"The dysfunctional immune response to excessive omega-3 fatty acid consumption can affect the body's ability to fight microbial pathogens, like bacteria," Hord said.
Generally, the researchers point out that the amounts of fish oil used in most studies are typically above what one could consume from foods or usual dosage of a dietary supplement. However, an increasing amount of products, such as eggs, bread, butters, oils and orange juice, are being "fortified" with omega-3s. Hord said this fortified food, coupled with fish oil supplement use, increases the potential for consuming these high levels.
"Overall, we support the dietary recommendations from the American Heart Association to eat fish, particularly fatty fish like salmon, mackerel, lake trout or sardines, at least two times a week, and for those at risk of coronary artery disease to talk to their doctor about supplements," he said.
"Our main concern here is the hyper-supplemented individual, who may be taking high-dose omega-3 supplements and eating four to five omega-3-enriched foods per day," Hord added. "This could potentially get someone to an excessive amount. As our paper indicates, there may be subgroups of those who may be at risk from consuming excess amounts of these fatty acids."
Hord said there are no evidence-based standards for omega-3 intake and no way to tell who might be at health risk if they consume too high a level of these fatty acids.
"We're not against using fish oil supplements appropriately, but there is a potential for risk," Hord said. "As is all true with any nutrient, taking too much can have negative effects. We need to establish clear biomarkers through clinical trials. This is necessary in order for us to know who is eating adequate amounts of these nutrients and who may be deficient or eating too much.
|Contact: Norman Hord|
Oregon State University