NEW YORK — Jews don't drink, the old myth goes.
And now there's scientific evidence to prove it.
Two new studies are bolstering the view that Jews don't drink as much as other Caucasians — and researchers attribute the difference largely to a genetic mutation that is found in a much higher proportion among Jews than among other whites.
Those surveyed possessed a particular genetic mutation that regulates an enzyme responsible for determining how the body breaks down alcohol.
A similar mutation is also found at relatively high rates among Asians.
The mutation makes people "more sensitive to alcohol — in other words, they get drunk very quickly," said Yehuda Neumark, an epidemiologist at the School of Public Health and Community Medicine at the Hadassah-Hebrew University Medical Center in Jerusalem.
Neumark, along with a team of researchers in Israel and the United States, recently completed a study that examined the DNA of 145 men in Israel's capital.
"In the Jewish Jerusalemites whom we studied, we found that those carrying this expression of the gene were very light drinkers," he said.
Additional research is currently under way among Jews in America and Russian Jews in Israel to study the genetic and cultural associations between Jews and alcohol.
The discovery of the gene and its impact comes on the heels of a series of groundbreaking studies of genetic mutations and their impact on cancer rates in the Ashkenazi Jewish population. The study also comes as awareness of Jewish alcoholism continues to rise.
A similar genetic mutation, which researchers described as "providing protective properties against alcohol," is known to be virtually absent in blacks and rare in the general white population, they said.
The mutation was found in about one-third of the men studied in Jerusalem — who were divided between Ashkenazi and Sephardi Jews — yet it is found only among 1 to 2 percent of Caucasians in the general American population, said one researcher, Dr. Lucy Carr.
Carr, an associate professor of medicine and pharmacology at the Indiana University School of Medicine, helped analyze the genetic material used in the Hadassah-Hebrew University study.
Another recently released study, conducted at U.C. San Diego, found that about half of the Jewish students examined had the genetic mutation.
The students with the mutation drank half as often as the Jewish students who didn't have it — three times a month rather than six times a month for the male students, and a little more than twice a month, compared with just under five times a month for the women.
There was no difference between those with the mutation and those without it in the amount of alcohol consumed each time they drank, said Dr. Tamara Wall, U.C. San Diego assistant professor of psychiatry, who headed the research team.
She and her associates are in the process of expanding the number of subjects — from 65 Jewish college students to 100. They also are studying an equal number of white, non-Jewish students for comparison.
The Jerusalem men studied ranged in age between 25 and 64. About two-thirds of them were randomly selected, healthy men; one-third were heroin addicts recruited from drug treatment facilities in Jerusalem.
All of the healthy men were light drinkers, according to Neumark, while most of the heroin addicts had been heavy drinkers. His team found that the amount of alcohol consumed each week was closely associated with the genetic mutation.
Other researchers are currently at work on studies examining the presence of the mutation and its effect on college students and other adults in Indianapolis, as well as the impact of the mutation and cultural factors on Jews from the former Soviet Union who are now living in Israel.
Carr of the Indiana University School of Medicine said she and her associates have studied a range of ethnic groups, including people from China, Japan, Korea and Taiwan; England and South Africa; and the Caribbean.
This year they expect to study 200 Jewish members of sororities and fraternities at Indiana University to find out how having the genetic mutation makes people feel when they drink — whether it makes them feel flushed quicker or gives them a headache sooner than those without the mutation.
Deborah Hasin, an epidemiologist and professor of clinical public health at Columbia University, is preparing to study the various factors that influence the rate of alcohol consumption among Russian Jews in Israel.
Russia has one of the highest rates of per-capita alcohol consumption in the world, Hasin said, while Israel has one of the lowest.