World Kidney Day 2023: Can excess consumption of coffee damage your kidneys?

Every year, March 9 is celebrated as World Kidney Day. Image for representational purpose only. Photo Courtesy: iStock

Drinking a cup of coffee to start the day is one of the most common habits around the world with many people enjoying its stimulating effect and rich flavour. "Coffee has long been established as having anti-inflammatory and anti-oxidant properties which appears to have a protective effect on chronic diseases, cardiovascular diseases, dementia and even cancer among others," says Dr. Garima Aggarwal, consultant nephrologist and transplant specialist at Manipal Hospital, Bengaluru.

According to Aggarwal, research in the past has shown a lower risk of kidney diseases among self-reported coffee drinkers. However, she adds, "Measuring the impact of coffee on health is not that simple - because coffee itself contains several chemical compounds, some good and some bad for the kidneys. The amount of these compounds in the blood depends on various factors like - type of coffee bean used, brewing method, roast, quantity consumed and also a person's genes."

How much coffee is too much?

"According to a recent data, some people metabolise coffee slowly in their bodies. If they take an excess of three cups of coffee a day, harmful chemicals get collected in the blood and hence they are three times more likely to develop kidney dysfunction. Almost half the population may have the gene variant causing slow metabolism of coffee. This means that some people may be more sensitive to the effects of caffeine than others, and may need to limit their intake accordingly. In 2021, a study in the Clinical Journal of American Society of Nephrology showed that coffee consumption was associated with the presence of at least 20 metabolites or chemicals in the blood, two of which are known to have detrimental effects on kidney health," explains Aggarwal.

Additionally, patients who already suffer from kidney diseases have specific dietary restrictions. Below, Aggarwal lists five things patients must keep in mind about consuming coffee:

1. One cup of coffee (especially black coffee) is actually low in potassium. However, if you take two or three cups of this in a day as a kidney patient, then you're taking a high amount of potassium. Health experts usually recommend a diet that is low in potassium for kidney patients as they are not able remove excess potassium from their bodies.
2. Addition of milk or creamer to coffee contains additional potassium and phosphorus, which is to be restricted.
3. Sugar in coffee is not recommended for diabetics, pre-diabetics and those with calorie restrictions.
4. Excessive coffee consumption adds to the daily fluid intake. Kidney patients need to carefully monitor their daily fluid intake. Excessive fluid intake can lead to fluid buildup in the body.
5. Coffee is a diuretic, which means it increases urine output and can contribute to dehydration if consumed in excess.

Coffee can be a delicious and healthy part of your diet if you consume it in moderation and according to your individual needs. To conclude, Aggarwal reiterates, "In general, you should avoid consuming more than 2 to 3 cups of coffee a day. If you have a history of kidney disease or risk factors for it (such as diabetes or high blood pressure), consult your doctor or dietician before drinking coffee or other caffeinated beverages."

Read More: World Kidney Day 2023: Experts say swelling in feet could be first signs of kidney trouble