Researchers have looked at the roles diet may play in arthritis. There are some scientific reasons to think that the foods you eat could affect certain kinds of arthritis. Evidence shows that excessive weight and the type of diet you follow may influence symptoms of certain types of arthritis and related conditions.

However, all persons with arthritis, young and old, can benefit from eating a healthy, well-balanced diet. This includes a variety of foods; plenty of vegetables, fruits and whole-grain products; and sugar, salt and fat (especially saturated fat found in animal products) in moderation. Taking the recommended daily amounts of vitamins and minerals also is an important part of a healthful diet. A good diet promotes overall health and helps to control weight.

What We Already Know
Research has shown several connections between food, nutritional supplements (vitamins, minerals and omega-3 fatty acids) and certain forms of arthritis or related conditions, such as gout, osteoporosis, osteoarthritis, rheumatoid arthritis, or RA, and reactive arthritis.

How Researchers Test Diets
To determine the effects of a particular diet on arthritis, researchers divide people who have arthritis into two groups at random. One group follows a diet containing the food or foods being studied; the other group follows a diet without those kinds of foods. Neither group of participants is told which food is being tested. Both groups follow their diets for a number of weeks while adhering to their regular medical treatment programs throughout the study.

Researchers measure the changes, such as decreased swelling in joints, in each study participant and compare the total changes between the two groups to determine if the tested diet made a difference. The study is then repeated three or four times with other groups of people to see if the results are similar. Only after such a series of tests do the researchers consider the test results conclusive and the diet treatments effective.