In 1981 the British Medical Journal reported the story of a London woman who had lived with severe arthritis for 25 years when she tried eliminating corn products from her diet. After one week the woman began feeling better than she had in years.

Six weeks later, however, her joint pain returned with a vengeance. The doctors and the woman were understandably disappointed. But then an explanation came to light. Around the same time the woman’s arthritis flared, the cook who prepared her food had begun using cornstarch as a thickening agent. Once the cornstarch was eliminated, the woman’s symptoms improved again – this time for good.

When your body’s wracked with pain, stories like this are pretty compelling. The prospect of easing your arthritis simply by giving up certain foods seems like a small sacrifice. But is giving up foods necessary? Is it safe? Is it likely to help?

Aside from gout, a form of arthritis known to be exacerbated by rich food and alcohol consumption, there are no clear-cut answers. While diet studies in peer-reviewed journals are scarce and largely negative, the answers to the food-arthritis question vary, depending on whom you ask or what you read.

The role of diet is one of the most written about, talked about and hotly debated subjects related to arthritis. In fact, in her book, Diet and Arthritis, British rheumatologist and arthritis researcher Gail Darlington writes, "There is probably more controversy, misunderstanding and conflicting advice about this subject than any other medical issue."

Much of this advice can be found in the abundance of recent books on the subject – Dr. Darlington’s included. While most of these books offer advice on what people with arthritis should eat, there is nearly as much advice on what they shouldn’t.

Controversies and Theories

The idea that certain foods might exacerbate arthritis is hardly new. As early as the 1960s certain people swore by food-elimination regimens such as the nightshade or Dong diet. The nightshade diet cuts out all of the so-called nightshade vegetables, which include such common foods as eggplant, bell pepper, potatoes and tomatoes. The Dong diet, even broader, forbids all additives, preservatives, fruits, red meats, herbs, alcohol and dairy products.

Such diets continue to draw devotees. But most doctors, including Isadore Rosenfeld, MD, author of Doctor, What Should I Eat? (Warner Books, 1996) write them off as fads – and, in the case of the Dong diet, an unhealthy way of eating.

"I don’t know of any scientific studies substantiating the claims made on [the Dong diet’s] behalf, nor can I recommend any diet, including this one, that would have you shun fruit," Dr. Rosenfeld writes. "After all, arthritis is a chronic condition, and no one should go through life without fruit."

More widely acknowledged is the theory that certain groups or types of foods are more likely than others to influence arthritis symptoms, but which foods from these groups bothers which individual varies. The theory is that certain foods trigger allergic-like reactions in people who have allergies or sensitivities to them.

Exactly how a food allergy might influence arthritis is not known, but some doctors have their speculations, says Neal Barnard, MD, author of Foods that Fight Pain (Harmony Books, 1998). Dr. Barnard is also president of the Physicians Committee for Responsible Medicine, a non-profit organization that promotes preventive medicine and conducts nutritional research, especially on vegetarian diets.

What some scientists suspect, says Dr. Barnard, is that certain food proteins can elicit the production of antibodies in some people. The antibody may join with the food protein (called an antigen) to form an antigen-antibody complex that irritates the joints. Another possibility is that the antibody itself may start attacking the synovium or lining of the joints.

A Common Problem?

While most scientists believe food sensitivities could – and probably do for certain people – play a role in inflammatory arthritis, they disagree on just how common the problem is. Dr. Darlington, for one, says that about 36 percent of her patients with "rheumatoid-like arthritis" (which includes diseases that appear to be RA, but haven’t been confirmed) do so well on elimination diets that they are able to stop taking drugs. That figure falls within the rage of Dr. Barnard’s estimate of about 20 to 60 percent.

Others, including Richard Panush, MD, who has conducted several published studies on the arthritis-food relationship, believe the percentage is a lot lower.

In one of the most widely cited studies on food sensitivities and arthritis, which was published in the Journal of Rheumatology, Dr. Panush fed 16 patients foods to which they suspected they were allergic in coded capsules. Neither he nor the patients knew which foods they were consuming.

The 16 patients were chosen from 100 screened. "These were people who swore up and down that a particular food caused their arthritis," says Dr. Panush, who is chairman of the department of medicine at St. Barnabas Medical Center in Livingston, N.J. But the study suggested otherwise. When challenged with capsules of the suspected offenders, only three patients actually became symptomatic. There was little change – positive or negative – in the rest of the patients.

Furthermore, the patients for whom diet did make a difference all had seronegative disease (meaning that their blood tested negative for rheumatoid factor, an antibody associated with RA), and none had joint damage. The results of the study led to Dr. Panush to conclude that dietary changes are most likely to help people with seronegative and nonerosive disease – in other words, people with mild, intermittent symptoms, not typical of RA.

Why the Difference?

So how can scientists trying to understand the same problem have such different conclusions about its prevalence? There are a number of factors that make the role of food allergies hard to pin down.

First is what doctors call the placebo effect. It’s the degree to which the expectation of an effect will actually bring on the effect. For example, let’s say you suspect an allergy to pizza sauce. In that case, just knowing you had eaten pizza sauce might be enough to make you feel worse. Conversely, knowing that you hadn’t eaten pizza sauce could make you feel better.

But if you were to unknowingly eat pizza sauce would you still feel worse? Or if you thought you had eaten it but hadn’t, would your arthritis feel better? Understandably it’s hard to say. It’s equally hard – yet certainly possible – to design a study in which the participants don’t know what they’re eating. Few scientists have been able to pull off such studies.

Another factor is the natural course of arthritis itself. Because the condition waxes and wanes, it can be difficult to determine whether an improvement or exacerbation following a dietary change is really related to the dietary change or not.

Finally, it may be difficult to know exactly which ingredient in a food is problematic. Returning to our original pizza sauce example, suppose you decided to eliminate all tomato-based products from your diet, not knowing that your problem was caused by, say, oregano. If, after eliminating tomatoes, your arthritis didn’t improve, you might incorrectly assume that you never had a food allergy.

Why? Why Not?

Regardless of the problem’s prevalence, at least some people may benefit from eliminating certain foods from their diet. So shouldn’t you at least give it a try? The answer to that varies too – from Dr. Barnard’s "absolutely" to other physicians’ emphatic "no."

Ronenn Roubenoff, MD, for one, warns that elimination diets can be harmful, causing people to give up nutritious foods at a time when they need them most.

"Research [at the USDA Human Nutrition Research Center on Aging] has shown that people with inflammatory arthritis lose muscle mass and gain fat mass," says Dr. Roubenoff, a rheumatologist and associate professor of medicine, nutrition and community health at Tufts University in Boston. "This change is accompanied by alterations in body metabolism that are driven by the immune system."

Because of this increased metabolic stress, Dr. Roubenoff encourages patients to eat a balanced diet – possibly with more protein than they would otherwise consume. "For the great majority of patients," he says, "the damage done by restricting the diet vastly outweighs the possible benefit of avoiding food allergies."

Dr. Panush, too, is skeptical of elimination diets. Though he is no longer conducting food research, he continues to conduct literature reviews on the subject, and what he has seen has not convinced him.

"As a scientist, I believe we need to study the issue more before we can recommend it to patients," Dr. Panush says. "I think we still need more data to better understand which patients may be affected by certain diets and how."

Finding the Culprit

Nevertheless, if you suspect a certain food, such as tomatoes, is exacerbating your arthritis, it certainly couldn’t hurt – or be too hard – to eliminate tomatoes from your diet for a few weeks and see what happens. But if you want to try a true elimination diet, it can be a long, tedious process. Yet it is the only way to determine if you have a sensitivity to a certain food.

Although the precise way of conducting an elimination diet varies, most diets begin with a fast, or exclusion, phase during which you can eat or drink only a limited number of beverages and foods.

After seven to 10 days, typically, you can start adding back single foods, about one every three days, says Dr. Barnard. Each time you add a food, observe your body for any change in symptoms. If your symptoms get worse, stop the new food and perhaps try it again at some point to see if a pattern occurs. If your symptoms are unchanged, you can assume the food is safe.

Good Advice

Should you decide to proceed with an elimination diet, experts offer the following advice:

• Consult your doctor. Make sure you have a proper diagnosis. If you have a problem such as infectious arthritis that should be treated with antibiotics, for example, an elimination diet won’t help.
• Don’t stop your medications. If you rely on medications to control joint or organ damage, abandoning them while you experiment with foods could cause arthritis flares or permanent joint or organ damage.
• Go one at a time. After completing the elimination phase, introduce new foods slowly. If you add more than one and then have a reaction, it will be difficult to determine which food was responsible.
• Find alternative sources of nutrients. You may want to take a multivitamin supplement or consume additional foods with the same nutrients and the ones you’re eliminating.
• Keep a diary. Document any change in symptoms, along with information of what you ate and when.
• Know when to give up. An elimination diet just may not work. If you don’t experience relief with any combination of foods, stop the diet and resume with a healthy, balanced diet, such as those recommended by the American Heart Association (online at www.americanheart.org or call 800/242-8721) or the American Cancer Society (also on the Web at www.cancer.org or 800/ACS-2345). Although such a diet may not help your arthritis directly, it can prevent other problems – ranging from heart disease to colon cancer – which you certainly don’t need in addition to arthritis.