Excess body weight is associated with higher uric acid levels and risk of gout[1] and diets that produce weight loss appear to reduce uric acid, with at least one noncontrolled study indicating diet-induced weight loss can reduce the rate of gout attacks.[2] In another study, weight loss led to reductions in uric acid regardless of whether the diet was low fat, low carbohydrate, or a Mediterranean diet.[3]
Milk and dairy products may reduce uric acid levels, with a couple of trials observing reductions in uric acid following the consumption of milk.[4][5] However, one randomized, controlled trial found no effect of skim milk powder on uric acid or gout symptoms in people with gout, though there was an indication of benefits to some gout symptoms when two milk extracts (known as GMP and C600) were added the skim milk powder.[6]
Two prospective cohort studies, one on men[7] and the other on women,[8] each found that higher coffee consumption was associated with a lower risk of developing gout. One Mendelian randomization study also observed that a genetically predicted increase in coffee consumption was linked to lower uric acid levels and a reduced risk of gout.[9] However, the effect of coffee on gout has not yet been tested in clinical trials and at least one randomized controlled trial failed to find an effect of coffee (either caffeinated or decaffeinated) on uric acid levels.[10]
Several clinical trials have observed a reduction in uric acid with increasing salt intakes, particularly when comparing low sodium intakes (1200–1380 mg per day) to either moderate or high sodium intakes.[11][12][13] However, such studies have not yet been conducted on people with gout. Because some research suggests sodium in joints may increase the tendency of uric acid to crystallize,[14] whether increasing salt intake will reduce the likelihood of gout remains uncertain.
Both extended fasting[15] and very low carbohydrate diets[16][17] have been at times shown to produce a rise in uric acid levels, in both cases potentially due to ketones inhibiting uric acid excretion. This effect may diminish over time.