Rheumatoid Arthritis: Nutritional Considerations

Rheumatoid arthritis may sometimes be ameliorated with proper diet. Studies have shown both symptomatic and laboratory evidence of improvement with vegetarian diets and various elimination diets. Omega–3 fatty acids may reduce pain and inflammation in RA. The key nutritional issues in RA are summarized below:

Vegetarian Diets

A body of evidence indicates that patients who follow vegan or vegetarian diets may experience significant improvement in rheumatoid arthritis symptoms. Improvement in laboratory values (rheumatoid factor, CRP) is a frequent finding on these diets, and correlates with a reduction in antibodies to food antigens.^2,3 Conversely, higher intakes of meat^4,5 and elevated serum cholesterol concentrations⁶ are associated with increased risk of developing this disease. Patients with RA are known to be at higher risk for cardiovascular disease and have higher serum levels of oxidized low–density lipoprotein (LDL).⁷

Eliminating Diet Triggers

Clinical tests have shown that consumption of allergenic foods increases pro–inflammatory chemicals (cytokines) that are considered a hallmark of RA.⁸ Studies have shown that eliminating certain foods brings symptomatic improvement.^9,10 To identify trigger foods, an elimination diet can easily be instituted on an outpatient basis. The procedure is as follows:

Start with a simple baseline diet, excluding foods that are more common triggers (dairy products, corn, meats, wheat, oats and rye, eggs, citrus fruits, potatoes, tomatoes, nuts, and coffee), and including only those foods not implicated in arthritis, listed below:

• Brown rice.
• Cooked or dried fruits (cherries, cranberries, pears, prunes).
• Cooked green, yellow, and orange vegetables (artichokes, asparagus, broccoli, chard, collards, lettuce, spinach, string beans, squash, sweet potatoes, tapioca, and taro).
• Plain or carbonated water.
• Condiments (modest amounts of salt, maple syrup, vanilla extract).

After approximately 4 weeks on this diet, if symptoms have improved or disappeared patients may introduce previously eliminated foods one at a time, every 2 days. Patients should keep a food diary and add these foods in generous amounts to observe which cause arthritic symptoms. Foods listed above as common triggers should be added last. A newly added food associated with increased joint pain should be removed from the diet for 1 to 2 weeks, and reintroduced to see if the same reaction occurs. If no symptoms are experienced, that food can be kept in the diet.

Antioxidants

Poor antioxidant status may be a risk factor for RA.¹¹ Studies have shown that a higher intake of certain carotenoids found in fruits and vegetables may protect against developing RA.^12,13 Foods containing beta–cryptoxanthin (eg, citrus fruits) and zeaxanthin (eg, green leafy vegetables) may be particularly helpful. The European Prospective Investigation of Cancer (EPIC)–Norfolk study of more than 25,000 individuals found that those consuming the highest amounts of these carotenoids had half the risk for developing inflammatory polyarthritis, compared with those consuming the least amount.¹⁴ Lower serum levels of vitamin E and selenium were also found to predict the development of rheumatoid arthritis.¹⁵

Oil Intake

A diet low in arachidonic acid, an omega–6 fatty acid found in animal products, was found to ameliorate inflammation in patients with RA.  This effect was strengthened by omega–3 fatty acid supplementation,¹⁶ Studies have also found a lower incidence of arthritis in Mediterranean countries, which may be attributable to olive oil intake4,¹⁷ possibly because this fat negates the production of pro–inflammatory chemicals that affect RA patients. Supplementing with gamma–linolenic acid (GLA) was found to be an effective strategy for reducing the symptoms of RA,¹⁸ and supplementation with a combination of GLA and omega–3 fatty acids was found to both reduce symptoms and decrease the need for NSAIDs in RA patients.^19,20 These fatty acids appear to work by blocking production of arachidonic acid–derived inflammatory mediators, an effect that is achievable with vegan diets as well (see above).

Folic Acid

Patients with RA are often treated with methotrexate, a folate antagonist that can increase plasma homocysteine concentrations.²¹ Folate supplementation is recommended to prevent methotrexate–induced toxicity, folate deficiency, and hyperhomocysteinemia.²²

Orders

Vegetarian diet, nondairy, to be tried on a prospective basis.   

Nutrition consultation: to advise patient in the above diet, consider elimination diet to evaluate for occult food allergies, and arrange follow–up to assist patient in long–term dietary modifications.

Physical therapy consultation: To recommend an individualized exercise program.

What to Tell the Family

Rheumatoid arthritis can be ameliorated through dietary measures and medication as needed to control symptoms. Due to the strong hereditary component of RA, family members may benefit from a similar diet. The patient should stay physically active through regular low–impact exercise, light strength training, and range–of–motion exercises. Exercises learned in physical therapy should be incorporated into the daily exercise routine.