A new review has established that Omega-3 fatty acids taken in excess could have unintended health consequences.
“What looked like a slam dunk a few years ago may not be as clear cut as we thought,” said Norman Hord, associate professor in OSU’s College of Public Health and Human Sciences.
“We are seeing the potential for negative effects at really high levels of omega-3 fatty acid consumption. Because we lack valid biomarkers for exposure and knowledge of who might be at risk if consuming excessive amounts, it isn’t possible to determine an upper limit at this time.”
Recent studies have pointed to an increased risk of advanced prostate cancer and atrial fibrillation.
Omega-3 fatty acids have long been hailed as possessing anti-inflammatory properties, which is one of the reasons they can be beneficial to heart health and inflammatory issues. The study determined that 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, a concern when products are fortified with eggs, bread, butters, oil and orange juice.
“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.”
“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.
“Until we establish valid biomarkers of omega-3 exposure, making good evidence-based dietary recommendations across potential dietary exposure ranges will not be possible.”
Jenifer I. Fenton, Norman G. Hord, Sanjoy Ghosh, Eric A. Gurzell. Long chain omega-3 fatty acid immunomodulation and the potential for adverse health outcomes. Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA), 2013; DOI: 10.1016/j.plefa.2013.09.011