BUFFALO, N.Y. — Beach lovers, rejoice. New research from the University of Buffalo and the University of Puerto Rico reports more sun exposure may lead to a lower breast cancer risk.
Buffalo is known for its harsh winter weather, but sunny Puerto Rico represented the perfect location for this research. After using a chromameter to compare skin pigmentation in unexposed and exposed skin among 307 cases and 328 controls, researchers report greater sun exposure is associated with a lower risk of breast cancer. Skin pigmentation differences among participants were used estimate usual sun exposure levels.
“This study was unique in that it was of Puerto Rican women, which allowed for us to look at this association in a population with a wide range of skin color and with year-round high sun exposure,” says study senior author Jo L. Freudenheim, a professor in the Department of Epidemiology and Environmental Health in UB’s School of Public Health, in a university release.
How does the sun help prevent breast cancer? Study authors say there are a number of possible explanations.
“One step in the internal production of vitamin D occurs when skin is exposed to sun,” Prof. Freudenheim explains. “Sun exposure also affects the body in a number of other helpful ways, with effects on inflammation, obesity and circadian rhythms. While recent recommendations have been to limit sun exposure to prevent skin cancer, there may also be a benefit to some sun exposure, especially exposure without sunburn.”
Earlier studies focusing on the connection between sun exposure and breast cancer risk had been conducted in areas with more seasonal variations in sunlight. Puerto Rico was chosen this time around because it is sunny there all year long.
“The study provided consistent results across different parameters,” concludes first study author Cruz Nazario, PhD, an epidemiology professor at the University of Puerto Rico. “Breast cancer risk was lower for women with the highest accumulated sun exposure. Similarly, the risk was lower independent of estrogen receptor status, and it was even lower among participants with darker skin color.”
The study is published in Cancer Epidemiology Biomarkers & Prevention.