Lack of effect of a low-fat, high-fruit, -vegetable, and -fiber diet on serum prostate-specific antigen of men without prostate cancer: results from a randomized trial.
OBJECTIVE
To determine whether a diet low in fat and high in fruits, vegetables, and fiber may be protective against prostate cancer by having an impact on serial levels of serum prostate-specific antigen (PSA).


METHODS
Six hundred eighty-nine men were randomized to the intervention arm and 661 to the control arm. The intervention group received intensive counseling to consume a diet low in fat and high in fiber, fruits, and vegetables. The control group received a standard brochure on a healthy diet. PSA in serum was measured at baseline and annually thereafter for 4 years, and newly diagnosed prostate cancers were recorded.


RESULTS
The individual PSA slope for each participant was calculated, and the distributions of slopes were compared between the two groups. There was no significant difference in distributions of the slopes (P =.99). The two groups were identical in the proportions of participants with elevated PSA at each time point. There was no difference in the PSA slopes between the two groups (P =.34) and in the frequencies of elevated PSA values for those with elevated PSA at baseline. Incidence of prostate cancer during the 4 years was similar in the two groups (19 and 22 in the control and intervention arms, respectively).


CONCLUSIONS
Dietary intervention over a 4-year period with reduced fat and increased consumption of fruits, vegetables, and fiber has no impact on serum PSA levels in men. The study also offers no evidence that this dietary intervention over a 4-year period affects the incidence of prostate cancer during the 4 years.
Shike
Moshe
M
Memorial Sloan-Kettering Cancer Center, New York, NY, and National Cancer Institute, Bethesda, MD. shikem@mskcc.org
Latkany
Lianne
L
Riedel
Elyn
E
Fleisher
Martin
M
Schatzkin
Arthur
A
Lanza
Elaine
E
Corle
Donald
D
Begg
Colin B
CB
D018752:Diet, Fat-Restricted; D004043:Dietary Fiber; D005247:Feeding Behavior; D005638:Fruit; D006293:Health Promotion; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000517:prevention & control*; D012044:Regression Analysis; D012306:Risk; D018709:Statistics, Nonparametric; D014675:Vegetables
D004043:Dietary Fiber; D017430:Prostate-Specific Antigen