Washington: Excess intake of omega-3 fatty acids - found in fish, walnut and spinach - could alter immune function and affect the body's ability to fight microbial pathogens, like bacteria, scientists, including one of Indian-origin, have warned. "We are seeing the potential for negative effects at really high levels of omega-3 fatty acid consumption," said Norman Hord, from Oregon State University's College of Public Health and Human Sciences and a coauthor on the paper. Previous research led by Michigan State University's Jenifer Fenton and her collaborators found that feeding mice large amounts of dietary omega-3 fatty acids led to increased risk of colitis and immune alteration.
As a follow-up, in the journal Prostaglandins, Leukotrienes & Essential Fatty Acids, Fenton and her co-authors, including Hord, reviewed the literature and discussed the potential adverse health outcomes that could result from excess consumption of omega-3 fatty acids. Studies have shown that omega-3s, also known as long chain polyunsaturated fatty acids (LCPUFAs), are associated with lower risk of sudden cardiac death and other cardiovascular disease outcomes. The researchers found excess amounts of omega-3 fatty acids can alter immune function sometimes in ways that may lead to a dysfunctional immune response to a viral or bacterial infection. "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. The researchers noted 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," he said. "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. Sanjoy Ghosh from University of British Columbia Okanagan and Eric Gurzell from Michigan State University also contributed to this study.
