Research shows roller coasters may help with kidney stones

SAN FRANCISCO (KGO) -- Some hair-raising research is suggesting a possible therapy for people suffering from kidney stones. The researchers looked at the effects of riding roller coasters.

Big Thunder Mountain Railroad is a runaway mine train adventure, but for kidney stone sufferers like Grace Wu, it could be good medicine. "If it works, great. I like roller coasters," Wu said.

Michigan State University researchers decided to test their theory after patients reported their kidney stones passed painlessly after riding Big Thunder Mountain at Walt Disney World, which is similar to the ride at Disneyland.

Scientists created 3D printed models and planted kidney stones of varying sizes. Then the silicone kidneys went for a ride. The results - even the largest stones got dislodged after two or three rides. Also, riding in the back was more effective than sitting up front.

"It really doesn't make sense," City of Hope urologist Dr. Clayton Lau said. Lau said you need more than turbulent motion to pass kidney stones, but added adrenaline may cause movement in the ureter that helps propel the stones.

"And actually that causes contraction. So theoretically the ureter can contract and move that stone all the way from the top to the bottom," Lau said.

But he says loosening the stone out of the kidney is only part of the journey. "The ureter is pretty long, it's about 30 centimeters. It's got a long ways to go."

MSU researchers said in the models, the stones did pass all the way out. They even suggest riding moderate-intensity roller coasters might be good preventative therapy for people prone to kidney stones.

Still, Lau said he's not ready to recommend thrill-ride therapy. "I think that's the last thing you want to do when you're in pain is to jump on a roller coaster," he said.

Wu agrees but loves the idea. "Probably do more the conservative route, what my physicians say, but if he thinks me riding in a roller coaster, here I come," Wu said.