Drinking one or more cups of coffee per day has been found to lower the risk of death from liver cancer in a study in Japan including men and women with hepatitis C and a history of smoking and alcohol use.

Lately, claims of health benefits from consumption of Asian green tea have brought about a virtual revolution in the tea aisles of US supermarkets. Wal-Mart sells numerous brands of green tea plus white and red teas and various flavors of black tea.

So it is interesting to see that in Japan recent studies have suggested a lower risk of liver cancer in coffee-drinkers.

Unless these studies are tied in with some public relations conspiracy to prepare the Japanese population for coffee-house chains (seriously, no evidence of that) they may have a message for Westerners: don’t throw out the coffee pot when you add green tea to your day.

According to an article in British Journal of Cancer (July 2007), “The inverse associations between coffee consumption and the risk of hepatocellular carcinoma (HCC) have recently been reported not only from case-control studies (Gallus et al, 2002; Gelatti et al, 2005; Ohfuji et al, 2006; Montella et al, 2007; Tanaka et al, 2007) but also from Japanese cohort studies (Inoue et al, 2005; Kurozawa et al, 2005; Shimazu et al, 2005). Cohort studies are superior to case-control studies in avoiding recall and selection bias (Ohfuji et al, 2006).”

Previous studies, the article goes on, “did not consider the infection status of hepatitis C virus (HCV) at baseline. As HCV is the major cause of HCC in Japan and certain other countries (Heathcote, 2004), it would be important if protective factors against HCC could be found among the HCV-positive population.” So the researchers looked for impact of coffee drinking on liver cancer risk among people already infected with hepatitis C (HCV infection).

“Coffee drinking,” they report, “was significantly associated with a decreased risk of death from HCC in all subjects and those infected with HCV.”

These new results support some earlier findings (Gelatti et al, 2005; Ohfuji et al, 2006). The authors point out that “some patients with hepatitis or liver cirrhosis, however, may have decreased coffee consumption at their physician’s advice or due to impaired caffeine metabolism in the liver (Hasegawa et al, 1989).” Further studies among people “without active hepatitis ” will “further clarify the role of coffee in the possible prevention of HCV-related HCC. Also, more study is needed to find out whether coffee lowers liver cancer risk in people who do not have hepatitis C.
Source:

British Journal of Cancer (2007) 97, 426-428.
doi:10.1038/sj.bjc.6603891 www.bjcancer.com Published online 17 July 2007

Liver cancer risk, coffee, and hepatitis C virus infection: a nested case-control study in JapanK Wakai, et al.