Coffee: Some may be predisposed to negative kidney effects

A longitudinal study suggests that high coffee consumption is associated with a nearly tripled risk of kidney dysfunction for adult slow caffeine metabolisers.

Caffeine may play a role in kidney disease for susceptible individuals

In an Italian study, 1,180 untreated adults with stage 1 hypertension from the prospective 'Hypertension and Ambulatory Recording Venetia Study' were followed up for 7.5 years. Participants were 18 to 45 years old, and people with nephropathy, diabetes, urinary tract infections, and cardiovascular disease were excluded.

Caffeine is detoxified over 95% via cytochrome P450 1A2 (CYP1A2) and genetic variations in CYP1A2 affect the rate of caffeine excretion.

Those with a genetic polymorphism of CYP1A2, who were slow metabolisers of caffeine, were 2.7 times more likely to develop albuminuria, 2.5 times more likely to develop hyperfiltration, and 2.8 times more likely to develop hypertension if they drank more than three cups of coffee daily compared with low coffee consumption. This association was not observed in people who metabolise caffeine quickly.

CYP1A2: important for whether coffee is harmful or not for kidney health

A large number of previous studies have repeatedly come to divergent conclusions as to whether coffee is harmful or protective. The different CYP1A2 variants and their influence on caffeine metabolism could partly explain the diversity of results. Other studies have already found that the same polymorphism alters the association between coffee consumption and the risk of heart attack, hypertension, and impaired fasting glucose in a dose-dependent manner.2-4

Also in these studies, only slow metabolisers were found to have an increased risk with increasing number of cups of coffee consumed per day, while in fast metabolisers a higher number of cups of coffee per day either reduced the risk or no association was found.

"We hypothesise that fast metabolisers may eliminate caffeine from their bodies more efficiently and thus avoid harmful caffeine accumulation," says the leader of the research group, Prof. Ahmed El-Sohemy, from the University of Toronto.5

  1. Mahdavi, S., Palatini, P. & El-Sohemy, A. CYP1A2 Genetic Variation, Coffee Intake, and Kidney Dysfunction. JAMA Network Open 6, e2247868 (2023).
  2. Cornelis, M. C., El-Sohemy, A., Kabagambe, E. K. & Campos, H. Coffee, CYP1A2 genotype, and risk of myocardial infarction. JAMA 295, 1135–1141 (2006).
  3. Palatini, P. et al. CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension. J Hypertens 27, 1594–1601 (2009).
  4. Palatini, P. et al. Association of coffee consumption and CYP1A2 polymorphism with risk of impaired fasting glucose in hypertensive patients. Eur J Epidemiol 30, 209–217 (2015).
  5. The Link Between Coffee & Kidney Disease Depends on a Gene Variant | Genetics And Genomics. Labroots

    Last website checks: 15 June 2023