An emerging area of research is the effect of coffee on liver health and liver disease. Coffee is one of the most consumed beverages worldwide, with epidemiologic studies showing a link between coffee consumption and lower levels of liver disease and all-cause mortality. The active constituent responsible for coffee’s protective effect of liver health has yet to be determined, but it is likely to include caffeine, chlorogenic acids and the diterpenes, cafestol and kahweol.
In patients with chronic liver disease, coffee consumption has been linked to a reduced prevalence of cirrhosis. One meta-analysis also found an inverse association between coffee consumption and liver cancer. Patients with chronic hepatitis C have been found to respond better to antiviral treatment when they consumed coffee on a regular basis and furthermore, have lower rates of disease progression.[3,4] Caffeine and coffee consumption has also been shown to be associated with reduced hepatic fibrosis and reduced steatohepatitis severity in patients with non-alcoholic fatty liver disease (NAFLD).
Effect on liver enzymes
Coffee is known to positively influence liver enzymes, reducing serum gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. These liver enzymes are markers of liver cell injury, inflammation and cirrhosis risk.
Non-alcoholic fatty liver disease (NAFLD)
NAFLD is the most common cause of primary liver disease and is often associated with metabolic disorders including type 2 diabetes mellitus, obesity, hypertension and hyperlipidaemia. Coffee appears to provide a protective effect against NAFLD development and disease progression, and may exert its effects through antioxidant, anti-inflammatory and antifibrotic pathways.[5,6]
The results of a 2013 meta-analysis confirmed that consumption of coffee is associated with a reduced risk of liver cancer. Caffeine has strong antioxidant properties and may prevent oxidative DNA damage, up-regulate phase 2 enzymes to reduce toxic metabolites within hepatocytes, modify apoptosis and inhibit the proliferation of hepatocellular carcinoma cells by altering signalling pathways.[2,3,7]
Kahweol and cafestol have also shown anti-carcinogenic activity and can reduce the toxicity of hepatocarcinogens by inducing liver enzymes involved in detoxification.[2,3,8]
- Walton HB, Masterton GS, Hayes PC. An epidemiological study of the association of coffee with chronic liver disease. Scott Med J 2013;58(4):217-222. [Abstract]
- Sang LX, Chang B, Li XH, et al. Consumption of coffee associated with reduced risk of liver cancer: a meta-analysis. BMC Gastroenterol 2013;13:34. [Full Text]
- Saab S, Mallam D, Cox GA 2nd, et al. Impact of coffee on liver diseases: a systematic review. Liver Int 2014;34(4):495-504. [Full Text]
- Freedman ND, Everhart JE, Lindsay KL, et al. Coffee intake is associated with lower rates of liver disease progression in chronic hepatitis C.Hepatology 2009;50(5):1360-1369. [Full Text]
- Chen S, Teoh NC, Chitturi S, et al. Coffee and non-alcoholic fatty liver disease: brewing evidence for hepatoprotection? J Gastroenterol Hepatol 2014;29(3):435-441. [Abstract]
- Birerdinc A, Stepanova M, Pawloski L, et al. Caffeine is protective in patients with non-alcoholic fatty liver disease. Aliment Pharmacol Ther 2012;35(1):76-82. [Full Text]
- Modi AA, Feld JJ, Park Y, et al. Increased caffeine consumption is associated with reduced hepatic fibrosis. Hepatology 2010;51(1):201-209. [Full Text]
- Johnson S, Koh WP, Wang R, et al. Coffee consumption and reduced risk of hepatocellular carcinoma: findings from the Singapore Chinese Health Study. Cancer Causes Control 2011;22(3):503-510. [Full Text]
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