Watermelon for Prostate Cancer?

I love tomatoes on my salads, but I’ve read that tomatoes have to be cooked in order to reduce the risk of prostate cancer. Is this true?

– December 10, 2002

The compound in tomatoes that reduces the risk of prostate cancer is lycopene, which is the carotenoid pigment responsible for their red color. Lycopene is a powerful antioxidant that a number of large studies have shown is particularly good at protecting against prostate, colon and rectal cancer, as well as heart disease. It is true that lycopene is much more available to the body from cooked tomatoes than from raw ones. And since it is fat soluble, you need to eat your cooked tomatoes with some fat to facilitate absorption. That doesn’t mean eating all the pizza you can get your hands on. However, it does suggest that homemade marinara sauce would be a healthful staple. I make my marinara with olive oil and keep some on hand in the freezer.

However, if you don’t like tomatoes, you could try watermelon. Results of recent research at the U.S. Department of Agriculture suggest that watermelon contains 40-percent more lycopene than an equivalent weight of tomatoes. As a matter of fact, one study suggests that watermelon may be a better source of lycopene than tomatoes. The amount of lycopene provided in watermelon is as well absorbed by the body as lycopene from tomatoes. (And, of course, you don’t have to cook watermelon to get the same benefits that you get from tomatoes.)

This new information about lycopene comes from a study at the USDA’s Agricultural Research Service laboratory in Maryland. Participants (all of them healthy) ate either a diet low in lycopene or one supplemented with cooked tomato juice or squeezed and frozen watermelon juice. Results showed that those who drank either juice doubled their blood lycopene concentrations by the end of the trial. Scientists say that this is the first study to show that the body takes up lycopene from raw watermelon.

The body converts about 500 different carotenoids into vitamin A. I recommend taking advantage of them all. A diet rich in fruits and vegetables, especially peaches, melons, mangoes, sweet potatoes, squash, pumpkins, tomatoes, and dark leafy greens – and now watermelon – can give you an abundant supply of these healthy pigments. (If you don’t get enough of these foods in your diet, you may want to use an antioxidant supplement. I recommend a mixed carotenoid supplement containing lycopene, lutein, alpha-carotene and zeaxanthin, as well as beta-carotene.)

Andrew Weil, M.D.

Dosage Update, October, 2004
In order to provide the most up-to-date health information, I may change my recommendations from time to time. Due to compelling new research on carotene, I now suggest that you take 15,000 IU of mixed carotenes. (My previous recommendation was 25,000 IU; please adjust your dosage accordingly.)

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