Summary: A study published in Neurology found an association between longer cumulative breastfeeding and a lower risk of developing multiple sclerosis (MS). Women who breastfed for a total of 15 months or more across one or more pregnancies had a lower likelihood of an MS diagnosis than women who breastfed for four months or less, or did not breastfeed.
Source: AAN
Breastfeeding for a cumulative 15 months or more may be linked with a reduced risk of developing multiple sclerosis (MS), according to research published online July 12, 2017, in Neurology.
Lead author Annette Langer-Gould, MD, PhD, of Kaiser Permanente Southern California in Pasadena and a member of the American Academy of Neurology, emphasized that this finding adds to known maternal health benefits of breastfeeding. “In addition to the well-established advantages for infants, breastfeeding has been associated with lower risks for mothers of breast cancer, ovarian cancer, type 2 diabetes and heart attack,” she said.
The study examined whether breastfeeding duration and reproductive factors related to ovulation might influence the risk of MS. Previous observations show that women with MS experience fewer relapses during pregnancy and while exclusively breastfeeding, and researchers wanted to explore whether cumulative breastfeeding time or fewer ovulatory years correlated with later MS risk.
The case-control study enrolled 397 women newly diagnosed with MS or clinically isolated syndrome (CIS) with an average age of 37, and compared them with 433 women matched by age and race who did not have MS. Participants completed in-person questionnaires covering pregnancy history, breastfeeding practices, hormonal contraceptive use and other reproductive factors.
Key results included a significantly lower likelihood of MS among women whose cumulative breastfeeding duration across all pregnancies was at least 15 months. After adjustment for relevant factors, women who breastfed a total of 15 months or more were about 53 percent less likely to develop MS or CIS than those who breastfed zero to four months. Among the control group, 85 women reported cumulative breastfeeding of 15 months or more compared with 44 women in the MS group. In the zero-to-four-month breastfeeding category, 110 controls reported that duration versus 118 women with MS.
The study also evaluated age at menarche and total years of ovulation. Women who began menstruating at age 15 or older had a lower risk of developing MS later in life compared with those whose first menstruation occurred at age 11 or younger. Specifically, 44 women in the healthy control group reported menarche at age 15 or older compared with 27 of the women with MS, while 120 controls reported menarche at age 11 or younger versus 131 in the MS group.
However, the investigators found no relationship between the total number of years a woman ovulated and MS risk. Other reproductive factors that contribute to ovulatory years—such as number of pregnancies, use of hormonal contraceptives and age at first birth—also were not associated with MS risk in this study.
Langer-Gould and colleagues cautioned that the study demonstrates an association, not a proven cause-and-effect relationship. Observational designs cannot establish causality, and the research cannot definitively show that breastfeeding itself prevents MS.
The authors acknowledged several limitations. Data were collected via participant recall of events that in many cases happened years earlier, which could introduce recall bias or inaccuracies. The study also did not investigate reasons why some women did not breastfeed or stopped breastfeeding early, factors that could be linked to health, socioeconomic status, or other confounders.
Despite these caveats, the findings support the public health message that breastfeeding has potential long-term benefits for mothers as well as infants. “This study provides additional evidence that women who are able to breastfeed should be supported and encouraged to do so,” Langer-Gould said. “Among other maternal and infant health advantages, breastfeeding may be associated with a reduced future risk of developing MS.”
Funding: The study was supported by the National Institute of Neurological Disorders and Stroke.
Source: AAN
Image Source: NeuroscienceNews.com image used for illustration purposes.
Original Research: Study published in Neurology.