Kahweol is a natural compound found in coffee, representing one of the many bioactive molecules present in this widely consumed beverage. This diterpene has garnered scientific attention due to its diverse biological activities. Research continues to explore the various ways kahweol interacts with the human body.
Understanding Kahweol
Kahweol is a type of organic compound known as a diterpene, characterized by its unique chemical structure. It is primarily found in the oily fraction of coffee beans, distinguishing it from other coffee components that are water-soluble. Specifically, kahweol is abundant in Coffea arabica beans. Kahweol shares a nearly identical structure with another coffee diterpene, cafestol, differing only in the saturation level of one conjugated bond to its furan ring.
Health Implications of Kahweol
Kahweol exhibits various properties, including antioxidant, anti-inflammatory, and cell-regulating activities.
As an antioxidant, kahweol helps protect cells from damage caused by reactive oxygen species. It has been shown to induce the Keap1/Nrf2/ARE signaling pathway, which is involved in protecting liver cells against oxidative stress. Additionally, kahweol can promote the expression of HO-1, an enzyme with antioxidant properties.
Kahweol also demonstrates anti-inflammatory effects by inhibiting key inflammatory mediators. It can reduce the levels of COX-2 and iNOS, thereby inhibiting the synthesis of PGE2 and NO. In studies, kahweol has been observed to significantly reduce inflammatory cytokines like interleukin 1 alpha, interleukin 1 beta, interleukin 6, and tumor necrosis factor alpha by downregulating NF-κB and STAT3 activation.
Research indicates kahweol’s potential role in cell regulation, particularly in anti-cancer studies, showing anti-proliferative, cytotoxic, and pro-apoptotic effects in various in vitro and in vivo cancer models. Kahweol can induce apoptosis, a form of programmed cell death, in cancer cells. It also appears to inhibit tumor growth and migration by targeting specific signaling pathways such as Src/mTOR/STAT3. For instance, kahweol has been shown to inhibit proliferation and induce apoptosis in breast cancer, colorectal cancer, lung cancer, prostate cancer, and renal cancer cell lines. It also exhibits anti-angiogenic properties, inhibiting the formation of new blood vessels that tumors need to grow.
Regarding cholesterol levels, kahweol’s impact is less pronounced compared to cafestol. While both diterpenes can raise serum cholesterol, kahweol has a smaller effect. For example, a daily intake of 10 mg of kahweol for four weeks was associated with a minimal increase in serum cholesterol compared to cafestol.
Kahweol in Coffee Preparation
The concentration of kahweol in a cup of coffee is significantly influenced by the brewing method used. Since kahweol is found in the oily fraction of coffee beans, brewing methods that allow these oils to pass into the final beverage tend to retain more of the compound.
Unfiltered brewing methods, such as French press, Turkish coffee, and espresso, result in higher concentrations of kahweol in the brewed coffee. For instance, Scandinavian boiled coffee and Turkish-style coffee contain substantial amounts of kahweol, ranging from 5.4 to 7.2 mg per cup. French press coffee also contains relatively high levels, around 3.5 mg of cafestol and 3.5 mg of kahweol per cup. Espresso can contain intermediate amounts, with one study reporting about 1 mg of kahweol per cup.
Conversely, filtered brewing methods, such as drip coffee and pour-over, use paper filters that effectively trap the coffee oils, thereby significantly reducing the amount of kahweol in the final drink. For consumers looking to maximize their kahweol intake, opting for unfiltered coffee preparation methods would be beneficial. Those aiming to minimize it might choose filtered coffee.