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Kava Fact of the Day Kava and GGT

The Kap'n

The Groggy Kaptain (40g)
KavaForums Founder
blood-sample-liver-function-test-blood-sample-tube-laboratory-requisition-form-liver-function-...jpg

GGT - Gamma-glutamyltransferase

Today’s fact of the day will be in relation to the one we had yesterday regarding Australia's laws about kava. Today we’re going to focus on one piece of that and expand on it. This topic is liver tests and increased GGT.

GGT is short for gamma-glutamyltransferase. This is a liver enzyme that is tested for in a good majority of metabolism tests. GGT is present in the cell membranes of tissues including liver, kidneys, bile ducts, pancreas, heart, and brain. It is involved in the metabolism of glutathione and the detoxification of pharmaceutical compounds among hundreds of different functions. Introduced over 40 years ago, tests for quantification of this enzyme are commonly measured as a sensitive but not very specific liver function test (Whitfield 2001).

We should also address two other common terms seen when viewing a liver metabolic test and those are AST and ALT. Both are highly concentrated in the liver, however ALT is a more specific indicator of liver injury. Normal ranges of ALT are from 3-30 U/L. Liver damage with ALT will begin to indicate when levels reach 3 times the normal upper range. GGT can help confirm the origin of other elevated enzymes, or can help support the suspicion of alcohol use in patients (Fancher, Kamboj, and Onate 2017).

In 2007 a study was performed on predominantly Tongan individuals in Hawaii. 62 subjects were tested. Subjects were screened for compromising liver conditions prior to the tests such as hepatitis, and co-administration of drugs which may affect the liver. Participants which were regular kava drinkers were found 5 times more likely to have increased levels of GGT on metabolism tests. This number closely correlates to BMI in kava drinkers linearly. Increased BMI → Increased GGT. This study found no association between kava drinking and elevated AST and ALT values which classically indicate liver issues/damage. Aqueous kava was, in this study, considered a possible contributing factor to increased levels of GGT. This study goes on to say that GGT elevation in these kava drinkers may be an artifact of GGT induction, rather than a sign of liver toxicity (Brown et al. 2007).

Brown, Amy C., Janet Onopa, Peter Holck, Pakieli Kaufusi, Derek Kabasawa, Winston J. Craig, Klaus Dragull, Arieh M. Levine, and Jonathan D. Baker. 2007. “Traditional Kava Beverage Consumption and Liver Function Tests in a Predominantly Tongan Population in Hawaii.” Clinical Toxicology 45 (5): 549–56.

Fancher, Tonya, Amit Kamboj, and John Onate. 2017. “Interpreting Liver Function Tests.” Current Psychiatry 6 (5): 61–68.

Whitfield, J. B. 2001. “Gamma Glutamyl Transferase.” Critical Reviews in Clinical Laboratory Sciences 38 (4): 263–355.
 

Alia

'Awa Grower/Collector
GGT - Gamma-glutamyltransferase

Today’s fact of the day will be in relation to the one we had yesterday regarding Australia's laws about kava. Today we’re going to focus on one piece of that and expand on it. This topic is liver tests and increased GGT.

GGT is short for gamma-glutamyltransferase. This is a liver enzyme that is tested for in a good majority of metabolism tests. GGT is present in the cell membranes of tissues including liver, kidneys, bile ducts, pancreas, heart, and brain. It is involved in the metabolism of glutathione and the detoxification of pharmaceutical compounds among hundreds of different functions. Introduced over 40 years ago, tests for quantification of this enzyme are commonly measured as a sensitive but not very specific liver function test (Whitfield 2001).

We should also address two other common terms seen when viewing a liver metabolic test and those are AST and ALT. Both are highly concentrated in the liver, however ALT is a more specific indicator of liver injury. Normal ranges of ALT are from 3-30 U/L. Liver damage with ALT will begin to indicate when levels reach 3 times the normal upper range. GGT can help confirm the origin of other elevated enzymes, or can help support the suspicion of alcohol use in patients (Fancher, Kamboj, and Onate 2017).

In 2007 a study was performed on predominantly Tongan individuals in Hawaii. 62 subjects were tested. Subjects were screened for compromising liver conditions prior to the tests such as hepatitis, and co-administration of drugs which may affect the liver. Participants which were regular kava drinkers were found 5 times more likely to have increased levels of GGT on metabolism tests. This number closely correlates to BMI in kava drinkers linearly. Increased BMI → Increased GGT. This study found no association between kava drinking and elevated AST and ALT values which classically indicate liver issues/damage. Aqueous kava was, in this study, considered a possible contributing factor to increased levels of GGT. This study goes on to say that GGT elevation in these kava drinkers may be an artifact of GGT induction, rather than a sign of liver toxicity (Brown et al. 2007).

Brown, Amy C., Janet Onopa, Peter Holck, Pakieli Kaufusi, Derek Kabasawa, Winston J. Craig, Klaus Dragull, Arieh M. Levine, and Jonathan D. Baker. 2007. “Traditional Kava Beverage Consumption and Liver Function Tests in a Predominantly Tongan Population in Hawaii.” Clinical Toxicology 45 (5): 549–56.

Fancher, Tonya, Amit Kamboj, and John Onate. 2017. “Interpreting Liver Function Tests.” Current Psychiatry 6 (5): 61–68.

Whitfield, J. B. 2001. “Gamma Glutamyl Transferase.” Critical Reviews in Clinical Laboratory Sciences 38 (4): 263–355.
I remember this study in real time. A tight budget made a broad range of test subjects impossible.
I've always wondered about-- "GGT can help confirm the origin of other elevated enzymes, or can help support the suspicion of alcohol use in patients" ... could that mean these subjects were also alcohol drinkers, in addition to kava drinkers?
 

The Kap'n

The Groggy Kaptain (40g)
KavaForums Founder
I remember this study in real time. A tight budget made a broad range of test subjects impossible.
I've always wondered about-- "GGT can help confirm the origin of other elevated enzymes, or can help support the suspicion of alcohol use in patients" ... could that mean these subjects were also alcohol drinkers, in addition to kava drinkers?
I believe they took into account for that, as they reviewed each participants drug/alcohol use history.

From Materials & Methods:

quote.jpg
 

Orz[EST]

Kava Enthusiast

I cannot see full text and numbers. If <10 micromols causes toxicity, I'd be a bit alarmed...
 

Orz[EST]

Kava Enthusiast
...cool water extraction should select safer and tastier ones, probably not much worry.

It definitely would benefit from research.
 

Alia

'Awa Grower/Collector
I believe they took into account for that, as they reviewed each participants drug/alcohol use history.

From Materials & Methods:

View attachment 11836
I remain confused regarding Brown, et/ al. study.
As the Exclusion criteria said, the study excluded subjects with-- "heavy alcohol consumption equal to or exceeding 3 drinks/day,"
I interpret this as saying the subjects could have been alcohol drinkers as well as kava drinkers.
Am I missing something? Or is there a highlight I missed that states these guys drink no alcohol, ever?
It is also not completely clear exactly how much kava the subjects were consuming.
pg. 151 indicates "1 cup kava" consumed? per session?
I mean no disrespect for this "Fact of the Day".
 
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The Kap'n

The Groggy Kaptain (40g)
KavaForums Founder
I mean no disrespect for this "Fact of the Day".
Absolutely no disrespect taken, good sir. I fully FULLY encourage this type of discussion on my facts of the day. If you see something odd that stands out, it's your duty to bring that to our attention :)

You wont hurt my feelings with these. I'm here to get to the absolute bottom of the issues :)

It seems like maybe they could have concurrently had alcohol as long as it was less than 3 drinks per day, but maybe this part of the study will address your question:

paragraph.jpg


Also from what I'm reading, it takes a considerable alcohol binge for longer periods of time to increase levels of GGT, so while it may be a good indicator of alcohol abuse, it may not be the best to indicate light usage.
 

Alia

'Awa Grower/Collector
Absolutely no disrespect taken, good sir. I fully FULLY encourage this type of discussion on my facts of the day. If you see something odd that stands out, it's your duty to bring that to our attention :)

You wont hurt my feelings with these. I'm here to get to the absolute bottom of the issues :)

It seems like maybe they could have concurrently had alcohol as long as it was less than 3 drinks per day, but maybe this part of the study will address your question:

View attachment 11837

Also from what I'm reading, it takes a considerable alcohol binge for longer periods of time to increase levels of GGT, so while it may be a good indicator of alcohol abuse, it may not be the best to indicate light usage.
Likely I am too subjective regarding this study. Ideally she would (somehow) have found folks who drink absolutely no alcohol and only drink kava.
I wonder about folks who (may) drink some alcohol on any given day and later have kava, same day. Would the GGT be more elevated with both rather
than just one? Personally, if a person drinks "3 (alcohol) drinks per day", I would call that person a heavy alcohol user.
My prejudice is against alcohol in general, I admit that.
 

Orz[EST]

Kava Enthusiast
Ideally she would (somehow) have found folks who drink absolutely no alcohol and only drink kava.
Finding a group of teetotalers would be a bit difficult from general public, the heavy drinking bar is not very high. From Easter European + Finland perspective.

I suspect British and Bourbon belt culture is also quite alcohol-prone. Russia is becoming a bit better from apalling starting point. Ppl drinking more beer and less vodka in formerly leading alcoholism country. OTOH, in China and Vietnam the situation has worsened lately, AFAIK.

 
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