Information and Resources from the U-M Comprehensive Cancer Center

Most Wanted Supplements:
Are They Cancer Killers or Frauds? What You Need to Know, con't.

Suspect: Lycopene

Charge: Lycopene is a plant chemical called a carotenoid. Research has shown that lycopene in food appears to reduce prostate cancer risk; however, this remains controversial.

Verdict: Once again, we don't know how lycopene works in the body -- or whether it's working alone -- to reduce cancer risk.

Consider this: Researchers noted that foods rich in beta-carotene -- a cousin to lycopene -- seemed to reduce lung cancer risk in smokers. But when beta-carotene supplements were tested by smokers as a preventive, cancer risk increased.

Leave lycopene supplements alone. Instead, eat more tomato sauce, low-sodium tomato juice, watermelon, guava, rose hips and pink grapefruit.

Suspect: Melatonin

Charge: Melatonin is a hormone found in the body. Doctors sometimes prescribe a synthetic form of it to supplement cancer treatment or ward off side effects. Melatonin also is used to treat insomnia. Research is under way to determine whether melatonin helps boost the immune system.

Verdict: If you are having problems sleeping, it might be worth talking to your doctor about melatonin. However, do not take this supplement -- or any other -- without consulting your doctor first.

Some melatonin supplements may contain contaminants. Melatonin is known to interact with certain medications -- including blood pressure drugs -- and may worsen depression.

Suspect: Resveratrol

Charge: Resveratrol is a polyphenol known to act as an antioxidant, an antiinflammatory and a weak plant estrogen.

These properties may help it to prevent cellular damage known to trigger cancer, but its ability to slow the growth of cancer cells has only been shown in early laboratory testing.

Verdict:Resveratrol is found in grape skins, so eat more red and purple grapes. It's too soon to know how resveratrol works or whether resveratrol supplements are safe, so don't take resveratrol pills -- or uncork the red wine. While it's true that resveratrol is found in wine, it's also true that alcohol consumption is associated with increased cancer risk. Resveratrol may have an estrogenic effect, so women with hormone-sensitive conditions, in particular, should avoid resveratrol supplements.

Suspect: Selenium

Charge: Selenium is a mineral found in poultry, fish, wheat and liver. It was once thought to be potentially beneficial in preventing cancer. However, several studies have shown that it is not only ineffective, but also potentially dangerous.

Verdict: Don't take it.

Studies have shown it does not prevent skin, lung, prostate, stomach and esophageal cancer. Furthermore, research conflicts as to whether it may increase risk for a type of skin cancer called squamous cell carcinoma. Last year, a trial examining vitamin E and selenium for prostate cancer prevention was halted after researchers noted a small increase in diabetes among men who took selenium.

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