KUDZU root hangover remedies are illogical

THE CASE

There are several preparations containing kudzu root (Pueraria lobata) on the market that claim to be "hangover cures". The instructions for one particular product are:

"For best results take 4 capsules while drinking. Alternatively take 4 capsules the morning after."

This product claims to contain the equivalent of 2.25 g of Pueraria lobata along with amino and minerals. The blurb continues:

"Great for a big night out. Contains Pueraria lobata traditionally used to relieve hangover symptoms."

Another product says:

"An alcohol protection formula that stops a hangover before it starts! ...... Unique flavonglycosides like isoflavones, diadzin, and puerarin in kudzu extract help limit alcohol's damage to the body."

The only problem is that kudzu root contains an inhibitor of aldehyde dehydrogenase, and therefore acts to increase the levels of acetaldehyde. It is acetaldehyde that produces many of the symptoms of hangover especially the flushing, and the throbbing headache. I can't find any reference to kudzu root (but see below) being used a "hangover cure" and as far as I can work out it will increase the liklihood and worsen the symptoms of a hangover.

There is a venerable Western drug on the market, disulfiram (marketed as Antabuse), that has long been used as a deterrent for alcohol abuse (called an antidipsotropic). It has a reaction named after it "The Disulfiram Reaction". Just like kudzu root, disulfiram inhibits the enzyme system responsible for the conversion of acetaldehyde to acetate. Ingesting alcohol after taking disulfiram results in raised blood acetaldehyde levels with accumulation in the tissues producing the very unpleasant and potentially dangerous "aldehyde reaction". Chronic use may cause an only partially reversible peripheral neuropathy. There is no reason to assume that kudzu root will not produce the same results if taken chronically along with alcohol.

Kudzu root is a traditional Chinese antidipsotropic medicine, like the drug disulfiram. It decreases the desire to drink by making the consequences more unpleasant, in other words behaviour modification. Therefore there are some kudzu root products that more logically claim to reduce the desire to drink. This gives rise to advertorial blurb like:

"....was developed as a direct result of the now famous 2005 Harvard Medical Center/McLean Hospital study in which participants drank significantly less alcohol when given herbal kudzu extract."

Traditional Chinese medicine (TCM) practitioners usually claim that kudzu is harmless:

"All in all, Kudzu is a benign herb with no observed toxicity, its actually a food commonly served in some Asian cuisines."

But Unfortunately there is some suggestion that kudzu ingestion may increase the risk of cancer formation.

There are two distinct kudzu preparations Radix pueraria lobata (a root extract) and Flos pueraria lobata (a floral extract). Apparently Pueraria flos does enhance acetaldehyde removal, so just may be useful for preventing or treating a hangover.

MY VERDICT
To the public:

If you really consider a kudzu "hangover cure" is worthwhile. Make sure that the one you select contains the floral extract (Flos puerariae) not the root extract (Radix pueraria). The root extract will make your hangover worse and is probably contraindicated at the same time as alcohol consumption. There is also no point in taking a medicine that is a mixture of the two, they will tend to cancel each other out.

To the regulatory authorities:

Purveyors of kudzu preparations should be required to identify their product as containing either root extracts, or floral extracts of the Pueraria lobata plant, as they have different pharmacological effects.

Herbal medicines must be marketed along with some sort of proof of efficacy, in this case kudzu can have entirely the opposite effect to that claimed, if it is derived from the wrong plant part.

NOTE

Originating in east Asia, kudzu (Pueraria lobata) is a noxious weed in many parts of the world, especially in the south- east of the United States. It was deliberately introduced into Australia in the belief that it would provide an new source of forage legume for stock. It is now becoming a problem in south east Queensland. If you see it growing, please notify the appropriate authority.