Yet another study showing how coffee can improve your health
By JOHNS HOPKINS MEDICINE
If you needed more justification to start your day with a cup of joe, a new study by Johns Hopkins Medicine researchers found that drinking at least one cup of coffee daily may lower the risk of acute kidney injury (AKI) as compared to those who don’t.
The results, which were recently published in the
journal Kidney International Reports, revealed that daily coffee
consumption was associated with a 15 percent reduced risk of AKI, with the
greatest decreases being seen in those who drank two to three cups (a 22
percent to 23 percent lower risk).
“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,” says study
corresponding author Chirag Parikh, M.D., Ph.D., director of the Division of
Nephrology and professor of medicine at the Johns Hopkins University School of
Medicine. “We can now add a possible reduction in AKI risk to the growing list
of health benefits for caffeine.”
The National Kidney Foundation defines AKI as “a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days.” The kidneys struggle to maintain the proper balance of fluids in the body as a result of the waste products that accumulate in the blood.
The signs and symptoms of AKI might vary depending on the
underlying cause and can include: insufficient urine output; swelling in the
legs, ankles, and eye area; weariness; shortness of breath; mental
disorientation; nausea; chest pain; and, in more severe instances, seizures or
coma. The condition is most often seen in hospitalized individuals whose
kidneys have been stressed by medical and surgical procedures and
complications.
Researchers examined 14,207 people with a median age of 54 who
were recruited between 1987 and 1989 in the Atherosclerosis Risk in Communities
Study, a continuing investigation of cardiovascular disease in four communities
in the United States. Over the course of a 24-year period, participants were
questioned seven times about how many 8-ounce cups of coffee they drank per
day: 0, 1, 2 to 3, or more than 3. 1,694 instances of acute kidney
injury were reported throughout the study period.
When accounting for demographic characteristics, socioeconomic
status, lifestyle influences, and dietary factors, there was a 15% lower risk
of AKI for participants who consumed any amount of coffee versus those who did
not. When adjusting for additional comorbidities — such as blood pressure, body
mass index (BMI), diabetes status, use of antihypertensive medication, and
kidney function — individuals who drank coffee still had an 11% lower risk of
developing AKI compared with those who did not.
“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,”
says Parikh. “Good kidney function and tolerance to AKI — is dependent on a
steady blood supply and oxygen.”
More studies are needed, Parikh says, 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,” he explains. “Perhaps caffeine helps the kidneys maintain a more
stable system.”
Parikh and his colleagues note that coffee additives such as milk,
half-and-half, creamer, sugar, or sweeteners also could influence AKI risks and
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.
Reference: “Coffee Consumption May Mitigate the Risk for Acute
Kidney Injury: Results From the Atherosclerosis Risk in Communities Study” by
Kalie L. Tommerdahl, Emily A. Hu, Elizabeth Selvin, Lyn M. Steffen, Josef
Coresh, Morgan E. Grams, Petter Bjornstad, Casey M. Rebholz and Chirag R.
Parikh, 5 May 2022, Kidney International Reports.
DOI: 10.1016/j.ekir.2022.04.091