A comparison of fish oil, flaxseed oil and hempseed oil supplementation on selected parameters of cardiovascular health in healthy volunteers

J Am Coll Nutr. 2008 Feb;27(1):51-8. doi: 10.1080/07315724.2008.10719674.


Objective: The impact of dietary polyunsaturated fatty acids (PUFAs) of the n-6 and n-3 series on the cardiovascular system is well documented. To directly compare the effects of three dietary oils (fish, flaxseed and hempseed) given in concentrations expected to be self-administered in the general population on specific cardiovascular parameters in healthy volunteers.

Design: 86 healthy male and female volunteers completed a 12 week double blinded, placebo controlled, clinical trial. They were randomly assigned to one of the four groups. Subjects were orally supplemented with two 1 gm capsules of placebo, fish oil, flaxseed oil or hempseed oil per day for 12 weeks.

Results: Plasma levels of the n-3 fatty acids docosahexanoic acid and eicosapentanoic acid increased after 3 months supplementation with fish oil. Alpha linolenic acid concentrations increased transiently after flaxseed supplementation. However, supplementation with hempseed oil did not significantly alter the concentration of any plasma fatty acid. The lipid parameters (TC, HDL-C, LDL-C and TG) did not show any significant differences among the four groups. Oxidative modification of LDL showed no increase in lag time over the 12 wk period. None of the dietary interventions induced any significant change in collagen or thrombin stimulated platelet aggregation and no increase in the level of inflammatory markers was observed.

Conclusion: From a consumer's perspective, ingesting 2 capsules of any of these oils in an attempt to achieve cardiovascular health benefits may not provide the desired or expected result over a 3 month period.

Publication types

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

MeSH terms

  • Adult
  • Cannabis / chemistry
  • Cardiovascular Diseases / blood*
  • Cardiovascular Diseases / drug therapy
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Dietary Supplements
  • Double-Blind Method
  • Fatty Acids / blood
  • Female
  • Fish Oils / administration & dosage*
  • Humans
  • Linseed Oil / administration & dosage*
  • Lipid Metabolism / drug effects*
  • Lipid Peroxidation / drug effects
  • Male
  • Plant Oils / administration & dosage*
  • Platelet Aggregation / drug effects
  • Risk Factors
  • Treatment Outcome
  • Triglycerides / blood


  • Cholesterol, HDL
  • Cholesterol, LDL
  • Fatty Acids
  • Fish Oils
  • Plant Oils
  • Triglycerides
  • Linseed Oil