What happens to your kidneys when you drink coffee regularly?

Drinking coffee every day not only helps with alertness, improves concentration, and reduces fatigue, but may also offer some benefits for kidney health. But the effects depend on the amount consumed, brewing method, and the drinker’s health.

A cup ofhot black coffee with bubbles in a white porcelain cup. Photo by Pexels

Supporting and protecting kidney function

"In coffee drinkers, there’s a decreased risk of type 2 diabetes, Parkinson’s disease, liver disease, certain cancers including liver cancer, depression and suicide, kidney stones and gallstones, and overall mortality," Donald D. Hensrud, M.D., M.S., medical editor of The Mayo Clinic, a U.S. research magazine, says.

A 2018 study published in the journal Nephrology Dialysis Transplantation analyzed data from more than 4,860 adults with chronic kidney disease in the U.S.

Participants were divided into four groups based on their daily caffeine intake.

They consumed under 28.2 mg of caffeine per day (equivalent to less than a third of a cup of black coffee), 28.2–103 mg, 103–213.5 mg, and more than 213.5 mg (two or more cups).

Over a five-year follow-up period, approximately 1,280 participants died. After adjusting for confounding factors, the results showed that all three higher caffeine consumption groups had a lower risk of death compared to the lowest, with reductions ranging from 22% to 26%.

Reducing kidney stones

According to the U.S National Kidney Foundation, caffeine increases urine volume, which can help reduce the accumulation and crystallization of stone-forming minerals in the urinary tract.

Some studies have noted a reduced risk of kidney stones in people who regularly consume coffee, but this does not mean drinking more coffee is better, according to Verywell Health, a health information website reviewed by medical professionals.

But experts recommend that healthy adults limit caffeine intake to around 400 mg per day, equivalent to three or four standard cups of brewed coffee.

Excessive intake can cause insomnia, restlessness, anxiety, and even heart palpitations. Caffeine can also cause a mild short-term rise in blood pressure, particularly in those who are sensitive to it.

Besides, the benefits may be diminished if the coffee is regularly made with large amounts of sugar, condensed milk, heavy cream, or flavored syrups, which increase sugar and calorie intake.

People with kidney disease, high blood pressure, or other underlying health conditions should consult a doctor about the appropriate caffeine intake.