Is Sun Good Or Bad For You?

(CBS)  A controversial report in the Journal of the National Cancer Institute indicates that patients in the early stages of melanoma, the deadliest form of skin cancer, are significantly more likely to survive if they've had a history of sun worshipping. But doctors still caution against getting too much sun.

So what are people to do with this conflicting information? Dr. Mallika Marshall explains on The Saturday Early Show.

Marshall notes another study found that prolonged UV exposure was associated with a lower risk of non-Hodgkin's lymphoma, a cancer of the lymph nodes. The authors of both studies think that vitamin D may be the key to the benefits of sun exposure since it has a role in regulating cell growth, and may be able to inhibit tumor growth.

But dermatologists say that more research needs to be done before we start making any recommendations about sunlight exposure. They don't want people to think that spending a lot of time in the sun is beneficial, because too much sun does present significant health risks.

According to the American Cancer Society, skin cancer is the most common of all cancers. It accounts for nearly half of all cancers in the United States, and more than 1 million cases of nonmelanoma skin cancer are found in this country each year. So skin cancer is still a very serious issue for people who spend too much time soaking up the sun.

It is well known that the sun's rays are a good source of vitamin D, which is essential in building strong bones and teeth. In addition, research suggests that low vitamin D levels may increase the risk of type I diabetes, muscle and bone pain, and again, certain types of cancers. It may also help normalize your blood pressure. In addition, the sun raises your levels of serotonin, which elevates your mood. Some people who suffer from depression or mood swings can benefit from exposure to UV light.

But most experts would recommend limiting your exposure to 5-15 minutes three times a week without sun block. They say that's probably enough time to reap the benefits of vitamin D without sustaining too much damage to your skin. You can also get vitamin D from supplements and from drinking fortified milk or eating certain types of fish.

If you spend a lot of time outdoors, Marshall says it is important to wear sunscreen with an SPF of 15 or greater on exposed parts of the body year-round. Other ways to help protect your skin is to wear light clothing, a hat and sunglasses that block UV light. If you tend to have a lot of moles or sun-damaged skin, have a dermatologist check you over every 6 to 12 months. And avoid getting sunburned, which can increase your risk of melanoma significantly.