Perhaps the tomato was ripe for a reality check. It appears that lycopene — a red pigment found in tomatoes and tomato-based products — may not be useful in preventing prostate cancer after all.
This was one of the conclusions of a large study conducted by researchers at the Fred Hutchinson Cancer Research Center in Seattle, as well as the National Cancer Institute in Rockville, Md., and several other centres. They found that levels of lycopene in blood serum were not associated with risk of prostate cancer. “Our study dampens the enthusiasm that lycopene and tomatoes reduce the risk of prostate cancer,” says Ulrike Peters, the lead study author.
Earlier studies had led to a great deal of hype that men should be eating more tomatoes and tomato sauce because of lycopene’s anti-cancer properties. This latest study measured actual levels of these compounds in blood serum, rather than relying on men’s ability to remember what they ate.
The study involved more than 28,000 men between the ages of 55 and 74 years. Of this group, 692 men were diagnosed with prostate cancer one to eight years after entering the study. Peters and her colleagues measured serum levels of lycopene, beta-carotene and four other plant pigments in these men and in 844 randomly selected men of similar ages who had not developed prostate cancer.
Not only did the study debunk prevailing attitudes about tomatoes and prostate cancer risk reduction, it also dethroned beta-carotene, which is found in deeply coloured fruits and vegetables such as carrots. High serum beta-carotene concentrations were associated with increased risk for aggressive prostate cancer. Researchers were surprised by this result. “This finding was not expected and it has not been consistently seen in previous findings,” Peters says.
None of the other pigments were associated with prostate cancer risk.
Though the study may cast doubt on the validity of taking lycopene and beta-carotene in pill form to prevent prostate cancer, it does not detract from traditional nutrition advice. “We still recommend men to follow a healthy diet with lots of fruits and vegetables,” Peters says.