Soyfoods, hyperuricemia and gout: a review of the epidemiologic and clinical data

Soyfoods have long been a part of traditional Asian diets; they provide plentiful amounts of high-quality protein and have a favourable fatty acid profile. In addition, provocative research suggests soyfoods offer health benefits independent of the nutrients they provide. However, there is a widely-held belief among Asian health professionals and the public that soyfoods increase risk of gout and potentially precipitate acute attacks in patients with this disease. To examine the veracity of this belief, this review critically evaluated the relevant clinical and epidemiologic data. In addition, background information on the etiology and prevalence of hyperuricemia and gout in Asia is provided along with the results of a small survey of Asian healthcare professionals about their attitudes toward soyfoods. Among the healthcare professionals who responded to the survey, 95% considered soyfoods to be somewhat or very healthy and nutritious. In contrast, 48% expressed the view that soyfoods are likely to cause gout. However, none of the six epidemiologic studies identified provided any evidence that soy intake was associated with circulating uric acid levels, hyperuricemia or gout. Data from the five human intervention studies evaluated indicate soy protein does elevate serum uric levels, but in response to amounts comparable to Asian intake, the expected rise would almost certainly be clinically irrelevant. Although there is a need for long-term research, on the basis of the existing data there is no reason for individuals with gout or at risk of developing gout to avoid soyfoods.