White Matter Integrity of the Corpus Callosum Mediates the Association Between Aging and Skin Condition

This study examines whether white matter integrity mediates the link between psychological stress and skin aging. This cross-sectional study included 92 healthy Japanese adults (aged 22–62 years) who underwent diffusion tensor imaging to obtain Fractional Anisotropy Brain Healthcare Quotients (FA-BHQs) for major white matter tracts, while skin aging was assessed using Motion Scan Technology. Correlation analyses revealed significant associations among stress, skin aging, and FA-BHQ in the corpus callosum (CC) and internal capsule (IC). Mediation analyses suggested, at the statistical level, a potential that the CC fully mediates the association between stress and skin aging. These findings suggest a relationship between interhemispheric white matter integrity, psychological stress, and skin aging in line with the concept of the brain–skin axis.