Cooke part of a study on benefits vs. hazards of summer sunlight exposure

The amount of sunlight you need for optimum vitamin D production may not be the same as someone else. That’s part of what a multi-disciplinary research team including Marcus Cooke, Ph.D., chair of the department of Environmental & Occupational Health, has determined, finding that low-level simulated sunlight exposures in light skin people confer vitamin D sufficiency, whereas the same exposures produce less vitamin D in darker skin people.

The study, funded in part by Cancer Research UK, examined the dual impact of repeated low-level sunlight exposures on vitamin D status (benefit) and DNA damage/repair (risk). The study used both skin and urinary biomarkers of DNA damage and was uniquely performed in light-skin adults and brown-skin adults. It concluded that low-dose summer sunlight exposures confer vitamin D sufficiency in light-skin people, concurrent with low-level, but non-accumulating DNA damage. Yet the same exposures produce minimal DNA damage but less vitamin D in brown-skin people.

“While previous studies have examined the impact of ultraviolet radiation vitamin D status, research examining accompanying UVR-induced DNA damage has been scarce,” said Cooke, adding, “Our findings are informative for tailoring differential sun exposure guidance, depending upon skin type.”

The research team’s manuscript Concurrent beneficial (vitamin D production) and hazardous (cutaneous DNA damage) impact of repeated low-level summer sunlight exposures has been accepted for publication in the British Journal of Dermatology.

At FIU, Cooke studies the role of genotoxicity in the pathogenesis of disease, focused primarily upon free radical mechanisms of DNA damage and repair. In the last five years, he has been involved, either as principal investigator or collaborator, in major research projects funded by Cancer Research UK, the UK Food Standards Agency, the European Union and industry.