The effect of gamma-linolenic acid, an in vitro cytostatic substance contained in evening primrose oil, on primary liver cancer. A double-blind placebo controlled trial

Prostaglandins Leukot Essent Fatty Acids. 1990 Jul;40(3):199-202. doi: 10.1016/0952-3278(90)90098-6.


The cytostatic effects of essential fatty acid metabolic intermediates and of some prostaglandins and leukotrienes in vitro have been extensively documented. The essential fatty acids (EFAs) exhibit no side-effects when taken as a dietary supplement, even in large doses. Primary Liver Cancer (PLC) is a fatal disease in our area as it is always multifocal in nature. In vitro studies have shown a cytostatic effect of gamma-linolenic acid (GLA) on primary liver cancer cells. In a double-blind placebo controlled trial, using Evening Primrose Oil (as a source of GLA) as a dietary supplement in PLC patients, no statistically significant effect was observed on survival time or liver size. There was however a statistical significant beneficial effect on Gamma Glutamyl transferase values as a measure of liver function. No side-effects were observed. The large size of tumour and the low doses of GLA used in this trial probably explain the lack of significant effect on survival times.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Clinical Trials as Topic
  • Double-Blind Method
  • Fatty Acids, Essential / pharmacology*
  • Humans
  • In Vitro Techniques
  • Linoleic Acids
  • Linolenic Acids / pharmacology*
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / epidemiology
  • Oenothera biennis
  • Plant Oils
  • South Africa / epidemiology
  • Survival Analysis
  • gamma-Linolenic Acid


  • Antineoplastic Agents
  • Fatty Acids, Essential
  • Linoleic Acids
  • Linolenic Acids
  • Plant Oils
  • evening primrose oil
  • gamma-Linolenic Acid