(CBS News) Omega-3 fatty acid supplements like fish oil pills are taken by many to boost heart health, but new research suggests the pills aren't having their intended effects.
The study of nearly 70,000 people found taking omega-3 fatty acid supplements did not reduce a person's risk for heart attack, stroke, cardiac or sudden death or death from any cause.
Previous research has shown that omega-3 pills may be effective in staving off major heart problems because of the supplement's ability to lower triglyceride levels (fat in the blood), lower blood pressure, prevent against dangerous arrhythmias and decrease clotting.
According to the National Center for Complementary and Alternative Medicine, the capsules may also slow the progression of atherosclerosis (hardening of arteries) and reduce the risk of heart attack, stroke and death among people with heart disease.
The researchers also say that treatment guidelines from major medical societies recommend their use - either as supplements or through the foods they eat (such as fatty fish) - for patients after a heart attack. The American Heart Association recommends eating fatty fish at least twice a week for cardiovascular benefits and says people may want to discuss taking supplements with their doctor if they don't get enough omega-3 fatty acids from their diets.
For the study, led by Dr. Evangelos C. Rizos, a researcher at the University Hospital of Ioannina in Greece reviewed 20 rigorous trials that involved omega-3 polyunsaturated fatty acids. Of the large study pool, the researchers identified 1,837 heart attacks, 1,490 strokes, 3,993 heart-related deaths, 1,150 sudden deaths and 7,044 deaths.
The researchers found that people taking the supplements showed no statistically significant risk reduction when it came to these areas.
"Our findings do not justify the use of omega-3 as a structured intervention in everyday clinical practice or through dietary supplementation," the authors said.
Dr. David A. Friedman, chief of heart failure services at North Shore-LIJ Plainview Hospital in Plainview, N.Y. aptly chose to call the results "disheartening" in an interview with WebMD, and added, "It may be that food sources of omega-3, rather than supplements, are a better choice."
USA Today reports that Americans spent more than $1 billion on fish oil supplements in 2011.
Duffy MacKay, vice president for scientific and regulatory affairs at the industry trade group the Council for Responsible Nutrition, told USA Today his group disputed the findings, noting that several of the studies the researchers reviewed included people who were already sick so the findings may not apply to disease prevention.