ScienceDaily (Nov. 16, 2009) "This soybean oil could be an effective alternative to fish oil as a source of heart-healthy omega-3 fatty acids," said William Harris, Ph.D., lead author of the study and chief of cardiovascular health research at Sanford Research/USD and professor of medicine at Sanford School of Medicine, University of South Dakota in Sioux Falls, S.D.
"We know that giving pure EPA to people reduces their risk for heart disease," he said. "Presumably, if you gave this special soybean oil to people, you'd do the same thing -- reduce heart attacks."
The American Heart Association recommends eating two servings per week of fatty fish which is high in EPA and docosahexaenoic acid (DHA), like mackerel, lake trout, herring, sardines, albacore tuna and salmon. Eating fish containing these omega-3 fatty acids has been associated with a decreased risk of cardiovascular disease.
Fish oil contains two forms of heart-healthy, long-chain omega-3s, EPA and DHA. However, many Americans don't like eating fish because of the taste, preparation and/or concern that it may be contaminated by mercury and other pollutants.
A few plants, particularly soybeans, produce oils that contain alpha-linolenic acid (ALA), which is another type of omega-3 fatty acid. The human body converts ALA to stearidonic acid (SDA), but this is a very inefficient process. The body converts SDA to EPA far more effectively, resulting in more EPA per gram consumed.
The researchers sought to bypass the ALA-to-SDA conversion step in the body by doing so in the soybean plant. They developed the new soybean variety by inserting one gene from another plant and one from a fungus to allow the soybean plant to produce SDA. The result is a soybean oil enriched in SDA, which when consumed allows the body to produce more EPA than if it started with ALA.
Harris and his colleagues recruited healthy volunteers in Cincinnati, Sioux Falls and Chicago into the double-blind study. "Our goal was to see if the oil from the genetically engineered soybean would raise red blood cell levels of EPA," he said.