Breastfeeding is recommended for an infant's first 12 months of life because of its correlation with improved health. And mothers receive some benefits too, such as quicker recovery from delivery and in some cases quicker loss of 'baby weight'. Now a new study, reported in JAMA Internal Medicine, extends these maternal benefits to a decreased risk of developing diabetes — even in women who had gestational diabetes when pregnant.
Dr. Erica P. Gunderson of Kaiser Permanente Northern California and colleagues analyzed data from 1,238 young women who participated in the Coronary Artery Risk Development in Young Adults (CARDIA) study. The women were 18-30 years of age at the initiation of the study (1985-1986); they did not have diabetes at that time. They were followed for up to 30 years with their pregnancies and lactation durations (if any) noted. Further, the occurrence of gestational diabetes during any pregnancy was noted, and the participants were reassessed with respect to several biochemical and metabolic parameters up to 7 times over the course of the study (i.e., at 0,7,10,15, 20, and 30 years post initiation).
Participants' lactation duration ranged from none to 12 months or more. As shown in the figure below, the longer the duration of reported breastfeeding, the less likely a woman would develop diabetes over the course of the study. The trend for decreased risk with longer lactation was statistically significant for women who did and did not have gestational diabetes (GD), though it was obviously greater in the women who did develop that condition. This was true even though the occurrence of GD is known to increase the risk of a woman developing diabetes later.
This pattern persisted in both black and white women, although initially the women who were more likely to develop diabetes were more likely to be black, multiparous, and have higher BMIs and waist circumferences.
The strengths of this study included the relatively large sample, the periodic laboratory screening for diabetes over the course of the 30-year follow up, in contrast the authors stated, to other studies that examined women years post-pregnancy.
Results of this study reinforce current recommendations for breastfeeding for the first year of an infants' life — and indicate that following this recommendation would benefit the mother as well as the child. Further, these data indicate that longer breastfeeding could be valuable for lessening the known risk posed by the development of gestational diabetes.