Several studies have found that dietary supplements made from avocado and soybean oil can help ease osteoarthritis pain for up to six months.

Nearly half of Americans will suffer from knee osteoarthritis, a disease that causes pain and stiffness, according to the Centers for Disease Control and Prevention.

Medications commonly used to relieve arthritis pain have been shown to cause ulcers and, in high doses, increase the risk of heart attack or stroke.

Avocado-soy supplements have anti-inflammatory properties and also appear to help build joint cartilage and slow its destruction over time, said Jason Theodosakis, M.D., chief executive of Supplement Testing Institute Inc., in Tucson, Ariz.