Although patients with kidney stones are urged to consume large quantities of fluid, some drinks can actually increase the risk of stones forming.
Grapefruit juice, for instance, increases the chance of stones forming by 44 per cent. A daily dose of eight oz (240 ml) of wine, however, reduces the risk by 59 per cent decaffeinated coffee and tea by 9 per cent. Caffeinated coffee was slightly better, lowering the risk by 10 per cent.
The results were based on a study of 81,093 women aged between 40 and 65 who had no history of kidney stones (Annals of Internal Medicine, 1998; 128: 534-40).