Purines are compounds that occur in all human tissue and are found in many foods. They perform important functions in the body, but a diet high in purines can increase the risk of painful conditions, such as gout or kidney stones, in susceptible people. Avoiding purine-rich foods can help prevent or manage these conditions.
Risks
When the body digests foods containing purines, a byproduct is uric acid, which is normally eliminated in the urine. Eating too many high-purine foods can lead to a buildup of uric acid in the blood, or hyperuricemia, which over time may result in the formation of uric acid crystals. These may accumulate in the joints, causing the acute, painful form of arthritis called gout, which affects an estimated 6.1 million Americans, according to the Arthritis Foundation. Men in their 40s and 50s are most likely to develop gout, but it can affect younger people and women, especially those over 60, as well. Cedars-Sinai Medical Center reports that hyperuricemia is also a cause of kidney stones, which affect one in every 1,000 American adults.
Limits
The Litholink Corporation states that the normal diet contains between 600 and 1,000 mg of purines per day. In a low-purine diet, this is restricted to approximately 100 to 150 mg per day. High-purine foods typically contain 100 mg to 1,000 mg per 3 oz serving, while foods with moderate purine levels might contain 9 to 100 mg per 3 oz serving.
Specifics
The Johns Hopkins Arthritis Center lists several foods as very high in purines, including yeast; organ meats such as heart and sweetbreads; and seafood such as herring, mussels, smelt and sardines. Moderately high in purines are anchovies, grouse, mutton, veal, bacon, liver, salmon, turkey, kidneys, partridge, trout, goose, haddock, pheasant and scallops. Vegetables, such as peas, beans, mushrooms, cauliflower and spinach, are also considered high in purines but a large-scale study in the "New England Journal of Medicine" in March 2004 found these foods were not linked to an increased risk of gout.
Considerations
In addition to avoiding high-purine foods, further lifestyle measures can help prevent hyperuricemia. These include avoiding or limiting alcohol, which increases purine production; limiting high-fat foods, as fat helps retain uric acid in the kidneys; and drinking 8 to 12 cups of fluid every day. Losing excess weight can improve gout and kidney health, but be careful not to lose weight too rapidly as this can increase uric acid levels.
References
- National Institute of Arthritis and Musculoskeletal and Skin Diseases: Gout
- Arthritis Foundation: What is Gout?
- Cedars-Sinai Medical Center: Kidney Stones
- Litholink Corporation: Your Guide to Purines, Urine pH and Citrate
- Johns Hopkins Arthritis Center: Treatments for Gout
- "New England Journal of Medicine"; Purine-Rich Foods, Dairy and Protein Intake, and the Risk of Gout in Men; HK Choi; March 2004
