Diet, supplement use, and prostate cancer risk: results from the prostate cancer prevention trial.

What Was Tested

This randomized controlled trial looks at the intervention named in the title.

The presence or absence of cancer was determined by prostate biopsy, which was recommended during the trial because of an elevated prostate-specific antigen level or an abnormal digital rectal examination and was offered to all men at the trial's end.

Cancer was detected in 1,703 men; 127 cancers were high-grade (Gleason score 8-10).

Who Took Part

The study group was 9,559 participants.

PubMed indexes the participants as middle-aged adults and older adults, men only.

Nutrient intake was assessed using a food frequency questionnaire and a structured supplement-use questionnaire.

How the Study Was Run

In design terms this was a randomized study.

Random assignment meant chance, not the researchers, decided who got the intervention named in the title and who got the comparison, which limits bias.

What Was Measured

The presence or absence of cancer was determined by prostate biopsy, which was recommended during the trial because of an elevated prostate-specific antigen level or an abnormal digital rectal examination and was offered to all men at the trial's end.

Cancer was detected in 1,703 men; 127 cancers were high-grade (Gleason score 8-10).

PubMed files the paper under topics including Age Factors, Body Mass Index, Diet, Dietary Supplements, Digital Rectal Examination, Exercise and Prostate-Specific Antigen.

What This Means in Plain Language

The paper is a randomized study in 9,559 participants.

With several hundred people or more, it is a fairly large study for this kind of research.

The publication is from 2010 (American journal of epidemiology), a journal based in United States.

More context: all human trials.