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Can Rheumatoid Arthritis Be Modified with an Anti-inflammatory Diet?

January 23, 2020
Recent papers suggest that certain regimens, such as the Mediterranean Diet, may in fact lower disease activity and painful inflammation.

Control of inflammation has been identified as one of the most important methods of achieving treatment goals in patients with rheumatoid arthritis (RA). Indeed, research has indicated that an anti-inflammatory diet can lower inflammation and control symptoms, and this type of diet is commonly recommended for patients with RA on various patient counseling websites. The Mediterranean Diet, in particular, has recently been noted as the best overall diet for all individuals in consumer reports,1 and from a clinical perspective, the diet’s emphasis on increasing intake of polyunsaturated fats, which are rich in omega-3 fatty acids, may have significant implications for RA and other autoimmune disorders.

Omega-3 fatty acids are known to have a beneficial effect on inflammation, as omega-3 fatty acid supplementation lowers inflammatory markers such as C-reactive protein, interleukin-6, and tumor necrosis factor.2 In addition to having an effect on inflammation, omega-3 fatty acids as well as the ration of omega-6 to omega-3 fatty acids have been shown to have an inverse association with pain in patients with RA that is independent of any anti-inflammatory effects.3

Some trials suggest that the Mediterranean diet improves clinical scores in patients with rheumatoid arthritis. (Image: iStock)

Mediterranean Diet May Impact Disease Activity

The most recent annual meeting of the American College of Rheumatology (ACR), held in November 2019, highlighted several studies which examined the clinical and molecular benefits of an anti-inflammatory diet in patients with rheumatoid arthritis. In one study, Ingegnoli and colleagues investigated the association between patient adherence to the Mediterranean diet and disease activity, general health, and comorbidities.4 A significant positive correlation was found between high scores on a self-reported questionnaire called the MD score and patient general health. A negative correlation was also found with Mediterranean diet adherence and the Disease Activity Score on 28 joints (DAS28) and the Simple Disease Activity Index (SDAI), which, although not statistically significant, suggested an association between a higher MD score and lower disease activity.

The authors concluded that the Mediterranean diet may provide an overall beneficial effect in patients with RA, although further study is warranted to understand the role of specific lifestyle modifications in achieving disease control.

Fish Oil May Lower Disease Activity and Remission Scores

Another study by Brown and colleagues examined whether supplementation with fish oil, a key source of omega-3 fatty acids, would improve RA outcomes in those with early disease, as measured by DAS28 remission and DAS28 low disease activity (LDA) scores.5 In this study, patients who had their disease for less than 1 year were initiated on triple therapy with methotrexate, sulfasalazine, and hydroxychloroquine and advised to take fish oil supplements at anti-inflammatory doses. At the 12-month visit, prognostic variables for DAS28 remission and DAS28 LDA were identified using logistic regression models, correcting for potential confounding variables. Omega-3 status was assessed as levels of plasma eicosapentanoic acid (EPA).

After one year, 57.76% of patients reached DAS28 LDA and 43.7% were in DAS28 remission. Increases in plasma EPA were associated with an increase in the odds of having low disease activity (OR = 1.28; P < 0.0001) and remission (OR = 1.22; P < 0.001). Researchers also found that being overweight decreased the odds of having low disease activity in current and former smokers. However, they concluded that although lifestyle modification in general is important, among all prognostic factors fish oil supplementation provided the greatest benefit.  

Anti-Inflammatory Diet Shows Clinical and Biological Correlations after Two Weeks

In another study presented at the ACR 2019 annual meeting, Cedola and colleagues correlated clinical measures of RA with changes in pro and anti-inflammatory oxylipins,6 which have been identified as compounds derived from polyunsaturated fatty acid oxidation important in the resolution of acute inflammation. After two weeks of an anti-inflammatory diet, changes in circulating oxylipins were noted and could be positively correlated with clinical measurements.

Patients with a diagnosis of RA and at least three tender and three swollen joints who had no medication changes within the previous three months were offered a two-week anti-inflammatory diet that was intended to increase the omega-3:omega-6 fatty acid ratio.

“Some trials suggest that the Mediterranean diet improves clinical scores in RA. In our trial, we included several anti-inflammatory nutrients,” Monica Guma, MD, PhD, associate professor of medicine and rheumatology researcher at UC San Diego, told PPM. The diet included such anti-inflammatory items as turmeric, anti-oxidants, and prebiotics and probiotics. Patients were also instructed to eliminate pro-inflammatory ingredients, such as lactose, gluten, and red meat.

Trends in clinical changes were measured from two weeks before the start of the diet (visit 1) until the start of the diet (visit 2) and again from the start of the diet until two weeks later (visit 3). Serum oxylipins were determined by mass spectrometry before and after the diet.   

Patients showed good adherence to the diet and, after two weeks, several clinical outcomes were significantly lower. These included the number of tender and swollen joints; Health Assessment Questionnaire and assessments of pain, fatigue, global disease severity, and composite measures of peripheral arthritis (DAS28-CRP and Clinical Disease Activity Index). Several pro and anti-inflammatory linoleic acid-derived oxylipins significantly changed after two weeks of the diet. These results suggest that oxylipins could play a role as mediators of anti-inflammatory changes as demonstrated by the clinical effects seen in the patients.

Counseling Patients

An anti-inflammatory diet emphasizes increasing foods that reduce inflammation and minimizing foods that promote inflammation in the body. Inflammation promoters include trans fats, saturated fats, red meat and egg yolks, which are rich in arachidonic acid, and high-glycemic carbohydrates.

Clinicians can advise their patients to eliminate partially hydrogenated oils, margarine, and vegetable shortening; limit saturated fats and omega-6 fats contained in vegetable oils; limit refined and processed carbohydrates and increase fiber intake. Several online resources, particularly those published by the Scripps Center for Integrative Medicine and the Chopra Center, are available with specific recommendations on which foods to modify to reduce inflammation.7,8


Last updated on: January 23, 2020
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