Some foods contain a high amount of purines, which increase the levels of uric acid in the blood. Increased levels of uric acid can be dangerous for people with diabetes or who are prone to gout and joint pain, and can lead to kidney problems. People who have uric acid issues may be told by their doctor to avoid foods that increase uric acid levels. Purines are found mostly in meats and fats, but can be found in moderate levels in certain vegetables.
Seafood like mackerel, herring, sardines and eel contains high levels of purine. Shellfish such as scallops, clams, oysters, shrimp, crab and lobster can also increase uric acid levels, and this is also true for tinned or smoked versions of these products.
Organ meats such as liver, kidney and brains are high in purines and can raise uric acid in the blood. While some meats like chicken and beef contain a small amount of purines, the chemical is most concentrated in the organs of these animals.
Beans, lentils, soy and peas raise the uric acid levels in the blood, and this includes fresh or dried legumes. Legumes that contain caffeine, like cocoa and coffee beans, also raise uric acid levels along with any other food containing caffeine.
Brewer's and baker's yeast contain high amounts of purines, which means that beer and yeast-leavened baked goods should be avoided or eaten sparingly.
Most purine-rich foods are protein-based and there are very few fruits and vegetables that have very high purine levels.. Avocados should be avoided because of their high fat content, and asparagus, cauliflower, mushrooms and spinach have moderate levels of purines. Fried foods also increase uric acid production, so fried vegetables should be avoided.