Fish oil lowers heart rate

There is significant evidence that omega-3 fatty acids have anti-arrhythmic effects, which is associated with decreased death from various cardiovascular diseases.

A recent meta-analysis published in the Journal Circulation, further confirms this association. Researchers from the Harvard School of Public Health combined statistical analysis of thirty studies published from 1996 to 2005. These studies involved nearly 1,700 individuals treated with fish oil or placebo for up to one year. The median combined dose of EPA and DHA was 3.5 grams/day for an average of 8 weeks.

The overall estimated change in heart rate of those treated with fish oil was 1.6 beats per minute. The reduction in heart rate was even greater among trials whose participants had higher baseline heart rates. In those studies, treatment with fish oil resulted in a decreased heart rate of 2.5 beats per min. There was no evidence of a dose-response effect, and heart rate was not significantly different between higher and lower doses compared with placebo.

Although the overall effect of fish oil on heart rate appears small, researchers estimate that on a population basis this could correspond to as much as a 5% reduction in sudden death.

Mozaffarian D, Geelen A, Brouwer IA, Geleijnse JM, Zock PL, Katan MB. Effect of fish oil on heart rate in humans. A meta-analysis of randomized controlled trials. Circulation 2005;112:1945-1952.