A research team at Myongji Hospital has confirmed that exposure to sunlight can reduce the incidence of prostate cancer.

The team, led by Professor Kim Hong-bae at the hospital, concluded so after conducting a meta-analysis on 30,000 prostate cancer patients by collecting 12 observational studies published from 2001 to 2016.

The result confirmed that those with the most sun exposure were 33 percent less likely to develop prostate cancer than those with the least sun exposure. Those with an average sun exposure also had a 13 percent lower chance of having prostate cancer than those with little sun exposure.

Also, intermittent but intense sun exposure during childhood lowered the risk of developing prostate cancer in adulthood by 58 percent.

According to Professor Kim, a particularly impressive result of this study was that exposure to sunlight had a sizeable preventive effect, as there was a strong association between high-grade prostate cancer and the elderly over 65 years of age.

Exposure to sunlight reduced early cancer risk by 15 percent, terminal cancer by 32 percent, and developing cancer under and over 65 of age by 23 and 45 percent, respectively.

“When exposure to sunlight is sufficient, the production of vitamin D, melatonin, and nitric oxide increases, and the interaction of these metabolites inhibit prostate cancer cell proliferation,” Professor Kim said. “Since this meta-analysis collected only observational studies, it is difficult to establish a clear causal relationship.”

Also, the study results are only limited to Europe and North America, where sunlight is insufficient, Kim added.

European Journal of Public Health has published the results of the study.