Cholesterol-raising substances in office machine coffee
Coffee from most workplace coffee machines contains relatively high levels of cholesterol-raising compounds. The difference is striking compared to regular drip coffee makers with paper filters, which remove most of these substances.
This is shown in a new study led by Uppsala University, in collaboration with Chalmers University of Technology. The study is published in Nutrition, Metabolism & Cardiovascular Diseases.
“Considering how much coffee is consumed in Swedish workplaces, we wanted to investigate the levels of cholesterol-raising compounds in that coffee. We examined fourteen machines and found that the levels were much higher than in regular drip coffee. We interpret this to mean that the filtration process is critical for removing these compounds. Clearly, not all coffee machines manage to filter them out. However, the problem varies between different types of coffee machines, and concentrations also showed large variations between sampling occasions,” says David Iggman, researcher at Uppsala University, who led the study.
Paper Filters Most Effective
It is already well-known that boiled coffee contains high levels of the strongly cholesterol-raising compounds, the diterpenes cafestol and kahweol. This is mentioned in the latest Nordic Nutrition Recommendations, which advise reducing or avoiding boiled coffee. In contrast, a standard drip coffee maker with a paper filter almost completely removes these cholesterol-raising compounds.
Until now, it had not been studied to what extent coffee machines in public settings filter out these substances. In the study, researchers examined fourteen coffee machines in break rooms at various workplaces. The coffee used came from five common brands of pre-ground coffee. Samples were taken from the machines on several occasions and analyzed. There were large differences between machines in terms of cafestol and kahweol levels, and levels also varied between different sampling times.
Potential to Increase Cardiovascular Risk
The most common type of coffee machine, referred to in the study as a “brew machine,” produced coffee with the highest concentration of diterpenes. For comparison, the researchers also analyzed percolator coffee, espresso, French press, boiled coffee, and boiled coffee filtered through cloth. Boiled coffee had the highest levels of diterpenes per cup. Some espresso samples also contained high levels, but with considerable variation.
“Most of the coffee samples contained levels that could potentially affect drinkers’ blood lipids and future risk of cardiovascular disease. For heavy coffee drinkers who consume coffee every day, it is clear that drip coffee or other well-filtered coffee is preferable. To determine the exact effects on blood lipids, we would need to conduct a controlled study with test subjects drinking the coffee,” says David Iggman.
How the Study Was Conducted:
- Two samples were taken from each machine, two to three weeks apart. The coffee types were both medium roast and dark roast from five common brands of pre-ground coffee.
- Most machines used pre-ground coffee; a few ground beans on site, but researchers believe this would not have made a difference. Of the 14 machines tested, 11 were brew machines and 3 were liquid models (lower levels, coffee mixed from concentrate).
- For comparison, the same analysis was carried out on other brewing methods: percolator, espresso, French press, boiled coffee, and boiled coffee filtered through cloth.
- All coffee was analyzed at Chalmers University of Technology. Coffee samples were collected by medical student Erik Orrje during spring 2024.
Source: Info Express / Uppsala University
