The effect of gamma-linolenic acid on human diabetic peripheral neuropathy: a double-blind placebo-controlled trial

Diabet Med. 1990 May;7(4):319-23. doi: 10.1111/j.1464-5491.1990.tb01397.x.


Twenty-two patients with distal diabetic polyneuropathy confirmed both clinically and by objective nerve function studies, completed a double-blind, placebo-controlled study to assess the effect of dietary supplementation with gamma-linolenic acid on their neuropathy. Patients received either 360 mg gamma-linolenic acid (12 patients) or indistinguishable placebo capsules (10 patients) for 6 months. All patients were assessed at the beginning and end of the study period by neuropathy symptom and sign scoring, motor and sensory nerve conduction studies, and thermal threshold measurements. When compared with the placebo group, patients on gamma-linolenic acid showed statistically significant improvement in neuropathy symptom scores (p less than 0.001), median nerve motor conduction velocity (p less than 0.01) and compound muscle action potential amplitude (p less than 0.01), peroneal nerve motor conduction velocity (p less than 0.05) and compound muscle action potential amplitude (p less than 0.05), median (p less than 0.01) and sural (p less than 0.001) sensory nerve action potential amplitude and ankle heat threshold (p less than 0.001) and cold threshold (p less than 0.01) values. gamma-Linolenic acid therapy might have a useful role in the prevention and treatment of distal diabetic polyneuropathy.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial

MeSH terms

  • Action Potentials / drug effects
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use
  • Clinical Trials as Topic
  • Diabetes Mellitus, Type 1 / physiopathology
  • Diabetes Mellitus, Type 2 / physiopathology
  • Diabetic Neuropathies / drug therapy*
  • Diabetic Neuropathies / physiopathology
  • Double-Blind Method
  • Fatty Acids, Essential / blood
  • Fatty Acids, Essential / therapeutic use*
  • Female
  • Follow-Up Studies
  • Humans
  • Linoleic Acids
  • Linolenic Acids / therapeutic use*
  • Male
  • Middle Aged
  • Neural Conduction / drug effects
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / physiology
  • Oenothera biennis
  • Phospholipids / blood
  • Placebos
  • Plant Oils
  • Random Allocation
  • Reference Values
  • gamma-Linolenic Acid


  • Anti-Inflammatory Agents, Non-Steroidal
  • Fatty Acids, Essential
  • Linoleic Acids
  • Linolenic Acids
  • Phospholipids
  • Placebos
  • Plant Oils
  • evening primrose oil
  • gamma-Linolenic Acid