Staying out of the sun entirely isn’t a practical strategy for most. Instead, many doctors have, for decades, recommended limiting sun exposure as much as possible. Ultraviolet light from the sun can age skin and cause skin cancer, and people can get vitamin D from food or supplements rather than the sun.
But recent research has suggested that moderate sun exposure may, in certain contexts, at least, have some benefits. And that vitamin D supplements may not always be a good substitute.
Are there health benefits to sun exposure?
To be clear, there’s no debating that the sun’s rays can damage your skin in ways that result in premature skin aging and cancer.
But in recent years, researchers have also identified a handful of potential, if limited, associations between sun exposure and health benefits.
A 2021 study found that spending more time in the sun is associated with lower blood pressure. Blood pressure tends to be higher in the winter than in the summer, and heart problems are more common then, too. A separate study found that people who reported more sun exposure were less likely to develop heart failure.
It’s unclear why sunlight might improve heart health, but researchers do know that it causes the skin to release a gas called nitric oxide, which relaxes blood vessels and reduces blood pressure.
Some researchers have wondered whether this could lead to a longer life. A 2014 study that followed nearly 30,000 Swedish women for 20 years reported that those who avoided the sun were twice as likely to die during that time period as those most exposed to the sun – even though the sun-seeking women were more likely to be diagnosed with melanoma.
Sunlight may also help support the immune system by controlling inflammation and immune cells. Research has shown that UV light exposure can improve symptoms in some immune-related conditions, including eczema and psoriasis.
Some studies suggest that UV light exposure can also increase blood levels of serotonin, a chemical that helps regulate mood.
Of course, it’s hard to say if the sun is causing these health benefits. People who are exposed to a lot of sunlight may also engage in more physical activity and spend more time in nature than other people do, and that may boost mood and physical health.
Up until this point, perhaps the most well-known benefit of sun exposure is that it causes the body to produce vitamin D, which helps build and maintain bones. Past observational research has linked low levels of vitamin D with increased risks of certain conditions like Type 2 diabetes, heart disease, and colorectal cancer.
However, large clinical trials over the past several years have not shown that ingesting vitamin D from fortified foods or supplements can reduce the risk of these conditions, eliminating the need for potentially harmful sun exposure.
Even more, these studies, along with those showing the blood pressure and immune benefits of sun exposure, suggest that sunlight may benefit us beyond just vitamin D production.
Keep applying sunscreen
The research on the sun’s potential benefits is still pretty limited, so it’s hard to know what to make of it or how to apply it – or how to square it with the risks of skin cancer. Certainly, don’t stop using sun protection.
Skin cancer remains a serious threat. But we may ultimately need to move beyond treating sun exposure as if it’s universally harmful.
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