Breastfeeding is associated with reduced risk of multiple sclerosis in males, predominantly among HLA-DRB1*15:01 carriers. Issue 2 (May 2020)

• Record Type: Journal Article
• Authors: Hedström, AK; Adams, C; Shao, X; Schaefer, C; Olsson, T; Barcellos, LF; Alfredsson, L
• Is Part Of: Multiple sclerosis journal, experimental, translational and clinical. Volume 6:Issue 2(2020)
• Publication Date: 2020-05
• Subjects: Multiple sclerosis -- breastfeeding -- case–control study -- epidemiology -- human leukocyte antigen -- interaction; Multiple sclerosis -- Periodicals; 616.834
• DOI: 10.1177/2055217320928101
• Languages: English
• ISSNs: 2055-2173

Abstract

Background: Breastfeeding as an infant appears protective against later development of some autoimmune diseases, but research into its influence on multiple sclerosis (MS) risk has yielded inconclusive results. Objective: We investigated the possible impact of breastfeeding on MS risk. Methods: We used two population-based case–control studies comprising 3670 cases and 6737 matched controls. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for association between MS and exposure to prolonged breastfeeding (4 months or longer) versus reduced breastfeeding (less than 4 months). A meta-analysis of case–control studies that assessed the impact of breastfeeding on MS risk among women and men was conducted. Results: Prolonged breastfeeding was associated with reduced MS risk among men (OR 0.7, 95% CI 0.5–0.9) but not among women (OR 0.9, 95% CI 0.8–1.1). Among men, a synergistic effect was observed between HLA-DRB1*15:01 carrier status and reduced breastfeeding. Conclusions: Findings from the current study add to accumulating evidence that breastfeeding may be a modifiable protective factor for reducing the risk of MS in offspring. When possible, mothers should be supported to breastfeed their infants; however, the mechanism of a sex-specific biologic effect of breastfeeding on MS risk is unclear.