High-Fiber, Low-Fat Diet May Not Protect Against ProstateCancer

High-Fiber, Low-Fat Diet May Not Protect Against ProstateCancer

NEW YORK--A four-year dietary intervention that includedincreased consumption of fruits, vegetables and fiber, and reduced fat intakewas not found to improve serum prostate specific antigen (PSA) levels, a markerfor prostate cancer, according to research published in the September issue ofthe Journal of Clinical Oncology (20, 17:3592-8, 2002) (www.jco.org).Researchers from the Memorial Sloan-Kettering Cancer Center, who collaboratedwith a team from the National Cancer Institute in Bethesda, Md., concluded thedietary intervention did not affect the incidence of prostate cancer, either.

Of 1,350 men, 689 were randomly assigned to the intervention arm of thestudy, for which they received intensive counseling to consume a diet low in fatand high in fiber, fruits and vegetables. The remaining 661 subjects wereassigned to the control arm, for which they received a standard brochure onhealthy diet. Researchers measured each man's serum PSA level at baseline andannually thereafter for four years, during which time newly diagnosed cancerswere recorded.

To determine the effects of the dietary intervention on PSA levels andprostate cancer incidence, researchers calculated an individual PSA slope foreach participant and compared the distributions of the slopes between the twogroups. Results indicated there was no significant difference in distributionsof the slopes, and the groups were identical in the proportions of participantswith elevated PSA at each time point. There was no difference in the PSA slopesbetween the two groups nor was there a difference in the frequencies of elevatedPSA values for those with elevated PSA at baseline. In addition, researchersfound the incidence of prostate cancer during the study period was similar inboth groups--19 cases in the control arm and 22 cases in the intervention arm.