Patients with arthritis are often encouraged to use diet to manage their condition. In one of the largest analyses of diet and various types of arthritis, researchers looked at data on more than 800 patients from 15 studies. They examined several diets popular among arthritis patients and found that the one that had the greatest effect was a Mediterranean-style. In 12 weeks, people on the diet reported about 15 percent less pain.
In other studies, patients who were given daily capsules of fish oil saw greater benefits for swollen and tender joints than patients given a placebo, most likely because of the oil’s anti-inflammatory properties.
In contrast, vegetables in the nightshade family, like potatoes and tomatoes, have long been said to contribute to arthritis pain. Some researchers have speculated that a group of compounds in the vegetables called alkaloids might worsen inflammation.