The hangover tree

Alcohol is a drug, it’s legal, but it is a drug with real physical and psychological effects. In moderation it can be healthy but in excess and in the long term it can be immensely damaging and addictive. Of course there are also the short term implications of a spot of overindulgence to consider; the effects of a hangover are not to be sneezed at (because sneezing while hungover could result in your head exploding).

There are lots of hangover cures available, most of them of dubious efficacy. The famous Texan remedy of drinking a tea made from rabbit droppings for example, has no obvious physical capacity to ease a hangover (although psychologically, perhaps drinking a decoction of rodent excrement might make the symptoms of a hangover seem trivial by comparison). Now however, something a little more serious has come to light; so serious in fact that it has been published in the Journal of Neuroscience. While this new discovery may do something to ease a hangover the real news is that it might also offer some help in resisting alcohol in the long term.

The “discovery” is really no discovery at all, since in Asia it has been used to treat hangovers for at least 500 years. Now however, scientific understanding is discovering what the seed of a tree called Japanese Raisin Tree (Hovenia dulcis)can do. Researchers from the University of California decided to investigate the plant because they noted that when people consumed alcohol along with food cooked using Hovenia seeds as a spice, they seemed to avoid getting drunk.

After conducting many tests the researchers settled on a compound from the seeds called dihydromyricetin (DHM) as the active component that yielded the effect. They then gave alcohol to one group of rats but no DHM and to another group of rats gave alcohol laced with DHM from Hovenia. The researchers noted that drunk rats behave very much like drunk humans although, one assumes, with less of a propensity to sing John Farnham songs.

The results showed that rats given alcohol without DHM showed distinct intoxication behaviours while those given DHM showed minimal signs of intoxication. For instance, rats given alcohol without DHM slept for an average of 70 minutes while those given DHM slept for an average of ten minutes and some did not sleep at all.

While a treatment for hangover is interesting it is not as profound as another finding from the research. In another study the researchers gave rats alcohol regularly for a long period of time. They then began giving some of the rats DHM. They found that those given DHM had less of a dependency on alcohol and consumed less than did other rats. This is promising in terms of treating alcohol dependency but the question then becomes what is it that DHM is doing?

Investigations showed that DHM stops the effect that alcohol has on receptors in the brain for a neurotransmitter called gamma-amino-butyric acid (GABA). Alcohol’s effect on these GABA receptors is to slow brain cell activity therefore reducing the ability to communicate and so increasing sleepiness; DHM blocks this effect.

Given that DHM does not seem to impact the liver or blood sugar levels, it would seem unlikely that all effects of a hangover would be eradicated by this herb. However, it might diminish drunkenness and could reduce the morning after effects. After all, 500 years of usage would suggest there is something to it. The more important thing though is that Hovenia might have something to offer in treating alcohol abuse which is estimated to affect more than 76 million people worldwide.

It is an exciting finding and it is beautifully poetic: that the cure for feeling seedy should come from a seed.