Some of you may be familiar with the “Nurse Health Study,” a longitudinal, prospective study which began in 1976, enrolling 121,700 women from 11 states. Nurses enrolled in this study fill out questionnaires every 2 years regarding medical diagnoses and health-related topics. In a Feb. 2009 study published in the American Journal of Obstetrics & Gynecology, researchers found that nurses enrolled in the study who breastfed for longer than 23 months were at a lower risk of having a heart attack INDEPENDENT of known risk factors for cardiovascular disease. Theories about why this is so include positive effects of lactation on carbohydrate and lipid metabolism, less stressful life (factors that enabled women to breastfeed for long durations may correlate with less stress), and positive changes in stress response due to exposure to oxytocin during breastfeeding. Interesting!