Led by Athena A. Moutsioulis of University of New Hampshire, the researchers designed a study to find out how long it takes for CLA that mothers eat in foods to appear in breast milk. Conjugated linoleic acid is a group of fatty acids with possible health benefits, including anticancer and antioxidant effects.

In the study, seven nursing mothers ate cookies made with CLA-enriched butter or with regular butter. The women then pumped samples of their breast milk every four to six hours for two days. The enriched cookies contained about eight times more CLA than the regular cookies.

Breast milk from women who ate the CLA-enriched cookies had significantly higher levels of CLA. Across the 48-hour study period, CLA levels were 46 percent higher in milk from women who ate CLA-enriched cookies, compared to those who ate regular cookies. Levels of CLA in breast milk were highest between 8 and 28 hours after the mothers ate the CLA-enriched cookies. Nutrition researchers are interested in the health benefits of CLA, including possible reductions in heart disease risk. High levels of CLA are found naturally in foods such as butter, milk, cheese, and certain meats. Most CLA studies in humans have used commercially available supplements, which may not be the same as the CLA found in natural food products.

Previous studies have shown long-term increases in breast milk CLA levels in women who ate cheese and alpine butter for up to eight weeks. The new results suggest that higher levels of CLA in breast milk can be achieved in the short term as well-within a few hours after eating CLA-enriched foods.

Despite its small size and other limitations, this pilot study suggests that CLA appearance in human breast milk can be increased by an acute ingestion of a CLA-rich food in the maternal diet," the researchers write. Given the possible benefits of CLA on infant health and development, further studies are needed to see how CLA intake from natural foods affects CLA levels in breast milk, and whether higher CLA levels translate into additional health benefits for breast-fed babies.

elsevier/locate/nutres