Should you avoid nightshade foods if you have arthritis?

As of 2015, scientific evidence does not show that nightshade foods, including eggplant and tomatoes, aggravate arthritis, states the Arthritis Foundation. Some experts believe the vegetables contain a powerful mix of arthritis pain-blocking nutrients. They also contain the chemical solanine, which has been identified as a cause of arthritis pain.

Many patients report relief from arthritis symptoms with nightshade-free eating. To test the effect, a patient needs to eliminate all nightshade vegetables from his diet for a few weeks. If he experiences reduced pain, then he may want to continue nightshade-free meals, notes the Arthritis Foundation. Eggplant contains anthocyanins, anti-inflammatory agents, and tomatoes are rich in lycopene, a powerful antioxidant. Other nightshades such as red peppers are full of vitamin C, which boosts the immune system, and potatoes contain potassium, which aids blood pressure stability.