Press Release

​Researchers at Kaiser Permanente and UC San Diego School of Medicine have discovered that mothers who breastfed a child or children for 6 months or more are at lower risk for developing non-alcoholic fatty liver disease (NAFLD) years later during mid-life. With no other current prevention options aside from a healthy lifestyle, they say the finding may represent an early modifiable risk factor for a serious and chronic disease.

The study, “Long Lactation is Associated with Decreased Prevalence of Nonalcoholic Fatty Liver Disease in Women in the CARDIA study,” was published Nov. 1 in the Journal of Hepatology.

Erica Gunderson, PhD, MS, MPH

The study employed data collected through the Coronary Artery Risk Development in Young Adults (CARDIA) study, a multicenter prospective cohort study of 844 black and white women who were monitored every 2 to 5 years for up to 30 years. The women were assessed for biochemical and other risk factors at enrollment in 1985-1986. Those who subsequently gave birth reported the duration of breastfeeding for each birth over the following 25 years. At the end of the study, participants underwent a computed tomography (CT) scan of their abdomens, which allowed researchers to look at levels of liver fat, a sign of non-alcoholic fatty liver disease.

“The CARDIA study’s unique strength is the evaluation of cardiovascular and metabolic risk factors in young women before pregnancy and across the childbearing years,” said senior author Erica P. Gunderson, PhD, MS, MPH, a senior research scientist with the Kaiser Permanente Northern California Division of Research and investigator at CARDIA’s Oakland, Calif., field site. “This design accounts for pre-pregnancy risk factors and identifies more closely the specific relation of lactation to a woman’s future disease risk.”

Non-alcoholic fatty liver disease is the most common cause of chronic liver disease in the United States. Weight loss and a healthier diet are the current standards of care.

The research team adjusted for pre-pregnancy metabolic risk factors, physical activity, dietary intake and other risk factors related to non-alcoholic fatty liver disease. The analysis helped demonstrate that any beneficial impact of lactation duration goes beyond confounding factors of pre-pregnancy risk and lifestyle behaviors.

Women in the cohort who breastfed one or more children for longer than 6 months had a lower risk of non-alcoholic fatty liver disease compared to those who did not breastfeed or breastfed for under 1 month. Typical of non-alcoholic fatty liver disease, women diagnosed with the disease 25 years later had a higher body mass index, larger waist circumference, higher triglycerides and lower HDL cholesterol when compared to those without the disease.

“Breastfeeding and its benefits to the child have been widely studied for years,” said lead author Veeral Ajmera, MD, hepatologist and assistant professor of medicine at UC San Diego Health. “However, this new analysis contributes to the growing body of evidence showing that breastfeeding a child also offers significant health benefits to the mother—namely, protecting her from developing non-alcoholic fatty liver disease in middle age.”

Co-authors include Norah A. Terrault and Monika Sarkar, UC San Francisco; Lisa B. VanWagner, Northwestern University; Cora E. Lewis, University of Alabama Birmingham; and John J. Carr, Vanderbilt University.