- Epidemiological evidence suggests that moderate coffee consumption may help to reduce the risk of liver cancer, and the risk falls as coffee consumption rises.
- Epidemiological studies in patients with various liver diseases have all found a positive effect of moderate coffee drinking on limiting disease progression.
- Patients with alcoholic liver disease who have a higher coffee consumption have a slower rate of fibrosis* than those who drink less coffee.
- Caffeine consumption is related to less severe fibrosis in patients scheduled for liver biopsy.
- Coffee consumption is related to slower development of cirrhosis in patients with chronic liver disease.
- Patients with Hepatitis C-related liver disease, who have a higher consumption of coffee, have a lower rate of disease progression than those drinking less coffee.
- However, patient studies should be interpreted with caution as there are many confounders which can bias results, e.g. small subject numbers and patients changing their habits or diet as a result of their disease.
- Several mechanisms underlying the association between moderate coffee consumption and reduced risk of liver cancer and disease progression are under investigation.
- One of the breakdown products of caffeine, paraxanthine, has been shown to slow down the growth of the type of tissue seen in liver fibrosis, alcoholic cirrhosis and liver cancer.
- Other alternative mechanisms are related to the anti-carcinogenic effects of cafestol and kahweol, and possible anti-viral effects of chlorogenic acids and caffeic acid.
*Many liver diseases cause scar tissue, known as fibrosis, to develop. In the early stages of fibrosis, the liver functions relatively well and few people experience symptoms. But as the inflammation and liver injury continue, scar tissue builds up. This can eventually disrupt the metabolic functions of the liver and lead to cirrhosis in which the liver is severely scarred, its blood flow restricted and its ability to function severely impaired.