Can supplements prevent skin cancer?
Reports of foods and dietary supplements protecting us from skin cancer are highly exaggerated. There is little rigorous research to support such claims. The World Cancer Research Fund / American Institute for Cancer Research has recently sorted though countless medical studies to help us find truths about cancer and diet. Their recent 500-plus page report has some important findings.
Vitamin A (retinol) might reduce the risk of skin cancer, but can be toxic
Retinol is a fat soluble vitamin that belongs to a family of compounds called retinoids. Other retinoids include beta carotene, isotretenoin (Accutane®) and tretinoin (Retin-A®). Their effects on the skin are profound: they correct wrinkles, smooth brown spots, and treat acne and skin conditions such as psoriasis. In patients at high risk for developing skin cancer, such as transplant patients, high doses of vitamin A (25,000 IU) helps protect them from developing skin cancer, particularly squamous cell carcinoma. Unfortunately vitamin A can also be toxic causing headaches, dizziness, vision changes, and even osteoporosis and liver damage. Doses greater than 10,000 can dangerous and should never be taken without the supervision of a physician.
Do beta-carotene supplements prevent skin cancer?
Beta-carotene is a precursor of vitamin A and is found in sweet potatoes, carrots, kale, spinach, and winter squash. Although good for your health when obtained from natural sources, the report concluded that there was no prevention of skin cancer afforded by taking beta-carotene supplements. We also know that in smokers, taking beta-carotene supplements might actually increase their risk of developing lung and prostate cancer.
Should I take selenium supplements?
Not if you are trying to prevent skin cancer. The study concluded that taking selenium supplements failed to protect against skin cancer and was associated with an increase in skin cancer when taken at 200 micrograms a day. The evidence to support this increase was weak, but there was clearly no evidence that taking selenium was preventative.