Does diet play a role in arthritis?

Many people assume that diet has a lot to do with the development of certain diseases, including arthritis - after all, "you are what you eat." When it comes to arthritis, this notion may be largely myth.

While healthy diets may increase the chances of good health, current understanding of the most common forms of arthritis suggests a limited role of diet in prevention or treatment. While it is true that diet may affect certain joint disorders, our current understanding suggests a limited role of diet in most people with arthritis.

When diet can matter: Gout and celiac disease

For example, gout may be worsened by diets high in purines, a form of protein found in sardines, liver, and other organ meats, but this effect is rather weak for most people. Alcohol intake, if a major part of one's diet, plays a stronger role. Studies have linked the risk of developing gout with alcohol (especially beer), meat, and seafood intake. However, the large majority of people who drink beer or eat meat or seafood never develop gout. And for most gout sufferers, taking medications to treat or prevent gout tends to be more effective than trying to stick to a particular diet.

Patients with celiac disease, a condition in which there is an autoimmune reaction to gluten in the diet, occasionally have arthritis as part of the illness. Removal of gluten from the diet can reverse this condition.

Small role for diet in most common types of arthritis

For the more common forms of arthritis and joint pain (including degenerative arthritis, rheumatoid arthritis, lupus, tendinitis, and bursitis), there is not yet a clear connection to diet. Efforts to remove individual foods or add others in an effort to treat arthritis have met with inconclusive or disappointing results. Even so, the American College of Rheumatology's guidelines for the treatment of rheumatoid arthritis recommend a plant-based Mediterranean-style diet, in part because of its potential anti-inflammatory effect and cardiovascular benefits.

In the absence of a particular vitamin deficiency, no clear benefit from supplemental vitamins or nutrients has been established. Loss of excess weight may help to prevent or treat gout or degenerative arthritis, but it's not reliably effective.

A connection between your joints and your gut?

While diet may not cause most arthritis, the joints and the intestinal tract are closely linked in certain diseases. For example, inflammation of the joints (arthritis) and the intestinal tract (colitis, proctitis, ileitis) occur together in inflammatory bowel disease (IBD), a group of illnesses that includes Crohn's disease and ulcerative colitis. The cause of IBD is unknown.

While bowel problems are the major feature for most patients with IBD, up to 20% develop a type of arthritis that can be a serious cause of suffering and reduced function. When arthritis is present in IBD, it most commonly affects the spine (spondylitis) and/or one to three joints in the extremities, especially the ankles and knees. Some people feel better avoiding certain foods or modifying their diet when the colitis is active - for example, avoiding high-fat, high-fiber meals. But there is no single food or diet thought to trigger the disease or cause it to flare up.

The assumption that diet is closely connected to arthritis has probably gotten ahead of the science. As is true with many aspects of health and disease, This may be, at least in part, due to the appeal of having control: one can (presumably) control diet, so if dietary modifications helped, that would be a way to gain some control over the disease. On the other hand, accepting the unpredictability of a disease with no known cause and relying primarily on medications is much less appealing. It's certainly possible that diet matters more than is currently recognized, and we just do not yet have a good grasp of which diets matter in which diseases.

Ongoing research

It's worth mentioning that researchers continue to explore connections between diet, intestinal microorganisms (the microbiome), and various illnesses, including rheumatoid arthritis. While the potential connection between the microbiome and rheumatoid arthritis is a hot topic of research, we are only just starting to explore how modifications in diet might lead to changes in the microbiome to improve or even prevent arthritis.

It may be true that you are what you eat, but having arthritis or worrying that you may someday develop arthritis are not reasons to restrict your diet in most cases. Beyond the usual recommendations of maintaining a balanced diet and trying to achieve optimal body weight, the impact of diet modifications for most people with arthritis is uncertain at best. Of course, that could change - the day could come when a better understanding of the links between nutrition and disease changes routine dietary recommendations for people with arthritis. Given how limited our current understanding is, that day can't come too soon.