Does Coffee Cause Kidney Stones?

Around 500,000 Americans go to emergency rooms each year because of kidney stone problems, with rough estimates stating one in ten will have one at some point in their life. But while living with lowered kidney function can open you up to a number of health issues that will inevitably restrict your diet, one question you may ask yourself is whether coffee causes kidney stones. 
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The short answer is no, coffee does not directly cause kidney stones. However, decreased kidney function is often a symptom of other diseases that could, in fact, cause kidney stones such as gout or diabetes.

Here we'll go over more details about kidney stones, their causes, and the effects that various food types may have on them.

What Is a Kidney Stone?

Your kidneys filter out chemicals from your bloodstream and then expel them from the body via urine; and kidney stones are hardened objects composed of these chemicals. However, under the right conditions (dehydration, eating too much salt or sugar, or due to certain diseases) these chemicals can crystallize inside of the kidneys if there isn't enough fluid to dissolve them. 

While kidney stones themselves aren't a serious health issue, they can be extremely painful to pass and if the build-up is significant enough, removing them via surgery may be required.

Is Coffee Bad For Kidney Stones?

Current data suggests that no, coffee is not bad for kidney stones. As a matter of fact, recent studies have shown that coffee and caffeine consumption can actually prevent kidney stones. One study, published by the National Kidney Foundation, states:

"Our findings show that going from, for example, one cup a day to 1.5 cups per day, reduces the risk of kidney stones by 40 percent,'” said co-author of the study, Susanna C. Larsson, PhD, Institute of Environmental Medicine, Karolinska Institute, Stockholm. “Our findings strongly suggest that regular coffee consumption reduces the risk of kidney stone formation.”
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So, you can breathe a sigh of relief knowing your daily wake-me-up won't cause kidney stones!

Does Caffeine Cause Kidney Stones?

According to currently available research, no, caffeine does not cause kidney stones. Connections between caffeine and kidney stones are still being observed, however, and it is important to recognize some misconceptions that may lead you to false conclusions. 

One such misconception is that coffee causes dehydration. Yes, dehydration can cause kidney stones and yes, caffeine is a diuretic, meaning it increases urine production. But coffee, and caffeine in general, does not actually cause dehydration because the fluids present in a cup of coffee balance out any diuretic effects.

However, drinking too much caffeine is linked to serious health conditions, so drink your coffee in moderation.

What Are the Best Drinks For Your Kidneys?

Staying hydrated is the best way to combat kidney stones and keep your kidneys healthy. Here are a few of the best options:

• Water — By far the best way to stay hydrated is to drink regular, reliable water. It has no calories, is usually readily available, and is the healthiest thing to drink on a daily basis. Keep in mind that if you do have CKD or another kidney disorder, your doctor may limit the amount of water (and other fluids) you can drink in a day to avoid overhydration.
• Unsweetened herbal or green teas — If you aren't the biggest fan of plain water, unsweetened herbal tea is a tasty, zero-calorie alternative. Green tea's caffeine may also help to reduce the risk of kidney stones and is perfectly safe even for kidney disease patients.
• Black coffee — The key to ensuring coffee consumption has minimal negative effects on the kidneys is to drink it black. Again, coffee and caffeine themselves do not dehydrate the body, so as long as it is consumed in moderation it will not harm your kidneys.
• Sparkling water — For people who love soda, sparkling water with a squeeze of lemon (or other citrus) juice, cranberry juice, or mint is a great healthy alternative that isn't harmful to your kidneys! However, not all sparkling water is created equally so be sure to read nutritional facts to ensure there are no harmful additives.

What Drinks Are Bad For Your Kidneys?

• Sodas — Soda is high in sugar and thus linked to increased risk of kidney disease. This, in turn, makes soda — and any other high-sugar drink — one of the most harmful drinks to your kidneys. Additionally, another ingredient commonly found in sodas (both diet and regular) is phosphoric acid, which is directly linked to the formation of kidney stones.
• Juices that are high in sugar — People are generally aware that soda is bad for you, but deceptive marketing may have you thinking that juice is a healthy alternative. However it is often the case that these juices contain just as much sugar as a soda. When taking your kidney health into consideration, be sure to read labels as you browse the aisles of your local grocery store to avoid added sugar!
• Alcohol — Once more, alcohol contains sugar, which is bad for kidneys. But while sugar levels generally aren't as high as soda, the biggest issue is that people drink a lot of it in one sitting all too often. Additionally, alcohol can cause kidney issues indirectly due to how it affects other organs/bodily functions, making it clear how damaging it can be to overall health.

​One common misconception that our nephrologists see is that milk is a cause of kidney stones, due to the calcium it contains. As its namesake may lead you to believe, calcium stones are avoidable if you avoid calcium, right? Wrong. Most calcium stones are created from oxalates, which are not found in dairy milk. 

Non-dairy milk, however, is not rich in calcium but is usually derived from ingredients that do contain oxalates, such as nuts and other plants. This means non-dairy milk is more likely to cause development of kidney stones than dairy milk.
Avoiding milk, which otherwise has health benefits, because you are worried about kidney stones is not recommended. For more details, read our full post on the topic.

Milwaukee Nephrologists are Leaders in Renal Health

Being health-conscious and informed is the best way to protect your overall kidney health. Read nutrition labels, watch what you eat, and consume harmful foods such as soda and alcohol in moderation, if at all. 
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However, these recommendations change drastically if you are already affected by a kidney disorder or if you suspect you may have a kidney disorder. For patients that have concerns about their renal health or want to know how to follow a kidney-friendly diet, talk to Milwaukee Nephrologists today!