5 tips to reduce risk of kidney stones

Cutting back your risk of getting kidney stones can be as easy as a glass of juice in the morning. This and a few other simple lifestyle changes can help prevent this painful experience down the road.

The facts are clear: one out of every 10 adults will experience the excruciating pain of trying to pass a kidney stone at some point in their lives. Some say it's worse than the pain of childbirth.

• Kidney stones result from microscopic deposits in urine that eventually solidify, much like the salt left at the bottom of a glass of salt water after the liquid evaporates.
• There are several types of kidney stones. If you've had a stone that passed, your doctor can test its composition and measure chemicals in your blood and urine to decide on the best way to prevent stones in the future.

Here are five easy ways that you can reduce your risk on a daily basis:

Drinking more fluids is the best way to prevent all types of kidney stones.

• One study found that men who produced a prodigious 2.4 litres (2.5 quarts) or more of urine a day (the average is 1.4 litres) were 29 percent less likely to develop symptomatic stones than those who excreted 1.2 litres (1.3 quarts) or less.
• In women, urinating 2.5 litres (2.6 quarts) or more reduced their risk by 49 percent compared with urinating less than 1.4 litres (1.5 quarts) a day. You'll need to drink 3.3 to 3.8 litres (3.5 to four quarts) of liquid a day to get there, which should make you urinate every two hours or so.

Doctors used to warn all patients at risk for kidney stones to limit their calcium intake. After all, most kidney stones are composed primarily of calcium.

• It turns out that people who have the least calcium in their diets can have the highest risk of kidney stones. (A few patients, those with absorptive hypercalciuria, are still asked to reduce their calcium intake.)
• Researchers think that calcium protects against stones by binding to oxalic acid, a salt found in certain foods that contributes to kidney stones, thus preventing it from getting into urine.
• The best sources are low-fat milk, yogurt and cheese. Edamame (green soybeans) and whole grains are also calcium packed.
• Note that we're talking about dietary calcium; there's no evidence that calcium supplements reduce your risk.

Experts have long prescribed tart (very lightly sweetened) lemonade as a way to keep stones at bay. But recent studies suggest that orange juice may be an even better choice. Both are great sources of potassium citrate, which is often prescribed to prevent kidney stones.

• Stay away from grapefruit juice; it seems that quaffing as little as 236 ml (eight ounces) a day can increase the risk of kidney stones, though researchers have no idea why.

• When researchers crunched the numbers, they found that men who weighed more than 100 kilograms (220 pounds) were 44 percent more likely to develop kidney stones than those who weighed less than 68 kilograms (150 pounds).
• For women, the danger of being overweight was greater. Those who weighed more than 100 kilograms (220 pounds) were between 89 and 92 percent more likely to develop kidney stones than those under 68 kilograms (150 pounds).

It's not that easy to do since so many packaged foods and drinks these days contain it, but kicking the pop habit, avoiding sweetened fruit drinks and eating fewer snacks out of boxes is a good start.

• Cutting back may significantly reduce your risk of stones. Researchers suspect the connection has to do with fructose's tendency to increase the amount of calcium in urine.