Shown is the shape of a liver made from coffee beans. Coffee proven to protect against chronic liver disease.
A new and major study by UK Biobank published in BMC Public Health found a strong association between drinking coffee and lowering the risk of chronic liver disease (CLD). Over an 11- year period, UK Biobank conducted a study of almost half a million people (384,818 coffee drinkers and 109,767 non coffee drinkers). Compared to non-coffee drinkers, coffee drinkers had much lower death rates from CLD, and this was for consumption of any kind of coffee – decaffeinated, instant, and ground coffee individually were similar to all types combined.
The UK Biobank conclusion that all types of coffee are protective against CLD is significant given the increasing incidence of CLD worldwide and the potential of coffee as an intervention to prevent CLD onset or progression.
CLD is a growing cause of morbidity and mortality worldwide, particularly in low to middle-income countries with high disease burden and limited treatment availability. Coffee consumption has been linked with lower rates of CLD, but little is known about the effects of different coffee types, which vary in chemical composition. This study aimed to investigate associations of coffee consumption, including decaffeinated, instant, and ground coffee with chronic liver disease outcomes
The risk of developing either chronic liver disease or chronic liver or fatty liver disease was reduced by 35% ; developing hepatocellular carcinoma by 34%, and dying of liver disease by 61%. Among total study group, there were 3,600 cases of CLD, 5,439 cases of CLD or steatosis, 184 cases of HCC, and 301 deaths from CLD during a median follow-up of 10.7 years. Compared to non-coffee drinkers, coffee drinkers had lower adjusted hazard ration s (HR) of CLD, CLD or steatosis, death from CLD, and HCC. The associations for decaffeinated, instant, and ground coffee individually were similar to all types combined.
Chronic liver disease is a major health problem worldwide. Between 1990-2017, global deaths due to CLD increased from 899,000 (1.9% of total) to 1.32 million (2.4% of total). During the same period, disability-adjusted life-years lost to CLD increased from 30.5 million to 41.4 million. The burden of CLD is highest in low to middle-income countries where treatment options are also limited. Sub-Saharan Africa is the region that is most affected followed by Central and South America, Eastern Europe, and Southeast Asia. The most common etiologies of CLD are alcohol-related liver disease (ALD), chronic hepatitis B and C infection, and non-alcoholic fatty liver disease (NAFLD). These conditions involve destruction and regeneration of liver parenchyma leading to liver fibrosis and then cirrhosis. Cirrhosis can be fatal due to complications related to portal hypertension, liver failure, or the development of hepatocellular carcinoma (HCC).
Of coffee drinkers, 73,644 (19%), 212,586 (55%), and 86,987 (23%), respectively, were drinkers of decaffeinated, instant, and ground (including espresso) coffee. Decaffeinated coffee drinkers were more likely to be female (63.1% vs. 50.5% for instant and 51.7% for ground), older (median age at baseline 59 vs. 58 and 57), and less likely to be current smokers (6.7% vs 12.6 and 9.2%). Drinkers of ground coffee had the highest median weekly alcohol consumption (20.2 units vs. 17.2 for instant and 12.8 for decaffeinated) and were least likely to have diabetes (3.9% vs. 5.4 and 5.0%).
The study claims to be the first to directly investigate the effect of different coffee types on CLD outcomes in a single large cohort. There are few reports in the literature about specific coffee types. A small study in France found that filtered ground coffee but not espresso was associated with a reduced risk of fibrosis in obese women with NAFLD Indirect conclusions about other coffee types can be inferred from studies in countries where drinking preferences differ. For example, in Finland and Japan instant coffee is the most popular type, and inverse associations with CLD outcomes have been reported in both those countries.
In the present study, decaffeinated coffee consumption was associated with similar reductions in risks of incident CLD and incident CLD or steatosis to all coffee types combined and a larger reduction in risk of death from CLD (63% compared to 49%). A meta-analysis of three studies reported inverse associations between decaffeinated coffee and HCC, though smaller in magnitude compared to caffeinated coffee. A cohort study in the United States reported a lower risk of death from CLD among drinkers of two cups of decaffeinated coffee each day compared to none, even after adjustment for caffeinated coffee intake. The observation of a protective effect of decaffeinated coffee is highly relevant to the development of a coffee-based intervention for preventing CLD onset or progression. Caffeine intolerance may limit increases in coffee consumption, and thus decaffeinated coffee may be a preferable alternative. Given its well know safety profile and cheap cost, coffee has potential as widely accessible lifestyle intervention, even in low to middle-income countries.