Beyond vitamin D: Sunlight exposure reduces weight gain and helps stop diabetes

(NaturalNews) In recent years, health experts have emphasized the importance of increasing blood levels of vitamin D as a way to prevent not just bone and tooth disorders but also autoimmune disease, cancer and many other chronic health conditions. Yet, rather than recommending that people spend more time in the sun, many health officials have instead recommended vitamin supplementation.

But according to a new study led by researchers at the Telethon Kids Institute in Perth, Western Australia, and published in the journal Diabetes, vitamin D is not the only mechanism through which sun exposure improves health. The researchers found that sun exposure causes the skin to produce nitric oxide gas, which in turn helps the body regulate its metabolism and slows weight gain.

"We know sun-seekers live longer than those who spend their lives in the shade," said dermatology researcher Richard Weller of the University of Edinburgh. "Studies such as this are helping us to understand how the sun can be good for us. We need to remember that skin cancer is not the only disease that can kill us and should perhaps balance our advice on sun exposure."

Benefit not from vitamin D

In the new study, researchers fed mice a high-fat diet until they developed both obesity and diabetes. Some of the mice were then exposed to ultraviolet (UV) radiation -- which causes the skin to produce both vitamin D and nitric oxide.

When exposed to UV radiation, the mice showed lower levels of weight gain, blood sugar and insulin resistance.

Because prior research has suggested a connection between UV exposure, nitric oxide and blood pressure, the researchers then exposed the mice to a skin cream containing either nitric oxide or vitamin D. The mice given the nitric oxide cream experienced the same effects on their obesity and diabetes symptoms as the mice exposed to UV radiation. No effect was seen, however, in the mice given the vitamin D cream.

"Our observations indicate that the amounts of nitric oxide released from the skin may have beneficial effects not only on heart and blood vessels but also on the way our body regulates metabolism," said researcher Martin Feelisch of Southampton University.

Why sunlight is essential for good health

Obesity and type 2 diabetes are both considered major public health problems globally, particularly in wealthier countries where people are more likely to have a poor diet and a sedentary lifestyle. Both diseases are on the rise in children as well as adults. According to the U.S. Centers for Disease Control and Prevention, rates of childhood obesity in the United States have doubled over the past 30 years, such that 18 percent of children between the ages of 6 and 11 are now classified as obese.

"Our findings are important because they suggest that exposure to sunlight, together with plenty of exercise and a healthy diet, may help prevent the development of obesity in children," said researcher Shelley Gorman of the Telethon Kids Institute.

The findings suggest that spending too much time indoors from a young age may be contributing to a lifetime of ill health.

"These findings support the idea that a healthy lifestyle should include time outside in the sunshine, not only for exercise but also to benefit from sunlight on skin," said David Ray of Manchester University.

Although it is unknown how much sun exposure is necessary to benefit metabolic health, health experts advise that light-skinned people get a minimum of 15 minutes of unprotected sun exposure on the face and hands each day to assure minimum acceptable levels of vitamin D. The darker a person's skin and the farther they live from the equator, the more sunlight they need.

Sunscreen and clothing block the skin's ability to synthesize both vitamin D and nitric oxide.

Sources:

http://www.express.co.uk

http://www.naturalnews.com

http://www.medicalnewstoday.com

http://truthwiki.org/Vitamin_D