Kava, Caffeine, and CYP1A2
**02/23/2022 THIS ARTICLE IS CURRENTLY UNDER REVIEW. INTERACTIONS BETWEEN KAVA AND CAFFEINE MAY IN FACT BE DUE TO PHARMACODYNAMIC INTERACTIONS INSTEAD OF A KINETIC INTERACTION AT CYP**
**10/31/2023 We still do not have subsequent in-human with probe compound testing in regards to CYPs beyond what we had when this study was made**
(Icey, Public domain, via Wikimedia Commons)
Recently, we covered CYP450 enzymes and how kava may inhibit activity in some of these areas. Today, we will focus specifically on the enzyme CYP1A2 and how inhibiting it affects caffeine metabolism.
We’ve seen quite a few kava drinkers over the years remark about how their morning coffee began to be somewhat more of a stimulating experience. Some kava drinkers find this extra boost to be a side benefit of drinking kava. Other people experiencing this marked increase in stimulation may find it overpowering.
Caffeine metabolism occurs primarily in the liver, with a half-life of 5 h, and requires approximately 8–10 h to completely clear. First-pass metabolism accounts for 75-80% of caffeine metabolism in the body. The enzyme responsible for this is CYP1A2 [1].
Kava has been shown in its different forms to inhibit the enzyme CYP1A2 to varying degrees. In 2005, a study was conducted on kava drinking volunteers. They had the subjects stop drinking kava for 30 days and measured the metabolic rate of caffeine both before and after the break. The caffeine metabolism ratio increased by 200% after 30 days. This indicated that when consuming kava on a regular basis, some users can see what feels like DOUBLE the amount of caffeine they’ve ingested. This study also suggested that these values return to normal once kava drinking is stopped [2].
Therefore, kava lovers, if you’ve been drinking your morning coffee and are seeing a definite increase in the stimulatory properties, this could be the reason.
[1] Institute of Medicine (US) Committee on Military Nutrition Research. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington (DC): National Academies Press (US); 2001. 2, Pharmacology of Caffeine. Available from: https://www.ncbi.nlm.nih.gov/books/NBK223808/
[2] Cabalion, P., Barguil, Y., Duhet, D., Mandeau, A., Warter, S., Russmann, S., Tarbah, F., & Daldrup, T. (2005). Kava in modern therapeutic uses: To a better evaluation of the benefit/risk relation: researches in New Caledonia and in Futuna. Revista de Fitoterapia, 5(special issue), 53–70.