Drinking one to three cups of coffee a day is associated with a 40% decrease in the risk of alcoholic cirrhosis versus drinking less than one cup. People who drink two or three cups a day are 40% less likely to contract cirrhosis, while those who drink four or more cups are 80% less likely to suffer the disease.
The findings, conducted by researchers at the Kasier Permanente, in Oakland, California, are thought to be the largest study to look at the inverse relationship between coffee and cirrhosis. The link was first reported by researchers at the same institute in 1993 but this new study - of 125,000 people over 22 years - "solidifies the association", Arthur L Klatsky, the lead author of the study, said.
Dr Klatsky, who was involved in the earlier research, added: "Consuming coffee seems to have some protective benefits against alcoholic cirrhosis, and the more coffee a person consumes the less risk they seem to have of being hospitalised or dying of alcoholic cirrhosis. We did not see a similar protective association between coffee and non-alcoholic cirrhosis."
The researchers, whose findings are published in the US journal Archives of Internal Medicine, followed more than 125,000 health plan members who underwent a medical examination between 1978-1985 and who, at the time, had no diagnosed liver disease. Participants filled out a questionnaire detailing how much alcohol, coffee and tea they drank daily.
By the end of 2001, 330 participants had been diagnosed with liver disease, including 199 with alcoholic cirrhosis - caused by the consumption, each day, of three or more units of alcohol.
Researchers - who only counted those who had been hospitalised or died because of the disease - found that the more coffee a person drank the less likely they were to develop alcoholic cirrhosis.
Drinking tea had no effect, suggesting the ingredient that protects against cirrhosis is not caffeine.
Blood tests conducted on the 5% of drinkers who consumed the most alcohol confirmed that coffee drinkers were less likely to have high levels of enzymes in the liver - a key indicator of liver damage, according to The Guardian.
The risk of cirrhosis, both alcoholic and nonalcoholic, increased with age, male sex, and obesity, but education was protective-cirrhosis risk declined as years of education increased.
Among the findings:
- Coffee drinking was positively correlated with smoking and alcohol drinking.
- As expected mean blood levels of AST and ALT increased as alcohol consumption increased.
- In a cross-sectional analysis coffee drinking was inversely related to AST and ALT levels, people who drank four or more cups of coffee daily reduced the risk of elevated AST by 50% (95% CI, 0.4-0.6; P <0.001) and for elevated ALT by 40% (95% CI 0.6-0.7; P<0.001).
Additionally, the inverse relationship between liver enzyme elevations and coffee consumption was strongest among heavy drinkers, MedPage Today reports.
The researchers said they could not be absolutely sure whether or not caffeine was the key ingredient because tea drinking was not particularly popular among the study population.
Identifying the ingredient responsible could open the way for potential preventive treatment and help develop greater understanding of the mechanisms of liver disease, says BBC.
Prepared by Alexander Timoshik
Discuss this article on Pravda.ru English Forum