New view of kidney stones

New research at University of Wisconsin School of Medicine and Public Health shows that calcium supplements may help prevent kidney stones. That's good news for kidney- stone sufferers who like to eat. It means they can have that spinach and beet salad, followed by strawberryrhubarb pie, as long as they take a calcium supplement with dinner. It would be even better to squeeze a bit of lemon juice on that salad and have a glass of skim milk with the pie.

It used to be that people who had suffered through the miseries of kidney stones were told to avoid high- oxalate foods, which include such healthful items as spinach, beets, strawberries, nuts, soybeans and black and green tea. They may have also been told to avoid calcium. The reason was that about 80 percent of kidney stones are made up of calcium oxalate. But it turns out that kidney stones — which are now on the rise in children and women — can't be blamed solely on foods. Instead, urology experts blame obesity, too much sodium, and too little fluids. Then, a few years ago, a Harvard University study showed the surprising result: Many kidney- stone sufferers actually had low levels of calcium in their bloodstream.

A newer theory is that some stone- formers lack enough calcium to bind up the oxalate in the GI tract, allowing it into the kidneys, where it can form stones. The important thing is to take the calcium with food so it can do its binding job.

Fresh lemon or lime juice squeezed into water is recommended. Citric acid inhibits kidney stone formation.

It was found that people with kidney stones, especially women, experience a lower health- related quality of life. But the good news from Wisconsin's urology department is that people can actually do some simple things with their diets to prevent one of the most painful afflictions from coming back.