October 29, 2013
Excessive Omega-3 Fatty Acid Intake Could Be Harmful To Your Health
redOrbit Staff & Wire Reports - Your Universe Online
While the consumption of omega-3 fatty acids has been previously associated with positive health effects, new research the journal Prostaglandins, Leukotrienes & Essential Fatty Acids suggests that excessive amounts of the substances could have negative consequences.
Previous research has linked omega-3s with a reduced risk of cardiovascular death and other cardiovascular disease outcomes, and WebMD reports that there is “strong evidence” that they can help lower triglycerides and blood pressure, the researchers believe that health organizations should establish dietary standards based on the best currently available evidence.
“What looked like a slam dunk a few years ago may not be as clear cut as we thought,” study co-author Norman Hord, an associate professor in the Oregon State University’s College of Public Health and Human Sciences, said in a statement Monday.
“We are seeing the potential for negative effects at really high levels of omega-3 fatty acid consumption,” he added. “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.”
Three years ago, research led by Michigan State University assistant professor Jenifer Fenton found that feeding mice large amounts of dietary omega-3 fatty acids (also known as long chain polyunsaturated fatty acids or LCPUFAs) could increase those rodents’ risk of immune system alteration and colitis. The newly published paper is a follow-up to that research.
As part of the new study, Fenton, Hord and their colleagues reviewed literature pertaining to omega-3 fatty acids, and discussed the potential adverse health outcomes that could potentially result from excessive LCPUFA consumption. Fenton explained that their work was inspired by recently published studies demonstrating “increased risk of advanced prostate cancer and atrial fibrillation in those with high blood levels of LCPUFAs,” Fenton said.
Omega-3 fatty acids have been found to have anti-inflammatory properties, which is one of the reasons that they are believed to be effective against inflammation and beneficial to heart health, the researchers said. However, they also found that excess amounts of LCPUFAs can negatively impact immune function, potentially leading to a dysfunctional response to viral or bacterial pathogens.
“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,” the university said. “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. 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 noted that there are currently no evidence-based standards for how much omega-3 is safe to consume, and that it isn’t possible to tell who could be at risk if they allow too much into their systems. He added that while they are not against taking fish oil supplements, that overdoing it could potentially be harmful to a person’s health.
“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,” Hord said. “Until we establish valid biomarkers of omega-3 exposure, making good evidence-based dietary recommendations across potential dietary exposure ranges will not be possible.”