While doctors and scientists have long agreed that physical activity has health benefits, Rutgers cancer researcher Allan Conney and his New Jersey colleagues have found that exercise can even protect against skin cancer.
Their study, reported in the May 13 issue of the journal Carcinogenesis, found that mice exposed to ultraviolet B light (UVB) - and with continual access to running wheels - took longer to develop skin tumors and developed fewer and smaller tumors than a group of similarly exposed mice that didn't have a gym handy.
This is the first time the relationship between skin carcinogenesis and increased activity by voluntary running wheel exercise has been studied in the laboratory.
In both groups, the number of tumors per mouse increased with time, but animals with access to running wheels had approximately 32 percent fewer tumors than animals without running wheels. Tumor size per mouse in the non-exercising group was on average more than three times greater than for the group with the running wheels.
As might be expected, the exercising mice ate and drank more but had less body fat than their more sedentary associates, and the number of tumors also decreased with lower body fat.
"This relationship between body fat and tumors may also play an important role in carcinogenesis and warrants further investigation, particularly with obesity on the increase in the Western world," said Conney, State of New Jersey Professor of Chemical Biology at Rutgers, The State University of New Jersey.