To Your Health
June, 2009 (Vol. 03, Issue 06)
The Sunscreen Dilemma
By Jacob Schor, ND
Wearing sunscreen prevents sunburns, but research suggests it might not reduce your risk of developing cancer; in fact, it might actually increase your risk.
That's the sunscreen dilemma.
In Hans Christian Andersen's fairy tale The Emperor's New Clothes
, two swindlers convince the emperor that they have made a suit of clothes for him out of special cloth. The cloth is magically invisible to people who are stupid, or so they tell him. The emperor, not wanting to appear stupid, says he can see the cloth and proceeds to parade naked through the city. None of the onlookers admits that he is naked, either, until an innocent child shouts out the obvious. Our reliance on sunscreen as protection against skin cancer is about as effective as the emperor's magic clothing.
Sunblock: Blocking Vitamin D
Experts have encouraged sunscreen use as protection against the skin damage that leads to malignant melanoma. Unfortunately, these sunscreens prevent the skin from making vitamin D from sunlight - and many studies now suggest that vitamin D is protective against cancer. Sunscreen is designed to block UV penetration into the skin. That's precisely why it prevents sunburn. This is also why it prevents production of vitamin D. Even relatively weak sunscreens (as low as SPF-8) will block UV and stop vitamin D production.
Malignant melanoma is relatively rare. It is responsible for less than 10,000 fatalities a year in the United States. Other cancers cause far more fatalities. Lung cancer causes about 150,000 deaths a year. Breast cancer about 40,000. In all, about half a million people in the U.S. die of cancer each year.
William Grant, a major vitamin D researcher, estimates that vitamin D deficiency causes 100,000 people to develop cancer each year who wouldn't have if they had adequate levels to provide protection, leading to 40,000 deaths per year. Cedric Garland concluded years back that 1,000 IU of vitamin D a day decreases risk of colorectal cancer by half. Giving everyone a moderate dose of vitamin D could, in theory, prevent 28,000 colon cancer deaths a year. Grant calculated that spending a billion dollars to provide 1,000 IU of vitamin D a day to everyone in Europe and North America would save between $16 and $25 billion in cancer care costs.
So, does sunscreen's protective action against skin cancer outweigh the decrease in vitamin D production and loss of protection against other cancers? If we all stopped using sunscreen, what would the trade-off be? How many more cases of skin cancer would we cause by increasing vitamin D production naturally?