An extract from a plant known in the US as “the vine that ate the South” may help reduce alcohol consumption in heavy drinkers, a small-scale study suggests.

Previous research has shown that kudzu plant extract has helped reduce alcohol drinking in rats and hamsters, but this is the first study to show the effect in humans. The plant was introduced to the US to combat soil erosion but has now become a persistent weed.

In the study, people who were given kudzu extract for seven days drank about one beer less in a monitored 1.5-hour drinking session than people who took the placebo, say researchers at McLean Hospital, Harvard Medical School and New England Research Institutes in Massachusetts, US. Those treated also drank more slowly.

The 14 subjects were all heavy drinkers, consuming an average of 25 alcoholic beverages per week, but none of them were alcohol dependent or had a family history of alcoholism. The experimental group took two 500-milligramme kudzu capsules three times a day.


Then they came into a laboratory which simulated a living room, with a television, stereo and bookshelf. A small kitchen was stocked with their favourite beer. Between swigs, the subjects were required to put their beer onto an end table with a built-in scale so researchers could track exactly how much beer they were drinking.

Long drink

All of the subjects reached for the first drink in the same amount of time. But after having the first beer, people taking kudzu took a longer time to get up and get another drink and an even longer time to finish it.

Chinese herbal medicine has long used kudzu to reduce drinking and cure hangovers. Researchers believe that an isoflavone called puerarin is the active ingredient.

The kudzu used in the study had far more puerarin than the supplements found at health food stores, about 25% compared to just 2%. Earlier studies have reported that people who take the kudzu supplement said they felt more tired and intoxicated after having one alcoholic drink.

“We suspect the kudzu treatment is causing the alcohol to get into the brain more quickly,” Scott Lukas, at McLean Hospital, told New Scientist. But researchers are unsure of the mechanism involved. He adds that after four weeks of treatment, the subjects did not show any side effects.

J C Garbutt, a psychiatry professor at the University of North Carolina, US, is interested by the findings but says more work is needed to determine whether the treatment is effective when used by alcoholics.

Lukas envisions kudzu being used alongside group therapy to treat alcoholism and would like to test it on college-age students – a group prone to binge drinking.

Journal reference: Alcoholism: Clinical and Experimental Research (DOI: 10.1097/01.ALC.0000163499.64347.92)