Conflicting study findings on the health benefits of fish oil may have confused many consumers in recent years, but a new analysis of research argues that consumers can bank on strong scientific evidence that shows — with very little doubt — that omega-3 fatty acids found in fish can prevent heart disease.
The analysis, by scientists in the Linus Pauling Institute at Oregon State University and published in the Journal of Lipid Research, reviewed the competing findings of hundreds of clinical trials, including some that have gained widespread media attention, on the benefits of omega-3 fatty acids for the prevention of heart disease.
"After decades of studying omega-3 fatty acids, it's clear that they have value in primary prevention of heart disease," said lead researcher Donald Jump, an investigator in the Linus Pauling Institute and professor in the OSU College of Public Health and Human Sciences.
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"It's less clear how much impact fish oils have in preventing further cardiovascular events in people who already have heart disease," Jump said. "The studies done several decades ago showed value even for that patient population, but the more recent studies are less conclusive. We believe that one explanation is the effectiveness of current state-of-the-art treatments now being offered."
The review came to several key conclusions:
• Fish consumption and dietary omega-3 fatty acid supplements help prevent heart disease.
• Some fatty acids, from certain sources, are more effective than others.
• These compounds may have enormous value for serious health problems other than heart disease.
• The very effectiveness of modern drug therapies for heart disease may be one explanation for the conflicting findings on the benefits of omega-3 fatty acids.
• An important type of omega-3 fatty acid for human health is DHA, which is the predominant omega-3 fatty acid that accumulates in tissues.
• Plant-derived sources of fatty acids, such as flaxseed oil or chia seeds, have less benefit than those from cold-water fish.
• For individuals unwilling or unable to consume fish or fish-oil supplements, some products made from yeast or algae are high quality.
Jump noted millions of people at risk for cardiovascular disease now take medications such as statin drugs for high cholesterol, fibrates for high triglycerides, and other drugs with anti-inflammatory or anti-arrhythmia effects. Fish oils can have positive effects on virtually all of these same cardiovascular risk factors, Jump said, but so can the drugs.
"When so many people in these studies are taking a regimen of medications to address the same issues that fish oil might also affect, it's easy to understand why any added benefit from the fish oils is more difficult to detect," he said.
SPECIAL: These 4 Things Happen Right Before a Heart Attack — Read More.
He also noted research has linked omega-3 fatty acids to other health benefits, including improved vision and cognitive function, as well as reduced risks of dementia, inflammation, and even some types of cancer.
The analysis was funded by the U.S. Department of Agriculture and the National Institutes of Health.