Rare Gene Discourages Alcoholism Among Jews

Study: Jews Have Fewer Problems With Alcohol Dependence

Genetic Diagram
Gene Protects Against Alcoholism. © Getty Images

For many years, it was generally believed that religious and cultural influences were the reason for low rates of alcoholism among Jewish males, but modern research has found a biological explanation for the phenomenon.

Scientists are not exactly sure why, but a gene variation first known as alcohol dehydrogenase 2 (ADH2*2), but later called alcohol dehydrogenase 1B (ADH1B), tends to discourage heavier drinking in the persons who have the gene.

Because an estimated 20% of the Jewish population has the ADH1B gene, it is believed to be a factor in the low rates of alcoholism reported in this ethnic group. The gene produces a more active from of the enzyme that catalyzes the first step in alcohol metabolism.

Gene Has Protective Effect for Alcoholism

The relatively high prevalence of the ADH1B gene in the Jewish population would account for the low rates of alcoholism more so than differences in religious practices or level of religiosity, studies have found.

Those who have the gene variant tend to drink less frequently, consume less alcohol overall or have more unpleasant reactions to alcohol.

But, the protective effects of the gene against alcoholism can be minimized by environmental or cultural factors that encourages heavy alcohol consumption, later research has found.

Looking at Cultural Influences to Drink

Deborah Hasin, PhD, of Columbia University, was one of the first researchers to find that cultural influences could lessen or negate the gene's protective effects.

When Hasin and her colleagues studied 75 Israeli Jews between the ages of 22 and 65, they found that the subjects with the ADH1B gene had significantly lower rates of alcohol dependence over their lifetimes. Hasin's study was the first to link the gene to rates of alcohol dependence, rather than just heavier alcohol consumption.

However, when the researchers divided the participants into groups based on their country of origin and recency of immigration to Israel, they found variations in the protective effects of ADH1B.

Influences of a Heavy Drinking Culture

The study's subjects were divided into Ashkenazis (those of European background and arrivals from Russia before 1989) and the Sephardics (those of MIddle Eastern or North African background) and more recent immigrants from Russia.

The more recent Russian immigrants had the highest rates of heavier drinking that the other two groups. They also had the highest rates of past and lifetime alcohol dependency.

The researcher concluded that both genes and environment are factors in the development of alcoholism. The heavy-drinking culture of the recent Russian immigrants overcame the protective effects of the ADH1B gene. Russia has an extremely high rate of alcohol consumption, while Israel has one of the lowest rates.

Earlier Immigrants Drank Less

"The study's findings suggest that the recent Russian immigrants' previous exposure to the heavy-drinking environment of Russian culture overcame the protective effects of the ADH2*2 gene." Hasin wrote.

"Their increased vulnerability to heavy drinking was evidenced by such study measures as peak lifetime alcohol consumption levels."

Therefore, the Russian immigrants who had been in Israel prior to 1989 were affected by Israel's culture of less alcohol consumption, the research believe, and had rates of alcohol dependence similar to the Ashkenazis and Sephardics.

Younger Israelis Influenced to Drink

In recent years, however, the Israel culture has changed to include higher levels of alcohol consumption. Heavy drinking has increased among younger Israeli Jews.

A later study by Hasin and colleagues looked at the differences in the effect of the ADH1B gene on the alcohol consumption of younger and older adult Israelis. Drinking levels among older participants were low, regardless of the type of ADH1B gene. However, in younger Israelis, those without the protective gene had greater rates of alcohol consumption.

Overall however, those over 33 years old had lower drinking rates that those younger than 33, indicating the environmental influences promoting greater drinking among younger Israelis can overcome the protective effects of the gene.

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