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Why does a Canadian specialist recommend that his patients with liver disease drink at least two or three cups of coffee a day? The answer lies in a recent study into the effects of coffee on the liver. The study,
Over the past 20 years, researchers have been uncovering evidence that coffee has protective effects on the liver. That’s the conclusion drawn by the lead authors of a new study. The study, conducted by a team of Canadian and U.S. researchers, reviewed research conducted over the past 20 years. Their specific conclusion was that drinking coffee can significantly curb the damage done by cirrhosis of the liver, and lower the risk of contracting liver cancer.
The paper, published in F100 Research with the intriguing title “I Drink for My Liver, Doc: emerging evidence that coffee prevents cirrhosis,” notes that the accumulated research on coffee and liver disease could “create effective, testable hypotheses that should lead to improved understanding on fibrosis pathogenesis.” That’s a mouthful, but what it boils down to is this: past research gives scientists some excellent starting points to figure out exactly why and how coffee is good for your liver.
Dr. Jordan Feld, the lead researcher and author, is a gastroenterologist at Toronto Western Hospital. He now recommends that his patients with liver disease drink two to three cups of coffee a day – more if they can tolerate it – to ward off further damage to their livers. He believes that coffee can be a useful therapy – even save lives, he told one reporter. The most quotable part of his interview notes why this coffee health news is so important:
“We really have almost nothing else that helps,” Feld told reporters.
Feld became interested in the role coffee can play in fighting liver disease when he was working with the U.S. National Institutes of Health.
Liver disease looms as a threat for an unprecedented number of Canadians, affecting an estimated three million people, many unaware they are sick. He says he was skeptical at first, but the more he learned, the more convinced he became that coffee actually does help protect – and maybe even heal – damage to the liver. This is especially important, he says, because currently, the only ways to prevent or treat liver disease and damage is to remove the primary cause.
This may be in part because liver disease doesn’t get enough attention, suggests the Canadian Liver Foundation. The foundation believes that the association of liver disease with alcoholism may prevent people from focusing their attention on a cure or on prevention. It’s not uncommon for people to think that alcohol abuse is the only – or at least the leading – cause of liver damage. In reality, many things cause liver damage, including so-called the so-called “silent virus,” hepatitis C. It notes that hundreds of thousands of Canadians have liver disease caused by viruses, and about 20 percent of those with chronic hepatitis C – one of the leading causes of liver damage – don’t even know they have it.
Feld and three U.S. researchers went back over research papers about coffee and liver disease that have been published since the early 1990s. Most of these papers were based on observational research, which is generally not considered as reliable as controlled clinical trials. Instead, the papers sifted through data compiled through health questionnaires, which ask people about their typical daily habits, and then correlates their answers with their health histories. Over the years, paper after paper has found that people who drink 2 or more cups of coffee daily are less likely to have liver disease. Those who do contract liver disease and drink coffee are often less sick than those who do not drink coffee.
This effect does not carry over to those who drink mostly decaffeinated coffee, nor does it hold completely true for those who drink other caffeinated beverages. This suggests, Feld says, that caffeine may be the active compound that helps protect the liver. He doesn’t rule out other botanicals as beneficial, however. The abstract for the paper specifically notes: “we do not dismiss the “botanical” hypothesis here; rather, we do not emphasize it at present due to the limitations of the studies examined”
The limitations that Feld references include the fact that most studies do not go into detail about the kind of coffee people drink, how it’s brewed and other factors that change the chemical composition of the beverage in the cup. Some studies, for example, suggest that filtered coffee may be more helpful coffee that is made without a filter. It’s also difficult to account for varying amounts of caffeine in different coffee varieties, or the effects of different ways of processing and roasting coffee beans.
Regardless, the research suggests that drinking coffee prevents liver scarring (cirrhosis) and hepatocellular carcinoma, cancer of the liver that develops in a damaged liver. In one 2009 study, people with liver disease who drank at least three cups of coffee a day were half as likely to develop liver cancer as those who don’t drink any coffee at all.
Even the skeptics are starting to come around to the health benefits of coffee for the liver. The head of gastroenterology at Vancouver Hospital, Dr. Eric Yoshida, told reporters at the National Post that it’s pretty hard to say everyone should drink coffee, but drinking coffee, “at least for your liver, is maybe a beneficial thing, and at least it’s not detrimental.”
In other words, drinking more coffee won’t hurt your liver, and it may even help, so drink up and enjoy.