Whole Tomatoes Key Against Cance

By Roni Rabin
STAFF WRITER

November 5, 2003

To reduce the risk of prostate cancer, it may take the whole tomato.

New research on rats suggests eating whole tomatoes can reduce prostate cancer deaths more effectively than taking supplements of lycopene, a chemical found in tomatoes that has been associated with lower prostate cancer risk.

Several earlier studies in humans had found a link between high lycopene blood levels and a lower risk of prostate cancer, but it was not clear whether lycopene was the effective agent or whether it simply signified tomato consumption.

The new research suggests lycopene acts in concert with other nutrients in the tomato, creating a synergistic effect, said study author John W. Erdman, a professor of food science and human nutrition at University of Illinois at Urbana-Champaign. Lycopene is a carotenoid, a type of antioxidant that plays a role in disease resistance and includes beta-carotene, found in carrots and dark leafy greens like kale.

"Lycopene clearly contributes to lower risk, but we never believed it was a magic bullet," Erdman said. "There are a number of other good things in tomatoes," including other carotenoids and vitamins C and E, to mention just a few.

"This study suggests that taking lycopene as a dietary supplement is not as effective as eating whole tomatoes," he said, encouraging the consumption of tomato products in pasta, salad, juice, even pizza.

The study, co-authored by Dr. Steven K. Clinton, professor of hematology and oncology and nutrition at Ohio State University in Columbus, was published in the current issue of the Journal of the National Cancer Institute, a peer-reviewed journal.

It is one of a number of studies that have raised questions about whether the benefits of nutrients like antioxidants can be bottled.

Jeffrey Blumberg, a researcher at Tufts University's The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy and a self-described "advocate of rational diet supplementation," said the question of food versus supplements doesn't necessarily have an either-or answer.

"No one ever suggested supplements are a substitute for eating whole food. They are what they say they are - supplements to a diet," he said. It is easier to absorb lycopene when tomatoes are pureed or sauteed, he said.

As part of Erdman's 14-month study, researchers treated 194 rats with a carcinogen to induce prostate cancer, and then assigned them to a diet of either whole tomato powder, pure lycopene or a control group.

The rats that consumed the tomato powder had a 26 percent lower risk of prostate cancer death than the control rats, researchers found. While 80 percent of the control group died of prostate cancer, 72 percent of those on lycopene died, and only 62 percent of rats on tomato powder died.

Half of each group had a diet of 80 percent of the average daily food intake, which also was found to lower the risk of developing prostate cancer.