Gout is a form of acute inflammatory arthritis characterized by tender, swollen joints, usually in the large toe. This disease results from elevated concentrations of uric acid from purine-rich foods. The uric acid crystallizes and is deposited in joints, causing pain. Consuming soy products actually will increase your uric acid concentration, but it also helps the body to eliminate the substance faster than it is produced.
Purines
Purines are nucleotides, which along with pyrimidines bind to form amino acids, the building-blocks of proteins. A diet with purine-rich foods, such as red meat and seafood, is believed to contribute to gout. To test this hypothesis, a study in the March 2004 issue of the "New England Journal of Medicine" examined the relationship between purine-rich foods and the occurrence of gout using the responses of more than 47,000 men to a questionnaire. The researchers documented 755 cases of gout and found that red meat and seafood consumption was indeed correlated to the disease. However, the study concluded that consumption of purine-rich vegetables, including soy products, was not correlated to the incidence of gout.
Effect of Soy on Gout
A study in the February 1998 issue of "Advances in Experimental Medicine and Biology" investigated the effects of tofu, made from soybeans, on uric acid metabolism. The researchers examined the uric acid production of 18 men who were placed on a restricted diet including tofu. There were eight healthy subjects and 10 with gout. The study found that the ingestion of tofu led to production of uric acid in the blood samples of all subjects, but the uric acid clearance was increased, thereby lowering the concentration in the participants. The authors concluded that tofu is a superior source of dietary protein for those suffering from gout.
Milk Products
An article appearing in the September 2010 issue of the "Annals of the Rheumatic Diseases" investigated the effects of milk products on lowering uric acid concentrations to reduce the incidence of gout. The researchers recruited participants for the study and assigned them to groups receiving soy milk or one of three varieties of skim milk. The study found that soy milk ingestion raised uric acid levels in urine by approximately 10 percent, while all skim milk products reduced the concentrations by 10 percent.
Soy and Uric Acid
The June 1992 issue of the "Journal of the American College of Nutrition" evaluated the effects of soy intake on 18 male participants with no history of gout. The men were fed purine-rich foods, including beef liver, haddock and soybeans, for three weeks. The researchers found that all three foods increased uric acid output in urine samples taken four hours after meals.
References
- "Journal of the American College of Nutrition"; Changes in Serum and Urinary Uric Acid Levels in Normal Human Subjects Fed Purine-Rich Foods Containing Different Amounts of Adenine and Hypoxanthine; D. Brule, et al.; June 1992
- "Annals of the Rheumatic Diseases"; Acute Effect of Milk on Serum Urate Concentrations: A Randomised Controlled Crossover Trial; N. Dalbeth, et al.; September 2010
- "Advances in Experimental Medicine and Biology"; Effect of Tofu (Bean Curd) Ingestion and on Uric Acid Metabolism in Healthy and Gouty Subjects; J. Yamakita, et al.; February 1998
- "New England Journal of Medicine"; Purine-Rich Foods, Dairy and Protein Intake, and the Risk of Gout in Men; H. Choi, et al.; March 2004
