RENEE MONTAGNE, HOST:
And now, we turn to something else related to your diet - those kidney stones. More Americans are getting them than ever before. And it's not joke. Doctors and patients say it's one of the worst kinds of pain. NPR's Richard Knox explains how kidney stones are treated these days and what you can do to prevent them.
RICHARD KNOX, BYLINE: Henry Owens is lying on an operating room table in Boston.
UNIDENTIFIED WOMAN: All right, Mr. Owens. We're going to take good care of you. OK?
HENRY OWENS: Thank you.
KNOX: Owens, who's 69, has Type II diabetes. He's conscientious about his health. But he's about to undergo kidney stone surgery.
DR. MARK MCKEEN: All right. The next thing we're going to do is give you an oxygen mask and have you take some big deep breaths.
OWENS: Then it's over.
KNOX: A little earlier Owens told me about his kidney stone attack.
OWENS: Two weeks ago, I had severe pain above the belt on the right side. I came into Mass General and they did a CAT scan and determined I have three stones, one of which is a half-an-inch. And I think that's big.
KNOX: He says it hurt a lot.
OWENS: Oh, the pain was so much that you'd be nauseous. And the pain was excruciating.
KNOX: A doctor installed a tube that allows urine to bypass the stone. Now urologist Dianne Sacco is going to smash his stones with a laser. She passes a thin tube through his urinary passage into his bladder. A fiber-optic cable gives a clear picture on a screen above the table.
DR. DIANNE SACCO: This is where the ureter enters into the bladder.
KNOX: Snaking the equipment up the ureter, Sacco finds her first target.
SACCO: And there's a stone. It's yellow and it's knobby-looking.
UNIDENTIFIED WOMAN: Yep.
SACCO: Laser ready?
UNIDENTIFIED WOMAN: Laser ready.
(SOUNDBITE OF BEEPING)
SACCO: You can see when the laser touches, you get that spray of dust. And that's a stone being broken up.
KNOX: Would you suspect that his diabetes is a risk factor for his stones?
SACCO: Yes. Definitely.
KNOX: Not only is diabetes a risk factor, but obesity is too. And although Owens has lost 50 pounds, a few years ago he was considered obese.
SACCO: That was one of his risk factors. And I think that's definitely one of the reasons why we're seeing so many more patients with stones.
KNOX: In fact, America is in the midst of a kidney stone epidemic.
DR. CHARLES SCALES: Clearly, the prevalence of kidney stones over the past 15 years or so has almost doubled.
KNOX: That's Dr. Charles Scales of UCLA. He led a study published this summer in the journal European Urology. It found one in 10 American men have had a kidney stone, and one in 14 women, and that being obese or diabetic raises the risk. Yet very little attention is paid to preventing this problem.
SCALES: If we treated heart disease today like we treat kidney stones, we would only treat people who are having chest pains or actual heart attack and we wouldn't think about things like smoking, cholesterol or high blood pressure.
KNOX: People can lower their risk of kidney stones by paying attention to what they eat and drink.
SCALES: You really cannot underestimate the value of drinking plenty of fluids in terms of preventing kidney stone formation.
KNOX: Beyond that, lay off salt-rich processed foods, cut down on meat and other animal protein, and generally take in fewer calories.
Most kidney stones are made of calcium. But experts don't tell people to cut their calcium intake. Because surprisingly, that can actually increase your risk.
SCALES: Too much is not good and too little is not good. You really want to be in the middle.
(SOUNDBITE OF BEEPING)
KNOX: In the operating room, Dr. Sacco's laser is pointed at Henry Owens' third kidney stone.
SACCO: This is the biggest stone that we'll take care of in him.
KNOX: And how big are we talking about here?
SACCO: One-point-one centimeters.
KNOX: A little bigger than a marble. Sacco shatters it into tiny pieces. She removes some, the rest will pass.
SACCO: That's it, we're done everybody.
KNOX: Owens has about a 50 percent chance of developing another kidney stone. To better those odds, Sacco will send his stone fragments to a lab and also analyze his urine. That will tell her just what dietary changes he needs to make and whether he'll need to take medicine to avoid another painful stone.
Richard Knox, NPR News, Boston.
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