Washington, Apr 2: Researchers from Yale University have revealed that
environmental changes may have prevented East Asian communities from
becoming alcoholics.

It is a known fact that that many Asians carry variants of genes that
help manage alcohol metabolism. Some of those genetic variants can make
people feel uncomfortable, sometimes even ill, when drinking small
amounts of alcohol.

As a result of the prevalence of this gene, many communities in
countries like China, Japan and Korea have low rates of alcoholism.

Previous studies led by Kenneth Kidd, professor of genetics, psychiatry
and ecology & evolutionary biology had provided evidence that
recent natural selection in East Asia had caused one particular variant
of the alcohol-regulating gene to become common.

In the present study led by Hui Li and researchers from Kidd’s team,
they studied the variant in the DNA of individuals in many different
population groups in several more East Asian countries.

They discovered that the gene variant became widespread through natural
selection in only some of those East Asian populations, particularly
Hmong- and Altaic-speaking groups.

Scientists said that the genetic clues suggest that something was
different in the environment of those populations and that the genetic
difference assisted survival in that environment, though they still not
identified that environmental difference.

However they believe that the genetic change could be triggered by any number of factors, like emergence of some new parasite.

Kidd believes that it is “just a serendipitous event’’ of evolution
that has restricted these populations from becoming alcoholics.

“What this finding does is highlight that something important in recent
human history has affected the genetic composition of many East Asian
populations,” he said.

Kidd’s team studied a gene variant known as ADH1B that code for alcohol
dehydrogenases, enzymes that help in metabolism of alcohols, including
ethanol and protect individuals from carrying them against alcoholism.

He said that lower rates of alcoholism in many of the Asian communities might well be due to cultural as well as genetic causes.

The study appears in April 2 issue of journal PloS One. (ANI)