Fructose linked to kidney stones
Sodas, ice cream, fruit punch, apple juice, canned fruit, and other food or drinks high in either fructose or sucrose are associated with an increased risk of kidney stones, researchers say. (The small intestine converts half of sucrose into fructose.)
The finding is based on periodic surveys of three groups of health professionals totaling nearly 240,000. During a combined 48 years of follow-up, 4,902 cases of kidney stones occurred. Compared with lowest quintile of total fructose intake, the highest quintile was associated with a 37% increased risk of a new kidney stone in the older women, a 35% increased risk in the younger women, and a 27% increase in the men, after adjusting for potential confounders, researchers affiliated with the Harvard University medical school reported in Kidney International (2008;73:207-212).
“Clinicians caring for patients with stone disease should ensure that individuals who decrease their intake of protein or fat do not subsequently increase their consumption of fructose-rich foods,” the authors write.
With the introduction of high-fructose corn syrup in 1967, fructose consumption has grown rapidly in the past few decades. “This intake,” the researchers note, “may increase the urinary excretion of calcium, oxalate, uric acid, and other factors associated with kidney stone risk.”