WASHINGTON — Contrary to previous findings, a high intake of lycopene and other carotenoids was not associated with a reduced risk of prostate cancer in a large case-control study, Ulrike Peters, Ph.D., said at the annual meeting of the American Association for Cancer Research.
To assess the association between the risk of prostate cancer and prediagnostic levels of serum carotenoids and serum retinol, Dr. Peters of the Fred Hutchinson Cancer Research Center in Seattle and her colleagues analyzed data from 692 cases of prostate cancer and 842 age-matched controls.
“Overall, there was no significant inverse association between carotenoids and prostate cancer risk,” Dr. Peters said.
Previous research has shown a 10%–20% reduced risk of prostate cancer associated with a higher intake of lycopene and tomato products, but this study was not able to confirm such an association, Dr. Peters noted.
The study did show that high serum retinol levels were significantly associated with a reduced risk of advanced prostate cancer, but that association was not significant for prostate cancer overall.
The subjects were part of the multicenter Prostate, Lung, Colorectal, and Ovarian Cancer Screening trial, which included more than 150,000 adults aged 55–74 years. Levels of retinol and several carotenoids were measured in each subject when they entered the study. Prostate cancer cases were diagnosed during an 8-year follow-up.
Should physicians encourage their male patients to eat tomatoes? “I think the jury is still out about eating more tomatoes as a way to prevent prostate cancer,” Dr. Peters said.