News Stories

Is Sunshine Good for Us?or Not?

Suicide rates worldwide are at the highest in the summer, and it turns out it's not just because of the heat. But people who get more sun actually have less cancer, so what's a person to do?

Elizabeth Svoboda writes in Discover Magazine about Australian neurochemist Gavin Lambert, who says that extended exposure to bright sunlight may cause chemical changes in the brain that trigger depression and suicide in some people.

Lambert discovered that in one part of Australia, from 1990 to 1999, 23% of the suicides took place during the summer (which is our winter season). He found that people committed suicide more often as the daily periods of sunlight got longer, and this pattern was especially true for violent suicides.

Exposure to long periods of bright sunlight raises serotonin levels. But isn't serotonin supposed to make people less depressed? That's true, but people who have suicidal tendencies have low levels to start with and sudden spikes may cause them to act. He says, "We're investigating the possibility that in some individuals who are predisposed to suicidal urges, the significant serotonin changes in the brain that occur in spring and summer might be a destabilizing factor."

Jerome Burne writes in The Independent that if you want to lower your risk of breast, prostate and colon cancer, as well diabetes, osteoporosis, hypertension and multiple sclerosis, you should get out in the sun. Epidemiologists have discovered that your risk of developing certain disorders has a lot to do with how far you live from the Equator.

Researcher Michael Holick says fear of the sun might be saving us from skin cancer, but it's damaging us more in other ways. Brief exposure to sunshine several times a week can ward off disease by increasing our levels of vitamin D.

The Sunshine Hypothesis was first put forward in the 1970s by epidemiologists Cedric and Frank Garland, who studied National Cancer Institute maps for the geographic distribution of colon cancer deaths in America. They found that they were significantly lower in the sunny southwest and higher in the cloudier northeast. They decided that the lower level of sunshine for half the year in the north prevents people from getting enough vitamin D in the winter.

Now it's been discovered that breast, ovary and prostate cancer are higher in the northeast as well. A medical journal says, "Differences in dietary or smoking habits do not appear to explain the geographic variation in cancer rates in USA."

The same pattern shows up for autoimmune diseases like multiple sclerosis and rheumatoid arthritis. A London study found that taking vitamin D supplements reduced the risk of insulin-dependent type 1 diabetes by 88%. Women with osteoporosis, which can also be caused by low vitamin D, are more likely to die of cardiovascular disease, although doctors don't know why.

Vitamin D maintains calcium levels and builds strong bones, but why should it protect us from so many diseases? Holick says, "The function of vitamin D is to be a modulator of cellular growth, preventing cells from being too active." This is why it helps stave off cancer.

We can get it from some foods, such as oily fish, but our main source is sunlight. The body makes it in the skin in response to ultraviolet B (UVB) light. It was once thought we needed between 200 and 400 international units (IU) of vitamin D a day, but now researchers say we need at least 1,000-2,000 IU. Researcher Reinhold Vieth says, "An adult with white skin, exposed to summer sunshine while wearing a bathing suit, generates about 10,000 IU of vitamin D3 in 15 to 20 minutes. That amount is equivalent to the vitamin D in 25 conventional multivitamin pills." You don?t need to sunbathe, because you don't get more vitamin D by staying out in the sun for a longer period of time.

The length of time you need to stay in the sun depends on how dark your skin is. The average African-American needs 5 to 10 times as much sun than a Caucasian. It also depends on what time of the year it is and how far from the Equator you are. Older people need more sun, which may be why they instinctively move to Florida. Your ability to synthesize vitamin D is cut in half by the time you?re 60.

If you have a typical white person's skin, known as type 2, and you live above the 42nd line of latitude, then you should try to get outside for 5 to 10 minutes between 11am and 3pm during the five months of summer in order to build up enough vitamin D to last you through the winter. But if you're depressed, be careful not to overdo it.

Want to beat the heat? Try some cool adventures beyond the body. William Buhlman is our special interview for subscribers this week.

To learn more,click here and here.

NOTE: This news story, previously published on our old site, will have any links removed.


Subscribe to Unknowncountry sign up now