The safety of sun exposure

Sunlight serenade

When I caught the NBC Nightly News one evening last week, anchor Brian Williams was shaking his head over yet another story that added confusion to a well-known health issue: the safety of sun exposure.

Here’s the news that was offered as a startling revelation: Sunlight is good for you!

Brian and his crew should join HSI. We could have told them the “news” about sunlight YEARS ago.

Cancer prevention

I guess when you’re packaging news in bite-sized chunks, any health topic that can’t be summed up in a couple of sentences is considered complicated and confusing. But what’s really confusing is when you constantly feed your viewers the accepted mainstream concept that sun exposure is dangerous, and then reverse that message when the evidence becomes too obvious to be ignored.

Researchers delivered a triple shot of evidence last week.

Two revealing vitamin D studies were presented at the Annual Meeting of the American Association for Cancer Research. The first comes from the University of California, San Diego, where researchers tested blood samples in more than 1,750 women.

Subjects who had blood levels of 52 nanograms per milliliter of D had a 50 percent reduced risk of developing breast cancer compared to women with low D levels. The UCSD team noted that in order to reach 52 ng/mL requires a vitamin D intake of about 1,000 IU daily – a level that is difficult to reach without daily sun exposure.

The second study also examined the link between vitamin D and breast cancer risk. Researchers at Mount Sinai Hospital in Toronto interviewed about 1,700 women. Approximately one-third of the women were breast cancer patients.

Researchers found that women who had the highest vitamin D intake (through extended sunlight exposure, or intake of cod liver oil or milk) between the ages of 10 and 29 had a 40 percent reduced risk of breast cancer compared to women with the lowest D intake. Researchers believe that high vitamin D levels during the years when breast tissue is in rapid development helps protect the breasts from cancer later in life.

Spreading the fear around

The third study was published earlier this month in the Journal of the National Cancer Institute. Researchers at Harvard Medical School examined data collected for more than 47,000 men who participated in the Health-Professionals Follow-Up Study. The amount of vitamin D exposure was assessed by examining data on vitamin intake through diet and supplements, outdoor physical activity, geographic residence and skin pigmentation.

The Harvard team found that low levels of vitamin D may be associated with increased cancer risk (particularly digestive-system cancers) and mortality in men. Researchers estimated that a daily vitamin D intake of 1,500 IU is required to offset cancer risk.

In the NBC report on this study and the two breast cancer studies, science and health correspondent Robert Bazell states that experts now recommend “a minimum of 1,000 units per day” of vitamin D. He notes that exposing your arms and face to direct sunlight at mid-day for ten minutes is all you need to get your daily 1,000 IU. (This is oversimplified. The recommendation may be exactly right if you live in Miami Beach, but ten minutes of direct sunlight exposure in January in Burlington, Vermont, is going to produce very little vitamin D.)

Bazell adds: “Amazingly, with our automobile and indoor lifestyle many Americans do not get even that much.”

Amazingly? Why would that strike him as amazing? For years now, the mainstream media has been urging people to avoid sunlight at all costs, portraying sunlight as a dangerous threat to skin health. The amazing thing is that people go outside at all, with that dreadful sun shining all over the place.

Ten or fifteen minutes of direct sunlight exposure daily is good advice for most people. For those who live in higher or lower latitudes, supplements that provide vitamin D will do what sunlight can’t do. For more details on supplementing with vitamin D, see the e-Alert “D Does It” (1/7/04) in the e-Alert archives on our web site at hsionline.com.

Sources:
“Vitamin D Linked to Lower Breast Cancer Risk” NutraIngredients, 4/4/06, nutraingredients.com
“Prospective Study of Predictors of Vitamin D Status and Cancer Incidence and Mortality in Men” Journal of the National Cancer Institute, Vol. 98, No. 7, 4/5/06, jncicancerspectrum.oxfordjournals.org
“Huh? I Should Spend More Time in the Sun?” Robert Bazell, NBC Nightly News, 4/4/06, dailynightly.msnbc.com