Coffee's List of Possible Benefits Gets Another Entry [WSJ]
By MARILYN CHASE
June 13, 2006; Page D3
Coffee may protect against alcoholic liver disease, according to a study that adds to the growing body of literature on the diverse health effects of the popular and addictive brew.
For every cup of java, up to four a day, the study charted about a 20% decline in risk of alcoholic cirrhosis. People drinking four cups a day had about an 80% lower risk. Although the study suggests coffee may be protective, it doesn't prove drinking it actually caused the benefit.
Researchers at the Kaiser Permanente Medical Care Program in Oakland, Calif., reviewed the medical and death records of 125,580 health-plan members through 2001. The new data, extending a 1992 report, were published yesterday in the Archives of Internal Medicine.
Caffeine isn't believed to be the top player, said Kaiser researcher and lead author Arthur Klatsky, because tea drinking produced no lower risk. The study didn't distinguish between regular and decaffeinated coffee. Coffee is a complex brew of more than a thousand chemicals, according to a recent Oregon State University review.
In countless conflicting and controversial studies, coffee has been variously linked to an array of positive health outcomes, including lower risks of Type 2 diabetes, suicide and liver cancer in some people. Studies have reached mixed conclusions about a possible link to lower risk of colorectal cancer and Parkinson's disease, the Oregon researchers noted. Coffee raises blood pressure in inexperienced drinkers, Dr. Klatsky said, but not in veteran coffee drinkers. On the negative side, Dr. Klatsky said some studies have found a slightly higher risk of heart attack, possibly linked to rises in cholesterol observed when people drink boiled coffee, but not the filtered kind.
According to the Oregon researchers, writing in a recent issue of the journal Critical Reviews in Food Science and Nutrition, adverse reactions to coffee can include: rapid heart rate, insomnia and nervousness. Caffeine withdrawal symptoms include headache, irritability and drowsiness. Some doctors counsel pregnant women and people with high blood pressure to limit their intake.
Dr. Klatsky said the new study bolsters a theory that there is a protective ingredient in coffee. The study was an observational cohort study, following patients' medical records and self-reported drinking habits. It wasn't a controlled clinical trial, the gold standard of medical research, in which volunteers are randomly assigned to a treatment or placebo.
Cirrhosis is caused by scarring of liver cells due to injury from alcohol, viruses or other factors, triggering jaundice and a buildup of toxins in the blood. In the study, coffee's risk-reducing effect was seen only in people with cirrhosis due to alcohol, and not those with other forms of cirrhosis.
The reduced cirrhosis risk was consistent across all groups, regardless of gender or race. "We don't need to encourage people (to drink alcohol). From a medical and social point of view, they should cut down," Dr. Klatsky said. "For people concerned about their liver, they shouldn't quit drinking coffee.
"Coffee has a bad rap," said Dr. Klatsky, a coffee drinker himself. Although overuse causes jitters or sleeplessness, and withdrawal can cause headaches, he said that for most people, "Moderate coffee drinking up to four cups a day isn't an unhealthy habit."
The study's real value, he said, "is that it may point to research that could uncover something about mechanisms of liver disease." Cirrhosis of all kinds causes about 26,000 deaths a year, according to the National Institute of Diabetes and Digestive and Kidney Diseases, a unit of the National Institutes of Health.
The study was funded by the Kaiser Foundation Research Institute, which administers research at Kaiser Permanente. Dr. Klatsky said his research team doesn't have any stake in or support from the coffee industry. From 1978 to 1985, his data collection was supported by a grant from the Alcoholic Beverage Medical Research Foundation, a nonprofit group financed by the brewing industries of the U.S. and Canada.
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