​​​​​​Taiwanese man develops kidney disease after years of improper coffee brewing

Hung Yung-hsiang, a nephrologist at a Taipei hospital, shared the case on Jan. 4 on his personal Facebook page as a warning about food safety risks, local news outlet ET Today said.

According to his post, the patient was taken to the hospital after collapsing during a morning run. Tests showed his estimated glomerular filtration rate had dropped below 10, indicating severe kidney failure, despite no history of diabetes, hypertension or gout.

Doctors found the man regularly bought large quantities of coffee beans at a discount and stored them in a kitchen cabinet for extended periods. He ground and drank the beans even after they changed color and developed mold, believing that brewing with boiling water at 100 degrees Celsius would eliminate harmful bacteria and fungi.

Coffee beans in a glass container. Photo by Pexels

Hung said boiling water does not destroy ochratoxin. The mold toxin is heat-resistant and only breaks down at temperatures above 280 degrees Celsius. Prolonged consumption of mold-contaminated coffee led to a buildup of toxins that gradually damaged the patient’s kidneys. Before collapsing, he had symptoms including persistent foamy urine and ankle swelling, which he attributed to intensive exercise.

He described ochratoxin as a "time bomb" to health. Unlike toxins that cause acute food poisoning and are cleared within days, ochratoxin remains in the body for 35-50 days. It damages the kidneys by triggering inflammation and cell death, impairing tubular metabolism, and causing chronic fibrosis of kidney tissue.

Hung compared ochratoxin exposure to pouring cement into a water filtration system, permanently clogging and damaging the kidneys’ filtering membranes. He advised the public not to consume food showing signs of mold, particularly in hot and humid conditions above 25 degrees Celsius and humidity over 18.5%, which are ideal for mold growth.

Being reluctant to discard spoiled food can cost long-term health, he says.