This has probably been addressed within this blogmunity already, but a highly publicized study of almost 130,000 Kaiser Permanante members in Northern California has concluded that coffee consumption decreases the risk of alcoholic cirrhosis in a dose-dependent manner.
…drinking one to three cups of coffee a day was associated with a 40% decrease in the risk of alcoholic cirrhosis versus drinking less than one cup (P<0.001), according to a report in the June 13 issue of the Archives of Internal Medicine.
Moreover … this protective effect appears to be dose-dependent. Those who drank four or more cups of coffee had an 80% decrease in the relative risk of alcoholic cirrhosis (95% CI 0.1-0.4, P<0.001).
Among subgroups of patients with nonalcoholic cirrhosis, coffee had a similar, weak, nonstatistically significant inverse relation to risk of either viral hepatitis-associated cirrhosis or to miscellaneous other cirrhosis.
I’ll offer the usual caveat (I’d have to read the entire thing to have a genuine clue) but I found it telling that lifestyle habits (i.e., amount of coffee and alcohol consumed) were collected only at baseline in a study in which enrollees were followed up 16 to 23 years later.
The authors noted a number of limitations to their study, including the fact that smoking, drinking, and coffee consumption are often related habits, which makes it “difficult to rule out residual confounding by alcohol amount or drinking pattern.”
The study was also limited by its reliance on baseline ascertainment of habits and incomplete follow-up of the cohort.
Finally, the “observational nature of the data and the absence of an established mechanism limit a causal interpretation.”
The study did note that coffee consumption and alcohol consumption were correlated. It’s easy enough to imagine that people drinking heavily enough over the years to eventualy incur cirrhotic damage at some point cut way back on coffee or quit drinking it altogether, even those who at one time indulged subtantially. It doesn’t seem far-fetched to surmise that people destined to develop liver problems as a result of their tippling may have reached this lifestyle point upon being enrolled in the study, even if there were at this stage no signs of cirrhosis in these people. This is supported ny the inverse relationship between elevated AST/ALT and coffee consumption, as serum elevations in these enzymes would certainly precede frank cirrhosis, perhaps by many years.
Okay, now that I’ve wrapped this up and committed myself to its content I’m going to see what Orac et al. might be saying so I can see exactly what region of left field I’m occupying. I reckon I’m right about one thing, though — millions of people have already consciously or subconsciously internalized the message that you can booze your ass off without incurring hepatic fallout as long as you stagger into 7-11 every morning for a 24-ounce cuppa en route to the package store. Hell, I think I was in college when the whole “two-glasses-of-red-wine-protects-the-heart” theory was broached, and right I way I figured that abstaining all week and then knocking back 14 Budwesiers on Saturday night would accomplish the same thing.