Fish Oil and Atrial Fibrillation

Researchers recently published an observational study on over 415,000 subjects in the UK Biobank database who took a fish oil supplement. During a follow-up period of almost 12 years, they statistically demonstrated a 13% increased hazard ratio (a measure over time of how often a particular event happens in one group compared to another group) in the development of atrial fibrillation in subjects. Atrial fibrillation is a type of arrhythmia, or abnormal heartbeat, that can result in extremely fast and irregular beats from the upper chambers of the heart. In those subjcts, there was a 5% increased risk of stroke.

The resultant impact was an attack on dietary supplements for being too easily available, leading to overconsumption, and questionable because of the lack of purity in dietary supplements. The Medscape Cardiology online section put out a video by a reputable researcher explaining who should take fish oil supplements. But if they’re so bad, why would she recommend them at all?

The other part of the results showed that if someone already had cardiovascular disease (CVD), the hazard ratio of developing major cardiac events was reduced if they took fish oil supplements. That’s why the expert made the video, taking the good and trying to make sense of it. Still, it gave the appearance of being a pitch for a pharmaceutical solution.

That’s the set-up for this week’s Memos. I’ll give you at least one of the questions you might have: Yes, this study tested only supplement use (and dietary intake) upon entrance to the study and nothing the rest of the 11.9 years, just like the multivitamin study from last week. But there’s so much more that I’ll cover on Saturday about the problems with this study. Just so you know, I’m still taking my fish oil supplements.

What are you prepared to do today?