Coffee, one of the most popular beverages worldwide, is enjoyed by millions of people for its stimulating effects and rich aroma. While moderate coffee consumption has been associated with several health benefits, concerns have been raised regarding its impact on kidney health. To learn about the harmful effects of coffee on kidneys, we spoke to Dr Tarun Kumar Saha, Sr Consultant Nephrologist and Transplant Physician, Yashoda Hospitals, Hyderabad.
"Coffee contains caffeine and antioxidants, with the latter being responsible for many of its positive effects, including kidney protection. However, as with most things, excessive consumption can be harmful to the organ," said Dr Saha.
How much Coffee is Okay?
According to Dr Saha, "A typical cup of coffee contains around 80 mg to 100 mg of caffeine, and the Food and Drug Administration (FDA) recommends a maximum daily intake of 400mg of caffeine. This translates to a limit of four cups of coffee per day."
"It's important to note that other beverages like tea, energy drinks, and soda also contain caffeine. If these are part of one's diet, it's crucial to consider their caffeine content alongside coffee," he added. "Consequently, if other sources of caffeine are present, consuming four cups of coffee might exceed the recommended limit," he added.
Effects of Coffee On Kidney
Drinking beverages that contain caffeine, like coffee and tea, can make you pee more calcium, which may increase the chance of getting kidney stones. However, in our previous studies, we found the opposite. We discovered that people who drink coffee and tea have a lower risk of getting kidney stones.
According to a study published by The American Journal of Clinical Nutrition, caffeine intake is associated with increased urinary calcium excretion and, as such, could potentially increase the risk of developing kidney stones. However, in their previous reports, they consistently found an inverse association between the consumption of caffeine-containing beverages, such as coffee and tea, and the risk of incident stones.
"A 2022 study published by Frontiers in Nutrition, revealed that while caffeine intake from coffee was associated with a lower risk of kidney stone formation in white non-overweight women, the same effect was not observed with caffeine from other sources," said Dr Saha.
Blood Pressure and Kidney Health
"Individuals with uncontrolled high blood pressure should restrict their coffee intake to less than three cups per day," said Dr Saha. Caffeine has been shown to have a short-term hypertensive effect, but this is generally mild and temporary. Regular coffee consumption does not appear to have a significant impact on long-term blood pressure or kidney health in most individuals, particularly when consumed in moderation.
High-Calorie Intake
"Another significant concern lies in what is added to coffee. Sugar and cream, for instance, can increase calorie intake and contribute to obesity and diabetes, which have a negative impact on kidneys," said Dr Saha.
Metabolism of Caffeine
"As with many diseases, the impact of drug or food intake is linked to genetic variations," said Dr Saha.
"A recent study conducted by the University of Toronto found that a specific genetic variation of CYP1A2, which affects the metabolism of caffeine, is associated with a threefold increased risk of developing kidney dysfunction," added the doctor.
Moderation is Key
"Until further research sheds more light on this topic, it is advisable to consume a maximum of three cups of coffee per day to obtain optimal benefits without posing any risks to the kidneys," he said.
Conclusion
While coffee can offer health benefits due to its caffeine and antioxidant content, moderation is key. Exceeding the recommended caffeine intake can have harmful consequences, including kidney dysfunction. Monitoring caffeine consumption from all sources, limiting additives like sugar and cream, and considering individual genetic variations are essential factors to safeguard kidney health. By being mindful of these factors, one can enjoy the positive aspects of coffee while minimizing any potential harm to the kidneys.
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