While fish oil supplements are widely used for heart health due to their omega-3 content, a recent study suggests they might not be as beneficial as previously thought. In the US, around 1 in 5 adults over 60 take these supplements regularly to protect their hearts. However, the study shows that for people with good cardiovascular health, regular fish oil use might increase the risk of experiencing a stroke or atrial fibrillation for the first time.
Atrial fibrillation (AFib or AF) is an irregular heartbeat that can feel like fluttering or pounding in the chest. "I can see the headline for this study as 'Fish oil supplements: Is it time to dump them or not?'" cardiologist, Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver told CNN.
"I say that because over-the-counter fish oil is very seldom recommended, is in none of the guidelines from professional medical societies, and yet that's what most people take," said Freeman, who was not involved in the study.
A large study involving over 415,000 people in the UK found a possible link between taking fish oil supplements and an increased risk of atrial fibrillation (irregular heartbeat) and stroke in people with no prior heart problems. The study followed participants for an average of 12 years. Researchers also noted that some over-the-counter fish oil supplements may not be pure or consistent and could contain contaminants like mercury.
"In addition, studies over the last 10 years have not been very positive for over-the-counter fish oil," he added. "Fish oil either has no benefit or in some cases it may harm, such as with stroke and AFib. So that's not new."
The study says that people with existing heart disease at the beginning of the research had a 15 % lower risk of progressing from atrial fibrillation to a heart attack and a 9% lower risk of progressing from heart failure to death when they regularly used fish oil.
Dr Freeman said prescription versions of fish oil, such as Vascepa and Lovaza, are used to counter risk factors such as high triglycerides, a type of blood fat, in people with cardiovascular disease risk.
"But even in the prescription strength, highly purified versions of fish oil, the risk for AFib and sometimes stroke has also been present and doctors are cautious about that," Freeman said.
"Overall, I would say that the days where people just go to the store and buy buckets of fish oil pills to keep them well should be over, but fish oil may still have a role in people who are already sick."
Alzheimer's preventive neurologist Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Boca Raton, Florida said that when it comes to fish oil, "the devil is in the details."
"First, we recommend testing for omega-3 fatty acid levels - there are finger-prick tests you can buy online which are accurate - and then you should continue to test. You don't want to take fish oil if you don't need it," he said.
Experts say people should try getting their omega-3 fatty acids from food sources. Algae and seaweed are decent nonfish sources of omega-3s as well. Chia seeds, edamame (soybeans), flaxseed, hempseeds and walnuts are other plant-based options that are high in omega-3s.
Experts say that prescription omega-3 fatty acids are superior to over-the-counter options.
