Effects of n-3 fatty acids on macro- and microvascular function in subjects with type 2 diabetes mellitus

Am J Clin Nutr. 2010 Mar;91(3):808-13. doi: 10.3945/ajcn.2009.28374. Epub 2010 Jan 13.


Background: Recent evidence supports the protective effects of n-3 (omega-3) fatty acids (n-3 FAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on vascular function.

Objective: We investigated the effects of EPA and DHA on postprandial vascular function in subjects with type 2 diabetes mellitus.

Design: In a double-blind, placebo-controlled, randomized, crossover manner, 34 subjects with type 2 diabetes mellitus received daily either 2 g purified EPA/DHA (termed n-3 FAs) or olive oil (placebo) for 6 wk. At the end of this period, we measured macrovascular (brachial ultrasound of flow-mediated dilatation; FMD) and microvascular [laser-Doppler measurements of reactive hyperemia (RH) of the hand] function at fasting and 2, 4, and 6 h after a high-fat meal (600 kcal, 21 g protein, 41 g carbohydrates, 40 g fat).

Results: Fasting vascular function remained unchanged after n-3 FAs and placebo. Postprandial FMD decreased from fasting after placebo, with a maximum decrease (38%) at 4 h-an effect that was significantly reduced (P = 0.03 for time x treatment interaction) by n-3 FA supplementation (maximum decrease in FMD was at 4 h: 13%). RH remained unchanged after placebo, whereas it improved significantly (P = 0.04 for time x treatment interaction) after n-3 FA supplementation (maximum increase was at 2 h: 27%).

Conclusions: In subjects with type 2 diabetes mellitus, 6 wk of supplementation with n-3 FAs reduced the postprandial decrease in macrovascular function relative to placebo. Moreover, n-3 FA supplementation improved postprandial microvascular function. These observations suggest a protective vascular effect of n-3 FAs.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Cross-Over Studies
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diet
  • Dietary Supplements
  • Docosahexaenoic Acids / pharmacology*
  • Docosahexaenoic Acids / therapeutic use
  • Double-Blind Method
  • Eicosapentaenoic Acid / pharmacology*
  • Eicosapentaenoic Acid / therapeutic use
  • Female
  • Humans
  • Hyperemia / drug therapy*
  • Microvessels / diagnostic imaging
  • Microvessels / drug effects*
  • Microvessels / physiology
  • Middle Aged
  • Olive Oil
  • Plant Oils / pharmacology
  • Postprandial Period / drug effects
  • Ultrasonography
  • Vasodilation / drug effects*


  • Olive Oil
  • Plant Oils
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid