Recent research from Uppsala University in Sweden has raised significant concerns regarding the effects of coffee brewed from machines commonly found in hospitals and care homes. Researchers examined coffee from 14 vending machines, discovering that 11 used brewing machines which steeped coffee grounds in hot water, while the remaining three utilized liquid coffee concentrate.
High Levels of Diterpenes
The study revealed that coffee from brewing machines contained alarmingly high levels of Cafestol and Kahweol, types of diterpenes that can elevate low-density lipoprotein (LDL) cholesterol levels. Elevated LDL cholesterol is a well-documented risk factor for cardiovascular diseases. In contrast, regular filtered coffee contains less than one-hundredth of the diterpene levels found in coffee from these machines.
Why the Difference?
One explanation for the disparity lies in the type of filters used in the brewing process. The absence of fine filters in brewing machines allows more diterpenes, combined with coffee particles, to seep into the beverage. In fact, manually brewed coffee in boiling water tends to have even higher Cafestol concentrations than that produced by brewing machines. When filtered through synthetic materials, however, Cafestol is largely eliminated.
The implications are compelling; the study suggests that coffee from brewing machines could affect cholesterol levels similarly to adding 60 milliliters of cream to a cup of regular filtered coffee. For individuals who consume large amounts of coffee daily, switching to filtered methods is advisable, according to study leader David Iggman.
Conflicting Results
The relationship between coffee filters and diterpenes isn’t new. A Norwegian study conducted in 2020 found that unfiltered coffee is linked to a higher mortality rate compared to its filtered counterpart. Uppsala’s research focused on vending machines in workplaces, where coffee consumption is typically higher. While the findings seem to align with previous studies, some results remain puzzling. For instance, French press and percolator coffee (which lack fine filters) surprisingly showed better results than expected. Additionally, the Cafestol content in espresso samples varied drastically, sometimes by up to 70 times. Note that espresso machines using portafilters and capsules were not part of the research.
Data Limitations
The study authors openly acknowledge that the data is still incomplete. Concentration levels varied significantly between different machines and even during the two to three-week sampling intervals. Cleaning intervals were identified as potential influencing factors. Furthermore, limitations included small sample sizes and a lack of details regarding machine construction, water pressure, temperature, brew contact time, grind size, and roast levels.
The Mixed Bag of Diterpenes
Yet, the implications of diterpenes are complex. While they have been shown to negatively impact not only cholesterol but also other lipoproteins like triglycerides, they also possess anti-inflammatory and anti-cancer properties. Thus, future coffee studies are highly anticipated as researchers continue digging into the benefits and risks associated with coffee consumption.
