Coffee is one of the most widely consumed beverages in the world and the most widely used stimulant throughout the world. A study recently published in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology, found a link between the method in which this drink is made, heart attacks and longevity. "Unfiltered coffee contains substances that increase cholesterol in the blood. Using a filter eliminates them and makes heart attacks and premature death less likely," says Professor Dag S. Thelle, from the University of Gothenburg, Sweden, one of the researchers in the study. An unfiltered cup of coffee contains about 30 times the concentration of lipid-enhancing substances compared to filtered coffee.
Thirty years ago, Thelle discovered that coffee consumption was linked to an increase in total cholesterol and LDL (bad) cholesterol, to the point where it could have harmful consequences for heart health. The harmful substances were identified and it was found that they could be eliminated using a simple filter. The team of researchers then began a large population study that has lasted several decades and now yields interesting results.
The participants in the study (508,747 healthy men and women aged 20-79 years living in Norway) had to fill out a questionnaire about the quantity and type of coffee consumed. Data on variables that could influence both coffee consumption and heart disease were also collected to be considered in the analysis. Examples included tobacco consumption, education, physical activity, height, weight, blood pressure and cholesterol. This set of data and participants were followed for 20 years; 46,341 participants died, 12,621 of these deaths were due to cardiovascular disease and 6,202 were caused by a heart attack.
What was seen is that drinking coffee was not a dangerous habit. In fact, drinking filtered coffee was safer than not drinking any coffee at all (15% reduction in the risk of death from any cause during follow-up). In terms of death from cardiovascular disease, the filtered infusion was associated with a 12% reduction in the risk of death in men and 20% in women, compared to no coffee at all. The lowest mortality occurred among participants who consumed 1 to 4 cups of filtered coffee per day.
"The finding that those who drank the filtered beverage did a little better than those who did not drink coffee at all, could not be explained by any other variable such as age, sex or lifestyle habits. So we believe that this observation is true," Thelle said.
Drinking filtered coffee was also safer, both in terms of not dying from cardiovascular disease or a heart attack. "Our analysis shows that this was partly due to the cholesterol-raising effect of unfiltered coffee," said Professor Thelle.
Thelle also noted that unfiltered coffee did not increase the risk of death compared to no coffee, except in men aged 60 and over, where unfiltered brewing was associated with high cardiovascular mortality. The professor explained that in the study only the measure of coffee consumption was available but that over time the way of preparing this drink was changing in Norway. The researchers believe that the youngest, who initially drank unfiltered coffee, began to filter it, thus reducing the association with cardiovascular mortality over a period of time. However, the study concluded that older men changed their habits less and continued to drink unfiltered coffee.
Professor Thelle stressed that this is observational data, but if asked for advice by public health authorities he would say: "For people who know they have high cholesterol levels and want to do something about it, stay away from unfiltered coffee, including coffee made from a coffee maker. For everyone else, drink your coffee with a clear conscience and opt for filtering.
References: Tverdal A, Selmer R, Cohen JM, Thelle DS. Coffee consumption and mortality from cardiovascular diseases and total mortality: Does the brewing method matter? Eur J Prev Cardiol. 2020. doi:10.1177/2047487320914443.