To detect and quantify the relationship between purine intake and risk of gout recurrence in patients with gout, Yuqing Zhang of Boston Medical School, USA, conducted a case-crossover study of a set of putative risk factors in patients with recurrent gout. Prospective gout patients were recruited and followed up for one year via a web-based approach. Patients were asked a number of questions about the gout attack: date of the attack, clinical signs and symptoms, therapeutic agents (including medications for gout), potential risk factors (including daily intake of a food spectrum with different purine content) two days prior to the gout attack, and information about the same exposure during a 2-day control period was also assessed. Results from the Department of Rheumatology and Immunology, Second Affiliated Hospital of Guiyang Traditional Chinese Medicine, Anyang, found that among the 633 gout patients included in the study, the ratio of gout recurrence was 1.17, 1.38, 2.21 and 4.76, respectively, when comparing the lowest quintile counterpart of total purine intake during the 2-day period, with a P-value trend of less than 0.001 per quintile counterpart. a P-value trend of less than 0.001 per quintile counterpart of animal-derived purine food was less than 0.001, corresponding to ratio ratios of 1.42, 1.34, 1.77, and 2.41, respectively, while the corresponding ratio ratios for purine foods of plant origin were 1.12, 0.99, 1.32, and 1.39, respectively (P=0.04). The effects of purine food intake were persistent across subgroups of gender, alcohol intake, diuretic use, allopurinol, NSAIDS, and colchicine. CONCLUSION: This study suggests that acute purine intake increases the risk of gout recurrence 5-fold in patients with gout. Avoidance or reduction of purine-rich food intake, especially of animal origin, may be helpful in reducing the risk of gout flare-ups.