URGENT ALERT: It’s kidney stone season

How to stop them before they start


The pain of passing a kidney stone is comparable to the pain of childbirth. And when you pass one, I guarantee you’ll never forget it.

Roughly one in 10 people will suffer from kidney stones in their lifetime. And according to recent research, the numbers have been rising steadily in recent years… with no sign of stopping anytime soon.

One 2012 study found that the number of people with kidney stones has doubled since 1990.1 But as more recent reports show, that increase was just the beginning…

In fact, research published earlier this year showed that, while kidney stone incidence has doubled among American men, it’s quadrupled among women—with a particular increase among young women aged 18 to 39.2

And unfortunately, this news spells extra trouble for those who enjoy getting out and about during the summer.

Why summertime is kidney stone season

First, let me explain exactly what kidney stones are: The “stone” is a hardened mass of calcium crystals that gets stuck in the urinary tract—most often formed from calcium oxalate or calcium phosphate.

So why do some people seem to get them again and again, while others escape them altogether? It turns out some people are predisposed to get kidney stones because of a common genetic variation in a gene called claudin-14.

The claudin-14 gene acts as the “gatekeeper” between your kidneys and bloodstream. When claudin-14 is inactive (as it should be normally), your kidneys’ filtration system works with ease. And any calcium in the urine flows right back into the bloodstream.

However, when people are dehydrated, claudin-14 is more likely to prevent calcium from re-entering your bloodstream. And when this calcium starts building up in the urine, kidney stones form.

Considering proper hydration is already a struggle for many people, you can see how the sweltering heat of summer can make things much worse for those with an active claudin-14 gene.

Water is your No. 1 weapon in this fight

If you want to prevent kidney stones, the best thing to do is drink the right amount of water. So, how much do you need?

It’s easier to figure out than you may think. Simply divide your body weight in half. That’s how many ounces you should be drinking every day.

Of course, that number may increase slightly based on how much exercise you’re getting, how much you’re sweating, and how much coffee or caffeinated tea you’re drinking. (As a general guideline, you should match each cup of coffee with another cup of water. And 30 minutes in the gym requires another 8 ounces to replenish the fluid you lost.)

As for the debate over bottled versus filtered versus tap water, that’s entirely up to you. But here are a few things to consider…

I only drink natural spring water bottled in glass. I don’t recommend ever drinking out of a plastic bottle—even BPA-free plastic. There are just too many chemicals involved in the production of plastic for me to feel comfortable drinking anything packaged in them.

And if you choose tap water, I recommend filtering it. Tap water is full of contaminants, so get the best filter you can afford.

This is easily the easiest, most effective strategy to ward off kidney stones. The second simple strategy is to quit sodas and sugary drinks (if you haven’t already). High-sugar diets ramp up excretion of calcium in the urine—which, in turn, raises risk of kidney stone formation.

Speaking of diet…

As I mentioned earlier, kidney stones form from a buildup of calcium oxalate. So some experts recommend avoiding oxalates in your diet.

Foods high in oxalates include spinach, rhubarb, beets, berries, nuts, okra, and cocoa.

For the genetically predisposed, that’s certainly an option. But considering these are all perfectly healthy foods, I rarely recommend anyone cut them out—especially when other factors (like poor hydration) are by far the bigger culprits.

That said, other commonly cited “high oxalate” foods include potato chips and French fries.

Which of these foods do you think your average kidney stone sufferer is likely to be eating too much of? I’ll give you a hint—it’s probably not the spinach or the rhubarb…

So if you’re going to cut down on oxalates, start with the chips and Fries. And for the other high-oxalate foods, simply pair them with calcium-rich food sources like leafy greens, nuts, and full-fat dairy. Calcium binds with oxalate in the intestines and can help to neutralize their effects (which are likely to be minimal for most).

The hidden culprit in processed foods

The other substance that forms kidney stones in the body is called calcium phosphate. So to round out my dietary recommendations for kidney stone prevention, let’s talk about phosphates.

Just to be clear, I’m not talking about phosphorus. (That’s an essential mineral found in foods like pumpkin seeds, cheese, salmon—all of which are A-List approved.)

I’m talking about inorganic phosphates—the preservatives and stabilizers food manufacturers routinely add to processed and packaged foods. There’s nothing essential or natural about them. And they have no place in a nutritious diet.

In fact, high phosphate consumption poses a direct threat to your kidneys. As part of a recent study, researchers looked at food recall data from 7,895 adults. And they found that inorganic phosphate additives significantly increase the concentration of phosphorus in your blood, which promotes kidney stones.3

Unfortunately, it’s not always clear from the nutrition label whether or not a product contains phosphates. In my view, you should try to avoid eating anything with a label altogether. The less packaging, the better. Opt for fresh and unpackaged fruit, vegetables, meats, and seafood.

A few supplements to keep kidney stones at bay

Beyond your dinner plate, a few natural supplements are also extremely effective in preventing painful kidney stones. Below are my daily recommendations. They should be easy to find in your local grocery store, pharmacy, or health supplement retailer:

  • Calcium. As I mentioned earlier, proper calcium intake is key—especially for kidney stone sufferers. When patients hear that kidney stones are formed from calcium oxalate or calcium phosphate, their first instinct is to avoid calcium supplementation. But that’s a huge mistake. In fact, calcium reduces oxalate absorption and lowers the risk of stone formation. So in addition to eating calcium-rich foods (like almonds, broccoli, and kale), take a calcium citrate supplement. I recommend 500 mg per day.
  • Vitamin B6. Studies show that a combination of magnesium and vitamin B6 (pyridoxine) may be able to dramatically reduce kidney stone recurrence.4-5
    A comprehensive vitamin B Complex formula with approximately 55 mg of B6 should cover your bases.
  • Magnesium. I recommend either magnesium orotate (32 mg per day) or taurate (125 mg per day). These forms are the ones best absorbed by the body.

Then, of course, there are my recommendations for general kidney health. I covered my complete protocol back in the August 2012 issue (“The silent killer hiding behind the diabetes epidemic”). Ad if you have a history of kidney stones, it’s absolutely worth revisiting. (To access my archives simply visit my website, www.DrPescatore.com, and log in to the Subscribers page with your username and password.)

The bottom line: With proper hydration, a sensible diet, and regular supplementation, you can avoid the agonizing, paralyzing pain of kidney stones—not just in the summer, but all year long.


    1. Thornton SN. Eur Urol. 2012 Sep;62(3):e67.
    2. Kittanamongkolchai W, et al. Mayo Clin Proc. 2018 Mar;93(3):291-299.
    3. Moore LW, et al. Am J Clin Nutr. 2015 Aug;102(2):444-53.
    4. Gershoff SN, et al. Am J Clin Nutr. 1967;20(5):393-399.
    5. Prien EL, et al. J Urol. 1974; 112:509-512.