A friend has told me that drinking a lot of coffee causes cancer. Is this true?

Coffee causes cancer, it's a common myth that drinking coffee might cauce breast, pancreatic or other cancers.

A study from several years ago implied that drinking coffee increased the risk of pancreatic cancer. Dr. Brian MacMahon, a professor of epidemiology at Harvard published a study called Coffee and Cancer of the Pancreas in the New England Journal of Medicine. Dr. MacMahon opined that drinking even three cups of coffee a day increased the risk of pancreatic cancer threefold, and that coffee may have caused nearly half the pancreatic cancers in the United States.

In 1995 the Italian Pancreatic Cancer Study Group concluded the association between coffee use and pancreatic cancer still held after controlling for potential confounding factors such as cigarette smoking or alcohol use, and when the analysis was restricted to nonsmoking coffee drinkers.

Recent headlines claims that drinking coffee can reduce our risk of liver cancer.

A team of Japanes researchers made new study of over 90.000 middle-aged men and woman, over a 10-year period. They found that people who drank coffee daily or nearly every day had half the liver cancer risk of those who never drank coffee. The study was published in the Journal of the National Cancer Institute.

The study found that those who drank one or two cups of coffee every day halved their risk of this type of cancer. This risk decreased slightly more if they drank three or four cups every day, while those who drank five or more cups a day, saw the risk fall by 76%.

Why did earlier study result in inaccurate and misleading results? I think the example demonstrates that one study can't be conclusive, and science is a process of exploration. If there exists a large, consistent body of evidence, there can be established credible association between as an example coffee and disease, else not.

If you ask the coffee industry, they maintain that other studies shows that coffee is beneficial to your health, lowering the risk of colon cancer, gallstones and cirrhosis of the liver. They also claims that coffee contains more anti-oxidants than green tea, and is an excellent antidepressant.

I wonder what coffee industry think of cappuccino?

Anyway, I can drink my coffee without having a bad conscience.