Research on the effects of cooking on purines is incomplete but does provide some answers on the behaviour of purines when food is cooked.
When food with high levels of purines is cooked, the component that contains the purines (nucleic acids) breaks down. This frees up the purines for easier absorption and increase this risk of gout.
However, one manner of cooking appears to have the opposite effect. If food is boiled in water the same process occurs with purines being freed up. The difference, however, is that a significant percentage of purines are lost in the water if it is discarded.
In other words, the effects of cooking on purines is one important factor to consider but what happens to the purines after the cooking process is perhaps more important – if the purines are lost rather than consumed.
Thus, all other things being equal, we will absorb more purines if we eat cooked food than when eating it raw. However, if it is boiled, and the water discarded, the food will have a lower concentration of purines than if eaten uncooked.
Thus, eating fried fish poses a greater impact on the risk of gout than eating raw sushi. However, boiling the same fish would lower the risk.
While we still don’t have a definitive picture on how we should handle purines to cure or control gout, we are getting closer to an answer. For a long time we focused on avoiding high purine diets. Then we learned that we can differentiate to some degree between good purines and bad purines. We now know that if we are to control uric acid level and gout by focusing on purines, we should now also consider the way our food is prepared and the effects of cooking on purines.
References
Brule, D.; Sarwar, G., and Savoie, L. Uricogenic potential of selected cooked foods in rats. J Am Coll Nutr. 1990 Jun; 9(3):250-4.
Sarwar, G. and Brule, D. Assessment of the uricogenic potential of processed foods based on the nature and quantity of dietary purines. Prog Food Nutr Sci. 1991; 15(3):159-81.
Schlesinger, N. and Schumacher, H. R. Jr. Gout: can management be improved? Curr Opin Rheumatol. 2001 May; 13(3):240-4.