Influence of dietary omega-6, -3 fatty acid sources on the initiation and promotion stages of photocarcinogenesis

Photochem Photobiol. 1992 Aug;56(2):195-9. doi: 10.1111/j.1751-1097.1992.tb02147.x.


To determine the segment along the carcinogenic continuum at which dietary lipid exerts its principal effect, six groups of 35 Skh-HR-1 hairless mice were placed on defined isocaloric diets containing either 0.75%, 12% corn oil or 12% menhaden oil as sources of omega-6 or omega-3 fatty acids, respectively. All animals received an 11 week course of UV-radiation from fluorescent sunlamps. Upon termination of UV, diets of some groups were crossed-over to either low fat, high fat, omega-6 or omega-3 fatty acid sources. The first tumor appeared at week 14. Life-table analysis of the tumor incidence curves and Wilcoxon tests of tumor multiplicity provided evidence that high corn oil diets significantly (P less than 0.01) enhance carcinogenic expression; that tumor enhancement by the omega-6 fatty acid source occurs during the post-initiation, or promotion, stage; that replacement with a low corn oil diet after UV-initiation will negate the exacerbating effect of high corn oil; and that an omega-3 fatty acid source inhibits UV-carcinogenesis even at high dietary levels, although not during the post-initiation stage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Corn Oil / administration & dosage
  • Corn Oil / toxicity
  • Dietary Fats, Unsaturated / administration & dosage*
  • Dietary Fats, Unsaturated / adverse effects
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-6
  • Fatty Acids, Unsaturated / administration & dosage
  • Fatty Acids, Unsaturated / adverse effects
  • Female
  • Mice
  • Mice, Hairless
  • Neoplasms, Radiation-Induced / etiology*
  • Neoplasms, Radiation-Induced / prevention & control
  • Ultraviolet Rays / adverse effects


  • Dietary Fats, Unsaturated
  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Fatty Acids, Unsaturated
  • Corn Oil