Coffee linked to longer life, according to large U.S. study

Do you feel guilty about that morning cup of coffee? What about the second, third or fourth cup?

According to a Statistics Canada article from a few years ago, coffee is second only to water as the most popular drink among Canadians. And for men above the age of 50, coffee tops the list.

Well, if you're anything like the typical Canadian, science has now given you one less reason to fret over your daily caffeine fix. It seems coffee is linked to longevity.

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In a study published in the latest issue of The New England Journal of Medicine, researchers followed a group of over 400,000 men and women between the ages of 50 and 71, from 1995 until 2008. They didn't include anyone who'd previously suffered from heart disease, a stroke, or cancer. The participants reported how much coffee they drank at the beginning of the study and researchers assumed that these habits would not change much.

During the study, just over 50,000 of the participants died. At first, the results didn't seem good for coffee fanatics. When researchers adjusted for age alone, coffee drinkers seemed more likely to die during the study period than those who didn't drink coffee.

But coffee drinkers were also more likely to smoke. So when researchers also adjusted for smoking, alcohol consumption and other confounding factors, coffee actually reduced the risk of dying.

"We found coffee consumption to be associated with lower risk of death overall, and of death from a number of different causes,'' says the study's author and researcher at the National Cancer Institute, Neal Freedman.

In fact, the study showed that anywhere from three to six cups of coffee a day led to a 10 per cent lower risk of death over the period of study.

And there was not a significant difference between regular coffee and decaf. Coffee consumption was associated with reduced death from heart disease, respiratory disease, stroke, diabetes and infections. But not for cancer.

But just because there's a link between coffee and life expectancy, this study doesn't prove that coffee is the cause of a longer life expectancy — nor do the researchers know which ingredients, if any at all, may be responsible.

"The mechanism by which coffee protects against risk of death -- if indeed the finding reflects a causal relationship -- is not clear, because coffee contains more than 1,000 compounds that might potentially affect health,'' says Freedman.

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Indeed. Toronto-based dietitian, Anar Allidina explains that with so many ingredients present in coffee, the research has failed to show which specific components are beneficial or harmful. But some effects have been determined.

"Heavy caffeine intake of more than 600 mg a day may cause nervousness, stomach upset, insomnia or restlessness," she says. But she notes that everyone seems to react differently.

And it might depend on how your coffee is prepared.

"Some studies suggest that unfiltered coffee may elevate the bad cholesterol," she explains.

As for the known benefits, she says the beverage contains lots of antioxidants, which help protect cells from damage. And coffee consumption has been linked to lower risk of Type 2 diabetes, and may reduce the risk of certain cancers and Parkinson's disease.

It can also improve cognitive function — not a surprise for many of us who depend on the stuff to do our daily thinking.

So, think away. Your daily brew might be helping you not just in the short term, but in the long term too.

Watch the video below about a new study is throwing into question whether "good cholesterol" really reduces heart attack risk.