Does Childhood Exposure to Sunlight Reduce MS Risk?

To address the role of childhood sun exposure on the risk for developing multiple sclerosis (MS), researchers studied 79 pairs of identical twins (each including one affected and one unaffected twin).

The twins were retrospectively asked to recall their childhood activities relative to those of their co-twin, using nine measures felt to reflect childhood sun exposure, such as “participating in team sports” and “spending more time outside during spring.” No attempt was made to quantitate sunlight; “the measures of exposure were comparative rather than absolute in nature.” A variety of statistical manipulations were performed on these data. According to the authors, each item related to potential sun exposure showed an inverse correlation with…