Coffee and the Real Risk of Kidney Injury

Coffee and the Real Risk of Kidney Injury


This is a review of a study that was conducted by the Johns Hopkins University School of Medicine, and was published in the Journal Kidney International Reports, which shows a correlation between coffee consumption and Acute Kidney Injury.

The Findings

The findings, which were published in the journal Kidney International Reports, showed that those who drank any quantity of coffee every day had a 15% lower risk of Acute Kidney Injury.

The largest reductions were seen in the group who drank two to three cups a day (they showed a 22% to 23% lower risk).


Dr. Chirag Parikh, MD, PhD the Director of the Division of Nephrology, and a Professor of Medicine at the Johns Hopkins University School of Medicine said, "We already know that drinking coffee on a regular basis has been associated with the prevention of chronic and degenerative diseases including type 2 diabetes, cardiovascular disease and liver disease, we can now add a possible reduction in AKI risk to the growing list of health benefits for caffeine."

Acute Kidney Injury

What is Acute Kidney Injury and over what timescale does it build up? Acute Kidney Injury, as defined by the National Kidney Foundation as a: 

"Sudden episode of kidney failure or kidney damage that happens within a few hours or a few days."

This causes waste products to build up in the blood, making it hard for kidneys to maintain the correct balance of fluids in the body.

AKI Symptoms

So, how can you tell if you are suffering from Acute Kidney Injury? Unfortunately the symptoms of Acute Kidney Injury differ depending on the cause, but may include the following:

  • Too little urine leaving the body
  • Swelling in the legs and ankles, and around the eyes
  • Fatigue
  • Shortness of breath
  • Confusion
  • Nausea
  • Chest pain, and¬†
  • In the most severe cases - seizures or even coma

The disorder is most commonly seen in hospitalized patients whose kidneys are affected by medical stress and/or complications.

The Cohort

Using data from the ‚ÄúAtherosclerosis Risk in Communities Study‚ÄĚ - this is an ongoing survey of cardiovascular disease in four U.S. communities. The researchers assessed 14,207 adults who were recruited between 1987 & 1989, with a median age of 54.¬†

Participants were surveyed 7 times over a 24-year period as to the number of 8-ounce cups of coffee they consumed per day, and categorized as zero, one, two to three, or more than three. 

During the survey period, there were 1,694 cases of acute kidney injury recorded.

The Results

The researchers accounted for demographic characteristics, socio-economic status, lifestyle influences and also dietary factors, and found there was a 15% lower risk of Acute Kidney Injury for participants who consumed any amount of coffee versus those who consumed none at all.

Even when adjusting for additional comorbidities such as blood pressure, their BMI score, diabetes status, use of anti-hypertensive medication and overall kidney function; the individuals who drank coffee still had an 11% lower risk of developing Acute Kidney Injury when compared with those who chose to abstain from coffee.


Professor Parikh said, "We suspect that the reason for coffee's impact on AKI risk may be that either biologically active compounds combined with caffeine or just the caffeine itself improves perfusion and oxygen utilization within the kidneys.

Good kidney function and tolerance to AKI is dependent on a steady blood supply and oxygen."

Dr. Parikh went on to say that, “More studies are needed to define the possible protective mechanisms of coffee consumption for kidneys, especially at the cellular level.

Caffeine has been postulated to inhibit the production of molecules that cause chemical imbalances and the use of too much oxygen in the kidneys, perhaps caffeine helps the kidneys maintain a more stable system."

Further Comments

Dr. Parikh and his colleagues note that coffee additives such as milk, half-and-half, creamer, sugar and/or sweeteners also could influence Acute Kidney Injury risks and most certainly warrant further investigation. 

Additionally, the authors say that consumption of other types of caffeinated beverages, such as tea or soda, should be considered as a possible confounding factor.


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