- A study involving nearly 500,000 people finds that drinking coffee significantly lowers the risk of developing liver disease.
- The health benefit applies to all kinds of coffee, including caffeinated, decaffeinated, ground, and instant coffee.
- The study finds that drinking 3–4 cups per day provides the greatest benefit.
For many, coffee is their favorite — some might say indispensable — part of each day. Yet there is also a constant stream of often contradictory research offering evidence for both coffee’s benefits and risks.
The greatest benefit is derived from drinking 3–4 cups of coffee, even decaffeinated, per day. Coffee from grounds is slightly more beneficial than instant coffee.
The study, from researchers at the Universities of Southampton and Edinburgh in the United Kingdom, appears in the journal BMC Public Health.
According to the study, the area most profoundly affected by liver disease is sub-Saharan Africa. Central and South America, Eastern Europe, and Southeast Asia follow.
Medical News Today spoke with Cleveland Clinic transplant hepatologist Dr. Talal Adhami, who called the study “absolutely amazing” thanks to its scope.
“There have been smaller studies, and there was an association [between liver health and coffee], but this study actually drew a much bigger association just from the sheer number of patients,” he said.
The authors of the study analyzed the UK Biobank health data of 494,585 people, following them for an average of 10.7 years.
Of the cohort, 384,818 were coffee drinkers, and 109,767 were not, serving as the study’s control group. Coffee drinkers consumed caffeinated, decaffeinated, ground, and instant coffee.
During the study period, the sample contained 3,600 diagnoses of chronic liver disease, 5,439 cases of chronic liver disease or fatty liver disease, and 184 cases of hepatocellular carcinoma. There were 301 deaths from chronic liver disease.
Compared with the participants who did not consume coffee, coffee drinkers’ risk of chronic liver disease was 21% lower.
They also had a 19% reduced risk of developing chronic liver or fatty liver disease, and they lowered their risk of hepatocellular carcinoma by 21%. Coffee drinkers were also 49% less likely to die from liver disease.
For people who drank coffee from ground beans, the reduction in risk was even greater.
Their risk of developing either chronic liver disease or chronic liver or fatty liver disease was reduced by 35%, of developing hepatocellular carcinoma — by 34%, and of dying of liver disease — by 61%.
Dr. Adhami explained that “[c]offee actually can help in early stages of liver disease,” as the liver becomes inflamed in response to a pathogen.
“It can also affect the scarring tissue process, and also later on in cirrhosis patients or patients with advanced scarred tissue who are prone to have primary cancer of the liver. Coffee is helpful at that level too,” he added.
A limitation of the study is that its sample consisted of white individuals from higher socioeconomic backgrounds, so its findings may not be universally applicable.
Biochemist Prof. Nathan Davies of University College London’s Institute for Liver and Digestive Health cautioned MNT that the study does not prove that coffee is an “anti-liver disease superfood.” He noted that other studies even “indicate the opposite.”
The long-term risk and benefit in the study was so small, said Prof. Davies — just 4 per 1,000 coffee drinkers not developing liver disease versus 5 per 1,000 non-coffee drinkers — “it is likely that other factors have a more substantial effect than coffee.”
Dr. Adhami remained enthusiastic, however, saying that it would be one thing if we already had effective remedies for all liver diseases: “At this point in time, with the lack of alternatives, having a drink that is actually the most consumed drink on Earth? You know what? I’ll take it.”
It is of note that the study does not delve into the mechanics of why coffee is so beneficial to the liver.
Dr. Adhami said that as a result of this study, he anticipates randomized controlled clinical trials that test various coffee molecules against liver disease. “Believe me, this is the absolute most exciting news for liver disease,” he commented.
Lead author Dr. Oliver Kennedy concludes:
“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.”