Does eating fish help treat rheumatoid arthritis? This is the question we will try to answer in this edition of RheumDoctor Journal Club. Rheumatoid arthritis is a common autoimmune condition that affects about 1% of the population. This disease can cause joint pain, swelling, and stiffness, as well as inflammation throughout the body. Disease modifying antirheumatic agents (DMARDs) are the standard of care for the treatment of rheumatoid arthritis. These medications help slow and stop the progression of the disease. Some of these medications include methotrexate, hydroxychloroquine, sulfasalazine, as well as biologic medications such as etanercept, tofacitinib, tocilizumab, etc.
We know from research from the 80s, that omega-3 fatty acids also help to decrease rheumatoid arthritis inflammation. We learned from the studies that supplementation with 3 g of omega-3 fatty acids is effective in decreasing inflammation. However, the studies focused on supplementation, not the consumption of whole natural fish.[1] [2]
Relationship between fish consumption and disease activity in rheumatoid arthritis[3]
The objective of the study was to determine whether people who ate fish frequently tend to have lower rheumatoid arthritis disease activity. The researchers conducted a cross-sectional analysis from a large group of patients evaluating cardiovascular disease. Their outcome was the disease activity score known as the DAS28, as well as C-reactive protein (CRP). CRP measures inflammation throughout the body.
Patients completed a 120 item food questionnaire. Because we think long-chain fatty acids degrade when exposed to high heat, fried fish, non-fried shellfish, and fish in mixed dishes, the research did not count them. It could be boiled, steamed, baked, or eaten raw.
Results
176 people were included in the analysis. The majority of these people were middle-aged, college-educated white women, who are taking DMARDs and who were seropositive, and had rheumatoid arthritis for a long time.
19.9% of the people reported infrequent fish consumption (never to <1/month), 17.6% were frequent consumers (≥ 2 times/week). People who supplemented with fish oil were more likely to eat fish infrequently (20%). Interestingly, people who smoked cigarettes, were more likely to eat more fish
After adjusting for age and sex, people who consumed fish more than two times per week compared to those who ate fish infrequently, had lower disease activity scores and had lower CRP levels. Moreover, each additional serving of fish per week decreased both the disease activity score and the CRP. In a sensitivity analysis, the researchers found similar results after adjustments for biologic DMARDs and fish oil supplements. Further adjustment for smoking produced similar results.
What does this mean?
Simply put, eating fish two or more times per week may decrease rheumatoid arthritis activity as well as systemic inflammation. Although supplementing with fish oil also decreases inflammation in rheumatoid arthritis, there is something about eating fish as a whole natural food. One serving of fish almost certainly includes less than 5.5 g of omega-3 fatty acids given that an 8 ounce serving of fatty fish generally provides 2 to 4 g of omega-3 fatty acids. Whole natural fish has various macronutrients and micronutrients including omega-3 fatty acids that could be beneficial.
Then again, maybe people who regularly eat fish tend to have a healthier lifestyle. This could be the case, however, in this particular group, people who ate fish more regularly tended to smoke more. I think we can all agree that this isn’t the healthiest of lifestyle choices!
What we learned today
People who eat fish two more times per week compared to those who never eat fish or those who eat fish less than one time per month, tend to have lower rheumatoid arthritis, disease activity as well as systemic inflammation.
Eating non-fried fish on a regular basis is an important part of eating to beat rheumatoid arthritis.
Medical Disclaimer
This information is offered to educate the general public. The information posted on this website does not replace professional medical advice, but for general information purposes only. There is no Doctor – Patient relationship established. We strongly advised you to speak with your medical professional if you have questions concerning your symptoms, diagnosis and treatment.
References
[1] Kremer JM, Bigauoette J, Michalek AV, Timchalk MA, Linenger L, Rynes RI, Huyck C, Zieminski J, Bartholomew LE. effects of manipulation of dietary fatty acids on clinical manifestations of rheumatoid arthritis. Lancet. 1985 Jan 26;1(8422):184-7.
[2] Kremer JM, Lawrence DA, Petrillo GF, Litts LL, Mullaly PM, Rynes RI, Stocker RP, Parhami N, Greenstein NS, Fuchs BR, et al. Effects of high-dose fish oil on rheumatoid arthritis after stopping nonsteroidal anti-inflammatory drugs. Clinical and immune correlates. Arthritis Rheum. 1995 Aug;38(8):1107-14.
[3] Tedeschi SK, Bathon JM, Giles JT, Lin TC Yoshida K, Solomon DH. Relationship between fish consumption and disease activity in rheumatoid arthritis. Arthritis Care Res (Hoboken). 2018 Mar;70(3):327-332.
