Can eating too much protein cause kidney stones

It’s a diet smorgasbord out there … and you want — no, you NEED – to know which one will get you results. You’ve finally picked your winner: a high-protein diet.

Table of Contents Show

Can high-protein diets cause kidney damage?
Should everyone avoid a high-protein diet?
How can you protect your kidneys and lose weight, too?
Calcium Oxalate Stones
Calcium Phosphate Stones
Uric Acid Stones
Cystine Stones
How much protein is too much for kidney stones?
Can Eating too much protein cause kidney problems?
Is high protein hard on kidneys?
What diet causes kidney stones?

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But before you start chowing down on steak, read the fine print: “Consult with your doctor before starting any diet plan.”

Too much protein can impact how your body works, and particularly how it gets rid of waste. Nephrologist Juan Calle, MD, has the lowdown on high protein.

Can high-protein diets cause kidney damage?

Your kidneys play a critical role in your overall health. They filter waste, acids and extra water from your body. But eating all that protein takes a toll.

“Eating a lot of protein, especially animal protein and red meat, creates more acid and toxins in the body,” Dr. Calle explains. “And it puts more pressure on the kidneys to filter and process all of those substances.”

As we age, it’s normal for our kidneys to experience wear and tear. The added stress of a high-protein diet can contribute to kidneys losing their protein-processing powers. It becomes harder for them to keep the protein for your body to use, so more and more comes out in your urine.

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“Protein that comes out in the urine is a reflection of kidney damage,” Dr. Calle says.

He notes that while there have been studies that seem to link protein-rich diets directly to kidney damage, the jury’s still out on these findings. So don’t panic, but do use caution.

Should everyone avoid a high-protein diet?

Dr. Calle advises patients with chronic kidney disease to take the “better safe than sorry” route. “They probably should limit protein,” he says.

His advice also applies to people who have a history of kidney stones or certain rare genetic conditions like phenylketonuria (PKU). “That can put them at higher risk of forming kidney stones, which may potentially affect their kidney function, too.”

But even if your kidneys seem to be firing on all cylinders, it’s still a good idea to check with a doctor before making any drastic changes to what you eat. Diets aren’t one-size-fits-all. A doctor can help you find an eating plan that’s appropriate for your health goals.

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How can you protect your kidneys and lose weight, too?

For weight loss that won’t compromise your kidneys, it’s all about balance.

“Don’t get your calories from one source — combine protein with more fruits and vegetables,” Dr. Calle recommends. “If you don’t have any major medical conditions, the most effective diet is usually decreasing the amount of calories you consume and eating a more balanced, low-sodium diet.”

And buyer beware when it comes to the health fads that show up on social media. Your favorite Instagram celebrity may look amazing after following some new grapefruit shake diet, but stick with your doctor, nutritionist or dietitian for reliable eating advice.

A kidney stone is exactly that -- a hard mass of minerals and salts that forms in the kidneys. Certain foods and drinks contain chemicals that can lead to these sometimes painful crystals. The stones come in several different types, and foods that are not so good for one kind may be OK to eat if you have another type.

If you’ve had a kidney stone, ask your doctor which it was. That’ll help you know which foods to avoid.

But if you aren’t sure -- or if you just want to be careful about all types of kidney stones -- a good rule is to stay away from too many salty foods and meats and other animal protein.

And don’t forget to drink lots of water. It helps dilute the waste in your urine to make stones harder to form.

Calcium Oxalate Stones

More people get this kind than any other. It forms when calcium in your pee combines with oxalate, a chemical that's naturally in many foods.

If you’ve had one of these, watch out for:

High-oxalate foods. Many plants contain oxalate, so it’s hard to avoid it entirely. But some foods have much more than others. Try to limit:

Spinach
Rhubarb
Almonds and cashews
Miso soup
Grits
Baked potatoes with skin
Beets
Cocoa powder
Okra
Bran cereals and shredded wheat cereals
French fries
Raspberries
Stevia sweeteners
Sweet potatoes

If you eat or drink calcium-rich foods at the same time, they can help your body handle oxalate without turning it into a kidney stone. So pair your spinach salad with low-fat cheese. Or mix nuts or berries into yogurt. Drinking milk does not cause kidney stones.

Salt. If you eat a lot of sodium, which is an ingredient in salt, that raises the amount of calcium in your urine. Once you finish eating, any extra oxalate “sticks” to calcium in the kidneys. That can produce stones. So limit canned foods, packaged meats, fast foods, and condiments in your diet.

Animal protein. Limit beef, pork, eggs, cheese, and fish, because they may raise your chances of most types of kidney stones.

Vitamin C. Too much can make your body produce oxalate. So don’t take more than 500 mg a day.

Calcium Phosphate Stones

These form when calcium in the urine combines with the mineral phosphorus. If you’ve had one of these, you don’t need to worry about oxalate. But do watch for:

Animal protein-rich foods:

Organ meats, like chicken or beef liver
Milk, cheese, and other dairy products
Eggs
Seafood

Foods that can make urine more alkaline, including:

Fresh fruit juices (except orange, cranberry, and nectarine)
Vegetable juices
Molasses

Processed foods. Phosphorus is a common additive and preservative. So limit fast foods, bottled colas, frozen foods, and luncheon meats. Read the label for ingredients starting with “phos.”

Sodium. Most Americans get too much already. Aim for no more than one teaspoon of table salt a day.

Uric Acid Stones

You get these if your pee is too acidic. These stones contain uric acid, a substance the body produces as it breaks down chemicals in food. Unlike with calcium oxalate and calcium phosphate stones, sodium isn’t a special issue here.

Animal protein. Eating too much red meat, poultry, eggs, and shellfish does two things. It makes your body make more uric acid. And it can rob your system of citrate, a substance that helps keep away kidney stones and maybe keep existing ones from growing.

To get enough protein, you can swap your meat and poultry for:

Beans, dried peas, lentils, and peanuts
Soy milk, soy butter, and tofu
Nuts, like almonds, walnuts, and cashews

Sugary drinks. Tart drinks like lemonade, limeade, and fruit juices are naturally high in citrate that helps keep kidney stones at bay. But hold back on foods and drinks flavored with sugar or, especially, high-fructose corn syrup. They can lead to stones.

Alcohol. It can make uric acid levels in your blood go up.

Cystine Stones

These come from a rare condition that runs in families called cystinuria. The disorder causes a natural substance called cystine to leak into your urine. Cystine stones tend to be larger than other types. If you’ve had one, you might have another.

Some issues you can watch for:

Too little water. Drink lots of water to help discourage cystine from forming stones.

Too much acid. Cystine stones grow more easily in acidic pee. That’s the opposite of calcium phosphate stones, which favor alkaline urine. So for this type of stone, curb your hunger for meat and eat more fruits and vegetables, which have lower acid levels.

Sodium: Once again, try not to overindulge on French fries, canned soups, packaged meats, and other salty foods.

Show Sources

SOURCES:

Cleveland Clinic: “Kidney Stones.”

Harvard Health Publications: “5 steps for preventing kidney stones.”

Mayo Clinic: “Kidney Stones,” “High uric acid level.”

National Institute of Diabetes and Digestive and Kidney Diseases: “Eating, Diet & Nutrition for Kidney Stones.”

National Kidney Foundation: “6 Easy Ways to Prevent Kidney Stones.”

University of Chicago Kidney Stone Evaluation and Treatment Program: “Kidney Stone Prevention Course.”

How much protein is too much for kidney stones?

We recommend that our patients with a history of stones restrict the amount of protein in their diets. Specifically, you should not exceed more than 80 grams of protein per day.

Can Eating too much protein cause kidney problems?

High dietary protein intake can cause intraglomerular hypertension, which may result in kidney hyperfiltration, glomerular injury, and proteinuria. It is possible that long-term high protein intake may lead to de novo CKD. The quality of dietary protein may also play a role in kidney health.

Is high protein hard on kidneys?

A high-protein diet may worsen how well a kidney works in people with kidney disease. This can happen because the body may not be able to get rid of all the waste products of protein that's broken down.

What diet causes kidney stones?

It is important to be mindful of the following foods that can lead to the formation of kidney stones in certain people: foods high in sodium, cola beverages, fast foods, processed meats, certain supplements, black tea, chocolate, spinach, soy milk, almonds, cashews, soy beans.