Does Dairy Cause Arthritic Pain?

Q: Does the lactose in dairy products cause pain and stiffness in the joints of people with arthritis?

A: There is no known association between lactose in dairy products and arthritis; however, our understanding of the causes of and effects of diet on most types of arthritis is limited. At some point in the future, researchers could discover an important role for lactose or other nutritional components in the development of arthritis.

There are more than 100 types of arthritis and for most there is no known dietary connection. However, diet can play an important role for a few forms of arthritis:

• Gout—Attacks of gout can be triggered in susceptible people by alcoholic beverages and foods rich in purines (a common protein contained in DNA) examples of foods with a high purine content include sardines, liver, and other organ meats. Even among people with gout, though, the effect of food choices is usually small, perhaps because foods with the highest purine content are not particularly popular in this country. Recent studies suggest that newly diagnosed gout is more common among people who consume a lot of meat, seafood and high fructose corn syrup while risk appears to be lower among those with high intake of vitamin C and dairy products. Another connection between diet and gout is that the risk of developing gout climbs as your weight increases.

• Osteoarthritis—The risk of osteoarthritis is higher among overweight people and weight loss is routinely recommended for people with this type of joint disease. In addition, recent studies report an association between a diet low in vitamin D and a higher risk of osteoarthritis. However, increasing vitamin D in the diet is not thought to treat the condition, nor is it clear that low vitamin D actually causes or contributes to the development of osteoarthritis.

• Osteoporosis—This common condition is marked by low bone density and a tendency to break bones easily; once a bone breaks in the wrist, hip or spine (the most common sites for an osteoporotic fracture), osteoarthritis may eventually develop. A lifelong diet rich in calcium and vitamin D (including dairy products) can help prevent osteoporosis.

• Celiac disease—People with this condition have stimulation of their immune systems as a reaction to gluten, a common component of grains in the diet; the activated immune system may, in turn, attack the lining of the intestine, the skin (causing a rash), and the joints, causing joint pain or arthritis, among other problems. Most symptoms can be reversed by a restrictive (and difficult) diet that eliminates gluten. Although dairy products with additives may contain a significant amount of gluten, it is not lactose that causes problems for people with celiac disease.

Other than these specific conditions, the role of diet is not considered by most experts to be important in the management of the common forms of arthritis. Increasing certain foods or eliminating others has demonstrated no consistent benefit for arthritis sufferers, so, while I do routinely encourage a balanced diet (and calorie restriction for people who are overweight), I do not recommend that people with arthritis avoid foods containing lactose.

Robert Shmerling, M.D., is associate physician and clinical chief of rheumatology at Beth Israel Deaconess Medical Center and an associate professor in medicine at Harvard Medical School. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program and has been a practicing rheumatologist for over 25 years.