Genetic differences among heavy coffee drinkers may lead some to show signs of kidney dysfunction over time while others show none, new research shows.
The research team said the genetic difference might explain why previous studies on coffee consumption and kidney health have shown mixed results.
Notably, the new study’s two main authors are prominent figures at Nutrigenomix Inc., a for-profit company that does genetic testing for personalized fitness and health. Lead author Ahmed El-Sohemy, a professor of nutritional sciences at the University of Toronto, is listed the founder of the company.
The study, published in the journal Jama Network Open, focuses on CYP1A2, the gene whose mutations determine whether caffeine is metabolized quickly or slowly in the human body.
Approximately half of the general population carries the genetic variant that makes caffeine metabolize more slowly. According to the new study’s authors, that group showed markers of kidney dysfunction that was three times higher than study participants who do not have the genetic variation.
The observational study involved questionnaires with more than 1,100 participants and urine analysis from more than 600 participants. Risks of albuminuria, hyperfiltration and hypertension increased only among heavy coffee drinkers (three cups or more per day) with the CYP1A2 variation.
“We think fast metabolizers can eliminate caffeine from their systems more efficiently and avoid harmful build-ups of caffeine,” El-Sohemy said in an announcement from the University of Toronto. “These individual differences in caffeine metabolism help explain why previous studies on coffee and kidney disease have been inconsistent.”
Does your coffee business have news to share? Let DCN’s editors know here.