Purines are amino acids, which are the building blocks of proteins. The two purines important in proteins in the body are guanine and adenine.
Some foods contain high amounts of purines, including:
Purines in food are broken down into uric acid. High levels of uric acid in the blood sometimes cause the deposit of uric acid crystals in a joint, such as a toe joint, or the ankle or knee. This condition is called gout and results in episodes of sharp pain in the affected joint.
WebMD Medical Reference from Healthwise