Several past trials have tested the effect of fish oil supplementation for patients who are living with rheumatoid arthritis. Now a new study suggests that lower disease activity may be associated with higher intake of fish as a whole food.
Researchers found a statistically and clinically significant reduction in Disease Activity Score 28 using C‐reactive protein (DAS28-CRP) among participants with rheumatoid arthritis who consumed fish more than twice a week, compared with those who consumed fish less than once a month or never.
“Our observed difference in DAS28-CRP of 0.49 between the highest and lowest categories of fish consumption is approximately one-third the magnitude of previously reported pre- and post-treatment differences in DAS28 among methotrexate users,” said the study authors, led by Sara K. Tedeschi, MD, MPH, of Brigham and Women’s Hospital and Harvard Medical School.
They reported their findings in a recent issue of Arthritis Care and Research.
This novel investigation of the relationship between consuming fish as a whole food and rheumatoid arthritis disease activity was conducted as a cross-sectional analysis using baseline data from participants in the Evaluation of Subclinical Cardiovascular Disease and Predictors of Events in Rheumatoid Arthritis (ESCAPE-RA) cohort study. The ESCAPE-RA study enrolled adults aged 45 to 84 years who met the American College of Rheumatology 1987 rheumatoid arthritis classification criteria.
Participants completed a 120-item food frequency questionnaire, which assessed diet over the past year. For each item, frequency of consumption was recorded on a 9-point scale, ranging from “never to less than once a month” to “twice a week or more.” Participants also indicated small, medium, or large servings for each item, which allowed total average energy per day to be calculated.
For the current study, frequency of fish consumption was calculated using 2 items: “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 categories were selected because of their higher omega-3 fatty acid content compared with other seafood items on the questionnaire. Fried fish, non-fried shellfish, and fish in mixed dishes were not included for the purposes of this study.
Of 176 participants, 35 (19.9%) reported infrequent fish consumption (never to less than once a month); 31 (17.6%) were frequent consumers (twice a week or more).
Linear regression models tested the relationship between frequency of fish consumption and DAS28-CRP. All models were adjusted for total average energy consumed per day. After adjusting for age and sex, DAS28-CRP was significantly lower, by an average of 0.65, among participants consuming fish twice a week or more compared with those eating fish less than once a month or never.
Tedeschi SK, Bathon JM, Giles JT, et al. “The relationship between fish consumption and disease activity in rheumatoid arthritis.” Arthritis Care Res (Hoboken). 2017 Jun 21. doi: 10.1002/acr.23295. [Epub ahead of print]