By Xinhua
Los Angeles : Contrary to popular opinion, lycopene, an antioxidant found in tomatoes, does not help prevent prostate cancer, a new study has found.
The new findings by researchers at the US Fred Hutchinson Cancer Research Center (FHCRC) contradict a long-held theory that touts lycopene as a magic bullet for prostate cancer, according to the May issue of the journal Cancer Epidemiology, Biomarkers and Prevention.
In fact, a higher intake of beta-carotene, another antioxidant found in many vegetables and commonly used as a dietary supplement, appears to increase the risk of aggressive prostate cancer.
Researchers enrolled 28,000 men in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial and collected data accordingly. All of the men had no prior history of prostate cancer.
They were screened for the disease at the start of the trial in 1993, and then followed with regular screening until the first occurrence of prostate cancer or death by the end of the trial in 2001.
During the course of the trial, 1,320 prostate cancer cases were diagnosed. The team found no significant difference in blood levels of lycopene between men who had prostate cancer and those who didn't.
In fact, they found an association between increased risk of aggressive prostate cancer and a higher intake of beta-carotene.
Beta-carotene has also been linked to an increased risk of lung cancer and heart disease among smokers, according to the findings.
The new study "hampers our enthusiasm for the beneficial effect of lycopene," said lead author Ulrike Peters, a research assistant professor at FHCRC.
"Tomatoes and tomato found in ketchup and pizza don't reduce the risk of prostate cancer," she added. "People should be very cautious about taking high doses of supplemental beta-carotene."
To live an active, healthy lifestyle is the best strategy for preventing cancer, the study suggests. To place one's faith in a particular food is not effective in preventing cancer, the study adds.
"Our guidelines suggest that people eat a mostly plant-based diet with a variety of vegetables and fruits," said Marji McCullough, a senior epidemiologist at the American Cancer Society.
"We don't recommend taking multivitamins or other supplements, especially beta-carotene supplements," she said.