Having a kidney stone is considered one of the most painful experiences you can have, even worse than childbirth. While the stones may be physically tiny, often measured in millimetres, they can feel like tiny little mines exploding as the stone makes its way through the urinary tract. Sometimes, these stones can lead to complications, like kidney infections, urinary tract infections and even sepsis, that require medical intervention.
Kidney stones are tiny accumulations of minerals and salts that form in the kidney. The most common type of kidney stone are calcium stones, which fall into two different subcategories ― calcium oxalate stones and calcium phosphate stones. The pain occurs when the stone tries to pass through the ureter to the bladder and urethra (for men).
Unfortunately, it’s a fairly common disease. The National Institute of Diabetes and Digestive and Kidney Diseases reported that in the U.S. around 11% of men and 6% of women have had at least one kidney stone. And unfortunately, if you’ve had one stone, there’s about a 50% possibility of it recurring, noted Dr. John Hollingsworth, attending urologist and chief of acute care quality and patient safety at Endeavour Health NorthShore Hospitals.
Dr. Amy Krambeck, a urologist at Northwestern Memorial, points out that kidney stones are not to be taken lightly. Not all stones pass, Krambeck said, and complications can occur, including kidney infection and even sepsis. So seek treatment to deal with stones and work to prevent stone formation.
But here’s some good news: Changing your diet can make a huge difference in kidney stone formation and recurrence.
While there’s a lot of information out there about what to avoid, there are some general things that people eat and drink that might prevent kidney stones from forming in the first place.
Drink more fluids.
The biggest diet change you can make is drinking more fluids. “Everybody thinks they drink a lot,” said Dr. Amy Krambeck, a urologist at Northwestern Memorial. “But if they do a test where they measure the amount of fluids they drink, they find out that they’re not drinking nearly as much as they think they are.” It does not have to be water, she noted ― people can drink other things, but water is the least irritating to the system.
The general recommendation from doctors is to drink between 2-3 litres of fluid a day to produce 2.5 litres of urine, potentially more if you exercise since fluids get lost with sweat. Make sure to space out the fluids during the day. Hollingsworth explained that drinking fluids helps to “flush the kidneys throughout the day, making the environment less suitable for precipitation of some of these crystals.”
Boost your citrus intake (but watch the sugar).
In addition to drinking lots of fluids, Krambeck recommends “prioritising a diet that’s high in citric acid or natural citrus fruits.” That includes lemons, limes and oranges, as well as drinks like Crystal Light Lemonade or squeezing some lemon juice into water. The citric acid helps to prevent crystallisation in the kidney.
Dr. Matthew Lee, a physician in urology at Ohio State Wexner Medical Center, cautioned that if people choose juice, they should select low-sugar juices like low-calorie orange juice. Recent research suggests that too much sugar can contribute to kidney stone formation, not to mention causing other issues like diabetes and heart disease.
Up your calcium intake.
Another recommendation is including calcium in your diet. Krambeck noted that three servings, or 1,000-1,200 international units of calcium daily, will help reduce stone formation. That may seem paradoxical because calcium is one of the main ingredients in the majority of kidney stones, but Hollingsworth explained that in the past, when patients were advised to cut back on calcium, that resulted in people getting more stones.
Calcium, it turns out, can be helpful in preventing kidney stones. The idea is that the calcium can bind to the oxalates (the other most popular kidney stone component) in the gut, which are then excreted through the digestive system, instead through the kidney and the rest of the urinary tract. Plus, calcium is beneficial for healthy bones, so cutting it out can have a lot of health repercussions.
Keep in mind that calcium-rich foods go beyond your basic dairy items. Some of foods highest in calcium are almonds, tinned fish, lentils and leafy greens.
Try the Mediterranean Diet.
Another option is to follow the Mediterranean Diet, which includes lots of fruits and vegetables, Lee suggested. Besides helping to reduce kidney stones, it’s generally a good diet to maintain healthy blood pressure, healthy cholesterol, and manage Crohn’s Disease, to name a few.
Myths to bust
One popular misconception is that cranberry juice will help prevent stones. Hollingsworth noted that drinking cranberry juice may help with urinary tract infections, though the evidence is a bit “equivocal on its benefits,” he said, because the juice won’t necessarily help prevent kidney stones. It does have some citric acid in it, but it could be high in sugar.
Here’s another one: In the past, people prone to kidney stones have been told to avoid high-oxalate foods, like spinach, rhubarb or peanuts. But those foods can be good for us in other ways, such as providing antioxidants and vitamins. Krambeck avoids advising patients to have a low-oxalate diet as a result. She recommended eating those high-oxalate foods with a serving of cheese or a glass of milk to try to prevent kidney stones. Ultimately, it’s about keeping things in moderation, explained Krambeck. Spinach and peanuts do not need to be cut out of your diet necessarily. But you shouldn’t be eating an entire container of spinach or can of peanuts every day, she noted.
Foods to cut back on
There are some foods that might be worth cutting out. Universally, the doctors we spoke to recommend reducing sodium and animal proteins in your diet. As such, you should watch for processed food and canned foods, which are high in sodium. As for animal proteins, that’s all proteins, not just red meat. Lee explained that animal proteins can increase acid in your urine and decrease the amount of citrate in your system, which we know is super helpful to prevent stones.
Even for people who have genetic disposition or a chronic disease that increases their risk of stone formation, a diet change may help reduce stone occurrences. But it’s always best to work with a doctor who can help figure out what is the best treatment for you.
All the doctors interviewed recommended a 24-hour urine collection, which can tell doctors a lot about what is in your diet. That way, they can potentially make a personal recommendation for what you need to do in your diet. In some cases, medication may be needed in various situations (for example, if there’s too much calcium leaking into the kidney or too much uric acid in your system).