If you have kidney disease, you’ve probably learned how diet affects your condition. Eating healthy is important for all types of kidney disease, including rare forms, such as complement 3 glomerulopathy (C3G) and immune complex membranoproliferative glomerulonephritis (IC-MPGN). This may make you wonder whether you should give up your morning coffee.

The good news is that coffee isn’t likely to harm your kidneys in most cases. In fact, it might even help improve kidney health. But there are a few things to keep in mind before you pour your next cup of joe. Here are four facts to help you decide whether to keep drinking coffee.

1. Coffee May Help Prevent Kidney Disease

For people with healthy kidneys, coffee doesn’t cause kidney damage. Some studies even suggest that drinking coffee could lower the risk of kidney disease.

One study looked at 14,209 people aged 45 to 64. Over the course of eight years, researchers found that coffee drinkers had an 11 percent lower risk of developing chronic kidney disease (CKD) compared to those who never drank coffee. The risk of being diagnosed with chronic kidney disease dropped by 3 percent for every extra cup of coffee consumed daily.

Another study reviewed 227,666 people aged 40 to 73. The study found that drinking an extra cup of coffee every day lowered the risk of developing severe kidney disease (stages 3 to 5).

A third study analyzed data from 505,841 people between 1960 and 2020. It showed that coffee consumption was linked to lower rates of chronic kidney disease. Drinking two or more cups of coffee daily was linked to an even lower risk of chronic kidney disease than drinking just one cup. Coffee drinkers also had a lower risk of dying from CKD.

Keep in mind that these studies focused on people without other health conditions, such as genetic variants (mutations) linked to rare kidney diseases, autoimmune conditions, or chronic illnesses. If you have another health condition, the impact of coffee consumption on your kidney health might be different.

For example, one study looked at the caffeine intake of 5,851 obese or overweight people aged 55 to 75. It found that those who drank two or more cups of caffeinated coffee daily had a higher risk of reduced kidney function.

Newer research confirms that this protection follows a “dose-response” pattern — meaning the more coffee you drink (up to a certain point), the lower your risk of CKD. For example:

• 1 cup per day: 13 percent lower CKD risk
• 2-3 cups per day: 18 percent lower CKD risk

Specialists believe this is because coffee contains powerful antioxidants and anti-inflammatory compounds that help protect kidney function over time. Both caffeinated and decaffeinated coffee showed similar benefits.

The same study also found that coffee might be more protective in men than women. Men who drink two or more cups of coffee a day may have a lower risk of ESRD (end-stage renal disease, or kidney failure), but this effect isn’t seen in women.

If you’re worried about your risk of developing kidney disease, talk to your doctor about whether coffee is safe for you.

2. Coffee Is Usually Safe for People With Kidney Disease

Fatigue is a common symptom of kidney disease, and many people turn to coffee or other caffeinated drinks for energy. The good news is that most people with kidney disease can safely drink coffee.

A study of 62,160 people with chronic kidney disease over 11 years found that those who drank caffeinated beverages were less likely to die from any cause.

If you have early-stage kidney disease, you’re encouraged to drink about eight glasses of water or other fluids daily. This can help your kidneys work properly. Coffee counts toward this fluid intake.

However, if you have advanced kidney disease or kidney failure, your nephrologist will likely ask you to limit fluids, including coffee. This is particularly true if you’re on dialysis, since people on dialysis are often advised to drink 32 ounces of fluid or less per day.

If you’ve had a kidney transplant, ask your doctor if coffee is safe for you. They may recommend limiting your caffeine intake or switching to decaf as part of your post-transplant diet to protect your new kidney.

Coffee and other caffeinated drinks can interact with certain medications (both prescription and over-the-counter). Always ask your doctor or pharmacist if it’s safe to drink coffee while taking your current medications.

3. Don’t Overdo It

If you have kidney disease, it’s best to limit your coffee intake to fewer than three cups a day. This is a general rule for regular coffee, but drinks like espresso may contain less caffeine than brewed coffee.

One reason for this limit is coffee’s potassium content. People with kidney disease often need to watch their potassium intake. Too much or too little potassium can cause imbalances that may lead to heart problems or muscle weakness.

An eight-ounce cup of coffee contains about 116 milligrams of potassium. Adding creamer, milk, or flavored syrups can increase potassium levels, which could be dangerous if you have decreased kidney function. Be mindful of high-potassium breakfast foods you might eat with coffee, like bananas or avocados. If you’re unsure about your potassium intake, speak to a dietitian.

Another reason to limit your intake to three cups of coffee is that some people have a gene variant (CYP1A2) that makes them metabolize caffeine more slowly. This means that caffeine stays in their system for longer after drinking coffee.

A study found that people with this gene and high blood pressure who consumed high levels of caffeine were more likely to develop kidney complications.

4. Keep an Eye on Your Blood Pressure

Drinking coffee or other caffeinated drinks can temporarily raise your blood pressure. High blood pressure is the second leading cause of kidney failure in the U.S., after diabetes. For people with chronic kidney disease, a rise in blood pressure could worsen kidney function.

Whether or not you have kidney disease, your doctor will work with you to keep your blood pressure stable. Let them know how much coffee or other caffeinated products you consume so they can consider this when working with you on solutions to keep your blood pressure in check.

Consult Your Nephrologist

If you’re unsure about whether coffee is safe for your kidneys, talk to your healthcare provider. They can offer personalized advice based on your health needs. They may also refer you to a registered dietitian-nutritionist. This specialist can help create a healthy eating plan for you, including specific guidelines about coffee.

Talk With Others Who Understand

MyKidneyDiseaseTeam is the social network for people with rare kidney diseases and their loved ones. On MyKidneyDiseaseTeam, members come together to ask questions, give advice, and share their stories with others who understand life with rare kidney diseases.

Do you drink coffee? Have you changed the amount of coffee you drink since your diagnosis? Share your experience in the comments below, or start a conversation by posting on your Activities page.