The omega-3 fatty acids found in breast milk may boost premature infants' growth and development soon after birth, new research suggests.
In a study of 37 preterm infants, Brazilian researchers found that the more omega-3 fatty acids there were in a mother's breast milk, the greater the child's gains in length, weight and head circumference over the first six months of life.
The findings underscore the importance of mothers' own omega-3 intake during pregnancy and while breastfeeding, the researchers report in the online journal Lipids in Health and Disease.
"It is clear that dietary polyunsaturated fatty acids are transferred into human breast milk and, subsequently, to the child," write the researchers, led by Dr. Maria G. Tavares do Carmo of the Federal University of Rio de Janeiro.
And it may be particularly important for premature infants, who tend to have lower levels of omega-3 fats in their blood at birth, to get enough through breast milk, according to the researchers.
It's known that omega-3 fats are vital for brain and eye development, both before birth and over the first few years of life. Breast milk naturally contains the fats, but the concentrations depend on the mother's diet.
The main dietary source of omega-3 fatty acids is oily fish, such as salmon, mackerel, sardines and albacore tuna. However, because fatty fish are also more likely to contain mercury, which is toxic to developing nerve cells, pregnant and breastfeeding women should not consume too much.
In the U.S., health officials recommend that expectant and breastfeeding mothers limit themselves to 12 ounces of fish — the amount in two average meals — per week. They should completely avoid certain fish that may contain high mercury levels, including shark, swordfish, tilefish and king mackerel.
Other omega-3 sources include flaxseed, canola oil and walnuts.