In at least some rheumatoid arthritis sufferers, the pain they feel may be an allergic reaction to a common group of food plants known as nightshades. Potatoes, tomatoes, peppers, zucchini, and eggplants are members of the same group of plants that has been implicated in arthritis pain.

Luckily, this problem is an easy one to identify; the sufferer simply needs to try an elimination diet for a few days. Here's what to do: eliminate all these foods from your diet for a week; then, one by one, add the foods back to your diet. If you're sensitive to any of these items, you'll most likely end up having a reaction to the food that mimics your arthritis pain, perhaps in addition to other physical symptoms.

So what if you're a meat and potatoes man, or your favorite comfort food is a big plate of pasta and marinara sauce? Do you have to give up all of your favorite foods forever? Maybe not. Try a second phase of the elimination diet, avoid all nightshades and then test one food at a time, for several days, before going on to the next. (Make sure you avoid all nightshades for at least four days between each test, and only include one of these foods at a time.) You may find that you can tolerate some members of the nightshade group better than others; and that you can tolerate potatoes, for instance, for two or three days in a row before you have a reaction.

Once you've defined the level of tolerance that you have for your favorite foods, develop a rotation diet based on your new knowledge. You may want to eat only one member of the nightshade group on a certain day; you may want to keep track of when you eat these foods and only eat them every three or four days. Of course, if you react to a particular food like peppers after a single instance of exposure, it's wise to eliminate those from your diet completely.

You may find that your arthritis pain disappears completely, or that the pain lessens once you've eliminated or reduced your use of the offending foods. But before you throw away prescribed pain or anti-inflammatory medication or begin to change your behavior (boosting your exercise routine or other activities, for instance), have a serious talk with your doctor. Discuss your allergies, discuss his or her plans for ongoing treatment of your health issue, and come to an understanding of how to proceed. Arthritis is a serious chronic, and sometimes progressive, illness, and you need professional help to manage it, even if you've succeeded in controlling the symptoms with diet.