Can Eating Fish Help Reduce RA Disease Activity?
When I was first diagnosed with rheumatoid arthritis (RA), it felt like everyone (and their mom!) encouraged me to try a gluten-free diet. I couldn’t find any scientific evidence that a gluten-free diet would necessarily help with RA, but there was a fair amount of anecdotal evidence from other patients and the symptoms of gluten sensitivity did seem eerily familiar. I figured it was worth a try, and I contentiously ate gluten-free for a full six months.
Unfortunately, in my personal experience, being gluten-free didn’t result in any improvements in my RA symptoms. Since then, I’ve honestly been pretty skeptical about any claims that changes to my diet could improve my RA symptoms – particularly when those claims lacked supporting scientific evidence. But recently the results of a new study caught my eye. This study suggests that eating fish more regularly may be associated with lower disease activity in people living with RA.
Looking at fish as a whole food and it's impact on RA
There has been some speculation that lower rates of RA in some countries may be related to cultural or environmental differences, including the frequency of fish consumption. While several past studies have looked at the potential benefit of fish oil supplements, this novel analysis focuses on fish as a whole food, with various macronutrients and micronutrients in addition to the omega-3 fatty acids found in supplements. The study, published in Arthritis Care & Research, looked at data from 176 people living with RA who were part of a larger study.
Participants completed a 120-item food frequency questionnaire, which asked how frequently they consumed “tuna fish, salmon, sardines (cooked or raw including sashimi or sushi)” and “other broiled, steamed, baked or raw fish (trout, sole, halibut, poke, grouper, etc.).” These types of fish were selected for the analysis due to their higher omega-3 fatty acid content, while other seafood items on the questionnaire (fried fish, non-fried shellfish, and fish in mixed dishes) were not considered in this study.
After controlling for age, sex, race, body mass index, smoking, education, and fish oil supplement use, the study found that eating fish more frequently may be associated with lower RA disease activity. Participants who consumed fish more than twice a week had a statistically and clinically significant reduction in their disease activity scores compared to participants who consumed fish less than once a month or never.
There are, of course, some caveats to this conclusion. First of all, this was an observational study – which means that it does not prove cause and effect. The group who consumed fish more than twice a week also had some baseline traits that are generally associated with improved disease activity, such as lower BMI and higher socioeconomic status. This means that, rather than the fish consumption directly causing lower disease activity, it’s possible that those who eat fish more often may just have generally healthier lifestyles. However, it’s also interesting to note that the high fish consumption group also had the highest prevalence of smoking, which is a risk factor for RA, yet they still had better disease activity scores than the low fish consumption group.
Another caveat is that participants in this study were predominately white, well-educated, married patients with longstanding RA, which isn’t exactly comprehensive or diversified. This means that the results may not turn out the same in different types of populations. So while the results are indeed promising, a randomized controlled trial would be required to provide firm evidence that greater fish consumption lowers rheumatoid arthritis disease activity.
In the meantime, these results were promising enough to remind me that fish is a healthy option for a lot of different reasons – and so I definitely ordered salmon for lunch today! After all, it couldn't hurt!
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