There has recently been a lot of attention in the media around links between coffee and liver health. Markus Peck-Radosavljevic, Secretary General at the European Association for the Study of the Liver, provides an overview of research on coffee and the liver.
Even though initial reports on the beneficial effect of coffee consumption on liver enzymes appeared around 20 years ago1, it was not until 2005 that this association was coming under closer scrutiny by clinical as well as basic researchers alike2-4. Since then, the topic has attracted considerable interest. Coffee consumption has repeatedly been shown to be associated with the reduction of liver enzyme levels, incidence of chronic liver disease, risk of liver cancer (HCC), disease progression in chronic hepatitis C5, reduction in liver fibrosis6, response to antiviral therapy in hepatitis C7, and the development of fatty liver and non-alcoholic steatohepatitis (NASH)8. Despite considerable efforts, no conclusive evidence about the active ingredient in coffee let alone the exact mechanism of action of coffee on liver disease progression can be elucidated to date. But with coffee consisting of over 1,000 different compounds and the lack of standardization in the coffee preparation used in the cohorts studied, this does not come as a big surprise.
Most recently the focus has mainly been on the effect of coffee on the progression of NAFLD (non-alcoholic fatty liver disease) as well as the development of liver cancer. A large Finnish study, including over 60,000 individuals across a 19 year follow-up period, was able to show a dose-dependent decrease of the rate of HCC-development in the consumption of up to 6 cups of coffee per day9. This year’s meta-analysis of the impact of coffee consumption on the risk of HCC-development was able to confirm this association10. Likewise, a meta-analytic review of the evidence for preventing development and progression of NAFLD by coffee consumption was able to substantiate the protective effect of coffee on NAFLD in the experimental as well as the clinical setting11. Taking the current evidence together, we still don’t have definitive proof of the protective effect of coffee from prospective trials and detailed mechanistic insight into how this could be facilitated. Nevertheless, considering the risks involved, it seems sensible to think about recommending coffee for prevention of liver disease in individuals at risk.
1Casiglia E, Spolaore P, Ginocchio G, Ambrosio GB. Unexpected effects of coffee consumption on liver enzymes. Eur J Epidemiol 1993;9:293-297.
2Ruhl CE, Everhart JE. Coffee and tea consumption are associated with a lower incidence of chronic liver disease in the United States. Gastroenterology 2005;129:1928-1936.
3La Vecchia C. Coffee, liver enzymes, cirrhosis and liver cancer. J Hepatol 2005;42:444-446.
4Gelatti U, Covolo L, Franceschini M, Pirali F, Tagger A, Ribero ML, Trevisi P, Martelli C, Nardi G, Donato F. Coffee consumption reduces the risk of hepatocellular carcinoma independently of its aetiology: a case-control study. J Hepatol 2005;42:528-534.
5Freedman ND, Everhart JE, Lindsay KL, Ghany MG, Curto TM, Shiffman ML, Lee WM, Lok AS, Di Bisceglie AM, Bonkovsky HL, Hoefs JC, Dienstag JL, Morishima C, Abnet CC, Sinha R. Coffee intake is associated with lower rates of liver disease progression in chronic hepatitis C. Hepatology 2009;50:1360-1369.
6Modi AA, Feld JJ, Park Y, Kleiner DE, Everhart JE, Liang TJ, Hoofnagle JH. Increased caffeine consumption is associated with reduced hepatic fibrosis. Hepatology 2010;51:201-209.
7Freedman ND, Curto TM, Lindsay KL, Wright EC, Sinha R, Everhart JE. Coffee consumption is associated with response to peginterferon and ribavirin therapy in patients with chronic hepatitis C. Gastroenterology 2011;140:1961-1969.
8Molloy JW, Calcagno CJ, Williams CD, Jones FJ, Torres DM, Harrison SA. Association of coffee and caffeine consumption with fatty liver disease, nonalcoholic steatohepatitis, and degree of hepatic fibrosis. Hepatology 2012;55:429-436.
9Hu G, Tuomilehto J, Pukkala E, Hakulinen T, Antikainen R, Vartiainen E, Jousilahti P. Joint effects of coffee consumption and serum gamma-glutamyltransferase on the risk of liver cancer. Hepatology 2008;48:129-136.10Sang LX, Chang B, Li XH, Jiang M. Consumption of coffee associated with reduced risk of liver cancer: a meta-analysis. BMC Gastroenterol 2013;13:34.
11Yesil A, Yilmaz Y. Review article: coffee consumption, the metabolic syndrome and non-alcoholic fatty liver disease. Aliment Pharmacol Ther 2013;38:1038-1044.
Source: Coffee and Health