Perhaps you’ve heard that salt is related to kidney stones. Spoiler alert: it is! Salt can cause kidney stones. But how? And how much salt can you eat with kidney stones?
Let’s dive into all things salt and kidney stones!
Table of Contents
What is a Kidney Stone?
A kidney stone is a crystallization of minerals that form in your urine. The most common type of kidney stone is made of calcium and oxalate. Kidney stones can also be made of phosphate, struvite, cystine or uric acid.
Kidney stones can form anywhere in the urinary tract. They most often form in the kidney, but can also form in the bladder.
Kidney stones are more likely to form when there are more stone-forming elements in your urine, such as calcium or oxalate.
How Does Salt Cause Kidney Stones?
Eating too much salt causes kidney stones by increasing how much calcium is in your urine. High urine calcium is one of the most common causes of kidney stones. (1)
How does this happen? The answer lies within how your kidneys handle salt.
Nearly all of the salt you eat gets excreted in your urine. Your body will hold onto a small amount of salt that it needs, but most of the salt we eat ends up in your urine. In order for your kidneys to get rid of that salt, they also have to get rid of calcium. This is simply how kidneys the kidneys work! So, the more salt you eat, the more calcium ends up in your urine. Higher urine calcium can cause kidney stones. (2)
Side note: Although high urine calcium causes kidney stones, eating foods high in calcium does not. In fact, eating enough calcium is key to oxalate kidney stone prevention!
How Much Salt Can You Eat with Kidney Stones?
Of course, the goal is not to completely avoid salt. Your body needs some salt to function properly! However, most of us are eating way more salt than we need.
The American Urological Association recommends a goal of 2,300mg of sodium per day. (3) The guidelines specify that a limit on sodium is important for people with calcium kidney stones and high urine calcium. A goal of 2,300mg is also how much salt the Dietary Guidelines for Americans recommends for general health.
The average American eats about 3,200mg of sodium each day. (4) This is about 40% more salt than we should be eating.
How to Eat a Low Salt Diet
The first step to a low salt diet for kidney stones is to read nutrition labels. So often, people think they are not eating a lot of salt diet because they don’t add salt to their food. However, about 80% of the salt we eat is already in the foods we eat. The most effective way to reduce your salt intake is to limit really salty foods!
Some of the saltiest culprits of hidden salt are:
- Salad dressing
- Deli and other processed meats
- Sauces & condiments
- Pickled foods & olives
- Prepackaged and convenience foods
- Fast food
In general, minimally processed foods are very low in sodium. Some examples are:
- All fruits
- All vegetables
- Grains (rice, quinoa, barley, etc.)
- Milk and yogurt
- Meat, Chicken, Fish & Seafood
The most common complaint I get when people start to take the salt out of their diet is that it is bland. A low salt diet shouldn’t be flavorless! There are tons of wonderful salt substitutes you can safely use to make your food delicious.
What Kind of Salt is Best For Kidney Stones?
There is a lot of la-dee-da out there about different kinds of salt. But, they are all essentially the same from a nutrition standpoint. One type of salt is not better for kidney stones.
All types of salt have about the same amount of sodium per serving. Some do have very tiny amounts of minerals in them. However, the amount of minerals you would realistically get from salt is negligible. It would not be enough to impact overall health unless you were eating dangerous amounts of salt.
What Else Can Cause Kidney Stones?
Nutrition for kidney stones is much more than salt! (5) Depending on your urine risk factors, there are many changes you could make to prevent kidney stones. Some of the most common changes I recommend for my students are:
- Drink more fluid
- Eat less non-dairy animal protein
- Eat more calcium-rich foods
- Eat less added sugar
- Eat more fruits and vegetables
- Avoid very high oxalate foods
Ultimately, there is NO single kidney stone diet that works for everyone. Nutrition for kidney stones MUST be personalized to your 24-hour urine test results. I help people learn