Assessment of the uricogenic potential of processed foods based on the nature and quantity of dietary purines.

Foods rich in nucleic acids, which elevate serum uric acid levels, are restricted in the diets of hyperuricemic individuals. This restriction has been based on the amount of total dietary nucleic acids or all purines, assuming no differences in uricogenic effects of individual purines (adenine, guanine, hypoxanthine, and xanthine). However, inspite of their biochemical similarity, purines are metabolized differently and produce different uricogenic effects in animals and humans. Among the four purine bases, adenine and hypoxanthine have been reported to be more uricogenic than guanine and xanthine. Moreover, free adenine has been shown to be more uricogenic than its nucleoside or nucleotide when fed to animals. Changes in the contents of purines and release of free bases have been reported to occur during various cooking procedures such as stewing, roasting, boiling, and broiling of meat, poultry, and fish products. The differences in metabolic effects of individual purines, and modification in the amount and form of purines caused by processing would suggest that the uricogenic potential of processed foods should be based on the nature and quantity of dietary purines. Recent data on purine contents of processed foods, and information on metabolic effects of dietary purines are reviewed to assess the uricogenic potential of processed foods.