"This information is important for women," comments lead author Julie Mennella, PhD, a biopsychologist. "If a mother is drinking alcohol just to improve the quality or quantity of her milk, she needs to know that there is no evidence to support this claim. In fact, what happens is quite the opposite, as alcohol disrupts the hormonal milieu of lactation in a way that could impede successful breastfeeding."
For centuries, breastfeeding women have been advised to drink alcohol as an aid to milk production and optimal lactation. Recent surveys indicate that 25% of women report being encouraged by their health professionals to drink alcohol while breastfeeding. But as Mennella points out, "There was no valid scientific evidence to support this claim."
To address this research deficit, the current study, reported in the April 2005 issue of the Journal of Clinical Endocrinology and Metabolism, is the first to analyze the effects of alcohol on lactational hormones of women who are breastfeeding.
Subjects were 17 women who were nursing infants between 2 and 4 months of age. While in a controlled clinical setting away from their infants, each woman drank a beverage containing alcohol in orange juice on one day and plain orange juice on a different day. The dose of alcohol was equivalent to that found in one to two glasses of wine. After consuming the beverages, the women used electric breast pumps to stimulate lactation. Blood samples taken throughout the procedure were analyzed for oxytocin and prolactin, the two key hormones that control lactation.