Yale study suggests evolutionary source of alcoholism's accidental enemy

Apr 02, 2008

Some change in the environment in many East Asian communities during the past few thousand years may have protected residents from becoming alcoholics, a new genetic analysis conducted by Yale School of Medicine researchers suggests.

The study by Hui Li and others in the laboratory of Kenneth Kidd, professor of genetics, psychiatry and ecology & evolutionary biology, will be released April 2, in the journal PloS One.

Scientists have long known that many Asians carry variants of genes that help regulate 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, but not all, communities in countries such as China, Japan and Korea have low rates of alcoholism.

Last year Kidd’s team reported evidence that recent natural selection in East Asia had caused one particular variant of the alcohol-regulating gene to become common. In this new paper Li and others in Kidd’s team analyzed this variant in the DNA of individuals in many different population groups in several more East Asian countries.

They uncovered evidence that the variant became widespread through natural selection in only some of those East Asian populations — specifically, the Hmong- and Altaic-speaking groups. Those genetic clues, say the scientists, suggest that something was different in the environment of those populations and that the genetic difference assisted survival in that environment. The researchers have not yet identified that environmental difference and say the genetic change could be triggered by any number of factors, such as the emergence of some new parasite.

That these populations turn out to be less prone to the ravages of demon rum, says Kidd, “is just a serendipitous event’’ of evolution. “What this finding does is highlight that something important in recent human history has affected the genetic composition of many East Asian populations,” he notes.

Kidd’s team was studying a variant of one of a set of related genes that code for alcohol dehydrogenases, enzymes that help in metabolism of alcohols, including ethanol. Variants of those enzymes have been known for many years to protect the individuals carrying them against alcoholism.

The particular gene studied, a variant of the ADH1B gene, is very common in some East Asian communities, as high as 90 percent in some areas.

But he also noted that lower rates of alcoholism in many of the Asian communities may well be due to cultural as well as genetic causes.

“If a large part of the people got sick after they ate one particular food or drank a particular drink, you would not find many social situations where that food was served,’’ Kidd said.

Source: Yale University

Explore further: Gene clues to glaucoma risk

add to favorites email to friend print save as pdf

Related Stories

Human races: biological reality or cultural delusion?

Aug 14, 2014

The issue of race has been in the news a lot lately with the canning of proposed amendments to Australia's Racial Discrimination Act, attempts by extremists to commit genocide on cultural minorities in Iraq and a new book by US autho ...

Recommended for you

A nucleotide change could initiate fragile X syndrome

20 hours ago

Researchers reveal how the alteration of a single nucleotide—the basic building block of DNA—could initiate fragile X syndrome, the most common inherited form of intellectual disability. The study appears ...

Gene clues to glaucoma risk

Aug 31, 2014

Scientists on Sunday said they had identified six genetic variants linked to glaucoma, a discovery that should help earlier diagnosis and better treatment for this often-debilitating eye disease.

Mutation disables innate immune system

Aug 29, 2014

A Ludwig Maximilian University of Munich team has shown that defects in the JAGN1 gene inhibit the function of a specific type of white blood cells, and account for a rare congenital immune deficiency that ...

Study identifies genetic change in autism-related gene

Aug 28, 2014

A new study from Bradley Hospital has identified a genetic change in a recently identified autism-associated gene, which may provide further insight into the causes of autism. The study, now published online in the Journal of ...

NIH issues finalized policy on genomic data sharing

Aug 27, 2014

The National Institutes of Health has issued a final NIH Genomic Data Sharing (GDS) policy to promote data sharing as a way to speed the translation of data into knowledge, products and procedures that improve health while ...

User comments : 0