Kahweol: It's Qahweh – University of Copenhagen

20 May 2019

Kahweol: It's Qahweh

Natural toxin

Kahweol is an antioxidant diterpene, mostly present in unfiltered coffee. After water, coffee is the most consumed drink in the world.

Figure 1. Turkish Coffee being poured from a copper cezve [8].

Coffee contains more than a thousand compounds. One of these is kahweol [Figure 2], an antioxidant diterpene up. The word Kahweol is derived from an Arabic word “Qahweh” meaning coffee [7]. Kahweol remains in unfiltered coffee, especially in Scandinavian and Turkish coffee (boiled coffee, Figure 1) with an approximate content of 7.2 and 5.4 mg per cup, respectively [3][2]. The content of diterpene kahweol in coffee depends on the genetics of plants, geographical origin and climatic conditions [6]. The kahweol is highly unstable in its pure form, therefore its biological properties have been studied with cafestol which is another diterpene of coffee [3].

The consumption of boiled coffee which may have potential content of kahweol is associated with an increase in serum cholesterol level. The elevated liver enzyme levels in serum is also associated with the consumption of unfiltered coffee [5].

Figure 2. Chemical structure of Kahweol [9]. Click image for interactive 3D model

The clinical and epidemiological studies have shown that an amount of 10 mg of kahweol par day is likely to have no effect on blood cholesterol level. In some regions such as Scandinavia where a large amount of unfiltered coffee was consumed, risk of coronary heart disease is high and was associated with the consumption of unfiltered coffee [5]. But the recent epidemiological studies show that drinking coffee with a high level of kahweol can lower the risk of colon cancer, which is one of the most frequent cancers in the western world. Some recent animal studies have shown the protective behaviour of kahweol against the action of some carcinogens [4]. In animal models and cell cultures system, kahweol along with cafestol were shown to produce a broad range of biochemical effects which reduce the genotoxicity of several carcinogens including 7,12-dimethylbenz[a]anthracene (DMBA), aflatoxin B1 (AFB1) and benzo[a]pyrene [3].

CAS number: 6894-43-5
SMILES code: CC12C=CC3=C(C1CCC45C2CCC(C4)C(C5)(CO)O)C=CO3

Note: You can continue drinking Coffee

References:

  1. C. Cardenas, A.R. Quesada, M.A. Medina, Anti-angiogenic and Anti-inflammatory properties of kahweol, a coffee diterpene, PLoS ONE 6 (2011) e23407.
  2. C. Cardenas, A.R. Quesada, M.A. Medina, Insights on the antitumor effects of kahweol on human breast cancer:Decreased survival and increased production of reactive oxygen species and cytotoxicity, Biochemical and Biophysical Research Communications 447 (2014) 452–458
  3. C. Cavin, D. Holzhaeuser, G. Scharf, A. Constable, W.W. Huber, B. Schilter, Cafestol and kahweol, two coffee specific diterpenes with anticarcinogenic activity, Food and Chemical Toxicology 40 (2002) 1155–1163
  4. H.G. Kim, J.Y. Kim, Y.P. Hwang, K.J. Lee, K.Y. Lee, D.H. Kim, H.G. Jeong, The coffee diterpene kahweol inhibits tumor necrosis factor-α-induced expression of cell adhesion molecules in human endothelial cells, Toxicology and Applied Pharmacology 217 (2006) 332–341
  5. M.V. Boekschoten, E.G. Schouten, Coffee bean extracts rich and poor in kahweol both give rise to elevation of liver enzymes in healthy volunteers, Nutrition Journal 2004, 3:7  doi:10.1186/1475-2891-3-7
  6. M.T. Benassi, R.C. EloyDias, Assay of kahweol and cafestol in coffee, coffee in health and disease prevention (2015), 993-1004
  7. R.O. Bengis and R.J. Anderson, The Chemistry of the Coffee-Bean, Department of Chemistry, Yale University, New Haven, The Journal of Biological Chemistry (1932), vol XCVII, pg. 100
  8. https://en.wikipedia.org/wiki/Turkish_coffee#/media/File:T%C3%BCrk_Kahvesi_-_Bakir_Cezve.jpg. Photograph by Müslüm Bayburs
  9. https://commons.wikimedia.org/wiki/File:Kahweol.svg. Attribution: Roland Mattern [Public domain]