Breastfeeding is associated with lower risk for multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease with known genetic and environmental susceptibility factors. Breastfeeding has been shown to be protective in other autoimmune diseases. OBJECTIVE: This case-control study analyzed the association of breastfeeding in infancy on the risk of developing MS. METHODS: A case-control study was performed in Berlin of 245 MS patients and 296 population-based controls, who completed a standardized questionnaire on their history and duration of breastfeeding in infancy and demographic characteristics. Univariable and multivariable logistic regression analysis was performed to investigate the association between breastfeeding and MS. The multivariate model was adjusted for age, gender, number of older siblings, number of inhabitants in place of domicile between ages 0 and 6 (categorized in each case), and daycare attendance between ages 0 and 3. RESULTS: In multivariable analysis, breastfeeding showed an independent association with MS (adjusted OR 0.58; p = 0.028). However, with no breastfeeding as reference, the protective effect only emerges after four months of breastfeeding (multivariable analysis for ≤ four months adjusted OR 0.87; p = 0.614 and for > four months OR 0.51; p = 0.016). CONCLUSION: The results of this case-control study support the hypothesis that breastfeeding is associated with a lower risk of MS. These results are in line with findings of previous studies on other autoimmune diseases, in which breastfeeding was shown to have protective effects.

Environmental factors in early childhood are associated with multiple sclerosis: a case-control study.

BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS) with increasing incidence mainly in high-income countries. One explanation of this phenomenon may be a higher prevalence of allergic and autoimmune diseases in industrialized countries as a consequence of otherwise beneficial advances in sanitation (hygiene hypothesis). We investigated environmental factors in early childhood associated with MS. METHODS: A case-control study was performed of 245 MS patients and 296 population-based controls in Berlin. The study participants completed a standardized questionnaire on environmental factors in childhood and youth, including aspects of personal and community hygiene. Multivariable logistic regression analysis was performed to investigate factors in childhood and youth associated with the occurrence of MS. RESULTS: Mean age was 46 years (range, 20-80) in the MS group and 42 years (range 18-80) in the control group, of which 73.9% in the MS and 61.5% in the control group were female. The multivariable analysis showed that having at least two older siblings (OR 0.54; p = 0.05, for individuals with two older siblings compared to individuals without older siblings), attending a day-care center (OR 0.5; p = 0.004) and growing up in an urban center with more than 100, 000 inhabitants (OR 0.43; p = 0.009) were factors independently associated with a lower chance for MS. CONCLUSIONS: The hygiene hypothesis may play a role in the occurrence of MS and could explain disease distribution and increasing incidence.