions of saturated and trans fats, while magnesium, vitamin E, vitamin D and vitamin B1 were each associated with higher omega-3 levels. Overall diet quality showed modest but similar patterns. The authors cautioned that the research was observational, so it cannot prove cause and effect, and they noted that the relatively healthy, highly educated study group may limit how broadly the findings can be applied.
The results fit with earlier research showing that trans fats in human milk can be associated with lower levels of essential omega-3 and omega-6 fats in infants, and that maternal diet influences the fat profile of breast milk. Taken together, the evidence points to maternal nutrition as one factor that may help shape the fatty acids available to breastfed babies during a period of rapid growth and development.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
