- A new review pinpoints five evidence-backed ways to prevent kidney stones.
- Those prone to stones are likely to experience recurrence, so these tactics are important.
- Some are as simple as dietary changes, and others are prescription-based.
If you’ve never experienced kidney stone pain, you’ve probably heard enough to know that it’s not fun. Not to mention, the stones are a risk factor for long-term kidney disease. The good news is, there’s quite a bit of research on their treatment and prevention, and scientists analyzed a large group of past studies to find a combination of factors they say prevent kidney stones.
Meet the experts: Daniel Marchalik, M.D., F.A.C.S., a urologist at MedStar Health; and Jason Fung, M.D., a nephrologist and disease prevention specialist.
There are different types of kidney stones, but the most common are calcium phosphate and calcium oxalate kidney stones, according to the National Kidney Foundation. Both are solid masses that form in the kidney when there are high levels of the minerals calcium, oxalate, or phosphate in urine, and there’s not enough urine or other elements to prevent them from forming.
“Kidney stones affect roughly one in 10 Americans, and incidence has been rising for decades,” says Daniel Marchalik, M.D., F.A.C.S., a urologist at MedStar Health. “They are significantly more common in patients with a personal or family history of stones. Stones may cause extreme pain, but more importantly, they may lead to urinary obstruction, which may cause lasting or even permanent damage to the kidney and increase the risk of sepsis if not treated promptly.” Recurrence of kidney stones is common, Dr. Marchalik says, which is why it’s important for those prone to stay vigilant about prevention.
Below are the strategies that were proven to work, per the recent review published in Annals of Internal Medicine. Before trying anything yourself, be sure to consult your physician.
How to prevent kidney stones, according to the latest research
“Each intervention targets a different part of the stone-forming process,” says Dr. Marchalik.
Hydration
Stones form when minerals in urine become concentrated enough to crystallize, explains Dr. Marchalik. More water keeps that concentration below the threshold needed to form stones. The Kidney Foundation recommends drinking enough so you pee about 2½ liters (or about 85 ounces) each day. That means aiming to drink about 100 fluid ounces (or 12 to 13 cups) of fluid daily.
A low-sodium, low-animal-protein, high-calcium diet
Higher protein diets may increase the acidity of urine and make people more prone to stones, explains Jason Fung, M.D., a nephrologist and disease prevention specialist. However, the findings hone in on prioritizing animal protein because it “raises uric acid and suppresses citrate in the urine, which naturally inhibits stone formation,” says Dr. Marchalik.
On the topic of sodium, too much of it causes the kidneys to excrete more calcium, which is the primary raw material for stones, adds Dr. Marchalik. That’s not to say patients should skip dietary calcium altogether, though. In fact, average to high calcium intake is recommended for kidney stone prevention, which can be a bit confusing. “Counterintuitively, restricting dietary calcium makes things worse, because when there isn’t enough calcium in the gut to bind oxalate, oxalate ends up in the kidney and leads to more stone formation,” Dr. Marchalik explains.
Put differently, according to the Kidney Foundation, dietary calcium helps lower how much oxalate gets absorbed from the healthy foods you eat. The foundation recommends getting 1,000 to 1,200 milligrams of calcium per day, which may look like two to three servings of dairy daily with meals.
Alkali therapy
Oral alkali therapy, most commonly in the form of potassium citrate tablets, says Dr. Marchalik, helps to raise urinary pH levels and increase citrate directly, restoring acidic balance to the body. This treatment showed 333 fewer recurrences per 1,000 patients across four trials reviewed by scientists. Treatment with lemon juice had a more modest effect and also showed a small increase in adverse events.
Diuretics
Thiazide diuretics—a medication that makes you pee—can reduce how much calcium the kidneys excrete into urine by having the kidney reabsorb it instead, explains Dr. Marchalik. In the review, this therapy showed roughly 217 fewer stone recurrences per 1,000 patients across three trials.
Allopurinol
This prescription medication lowers uric acid production. Per the review, there were 265 fewer recurrences per 1,000 patients in two trials, with no meaningful increase in adverse events.
The bottom line
The information provided by this review “reinforces current management of stones but highlights things you can do to prevent them,” says Dr. Fung. It’s also worth noting that the clearest effective prevention tactics were those that don’t require a prescription—drinking more water and reducing sodium and animal protein, Dr. Marchalik notes. “That matters for who can actually act on this information,” he concludes. Of course, consult your physician before making any changes to your routine.
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