Fish oil has had a great few years and a rough month. After fish oil was hailed by many as almost a miracle supplement for many ailments involving chronic inflammation like arthritis, this past month a single study showed that it could be associated with a slight uptick in prostate cancer risk. While the prostate study was the minority opinion of many studies showing the opposite, it made a big media splash. This week another study was just published that again touts the benefits of fish oil, now suggesting that fish oil reduces rheumatoid arthritis risk in women. Regrettably this one didn’t go viral.
Fish oil contains long-chain n-3 polyunsaturated fatty acids also known as omega 3s. These contain certain ingredients like EPA that can reduce inflammation. As a result, many studies have shown a benefit to arthritis patients who take fish oil. This new study prospectively examined more than thirty thousand women who were asked to fill out questionnaires about diet, including fish intake. There was a dose response relationship between the amount of fish oil consumed and the reduction in rheumatoid arthritis risk, with the highest fish oil consumption leading to a whopping 52% reduction in the risk of getting the disease. Is this the only study on the topic? A recent review of many studies showed that 6 of 14 randomized controlled trials linked fish oil supplements to reduced joint inflammation. A 2009 study looked at markers of inflammation in rheumatoid arthritis patients given fish oil supplements and found less swelling in these patients. A 2008 study showed a similar reduction in inflammatory biomarkers in healthy patients.
The upshot? Fish oil has had a great ride in the medical literature, with a raft of studies showing benefits that all revolve around decreased inflammation (heart, arthritis, cancers). One study went viral last month and drew attention away from hundreds of studies showing positive benefits. This week’s rheumatoid arthritis study is a nice reminder that the research needs to be looked at as a whole, not just the few studies that happen to draw the attention of our 24 hour news cycle.