Coffee can contain high levels of compounds that raise LDL—or “bad”—cholesterol, depending on how it’s brewed, according to Science Alert.
The Cholesterol-Raising Compounds in Coffee
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Diterpenes are plant-derived compounds that can have various effects on the human body. Two of them—cafestol and kahweol—are linked to increased LDL cholesterol. Studies show that their levels in coffee depend heavily on the brewing method.
How Brewing Method Affects Cholesterol?
Swedish researchers measured diterpene levels in coffee made with a variety of machines and popular brewing techniques. They found that boiling a large pot of coffee produced the highest levels. By contrast, simply filtering the coffee drastically reduced these compounds.
Coffee machines commonly used in workplaces worldwide also produced coffee with relatively high diterpene content.
Samples from each brewing method were frozen for storage and transport before analyzing diterpene concentrations. The team also collected four espresso samples from three cafés and one workplace.
Overall, manual brewing methods generated lower diterpene levels than machine brewing—whether from standard coffee makers, liquid coffee machines, or traditional espresso machines.
“We studied 14 coffee machines and found that coffee from these machines contained far higher levels of diterpenes compared to drip coffee makers using standard paper filters,” said David Iggman, a clinical nutrition specialist at Uppsala University. “From this we infer that filtration is closely tied to the amount of LDL cholesterol–raising compounds in coffee.”
Regular coffee machines produced on average 174 mg/L of cafestol and 135 mg/L of kahweol. The best choice appeared to be paper-filtered drip coffee, with only 11.5 mg/L of cafestol and 8.2 mg/L of kahweol.
Boiled coffee—a common unfiltered method in some countries like Sweden—resulted in extremely high concentrations: nearly 940 mg/L of cafestol and almost 680 mg/L of kahweol.
A Simple Way to Reduce the Risk
Fortunately, there is an easy way to cut these harmful compounds. When researchers filtered previously boiled coffee through cloth, the levels dropped to 28 mg/L of cafestol and 21 mg/L of kahweol. They used a simple sock as a filter, but any type of cloth or paper filter would work.
The researchers acknowledged major limitations, including small sample size and uncontrolled variables such as filter pore size, water pressure, temperature, and coffee bean roasting and grinding methods.
What This Means for Coffee Lovers?
These findings add to the growing—and sometimes conflicting—body of research on coffee’s health effects. Other studies suggest that drinking three or more cups of coffee a day may reduce the risk of cardiovascular disease by up to 40%. Regular coffee consumption has also been linked to lower risks of dementia, Parkinson’s disease, and cancers of the skin, mouth, and colon. Coffee may even offset some harms of prolonged sitting and extend lifespan.
But the health impact clearly depends not only on how much coffee you drink and when, but also how you brew it.
“Most coffee samples contain diterpene levels that can influence the drinker’s LDL cholesterol and their future risk of cardiovascular disease,” Iggman concluded. The study was published in Nutrition, Metabolism and Cardiovascular Diseases.