Effect of omega-3 fatty acids on rectal mucosal cell proliferation in subjects at risk for colon cancer

Gastroenterology. 1992 Sep;103(3):883-91. doi: 10.1016/0016-5085(92)90021-p.


The effects of 12 weeks of omega-3 fatty acid supplementation on rectal mucosal proliferation were assessed with [3H]thymidine autoradiography in a double-blind, placebo-controlled study of 20 patients with sporadic adenomatous colorectal polyps. In the group of 10 that received fish oil containing eicosapentaenoic acid (4.1 g/day) and docosahexaenoic acid (3.6 g/day), the mean percentage of replicative "S"-phase cells in the upper part of colonic crypts (considered a reliable marker of colon cancer risk) significantly dropped from the baseline level after only 2 weeks of treatment and remained lower throughout the study period; no change in upper-crypt labeling was observed in the 10 placebo patients. Rectal mucosal eicosapentaenoic acid content increased in fish oil patients, whereas arachidonic acid levels decreased. The fish oil-induced kinetic changes represent contraction of the proliferative compartment to the levels of a low-risk population and may be related to omega-3 fatty acid effects on the arachidonic prostaglandin pathway. In this short-term trial, fish oil appeared to exert a rapid effect that may protect high-risk subjects from colon cancer.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoradiography
  • Cell Division / drug effects*
  • Colorectal Neoplasms / diet therapy*
  • Docosahexaenoic Acids / administration & dosage
  • Docosahexaenoic Acids / pharmacology*
  • Double-Blind Method
  • Drug Administration Schedule
  • Eicosapentaenoic Acid / administration & dosage
  • Eicosapentaenoic Acid / pharmacology*
  • Humans
  • Intestinal Mucosa / pathology*
  • Intestinal Polyps / diet therapy*
  • Rectum / pathology*
  • S Phase / drug effects


  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid