A recent study was released showing a possible advantage to riding roller coasters to assist with kidney stone passage. Yes, you heard right, but before you head out to your local amusement park, or take the family to Disneyland, there are a few things to consider. The intent of the study makes sense, anything we can do to get those pesky stones out of our bodies quickly is of benefit. The concept is reasonable; because stones are heavier than the urine that they sit in, changes in G-forces and position could allow them to move out of the nooks and crannies in our urinary tract. But before we get ahead of ourselves, let look at how this study was done.
Research Study at Disneyworld Examines Roller Coasters' Impact on Kidney Stones
Dr. David Wartinger, a urologist from Michigan used a 3-D printed silicone model of a kidney, and then filled it with kidney stones in three different sizes, with approximate diameters of one to two millimeters, two to three millimeters, and four millimeters. These were real stones from the patient whose kidney anatomy was used to design the silicone model, and yes, real urine. Then by taking this model and riding a roller coaster (Big Thunder Mountain at Disneyworld Orlando), an amazing 20 times, they observed how often a stone would pass from the functional collecting units of the kidney, known as calyces, to the central and inferior portion of the kidney, indicating the beginning of the journey out of the body.
As anticipated, the rate of passage varied depending on the location of the stone within the kidney. The new knowledge gained from this study was that there was a higher rate of passage when the kidney model was in the back of the roller coaster (63.9 percent), as opposed to the front (16.7 percent).
Novel Idea but Real-World Application?
But what real conclusions can we draw from this study, or are there any real applications to this information? In reality this will not have major impact in how we manage kidney stones.
First, this was a study using a model, not a real live human, making the conclusions less reliable, though in the author’s defense, it would be challenging to gather a large number of patients with kidney stones and have them ride a roller coaster and get an X-ray of their kidneys before and afterwards.
And second, this model was only looking at the movement of the stone within the kidney, but the pain from kidney stones occurs more commonly after exiting the kidney before it enters the bladder, and this is really the time when we would like to assist and expedite passage.
Human Studies Would Be Needed
However, there is a potential utility to this knowledge in two common kidney stone contexts.
First, for patients with known asymptomatic kidney stones, if they would like to avoid a painful episode passing a kidney stone, perhaps they should sit in the front the roller coaster, it is more fun up there anyhow.
And second, for patients whom we treat with what is called Extracoporeal Shockwave Lithotripsy (ESWL), which is breaking up of stones with energy that is delivered outside the body, perhaps riding a roller coaster while sitting in the back would help clear out those stone fragments more efficiently.
Without human studies, and without a study comparing the outcomes of riding a roller coaster with this model with just walking around with the model, it is difficult to definitively say that Disney theme parks are now part of the kidney stone treatment algorithm.
Rely on Proven Prevention, Treatment for Kidney Stones
The real answer for kidney stones is in prevention. Hydration, drinking enough water to produce 2.5 liters to 3 liters of urine per day, is the strongest recommendation we have.
Avoiding a high-sodium, high-animal protein, and high-oxalate diet is also important, as is considering adding citrate to your diet via lemon juice. And if you do have stones, or have passed stones before, a friendly conversation with your nearby urologist is still your first step.
Questions About Kidney Stones?
Call 206-528-4944 to schedule a consult with Dr. Moskowitz.