Cows Milk Increases Food Folate Bioavailability

UNIVERSITY PARK, Penn.--Penn State scientists evaluated cows milk for any influence it may have on human bioavailability of food folate. Past animal and human studies have suggested a certain component in cows milk enhances food folate bioavailability. To test the hypothesis, 31 young women were fed low folate diets on a four-day rotation with (n = 17) or without (n = 14) cows milk for eight weeks. Plasma and erythrocyte folate and plasma total homocysteine (tHcy) concentrations were then monitored.

Plasma folate concentrations steadily declined in both the milk and the nonmilk groups; however, the declines were not significantly different between groups. In contrast, two significant differences were found when erythrocyte folate concentrations declined only in the nonmilk group and remained unchanged in the milk group; and when plasma tHcy concentrations significantly increased in the nonmilk group and remained unchanged in the milk group.

The scientists concluded inclusion of cows milk in the diet enhanced the bioavailability of food folate as assessed by the changes in erythrocyte folate and plasma tHcy concentrations but not in plasma folate concentrations. The mechanisms of action by the components of cows milk should be further investigated, they wrote. The study is published in the December issue of the American Journal of Clinical Nutrition (80, 6:1565-1569, 2004) (www.ajcn.org).