An increase in the incidence of hyperuriceamia associated with gout as well as phyertension, renaldiseases and cardiovascular disrases has been a public health concern. We examined the possibility of facilitated excretion of uric acid by change in urine pH by managing food materials.
Within the framework of the Japanese government's health promotion program, we created recipes consisting of more protein and less fruit and vegetable-based food materials for H+-load (acid diet) and others composed of less protein but more fruit and vegetable-based materials (alkali diet). Healthy female students were enrolled in this 5-day study for each test. From a whole day collected urine, total volume, pH. organic acid, creatinine, uric acid and all cations (Na+, K+, Ca2+, Mg2+, NH4+) and anions (CI-, SO42-, PO4-) necessary for the estimation of acid-base balance were measured.
Urine pH stabilized 3 days after switching from an ordinary daily diet to a specified regimens. The amount of acid generated ([SO42-]+organic acid-gut alkali) was linearly related with that of the excretion of acid (titratable acidity+[NH4+]-[HCO3-]), indicating that H+ in urine is generated by the metabolic degradation of food materials. Uric acid and excreted urine pH retained a linear relationship, where uric acid excrtion increased from 302 mg/d at pH 5.9 to 413 mg/d at pH 6.5, despite the fact that the alkali diet containes a smaller purine load than the acid diet.
We conclude that alkalization of urine by eating nutritionally well-designed food is effective for removing uric acid from the body.