7 Little-Known Benefits of Sunlight

This time of year, everyone wants to be outside. It feels so good to have the warm sun on our bare skin. If you haven’t heard that being out in the sun, unprotected by sunscreen, puts you at risk for wrinkles, at best, and skin cancer, at worst, then you’ve probably been living under a rock!

However, while most people are aware of the dangers of too much sun, many don’t realize that sunlight confers enormous health benefits as well. Keeping in mind that you need to protect your skin with a high-quality sunscreen when you go outdoors, let’s look at some of the surprising benefits of sunlight.

1. Sunlight and cancer prevention

It’s not just plants that metabolize sunlight. Humans do too. Through a complex process, our bodies turn sunlight into life-giving vitamin D. The connection between vitamin D deficiency and cancer was first made by Drs. Frank and Cedric Garland from the University of California, San Diego. After finding that the incidence of colon cancer was nearly three times higher in New York than in New Mexico, the Garland brothers hypothesized that lack of sun exposure, resulting in a vitamin D deficiency, played a role. Research now indicates that being deficient in vitamin D increases the risk of many cancers, especially breast and colon. For example, a four-year, placebo-controlled study involving 1,179 postmenopausal women concluded that vitamin D supplementation produced a dramatic 60% drop in the risk of developing any form of cancer.

2. Sunlight and Alzheimer’s patients

Clinical research has shown that exposure to full-spectrum light throughout the day coupled with darkness at night can help improve some aspects of Alzheimer’s disease—reducing agitation, increasing sleep efficiency, decreasing nighttime wakefulness, and decreasing nighttime activity in these patients.

3. Sunlight and risk for multiple sclerosis

MS is more common in populations that live farther from the equator. People who move from a low-risk area to a high-risk area before the age of 15 acquire a higher risk of developing MS, whereas those who make the same move after adolescence retain a lower risk. These observations suggest that environmental exposure, and in particular, early sunlight exposure (which is correlated with vitamin D levels) in the first two decades of life, influences the risk of developing MS. Related to this finding, several European population studies observed that there is a lower risk of MS for births occurring after October and a higher risk for MS for births occurring after May. This suggests that maternal levels of vitamin D during the third trimester of pregnancy may influence the risk of MS.

4. Sunlight and psoriasis. 

Exposure to sunlight is extremely beneficial for individuals with psoriasis. In one study, an outdoor four-week sunbathing therapy was shown to promote significant clearance of psoriatic symptoms in 84 percent of subjects. 

5. Sunlight and mild depression. 

There has been a lot of research on the link between sunlight and mood. One solid study found that sunlight actually increases levels of a natural antidepressant in the brain. On sunny days, the brain produces more of the mood-lifting chemical serotonin than on darker days. 

6. Sunlight and bone health in older adults.

 It is well known that vitamin D stimulates the absorption of bone-strengthening calcium. The process of vitamin D manufacture begins when sunlight changes the 7-dehydrocholesterol in the skin into vitamin D3. Emerging research is showing a direct correlation between both bone density and blood levels of vitamin D3. Higher blood levels of vitamin D3 are associated with a lower rate of fractures of virtually all types; lower blood levels of vitamin D3 are associated with a higher rate of fractures of all types. 

7. Sunlight and sleep quality.

 When sunlight hits your eyes, your optic nerve sends a message to the gland in the brain that produces melatonin (a hormone that helps you sleep); the gland decreases its secretions of melatonin until the sun goes down again. In other words, exposure to sunlight during the day increases the natural production of melatonin at night. Low levels of melatonin production are linked to poor sleep quality, especially in older adults.