Public health recommendations advocate breastfeeding in infancy as a means to reduce obesity in later life. Several prior studies relating breastfeeding to cardiovascular risk factors have been limited by lack of adjustment for maternal and participant confounding factors.

We ascertained breastfeeding history via questionnaire from mothers enrolled in the Framingham Offspring Study. In their young to middle-aged adult children enrolled in the Framingham Third Generation, we examined the relations between maternal breastfeeding history (yes, no) and cardiovascular risk factors, including body mass index (BMI), high-density lipoprotein (HDL) cholesterol, total cholesterol, triglycerides, fasting blood glucose, and systolic and diastolic blood pressure levels. We applied generalized estimating equations to account for sibling correlations and adjusted for maternal and participant lifestyle, education, and cardiovascular risk factors.

In Third Generation participants (n = 962, mean age = 41 years, 54% were women), 26% of their mothers reported breastfeeding. Compared with non-breastfed individuals, breastfed adult participants had lower multivariable-adjusted BMI (26.1 kg/m² vs 26.9 kg/m², P = .04) and higher HDL cholesterol levels (HDL 56.6 mg/dL vs 53.7 mg/dL, P = .01). On additional adjustment for BMI, the association between breastfeeding and HDL cholesterol was attenuated (P = .09). Breastfeeding was not associated with total cholesterol, triglycerides, fasting blood glucose, systolic blood pressure, or diastolic blood pressure.

Breastfeeding in infancy is inversely associated with adult BMI and positively associated with HDL cholesterol. Associations between breastfeeding and BMI may mediate the association between breastfeeding and HDL cholesterol.