In a Swedish population-based case-control study (1571 cases, 3371 controls), subjects with different body mass indices (BMIs) were compared regarding multiple sclerosis (MS) risk, by calculating odds ratios (OR) with 95% confidence intervals (95% CI). Subjects whose BMI exceeded 27 kg/m(2) at age 20 had a two-fold increased risk of developing MS compared with normal weight subjects. Speculatively, the obesity epidemic may explain part of the increasing MS incidence as recorded in some countries. Measures taken against adolescent obesity may thus be a preventive strategy against MS.
The authors used a large database of PwMS and compared MS’ers on this database to members of the population of similar age and background. Body Mass Index (BMI) is calculated from an individuals height and weight, and is used to assess if someone is over- or underweight. The authors found that the risk of MS was doubled in those who were significantly overweight at age 20.
What this study does not do is shed any light on why this might be – it is not clear whether being overweight increases MS by itself, or whether it is a result of something else that is the “real” MS risk factor (i.e. a surrogate marker), such as not getting out and getting your daily sunshine dose! We do know that obesity is a risk factor for all manner of diseases, so it is still important to keep exercising.