Review reaffirms benefit for omega-3 fatty acids
Tuesday, December 4, 2012. The December, 2012 issue of the Journal of Lipid Research published a review conducted by Donald B. Jump and his colleagues at Oregon State University's Linus Pauling Institute which concluded that omega-3 fatty acids (which include EPA, DHA and ALA), both from fish and supplements, do indeed help prevent heart disease and other conditions, despite widely publicized results of conflicting studies. "After decades of studying omega-3 fatty acids, it's clear that they have value in primary prevention of heart disease," stated Dr Jump, who is a professor in the OSU College of Public Health and Human Sciences. "It's less clear how much impact fish oils have in preventing further cardiovascular events in people who already have heart disease. 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 authors remark that observations from the 1970s concerning the low level of cardiovascular disease among Greenland Inuits, who consume large amounts of fish, may not have always been corroborated in recent trials involving members of societies in which drugs including statins, fibrates and antithrombotics are routinely used. "Some of the early studies done on fish oil were prior to so many effective medications being widely available and heavily used," Dr Jump explained. "And people often forget that nutrients, like fish oils, are less potent than prescription drugs, and often have their best value when used for extended periods. 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."
Another reason for some of the variation in current findings is attributed to differing sources of omega-3. Dr Jump and colleagues report that plant sources, including flax oil and chia seeds which are high in the omega-3 fatty acid alpha-linolenic acid (ALA), are less effective than fish due to how they are processed by the body, however, omega-3 from yeast and algae are of high quality. They also note that farm raised fish require omega-3 supplementation, which makes their omega-3 content less predictable than that of wild harvested fish.
Omega-3 fatty acids additionally have significant benefit for conditions other than cardiovascular disease and those, such as metabolic syndrome, that contribute to it. These conditions include visual acuity, cognitive development and decline, cancer prevention, and premature mortality.
"We still believe the evidence is strong that the EPA and DHA content in heart tissues and blood is important to health and to the prevention of cardiovascular disease," Dr Jump concluded.