Coffee, a widely consumed beverage across the globe, is more than just a morning pick-me-up; it is a complex mixture of various chemical compounds. These compounds contribute to coffee’s distinctive aroma, flavor, and its diverse effects on the human body. Among these naturally occurring substances are diterpenes, organic molecules found within the coffee bean. Understanding these compounds provides insight into how your daily cup of coffee interacts with your health.
Understanding Diterpenes in Coffee
Diterpenes are organic compounds found in various plants, and in coffee, they are particularly abundant in the oily part of the beans. These lipids are part of the bean’s natural composition. The two most recognized diterpenes in coffee are cafestol and kahweol.
These compounds are found in the coffee plant. They are primarily found in unroasted green coffee beans and persist through the roasting process, becoming available for extraction during brewing.
Health Implications of Diterpenes
The diterpenes cafestol and kahweol have been studied for their effects on human health, particularly concerning cholesterol levels. Research indicates that cafestol, and possibly kahweol, can increase serum cholesterol. Consuming approximately 10 milligrams of cafestol daily can elevate cholesterol levels by about 5 milligrams per deciliter (0.13 mmol/L). This effect primarily impacts low-density lipoprotein (LDL) cholesterol, often referred to as “bad” cholesterol.
A 20-year Norwegian study found an association between consuming unfiltered coffee and a higher mortality risk from cardiovascular causes compared to filtered coffee consumption. Beyond cholesterol, some studies suggest that diterpenes may possess other properties, including anti-inflammatory, antioxidant, and anti-cancer effects. However, these potential benefits require further research.
How Brewing Affects Diterpene Content
The method used to brew coffee significantly influences the amount of diterpenes. Unfiltered brewing methods allow more of these oily compounds to pass into the beverage. For example, French press, Turkish coffee, and Scandinavian boiled coffee typically contain higher concentrations of cafestol and kahweol due to direct contact between coffee grounds and hot water without a paper filter. A single cup of Scandinavian boiled coffee, French press, or Turkish coffee can contain around 3.0 to 3.9 mg of cafestol.
In contrast, filtered brewing methods substantially reduce diterpene content. Drip coffee and pour-over methods, which use paper filters, effectively trap cafestol and kahweol, resulting in significantly lower levels in the final brew. Paper-filtered coffees have reported cafestol concentrations as low as 8 mg/L, compared to much higher levels in unfiltered brews. Instant coffee also contains very low or negligible amounts of diterpenes because its industrial process removes most of these compounds.