Study suggests fish oil supplements may increase risk of stroke and heart problems

New study indicates that fish oil supplements could heighten the likelihood of stroke and heart issues. Caution is advised regarding their consumption.

CNN - Fish oil supplements, renowned for their heart-boosting omega-3 fatty acids, are commonly taken daily to reduce the risk of cardiovascular disease. Approximately one-fifth of adults over 60 in the U.S. regularly consume these supplements to promote heart wellness.

However, a recent study reveals that regular consumption of fish oil supplements may actually elevate the risk of experiencing a first-time stroke and atrial fibrillation, particularly among individuals with good cardiovascular health. Atrial fibrillation, often described as a flutter or pounding sensation in the chest, is a type of arrhythmia. Dr. Andrew Freeman, a cardiologist at National Jewish Health in Denver, suggests that this study prompts the question of whether it's time to reconsider the use of fish oil supplements, given that they are rarely recommended by medical professionals and are not included in any guidelines from medical societies.

Fish oil only helped people with existing heart disease

The research examined information from more than 415,000 individuals aged 40 to 69 enrolled in the UK Biobank, a long-term study tracking the health of UK residents. About one-third of these participants, monitored for an average of 12 years, reported regular fish oil supplement intake. Among individuals without heart conditions, consistent use of fish oil supplements was linked to a 13% higher likelihood of developing atrial fibrillation and a 5% increased risk of experiencing a stroke, as outlined in a study published in BMJ Medicine on Tuesday.

Dr. Freeman highlighted concerns regarding over-the-counter fish oil supplements, citing issues of inconsistent quality and purity, along with potential contamination by heavy metals such as mercury commonly found in fish.

Moreover, Dr. Freeman noted, "Over-the-counter fish oil hasn't shown positive outcomes in studies over the past decade. Its effects range from neutral to potentially harmful, as seen with stroke and AFib. This isn't new." Surprisingly, the recent study discovered that individuals with pre-existing heart conditions had a 15% reduced risk of transitioning from atrial fibrillation to a heart attack and a 9% lower risk of progressing from heart failure to death when regularly using fish oil.

Dr. Freeman emphasized the use of prescription fish oil variants like Vascepa and Lovaza to mitigate risk factors such as high triglycerides in those with cardiovascular disease. However, he cautioned that even in prescription-strength, highly purified fish oil, the risk of AFib and sometimes stroke remains, warranting doctors' vigilance.

He concluded, "In general, the era of indiscriminately buying large quantities of fish oil pills from stores should end, but fish oil might still benefit individuals already battling illness."

Try to use food sources for omega-3s

Dr. Richard Isaacson, an Alzheimer’s prevention specialist at the Institute for Neurodegenerative Diseases in Boca Raton, Florida, emphasized the importance of careful consideration regarding fish oil. He stressed the necessity of testing omega-3 fatty acid levels, advocating for accessible finger-prick tests for accuracy and continued monitoring. 

Isaacson advised against unnecessary fish oil consumption, suggesting obtaining omega-3s from dietary sources like sardines and wild-caught salmon due to their high unsaturated fat content and lower mercury levels. He cautioned against farm-raised salmon due to potential water impurities.

Dr. Isaacson also recommends lake trout, mackerel, herring, and albacore tuna as excellent omega-3 sources. However, due to mercury levels, he advises limiting albacore tuna consumption to twice weekly. Non-fish options like algae, seaweed, chia seeds, edamame, flaxseed, hemp seeds, and walnuts are rich in omega-3s but in a different form. Studies suggest plant-based omega-3s might be less metabolically efficient in individuals with elevated omega-6 levels, commonly found in vegetable oils.

If supplements are needed

Experts assert that prescription omega-3 fatty acids surpass over-the-counter choices in terms of purity and quality, albeit at a higher cost. However, for those opting for OTC omega-3s, Dr. Isaacson offers guidance to his patients. He emphasizes the importance of freshness in fish oil, cautioning against purchasing from online or retail giants like Amazon or Costco.

"We advocate purchasing from only a select few reputable companies, directly from their websites," stated Isaacson. "The disparity in quality between fish oil stored in suboptimal conditions and freshly produced oil kept in a home refrigerator is significant."

The FDA doesn't regulate the supplement industry to ensure label accuracy or check for contaminants like bacteria, heavy metals, pesticides, plastic residues, and other impurities. However, some companies conduct testing, including nonprofit organizations like USP, ConsumerLab.com, and NSF International, which set widely accepted supplement standards. Consumers should seek out their labels on supplements before buying.

Source: CNN