An interesting article appeared in New Scientist commenting on a April 2020 review (meta analysis) of scientific literature on how coffee consumption affects the way your genes are expressed (epigenetics).
Studies suggest that coffee consumption protects against type 2 Diabetes, heart disease and liver disease but the reasons why were un-known.
Mohsen Ghanbari at Erasmus University Medical Center in Rotterdam, the Netherlands, and his colleagues conducted a review of all studies on coffee (and tea) to see if coffee consumption affected certain epigenetic markers (methyl groups) – which are chemical tags on DNA that increase or decrease the activity of certain genes that may influence health.
The researchers found that the more cups of coffee a person drank per day the more likely they were to have altered levels of 11 epigentic markers (methyl groups).
The 11 Methyl Groups altered by coffee consumption tended to be associated with genes that play roles in digestion (aiding the processing of harmful chemicals and controlling inflammation). This also included breaking down fat within the liver (hepatic-lipid metabolism).
This is the first step in understanding why coffee consumption infers various health benefits – but more research is needed.