The link between food and arthritis has been difficult to prove because of the difficulty inherent in study design. However, observations made over the last several decades point to trends that may be important. Multiple studies have suggested that rheumatoid arthritis symptoms could be reproduced by the reintroduction of certain foods and ameliorated by excluding these foods from the diet.
More recently, rheumatoid arthritis has been shown to worsen when there is an excessive amount of Omega-3 fatty acids in the diet. Excessive ingestion of feedlot beef, refined cooking oils and margarines result in an increase of inflammatory symptoms. Some evidence has linked the consumption of saturated fats found in whole milk, cheese, as well as other animal products such as red meat and poultry to worsening RA symptoms. (O'Banion DR. J Holistic Med 1982; 4: 49-57)
An interesting connection has been proposed by some researchers that a food allergy to high saturated fat foods, meat, dairy, omega-6 fatty acids, and refined vegetable oils may be responsible for some rheumatoid arthritis flares (Hicklin JA, et al. Clin Allergy 1980; 10: 463-470.)
For centuries, nightshade foods such as potatoes, eggplant, and pepper have been claimed to aggravate arthritis. Firm data here, though, is not compelling. Study design has been a drawback. Doing a randomized double-blind study using foods is exceedingly difficult.
Small studies evaluating the effects of foods in rheumatoid arthritis sufferers have continued to make a case for food being a significant inciting factor in disease. Studies performed by researchers have demonstrated that partial fasting with avoidance of animal fat, refined sugar, citrus fruits, preservatives, coffee, tea, alcohol, salt, and strong spices which were associated with symptoms led to a reduction of symptoms.
Another study published by Beri et al showed that an elimination and rechallenge diet provided significant improvement in 71% of patients tested. (Beri, D, et al Ann Rheum Dis 1988; 47: 69-72)
In another study, Darlington evaluated 70 patients with rheumatoid arthritis. By eliminating foods deemed to provoke symptoms, he was able to eliminate symptoms as well as need for medications in 19% of patients. Darlington also identified foods such as grapefruit, cheese, malt, coffee, beef, eggs, rye, oats, milk, oranges, bacon, tomato, peanuts, cane sugar, butter, lamb, lemon, and soy as causative factors. (Darlington LG. Rheum Dis North Am 1991; 127: 273-285)
A recent study suggested that a diet high in vitamin D such as is found with salmon, tuna, shrimp, sunflower seeds, eggs, and vitamin-D fortified milk may prevent rheumatoid arthritis. (Merlino, LA et al. Arthritis Rheum 2004; 50: 72-77)
The upshot of these studies indicates that perhaps dietary manipulation should be considered as a possible therapeutic intervention. Elimination of all foods believed to be causing symptoms followed by single food reintroductions to determine which foods might be the culprits seems a reasonable course of action. Foods such as corn, wheat, cow's milk, pork, oranges, oats, rye, eggs, beef, coffee, malt, cheese, grapefruit, lemon, tomato, peanuts, and soy seem to be the most common offenders.
In our office we have found the Immunolab assay (Fort Lauderdale, FL) to be useful in excluding food allergies as a potentially important contributing factor to arthritis symptoms.