TROMSO, Norway (StudyFinds.org) — Coffee lovers could end up with heart disease — depending on how they brew their beans, a new study reveals.

A team from UiT-The Arctic University of Norway says men face greater risks if they drink espresso. Meanwhile, women are more likely to suffer from having too many filtered coffees. Naturally occurring chemicals in coffee have been found to raise levels of cholesterol in the blood depending on how people brew the beans.

High levels of cholesterol can increase the risk of cardiovascular disease, the world’s number one killer. However, little is known about the impact of drinking espressos, where a small amount of nearly boiling water is forced under pressure through finely-ground coffee beans.

Now, scientists have found that it could all depend on the drinker’s sex and how they prepare their coffee.

“Interestingly, coffee contains more than a thousand diverse phytochemicals,” says author Professor Maja-Lisa Løchen in a statement to SWNS. “The intake of each compound also depends on the variety of coffee species, roasting degree, type of brewing method and serving size.”

Several brewing methods lead to higher cholesterol

The study authors analyzed survey data from 21,083 people, collected between 2015 and 2016, as part of a long-term population study in Tromsø. Participants were asked how many daily cups of coffee they drank, ranging from none to six or more.

They were also asked what type of brew they preferred, with a choice of filtered, cafetière or espresso from a coffee machine, pods, mocha pots, or instant. Researchers then took blood samples from each participant and also measured their height and weight.

The team also factored in other relevant health information, like whether they smoked, drank alcohol, and how often they exercised. Overall, women averaged four cups of coffee a day, while men enjoyed five cups.

Results show drinking three to five daily cups of espresso “significantly” increased cholesterol levels, particularly among men. Consuming six or more cups of French press coffee led to higher cholesterol levels among both sexes. The same amount of filtered coffee increased cholesterol among women, but not men. Instant coffee also had a different impact on men and women’s cholesterol, increasing it but not at the same rates.

Does the size of the cup matter?

Researchers note their study did not use a standard coffee size, adding that Norwegians tend to drink out of larger espresso cups than Italians. Different types of machines or capsules are also likely to contain varying levels of the key naturally-occurring chemicals.

“This demonstrates how coffee contains compounds that may lead to multiple mechanisms operating simultaneously,” Prof. Løchen says. “Coffee is the most frequently consumed central stimulant worldwide. Because of the high consumption of coffee, even small health effects can have considerable health consequences.”

The findings are published in the open-access journal Open Heart.

South West News Service writer Tom Campbell contributed to this report.