Drinking coffee that is caffeinated (ground or instant) or decaffeinated is associated with a reduced risk of developing chronic liver disease and related liver conditions, according to a study published in the open access journal BMC Public Health.
Researchers at the Universities of Southampton and Edinburgh, UK, found that drinking any type of coffee was associated with a reduced risk of developing and dying from chronic liver disease compared to not drinking coffee, with the benefit peaking at three to four cups per day.
The authors studied UK Biobank data on 495,585 participants with known coffee consumption, who were followed over a median of 10.7 years to monitor who developed chronic liver disease and related liver conditions.
Of all participants included in the study, 78% (384,818) consumed ground or instant caffeinated or decaffeinated coffee, while 22% (109,767) did not drink any type of coffee. During the study period, there were 3,600 cases of chronic liver disease, including 301 deaths. Additionally, there were 5,439 cases of chronic liver disease or steatosis (a build of up fat in the liver also known as fatty liver disease), and 184 cases of Hepatocellular carcinoma, a type of liver cancer.
Compared to non-coffee drinkers, coffee-drinkers had a 21% reduced risk of chronic liver disease, a 20% reduced risk of chronic or fatty liver disease, and a 49% reduced risk of death from chronic liver disease. The maximum benefit was seen in the group who drank ground coffee, which contains high levels of the ingredients Kahweol and cafestol, which have been shown to be beneficial against chronic liver disease in animals.
Instant coffee, which has low levels of Kahweol and cafestol was also associated with a reduced the risk of chronic liver disease. While the reduction in risk was smaller than that associated with ground coffee, the finding may suggest that other ingredients, or potentially a combination of ingredients, may be beneficial.
Dr Oliver Kennedy, the lead author said: “Coffee is widely accessible and the benefits we see from our study may mean it could offer a potential preventative treatment for chronic liver disease. This would be especially valuable in countries with lower income and worse access to healthcare and where the burden of chronic liver disease is highest.”
The authors caution that, as coffee consumption was only reported when participants first enrolled in the study, the study does not account for any changes in the amount or type of coffee they consumed over the 10.7-year study period. As participants were predominantly white and from a higher socio-economic background, the findings may be difficult to generalise to other countries and populations.
The authors suggest that future research could test the relationship between coffee and liver disease with more rigorous control of the amount of coffee consumed. They also propose validating their findings in more diverse groups of participants.