The Way You Brew Your Coffee Can Affect Your Heart Health. Here’s The Best Method

It’s also long been known that paper filters removed those elements—something confirmed by a 20-year-long Norwegian study in 2020, which found that drinking unfiltered coffee was associated with a higher mortality, due to cardiovascular causes.

For the present study, the researchers aimed to measure the amounts of diterpenes found in coffee samples brewed by a variety of coffee machines in public places, including in hospital break rooms, comparing them to cups of joe made with paper filters.

“Considering how much coffee is consumed in Swedish workplaces, we wanted to get a picture of the content of cholesterol-elevating substances in coffee from these types of machines,” lead researcher David Iggman, of Uppsala University, explained in a news release. To that end, they studied 14 ways of brewing coffee typically used in public places, looking at the coffee produced by various commercial brewing machines. 

They then compared coffee—by average of about 4.5 ounces at a time—brewed by espresso maker, French press, boiling method, and boiled coffee poured through a fabric filter (pour-over coffee).

While the boiled coffee contained the highest levels of diterpenes per cup, some espresso samples also contained high levels, with great variation. Next, in order of high to low diterpenes levels, was the brewing machines, percolator, and French press, with paper-filtered coffee remaining the healthiest choice. 

“Most of the coffee samples contained levels that could feasibly affect the levels of LDL cholesterol of people who drank the coffee, as well as their future risk of cardiovascular disease,” said Iggman. “For people who drink a lot of coffee every day, it’s clear that drip-filter coffee, or other well-filtered coffee, is preferable. To determine the precise effects on LDL cholesterol levels, we would need to conduct a controlled study of subjects who would drink the coffee.”

But at this point, based on the concentrations of cafestol and kahweol from the investigated machine coffees, thoroughly filtered coffee “seems like the preferable choice for cardiovascular health,” the study concluded, noting that replacing three cups of machine coffee with paper-filtered coffee five days per week would reduce LDL cholesterol by an estimated 13% over five years and 36% over 40 years.