Genes may help explain why Jewish people typically have fewer drink problems than non-Jews, researchers said last month. A study has shown that a genetic mutation carried by at least a fifth of Jews appears to protect against alcoholism. The same inherited trait is fairly common in Asian people, but is much rarer in white Europeans. The findings could help explain why Israel has one of the lowest levels of alcoholism in the developed world.
The study’s author, Dr Deborah Hasin, from Columbia University and New York State Psychiatric Institute, said: “This finding adds to the growing body of evidence that this genetic variation has a protective effect against alcoholism among Jewish groups. “The mutation, called ADH2*2, is involved in the way the body breaks down alcohol in the bloodstream.
Scientists are unsure exactly how it protects against alcoholism, but it is thought to increase levels of the toxic chemical acetaldehyde – a by-product of alcohol metabolism. At high levels, acetaldehyde causes headaches, nausea and flushing. Almost all white Europeans lack the ADH2*2 variation and so produce less of the by-product. Thus drinking tends to be more pleasurable, increasing the risks of alcoholism.
Past research has shown that the variant is found in 20 per cent of Jewish people.Those with the variant tend to drink less frequently, consume less alcohol overall or have more unpleasant reactions to drink.
The new study, published this month in the journal “Alcoholism: Clinical and Experimental Research”, looked at the relationship between the gene variant and alcoholism among 75 Israeli Jews aged 22 to 65. Those with ADH2*2 had “significantly lower indicators of alcohol dependence”. The protective effect of the gene depended on the country of origin and how recently they had arrived in Israel.
The effect was strongest for Ashkenazis, Jews of European background and arrivals from Russia before 1989, and the Sephardics, those of Middle Eastern and North African background, than for more recent immigrants from the former Soviet Union. Among those with the gene variant, the recent Russian immigrants tended to have a history of much heavier drinking than their Sephardic and Ashkenazic counterparts.
Dr Hasin said: “Russia has one of the highest levels of alcohol consumption whereas Israel has one of the lowest.”