UVB exposure may reduce risk of arthritis

US researchers analysed data from >220,000 participants in the US Nurses’ Health Study, categorising their cumulative UVB flux — a composite measure of ambient UV exposure based on latitude, altitude and cloud cover plus state of residence — as low, medium or high.

More than 1300 cases of incident RA were discovered and those with the highest UVB exposure had a 21% decreased risk of RA compared to those in the lowest category of exposure, the researchers found.

Professor Bruce Armstrong, public health and cancer epidemiologist from the University of Sydney, said while not conclusive, because of lack of data on the relationship between personal sun-related behaviour and risk of rheumatoid arthritis, the study provided evidence sun exposure reduced RA risk.

“This is a plausible association because of other evidence that sun exposure may reduce risk of [other] autoimmune diseases,” he said.

Two possible