Phase II prospective randomized trial of a low-fat diet with fish oil supplementation in men undergoing radical prostatectomy.

Published

Journal Article

Preclinical studies suggest lowering dietary fat and decreasing the ratio of omega-6 to omega-3 polyunsaturated fatty acids decreases the risk of prostate cancer development and progression. We conducted a phase II randomized trial to test the effect of decreasing dietary fat combined with decreasing the dietary omega-6:omega-3 ratio on biomarkers related to prostate cancer development and progression. Patients undergoing radical prostatectomy were randomly assigned to receive a low-fat diet with 5 grams of fish oil daily (dietary omega-6:omega-3 ratio of 2:1) or a control Western diet (omega-6:omega-3 ratio of 15:1) for four to six weeks prior to surgery. The primary endpoint was change in serum insulin-like growth factor I (IGF-1) between arms. Secondary endpoints were serum IGFBP-1, prostate prostaglandin E2 levels, omega-6:omega-3 fatty acid ratios, COX-2, and markers of proliferation and apoptosis. Fifty-five patients were randomized and 48 completed the trial. There was no treatment difference in the primary outcome. Positive secondary outcomes in the low-fat fish oil versus Western group were reduced benign and malignant prostate tissue omega-6:omega-3 ratios, reduced proliferation (Ki-67 index), and reduced proliferation in an ex vivo bioassay when patient sera was applied to prostate cancer cells in vitro. In summary, four to six weeks of a low-fat diet and fish oil capsules to achieve an omega-6:omega-3 fatty acid ratio of 2:1 had no effect on serum IGF-1 levels, though in secondary analyses, the intervention resulted in decreased prostate cancer proliferation and decreased prostate tissue omega-6:omega-3 ratios. These results support further studies evaluating reduction of dietary fat with fish oil supplementation on modulating prostate cancer biology.

Full Text

Cited Authors

  • Aronson, WJ; Kobayashi, N; Barnard, RJ; Henning, S; Huang, M; Jardack, PM; Liu, B; Gray, A; Wan, J; Konijeti, R; Freedland, SJ; Castor, B; Heber, D; Elashoff, D; Said, J; Cohen, P; Galet, C

Published Date

  • December 2011

Published In

Volume / Issue

  • 4 / 12

Start / End Page

  • 2062 - 2071

PubMed ID

  • 22027686

Pubmed Central ID

  • 22027686

Electronic International Standard Serial Number (EISSN)

  • 1940-6215

International Standard Serial Number (ISSN)

  • 1940-6207

Digital Object Identifier (DOI)

  • 10.1158/1940-6207.CAPR-11-0298

Language

  • eng