Nutrient intake and use of beverages and the risk of kidney stones among male smokers

High intakes of calcium, potassium, and fluids have been shown to be associ ated with lowered risk of kidney stones. The authors studied the associatio ns between diet and risk of kidney stones in a cohort of 27,001 Finnish mal e smokers aged 50-69 years who were initially free of kidney stones. All me n participated in the Alpha-Tocopherol, Beta-Carotene Lung Cancer Preventio n Study and completed a validated dietary questionnaire at baseline. After 5 years of follow-up (1985-1988), 329 men had been diagnosed with kidney st ones. After data were controlled for possible confounders, the relative ris k of kidney stones for men in the highest quartile of magnesium intake was 0.52 (95% confidence interval (CI) 0.32-0.85) as compared with men in the l owest quartile. Intake of fiber was directly associated with risk (relative risk (RR) = 2.06, 95% CI 1.39-3.03). Calcium intake was not associated wit h the risk of kidney stones. Beer consumption was inversely associated with risk of kidney stones; each bottle of beer consumed per day was estimated to reduce risk by 40% (RR = 0.60, 95% CI 0.47-0.76). In conclusion, the aut hors observed that magnesium intake and beer consumption were inversely ass ociated and fiber intake was directly associated with risk of kidney stones .