Sunshine, sunbeds & a surprising health twist

An epidemiological study (Stevenson et al., 2024) with participants from the UK found that people who had more ultraviolet, or UV, light exposure tended to live longer compared to people with less UV exposure. That finding might sound strange, because exposure to UV light – which is part of sunlight – is commonly communicated as a health risk factor. In fact, too much UV exposure can increase the risk of skin cancer. These new findings, however, suggest a more nuanced relationship between UV light and health, especially in cloudy, low-sunlight countries like the UK.

Photo by Elizeu Dias on Unsplash 

The findings are based on data of 395,086 people from the UK Biobank study. For their study, the researchers quantified UV exposure from two proxies: (i) behaviour in terms of visits to solariums or sunbeds, and (ii) meteorological data of sunlight reaching the participants’ residential area. These data in turn were analysed with respect to the prevalence of deaths from heart disease, cancer, and other causes.

The main finding was that people with higher UV exposure had a lower risk of dying overall, including a lower risks of dying from cardiovascular disease and cancer. Solarium users had about a 15% lower risk of death overall compared with non-users, and people living in sunnier parts of the UK also had lower death rates.

In their publication, the authors discuss the mediating role of vitamin D, which is produced by the skin when exposed to UV-B light. An additional possibility discussed is UV-A light, which may help release nitric oxide in the skin. Nitric oxide, in turn, is suggested to relax blood vessels, lower blood pressure, and thereby support heart health.

Importantly, these results do not mean tanning endlessly is a good idea. The researchers mention that higher UV exposure could be linked to more melanoma cases. Hence, the take-home message is not “go and bake in the sun.” Rather, it means that overly strict avoidance of sunlight might carry negative rebound effects for health, which should be considered in the communication of health risks associated the UV – sunlight – exposure.

Since public health advice often focuses on the dangers of UV exposure, a more nuanced view might be warranted. Place of residence should be considered, as these findings from a UK cohort show, since countries like the UK, are limited in sunlight exposure with an increased prevalence of low vitamin D.

Based on research from the UK Biobank cohort study:

Stevenson, A. C., Clemens, T., Pairo-Castineira, E., Webb, D. J., Weller, R. B., & Dibben, C. (2024). Higher ultraviolet light exposure is associated with lower mortality: An analysis of data from the UK biobank cohort study. Health and Place, 89. https://doi.org/10.1016/j.healthplace.2024.103328