Omega-3 Fish Oils: The Research on Their Benefits Keeps Getting Better

Two new studies show that taking supplements of omega-3 fish oils leads to a significant reduction in deaths and hospitalizations due to cardiac problems.

In the first study, published in the British Medical Journal in late December 2008, researchers analyzed data from 12 earlier studies involving 32,779 patients. Ross T. Tsuyuki, MD, and his colleagues reported that the use of fish oil supplements lowered the risk of sudden cardiac death by 19 percent and deaths from all causes by 8 percent. Most striking was a 20 percent lower risk of dying specifically from heart disease.

The amounts of fish oils in the studies ranged from about 500 mg to 2 grams, though the most common dose was about 1 gram daily. The researchers were not able to determine how different doses influenced the risk of death.

In contrast, three of the studies found a "neutral" effect from implantable cardiac defibrillators (ICDs), a particular type of pacemaker designed to prevent arrhythmias and sudden cardiac death. In other words, fish oils yielded far greater benefits compared with ICDs.

In a separate study, researchers reported similar benefits from taking fish oil supplements. Luigi Tavazzi, MD, of the ANMCO Research Center in Florence, Italy, and his colleagues tracked the health of 6,975 patients who were asked to take either 1 gram of fish oils or placebos daily for about four years.

All of the patients had been previously diagnosed with chronic heart failure. People taking fish oils had a 9 percent lower risk of dying from any cause, and an 8 percent lower risk of being hospitalized for cardiovascular disease.

"Our study shows that the long-term administration of 1 gram per day of omega-3 polyunsaturated fatty acids was effective in reducing both all-cause mortality and admissions to hospital for cardiovascular reasons," Tavazzi and the other researchers wrote.

Meanwhile, Tsuyuki noted that the first report on the health benefits of omega-3 fish oils was reported by Danish researchers in 1976. In that study, Inuit living in Greenland had a relatively low risk of heart disease if they consumed large amounts of fish oils.

References: Leon H, Shibata MC, Sivakumaran S, et al. “Effect of fish oil on arrhythmias and mortality: systematic review.” BMJ, 2008;338:a2831. GISSI-HF Investigators. “Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HR trial): a randomised double-blind, placebo-controlled study.” Lancet, 2008;372(9645):1223-1230.