Study finds possible health benefits

For 40 years, Americans have been told that being exposed to the sun without protecting your skin from ultraviolet (UV) rays is dangerous. After all, the incidence of melanoma – the most dangerous form of skin cancer – has been increasing worldwide.

But a new study from the University of Edinburgh of 360,000 people living in the UK indicates that when the health benefits of sun exposure are taken into account, we can rethink the issue.

Correcting for confounders such as age, gender, smoking status, socioeconomic status and exercise, the study found that tanning bed users had a 23% lower rate of cardiovascular (CV) death and a 14% lower rate of cancer death overall.

Living in a sunnier southern part of the UK resulted in a 19% reduction in the risk of cardiovascular death and a 12% reduction in cancer death compared to living in the north.

Two different mechanisms are likely involved.

UV radiation increases the production of nitric oxide in the skin, which contributes to the dilation of blood vessels. The radiant energy of sunlight helps distribute it further into the general circulation, increasing blood flow to the heart.

Vitamin D produced from exposure to UV rays helps boost the immune system and can increase the efficiency of natural killer cells that help destroy many types of early cancer. Taking vitamin D supplements does not necessarily confer the same level of benefit.

Although the worldwide incidence of melanoma is increasing, for women under age 50 in the United States it has remained stable since the early 2000s and has shown a 1% decrease for men. For those aged 50 and over, there was an increase of 3% per year for women and remained stable for men.

Melanoma deaths in the US have fallen in recent years to about 8,000, mainly due to improved treatment, and most of the damage to our skin from cancer risk occurs by the time we are 18. But CV deaths and other cancer deaths in general kill 1.3 million. Americans every year.

This study illustrates a broader point: When we make decisions focusing on a single variable, it can sometimes mislead us. The more we learn, or when the facts change, we need to change our thinking.

It’s still a good idea to wear sunscreen and avoid sunburn, especially for children, but for most of us, a little more time in the sun can be a good thing.

William Culbert is a retired doctor. He lives in Oak Ridge.

This article originally appeared on Oakridger: Rethinking sun exposure: Study finds possible health benefits