"After oil, coffee is the second most valuable commodity in the world." (1) More than 50% of Americans drink coffee daily, on the average, consuming 3 cups each day. (2)
In a cohort study conducted by Arthur L. Klatsky, M.D., and a team of researchers at the Kaiser Permante Medical Care Program in Oakland, California, data supported the hypothesis that there is an ingredient in coffee which protects against cirrhosis, especially alcoholic cirrhosis.
The researchers studied 125,580 multiethnic members of a comprehensive prepaid health care plan. The participants had no known liver disease and provided baseline data at voluntary health examinations from 1978 to 1985. By 2001, 330 of the participants were diagnosed with liver cirrhosis. Long-term ingestion of alcohol is the common cause of liver cirrhosis in developing countries.
The 22 year follow-up concluded an inverse relation of coffee drinking to risk of alcoholic cirrhosis, more coffee consumption, the lower risk of developing disease. Of the subjects who consumed no (or seldom any) coffee daily, 1% had alcoholic and nonalcoholic cirrhosis. Of those who consumed 1 to 3 cups per day, 0.6% had alcoholic cirrhosis and 1.3% had nonalcoholic cirrhosis. Of those who consumed 4 or more cups of coffee daily, 0.2% had alcoholic and 0.7% had nonalcoholic cirrhosis.
The researchers acknowledge limitations to their study and conclude this is a casual interpretation. The primary approach to the reduction of alcoholic cirrhosis is avoidance or cessation of heavy alcohol drinking. (3)
Monami Inoune of the National Cancer Center in Tokyo and her research team analyzed the data of a ten year public health study to determine the protective effect of daily coffee consumption against developing liver cancer. They found that the protective effect occurred in individuals who drank 1 to 2 cups of coffee daily and increased with the increase of consumption of 3 to 4 cups daily. Inoune's team noted that coffee contains large amounts of antioxidants and thus links these compounds to inhibiting cancer in the liver. (4)
(1) CBS Sunday Morning "Caffeine Nation" September 7, 2003
(2) National Coffee Association Coffee Drinking Trends Survey 2000
(3) "Coffee, Cirrhosis, and Transaminase Enzymes" by Arthur L. Klatsky, M.D., et al
Archives of Internal Medicine vol. 166 no. 11 June 12, 2006
(4) "Coffee May Help Protect Against Liver Cancer", The Associated Press February 16, 2005