Researchers have discovered that an inherited gene means Polynesians are less likely to become alcoholics than European drinkers.
Geoff Chambers of Victoria University has found that many Polynesians have inherited a genetic factor from Asian ancestors that makes drinking alcohol less pleasant.
Dr Chambers said his research offered "the most compelling
evidence yet" in support of genes being used to predict behaviour and influence lifestyle choices.
"One day these new molecular tools might give you a genetic profile, which you would want to consider on a whole range of lifetime decisions beyond simply finding out whether you were genetically coded to process alcohol effectively."
Over the past 10 years Dr Chambers has looked at samples and blood provided by European and Polynesian men taking part in alcohol treatment programmes. These showed that more than two-thirds of Polynesians had inherited a gene from their Asian ancestors that made drinking alcohol less pleasant.
In Europeans, fewer than one in 10 carried the same gene.
"This discovery of the gene ADH2*2 in Polynesian people adds to the understanding of where New Zealand's indigenous people came from and the path they took to get here," he said.
Asians who were very sensitive to alcohol had two genes which made alcohol consumption unpleasant: ADH2*2, which increased the production of the toxic chemical acetaldehyde, and ALDH2*2, which prevented the liver detoxifying this.
Dr Chambers found that more than two-thirds of Polynesians had inherited the former from Asian ancestors, but not the latter.
Research showed the gene which prevented detoxification by the liver was carried from mainland China to Taiwan about 5000 years ago, but had migrated no further, he said.
At very high levels, acetaldehyde acts as a poison, causing headaches, flushing and nausea.
Dr Chambers said those with ADH2*2 "in their genetic kit" were unlikely to drink alcohol to excess and were unlikely to develop alcoholism.
"In contrast to the Asian and Polynesian group, almost all Europeans belong to a group that lacks this gene; their bodies produce a lower amount of acetaldehyde, which the liver is able to detoxify.
"So for most Europeans, drinking can be a more pleasurable experience, which leaves them open to developing alcoholism."
The research showed that a third of New Zealand's Maori population, like Europeans, lacked ADH2*2.
An analysis of blood samples from young Maori men with drinking problems showed that 75 per cent of them were drawn from that group.
- NZPA
