Soda appears to be associated with the progression of knee osteoarthritis in men. One explanation for this may be that soft drinks are taking the place of healthier food and drink choices such as milk and dairy products, fruit juice, fruit, and a variety of vitamins and nutrients. Another theory is that soft drinks may contain phosphoric acid, which has been shown to interfere with calcium absorption and to contribute to imbalances that lead to additional loss of calcium. People who have knee osteoarthritis are advised to reduce soda intake to less than five drinks per week.