Heart disease is the number one killer of women in the world. You may be surprised to learn that breastfeeding can lower women’s risk.
There was an intriguing study in the journal Diabetes (2010) of 704 women who were enrolled during their first pregnancy and followed for 20 years. At the end of the study period, they noted that women who had breastfed for at least nine months had a 56% reduction in developing metabolic syndrome during the study period.
Metabolic syndrome is the precursor syndrome to Type-2 diabetes and includes a cluster of symptoms such as:
- insulin resistance (a lowered level of response to insulin, the hormone secreted by the pancreas that helps to regulate the level of glucose (sugar) in the body)
- high triglycerides (a type of fat in the blood)
- high LDL (low-density lipoprotein) “bad” cholesterol—too much cholesterol in the blood can increase the risk of heart and circulatory diseases
- VLDL (very low density lipoprotein) cholesterol
- visceral fat (fat stored in the abdominal cavity)
These symptoms also increase the risk of cardiovascular disease.
Along these same lines, Schwartz et al. (2009) found that post-menopausal women (average age of 60) who had breastfed had significantly lower rates of heart disease, hyperlipidemia, high LDL cholesterol, and a host of other cardiovascular risk factors. Since cardiovascular disease is the number killer of women worldwide, these studies are of interest.
But why would breastfeeding lower women’s risk of heart disease?
From the perspective of a health psychologist, these findings make sense, when you examine the human stress response. Allow me to illustrate by describing what happens when this stress response is chronically activated. In the Dunedin Multidisciplinary Health and Development, Dunedin, New Zealand, a birth cohort of 1,037 participants was followed for 32 years. During the first 10 years of the study, the children were assessed for three types of adverse childhood experiences: socioeconomic disadvantage, maltreatment, and social isolation. These experiences, particularly if chronic, can permanently upregulate the stress response, increasing the risk for disease. As predicted, when study participants were 32 years old, researchers found that those who experienced adverse childhood experiences had higher rates of major depression, high levels of systemic inflammation, and higher rates of having at least 3 metabolic risk markers (January 2010, Archives of Pediatric & Adolescent Medicine). Each of these factors increases the risk for both cardiovascular disease and diabetes.
So how does breastfeeding lower women’s risk for metabolic and cardiovascular disease? The Dunedin study demonstrates that an upregulated stress response increases the risk for cardiovascular and metabolic disease. But what does breastfeeding do? Several studies conducted with mothers of infants have shown that breastfeeding downregulates stress in both mothers and babies. In fact, after breastfeeding, women are less stress-responsive in laboratory settings, meaning that when researchers try to stress them in the half-hour or so after breastfeeding, the mothers show less of a stress response. That’s the short-term effect of breastfeeding.
The results of the those studies on cardiovascular disease and metabolic syndrome suggest that breastfeeding has a far longer term stress-lowering effect than anyone suspected. Breastfeeding appears to have permanently changed women’s stress response, lowering their overall risk of disease in their 60s, 70s and beyond. And that is great news indeed.
Gunderson, E. P., Jacobs, D. R., Chiang, V., Lewis, C. E., Feng, J., Quesenberry, C. P., & Sidney, S. (2010). Duration of Lactation and Incidence of the Metabolic Syndrome in Women of Reproductive Age According to Gestational Diabetes Mellitus Status: A 20-Year Prospective Study in CARDIA (Coronary Artery Risk Development in Young Adults). Diabetes, 59(2), 495–504. http://doi.org/10.2337/db09-1197.
Poulton, R., Moffitt, T. E., & Silva, P. A. (2015). The Dunedin Multidisciplinary Health and Development Study: overview of the first 40 years, with an eye to the future. Social Psychiatry and Psychiatric Epidemiology, 50(5), 679–693. http://doi.org/10.1007/s00127-015-1048-8.
Schwartz, E. B., Ray, R. M., Stuebe, A. M., Allison, M. A., Ness, R. B., Freiberg, M. S., & Cauley, J. A. (2009). Duration of lactation and risk factors for maternal cardiovascular disease. Obstetrics & Gynecology, 113(5), 974-982.
Photo with title by Sebastián Puenzo
Kathleen Kendall-Tackett, PhD, IBCLC, FAPA
Dr. Kendall-Tackett is a health psychologist and International Board Certified Lactation Consultant, and the owner and Editor-in-Chief of Praeclarus Press, a small press specializing in women’s health. She is Editor-in-Chief of two peer-reviewed journals: Clinical Lactation and Psychological Trauma. She is Fellow of the American Psychological Association in Health and Trauma Psychology, Past President of the APA Division of Trauma Psychology, and a member of the Board for the Advancement of Psychology in the Public Interest. Dr. Kendall-Tackett specializes in women’s-health research including breastfeeding, depression, trauma, and health psychology, and has won many awards for her work including the 2016 Outstanding Service to the Field of Trauma Psychology from the American Psychological Association’s Division 56.
Dr. Kendall-Tackett has authored more than 400 articles or chapters, and is currently completing her 35th book, The Phantom of the Opera: A Social History of the World’s Most Popular Musical. Her most recent books include: Depression in New Mothers, 3rd Edition (2016, Routledge UK, in press), Women’s Mental Health Across the Lifespan (2016, Routledge US, in press, with Lesia Ruglass), Psychology of Trauma 101 (2015, Springer, with Lesia Ruglass) and The Science of Mother-Infant Sleep (2014, Praeclarus, with Wendy Middlemiss). Her websites are: