Researchers analyzed the coffee-drinking habits of 27,793 people, aged 20 and older, from 1999 to 2010. They had the subjects fill out diet questionnaires in the US National Health and Nutrition Examination Survey. More than 14,000 of the subjects drank coffee on a regular basis. The researchers factored in things like age, education, smoking, sex, and race, among others. They then tracked levels of four enzymes related to liver function.
What Came Out of It?
The researchers found those who drank three cups of coffee a day were approximately 25% less likely to have abnormal levels of liver enzymes linked to liver and bone disease, compared to the non-coffee drinkers of the study. The study included around 2,000 subjects who only drank decaffeinated coffee. Interestingly, their results were similar to the regular coffee drinkers. In short, the higher the coffee intake, the lower levels of liver enzymes.
What Does This Mean?
The reasons for the beneficial effects of coffee on the liver are still unclear, according to Dr. Qian Xiao. This is because there are over a thousand different compounds in coffee, so it is difficult to pinpoint exactly what is responsible for its therapeutic effects. Xiao made it clear, however, that this was an observational study, not a cause and effect study. Therefore, there might still be surprises hidden beneath the link between coffee consumption and risk of liver disease.
- Hepatology, Inverse associations of total and decaffeinated coffee with liver enzyme levels in NHANES 1999-2010, 2014