Scientists from China have found that regular coffee consumption may lower the risk of kidney and liver diseases. This effect is linked to metabolites of the beverage’s bioactive compounds, rather than to caffeine itself or individual substances. The findings were published in Food & Function (F&F).

The authors analyzed previously published studies to determine which components of coffee actually enter the bloodstream, how they are processed by the gut microbiota, and which transformed molecules exert significant biological effects. The results showed that it is the metabolites of chlorogenic acids, diterpenes, and other compounds that possess strong anti-inflammatory and antioxidant properties.

Systematic data from large cohort and clinical studies indicate that regular coffee consumption is associated with a lower risk of cirrhosis, hepatocellular carcinoma, non-alcoholic fatty liver disease, and chronic kidney disease. According to the researchers, the key role is played not by the beverage’s original molecules but by their transformed products, which circulate in the blood and act on tissues.

The strength of the protective effect also depends on the brewing method: filtration, degree of roasting, and grind size alter the concentration and bioavailability of active compounds. The researchers also emphasize significant individual variability — genetic features of metabolism and the composition of the gut microbiota may determine how coffee affects a particular person.