Effects of omega-3 fatty acid supplementation on heart rate variability at rest and during acute stress in adults with moderate hypertriglyceridemia

Psychosom Med. 2013 May;75(4):382-9. doi: 10.1097/PSY.0b013e318290a107. Epub 2013 Apr 16.


Objective: This study examined the dose-dependent effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation on heart rate variability (HRV) at rest and during standard laboratory stress tasks. We also investigated whether EPA + DHA supplementation was associated with changes in mood state.

Methods: This placebo-controlled, double-blind, randomized, three-period crossover trial (8-week treatment, 6-week washout) compared two doses of EPA + DHA supplementation (0.85 and 3.4 g/d) in 26 adults with elevated triglycerides. After each treatment period, HRV was assessed during an acute stress protocol that included a resting baseline, standard laboratory stress tasks (speech task and cold pressor), and recovery periods. In addition, mood state was assessed.

Results: Root mean square of successive differences in interbeat interval and total power increased 9.9% and 20.6%, respectively, after the high dose relative to placebo (Tukey p = .016 and .012, respectively). The low dose was not significantly different from the high dose or placebo dose. There was a trend for a treatment effect on high-frequency HRV (p = .058), with 21.0% greater power observed after the high dose compared with placebo (Tukey p = .052). Mood did not differ between treatments, and there was no association between mood state and HRV.

Conclusions: In healthy adults with elevated triglycerides, supplementation of 3.4 g/d EPA + DHA resulted in greater HRV, whereas 0.85 g/d EPA + DHA had no effect. These results indicate that EPA + DHA supplementation may improve autonomic tone in adults at increased risk for cardiovascular disease within 8 weeks.

Trial registration: NCT00504309 (ClinicalTrials.gov).

Keywords: acute stress; docosahexaenoic acid; eicosapentaenoic acid; heart rate variability; omega-3 fatty acids.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anxiety / etiology
  • Cold Temperature
  • Cross-Over Studies
  • Depression / etiology
  • Dietary Supplements*
  • Docosahexaenoic Acids
  • Double-Blind Method
  • Drug Combinations
  • Eicosapentaenoic Acid
  • Electrocardiography
  • Exercise Test
  • Fatty Acids, Omega-3 / pharmacology*
  • Fatty Acids, Omega-3 / therapeutic use
  • Heart Rate / drug effects*
  • Humans
  • Hypertriglyceridemia / drug therapy*
  • Hypertriglyceridemia / physiopathology
  • Hypertriglyceridemia / psychology
  • Rest
  • Speech / physiology
  • Stress, Physiological
  • Stress, Psychological / physiopathology
  • Stress, Psychological / psychology


  • Drug Combinations
  • Fatty Acids, Omega-3
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid
  • Omacor

Associated data

  • ClinicalTrials.gov/NCT00504309