Studies on coffee consumption and cardiovascular health are very contradictory.
Some studies show extreme benefits of coffee while others shows extreme dangers of heart attack and stroke.
So, a team of Norwegian researchers decided to research whether the way we brew our coffee might be what makes a difference.
Indeed, one type of coffee brewing was found to significantly decrease risk of heart attack while another type increased the risk.
From 1985 onwards, the research team recruited a large sample of 508,747 healthy Norwegian adults that was roughly representative of the population regarding age, race, gender, and so on.
They observed these participants for an average of 20 years and were interested to see who would die of cardiovascular disease, stroke and heart attacks.
During this period, the team also asked the subjects about their coffee drinking habits and brewing methods and recorded changes, if any.
During the 20 years of follow-up, 46,341 participants died, including 12,621 from cardiovascular disease.
Of these cardiovascular disease deaths, 6,202 were caused by heart attacks, and 2,894 were caused by strokes.
Compared with those who drank no coffee at all, those who drank filtered coffee were 15 percent less likely to die prematurely of any cause. Men were 12 percent and women were 20 percent less likely to die of cardiovascular disease.
Unfiltered coffee was a different matter, though, and no healthier than abstaining from coffee altogether for younger adults and causing deaths of any cause, deaths of cardiovascular disease, and deaths of heart attacks for those over the age of 60.
So why is filtered coffee healthier for our hearts than unfiltered coffee?
From the available literature, the researchers concluded that the culprits were the chemical substances in the coffee grounds and oils that remained in the coffee if it was unfiltered. These chemicals cause high cholesterol and, thus, cardiovascular disease and early death.
Using the study as a guide for coffee brewing, it means that you should stay away from Turkish coffee, which is yummy but unfiltered. Any other finely ground coffees in which the grains remain unfiltered at the bottom of your cup while you drink the liquid from the top are equally unhealthy.
A French press or any other plunger device that uses a meshed metal screen at the bottom of the plunger is not good enough to qualify as a filtering device either, as it can’t thoroughly filter out the oils from the coffee beans.
The best filters were found to be percolators with paper or fabric filters.