After years of telling people to avoid the sun to ward off skin cancer, scientists are now coming to the conclusion that moderate sun exposure is healthy.
Scientists Say Sunshine May Prevent Cancer (AP)
Scientists are excited about a vitamin again. But unlike fads that sizzled and fizzled, the evidence this time is strong and keeps growing. If it bears out, it will challenge one of medicine’s most fundamental beliefs: that people need to coat themselves with sunscreen whenever they’re in the sun. Doing that may actually contribute to far more cancer deaths than it prevents, some researchers think.
The vitamin is D, nicknamed the “sunshine vitamin” because the skin makes it from ultraviolet rays. Sunscreen blocks its production, but dermatologists and health agencies have long preached that such lotions are needed to prevent skin cancer. Now some scientists are questioning that advice. The reason is that vitamin D increasingly seems important for preventing and even treating many types of cancer. In the last three months alone, four separate studies found it helped protect against lymphoma and cancers of the prostate, lung and, ironically, the skin. The strongest evidence is for colon cancer.
Many people aren’t getting enough vitamin D. It’s hard to do from food and fortified milk alone, and supplements are problematic. So the thinking is this: Even if too much sun leads to skin cancer, which is rarely deadly, too little sun may be worse. No one is suggesting that people fry on a beach. But many scientists believe that “safe sun” — 15 minutes or so a few times a week without sunscreen — is not only possible but helpful to health.
The number of cases in recent years where medical science has created hysteria against behavior once considered perfectly fine–like eating bacon and eggs for breakfast or getting some sunshine and fresh air–only to have to reverse themselves after a number of years is growing.
Perhaps if we conducted medical research with standards at least as rigorous as those required by the social sciences, we could avoid this. I’m often shocked when I see that these widely-touted studies in leading medical journals are based on laughably small sample sizes and hand-selected groups that are obviously not representative of the general population.
Update (1201): Glenn Reynolds points to a related post from almost exactly a year ago by Bill Ardolino.
