Breastfeeding and Cholesterol

Study Finds Initial Breastfeeding May be Associated with Lower Blood Cholesterol Concentrations in Later Life

A study published in the August 2008 American Journal of Clinical Nutrition found that initial breastfeeding, especially when exclusive, may be associated with modestly lower blood cholesterol concentrations later in life. Researchers found this relationship was stronger when studies that examined "exclusive" feeding patterns were analyzed; however, these data were not available for many of the studies examined.

Owen and fellow researchers performed a systematic review of 17 published observational studies that examined infant feeding status and total blood cholesterol concentrations in adulthood (greater than 16 years of age). Total blood cholesterol in breastfed infants was compared to "bottle-feed" infants that the authors assumed to be infants fed formula milk. The breastfed group showed modest, but significantly reduced blood cholesterol levels as an adult; however, this relationship was not significant for adults greater than 50 years of age. Additionally, there was insufficient power to formally examine the influence of duration of exclusive feeding on cholesterol concentrations later in life.

A strength of this study is that the analysis was adjusted for potential confounders including socioeconomic position, body mass index, and smoking status in adult life. Such adjustment barely altered the relationship between breastfeeding and blood cholesterol later in life. However, a limitation of the study is the limited number of individual studies that assessed the exclusivity of breastfeeding. Another limitation of this analysis that the authors do not clearly address is that the "bottle-fed" group was fed formulas from the 1940's through the 1970's; infant formula composition from this time period is significantly different than modern infant formulas, not only in nutrient composition, but also in functional ingredients and fat and cholesterol content. For example, prior to the 1970s, non breastfed infants in the UK (site of nearly half the studies) were primarily fed modified whole cow's milk, which is significantly higher in cholesterol and has a different fatty acid profile than current infant formulas. Therefore, any findings that compare breastfeeding and formula feeding groups from this earlier time period may have little relevance to infants consuming today's infant formulas.

Although this study does not contribute significant information regarding modern day infant formula and blood cholesterol concentrations, the IFC agrees with the researchers, who conclude that "although breastfeeding has modest effects on blood pressure and adiposity in later life, it has numerous other health benefits."

Owen, C.G., et al., Does initial breastfeeding lead to lower blood cholesterol in adult life? A quantitative review of the evidence. Am J Clin Nutr, 2008. 88(2): p. 305-14.