verticity
I'm interested in things
One thing I've been wondering about since this came up is the possible role of naturally occurring glutathione in kava in the elevated GGT levels seen in the Australian studies.
The function of the enzyme GGT is to metabolize glutathione, which is an antioxidant that is naturally synthesized by the human body. But what happens when someone consumes a significant quantity of extra glutathione by, for example, drinking kava? Is it possible excess exogenous glutathione could stimulate higher GGT levels, simply because it is needed to metabolize the extra glutathione, and not indicate any damage or even stress on the liver? The usual reasoning is: if GGT is elevated, that means glutathione is being depleted. But if elevated GGT is a result of elevated glutathione, maybe it is just a normal homeostatic response...
The two Aboriginal studies were on traditionally prepared kava and aqueous extract, both of which would contain high levels of glutathione. A 1:1 ratio of glutathione to kavalactones, according to this paper which discusses the (unproven) hypothesis that glutathione in kava has a protective effect on the liver:
Whitton - Kava lactones and the kava-kava controversy
Important note about the above paper: it claims that kavalactones are hepatotoxic, which Dr. Schmidt convincingly argues is not true:
Schmidt - ARE KAVALACTONES THE HEPATOTOXIC PRINCIPLE OF KAVA EXTRACTS? THE PITFALLS OF THE GLUTATHIONE THEORY
The function of the enzyme GGT is to metabolize glutathione, which is an antioxidant that is naturally synthesized by the human body. But what happens when someone consumes a significant quantity of extra glutathione by, for example, drinking kava? Is it possible excess exogenous glutathione could stimulate higher GGT levels, simply because it is needed to metabolize the extra glutathione, and not indicate any damage or even stress on the liver? The usual reasoning is: if GGT is elevated, that means glutathione is being depleted. But if elevated GGT is a result of elevated glutathione, maybe it is just a normal homeostatic response...
The two Aboriginal studies were on traditionally prepared kava and aqueous extract, both of which would contain high levels of glutathione. A 1:1 ratio of glutathione to kavalactones, according to this paper which discusses the (unproven) hypothesis that glutathione in kava has a protective effect on the liver:
Whitton - Kava lactones and the kava-kava controversy
Important note about the above paper: it claims that kavalactones are hepatotoxic, which Dr. Schmidt convincingly argues is not true:
Schmidt - ARE KAVALACTONES THE HEPATOTOXIC PRINCIPLE OF KAVA EXTRACTS? THE PITFALLS OF THE GLUTATHIONE THEORY