Philadelphia ? Kudzu, often reviled as “the vine that ate the South,” apparently brings something else to the table: a promising treatment for binge drinkers.

Researchers at Harvard-affiliated McLean Hospital outside Boston report that heavy drinkers who took a concentrated extract of kudzu root for only one week downed a lot less beer — two or three brews in an hour and a half instead of their usual five or six.

“That’s a pretty powerful response,” said Scott E. Lukas, director of the hospital’s drug-abuse research lab and lead author of the study, which appeared in this month’s issue of Alcoholism: Clinical and Experimental Research.

Earlier kudzu studies have shown reduced consumption among alcohol-swilling monkeys, rats and hamsters. And while Lukas’ study is small and preliminary, it is the first to conclude what the Chinese have maintained for centuries: that compounds in the ancient vine, known as ge-gen, can help problem drinkers — human ones — imbibe less.

Researchers aren’t sure how it works, but Lukas suspects that active ingredients called isoflavones in the kudzu root increase blood flow, which helps alcohol get to the brain faster. This means drinkers “are getting cues that say, ‘I’m feeling good, I’m OK, no need to suck down this entire beer,”‘ he said.

Binge drinkers don’t usually pay attention to those cues. “They drink so darned fast, they don’t have the opportunity to perceive the effects of the alcohol,” Lukas said.

About 1 in 3 adult drinkers in the United States report binge drinking in the previous month, which some define as five or more drinks at one sitting for men and four or more for women, according to the federal Centers for Disease Control and Prevention in Atlanta.

“It’s a huge public health problem in this country, one that continues into middle age and beyond,” said Dr. Robert D. Brewer, the CDC’s alcohol team leader, citing its role in car accidents, unwanted pregnancies and sexual assaults.

Brewer isn’t certain what practical applications the lab study may have. But if Lukas’ results are confirmed in future clinical trials, kudzu could be used — along with counseling — to get problem drinkers who want to change to drink less.

“There may be a lot of different strategies we haven’t thought of yet,” he said.

Lukas recruited 14 heavy drinkers — 11 men and three women, aged 21 to 32 — for his study, which was carried out in a specially designed studio apartment at the research lab.

The study showed those who took kudzu drank an average of 1.8 beers per session compared to their original 3.5, while those on placebo drank the same as before. Kudzu subjects took 11 sips per 12-oz. can of beer, compared to the average of eight.

Unlike drug treatments for alcoholism, no side effects were reported from the kudzu. “Nothing,” Lukas said. “We were stunned.”

When kudzu was introduced to the United States in 1876 at the Philadelphia Centennial Exhibition, its large leaves and grape-smelling purple flowers delighted all who saw it in the elaborate gardens of the Japanese pavilion.

By the 1920s, kudzu was being grown for animal forage in the United States, and in the decades to follow, the federal government promoted it for erosion control, paying farmers up to $8 an acre to fill their fields with it.

Perhaps too late, the hairy-stemmed vine with 8-inch leaves and mammoth roots was declared a noxious invader. In the South, kudzu has smothered millions of acres of forest and all else in its path, including bridges, buildings, signs, utility poles and cars.

Lukas has photographed kudzu-covered tractor-trailers and homes on Saint Simons Island, Ga., where his in-laws live.

Although the Southeastern climate is perfect for the so-called “mile-a-minute vine,” which can grow a foot a day and 60 feet a season, it also has been spotted in more northern areas.