OSLO, Norway — Most coffee enthusiasts have a preferred method when it comes to brewing a cup of java. Some people like their coffee brewed in a Mr. Coffee machine, others prefer a slow brew in a French press. And while some enjoy the intensity of a fresh espresso, others are happy with a simple cup of the instant kind. But is one type better for your body than others? Perhaps so: a new study suggests that filtered coffee is the healthiest way to brew coffee.
About 30 years ago Professor Dag S. Thelle of the University of Gothenburg made a discovery that haunts many heart-healthy coffee lovers: drinking too much is associated with higher levels of total cholesterol and LDL cholesterol (the bad kind). Poor cholesterol levels are bad for the heart and can lead to coronary heart disease and heart attacks. Thelle wanted to continue researching the relationship between coffee drinking and heart attacks, but he ran into a minor moral roadblock.
“We wondered whether this effect on cholesterol would result in more heart attacks and death from heart disease. But it was unethical to do a trial randomising people to drink coffee or not,” Thelle says in a statement. “So we set up a large population study and several decades later we are reporting the results.”
To make their study as inclusive as possible, researchers recruited a representative sample of the Norwegian population between 1985-2003. In total, they studied 508,747 healthy men and women aged 20-79. Researchers had participants complete questionnaires about how much coffee they drink and the way they brew their usual cup. Participants also provided information about their lifestyle habits, education, height, weight, blood pressure, cholesterol, etc. — things that might influence their coffee consumption and heart health.
Researchers tracked participants for an average of 20 years. Over the course of the study, 46,431 participants died. Of those deaths, 12,621 were due to cardiovascular disease. Nearly half of the cardiovascular disease deaths were the result of a heart attack.
The results of this long-term study show that drinking filtered coffee is safer than drinking none at all. Filtered coffee was associated with a 15% lower risk of death from any cause, when compared to drinking no coffee. Further analysis of cardiovascular disease deaths shows that going filtered is linked to a 12% lower risk in men and 20% lower risk in women.
“The finding that those drinking the filtered beverage did a little better than those not drinking coffee at all could not be explained by any other variable such as age, gender, or lifestyle habits,” says Thelle. “So we think this observation is true.”
Drinking unfiltered coffee does not raise the risk of death when compared with drinking no coffee, but it is worse than going filtered, researchers say. Filtered coffee overall bring less risk of death from any cause, and particularly lower risk of dying from cardiovascular disease and heart attack. This is partially because of the filtering process, which removes most of the harmful substances in coffee that cause cholesterol levels to rise.
Overall, those that drink up to four cups of coffee a day were found to have the lowest mortality.
Professor Thelle emphasizes that these are observational data, but that if public health authorities asked for his advice, he’d tell them: “For people who know they have high cholesterol levels and want to do something about it, stay away from unfiltered brew, including coffee made with a cafetière. For everyone else, drink your coffee with a clear conscience and go for filtered.”
The study is published in the European Journal of Preventive Cardiology.