Kidney stones are a global issue with a high recurrence rate. Kidney stones removal is expensive prevention is much cheaper. Hydration and increased water intake to enhance urinary output is known to be helpful. Caffeine use in terms of risk benefits for prevention of kidney stones has been controversial. This review article looks to find if caffeine is beneficial or harmful in terms of kidney stone recurrence. Caffeine contains oxalate which can help increase urinary calcium excretion.
Caffeine and the kidney:
Urine volume depends on a balance between glomerular filtration rate (GFR) and tubular reabsorption rate. Caffeine is a diuretic and enhances GFR and reduces tubular reabsorption. . In addition to its diuretic action, caffeine also has a natriuretic property because the caffeine-induced increase in urine flow is related to the increased urinary excretion of solutes (i.e., sodium, chloride, calcium, phosphate, and magnesium).
Evidence have been controversial in the past.
Caffeine has properties that both can cause and inhibit kidney stones. But the evidence suggest it is better at inhibiting stone formation than causing it to form.
3 large cohort studies show caffeine is beneficial in preventing recurrence. The mechanisms involve translocation of a CaOx crystal-binding protein, annexin A1, from apical membranes to cytoplasm. This causes reduction of CaOx crystal adhesion on the apical surface of renal tubular epithelial cells. Decaffeinated beverages have also been helpful. Going forward more research is needed on the subject.
