Genes 'explain' why some drinkers and smokers die young

Ever wondered why only some heavy drinkers and smokers die young while others live to a ripe old age? Well, the answer lies in the genes, say scientists.

An international team has identified two genes that it claims increases the chances of an unhealthy lifestyle, giving a drinker or a smoker cancer -- in fact the genes put carriers more at a heightened risk of developing cancers of skin, lung, bladder, prostate and cervical.

Lead scientist Prof Tim Bishop of University of Leeds said cancer was often caused by a "complex" interplay between genetic and environmental factors, and these newly identified genes could go some way to explaining their relationship.

The findings, according to them, could allow doctors to identify those most at risk from suffering the potentially deadly conditions due to a combination of genetics and their lifestyle, The Daily Telegraph reported.

In fact, the scientists were able to isolate the genes by looking at the genetic make up of more than 33,000 cancer survivors and another 45 ,000 people who had never suffered from the disease.

They then compared the genes against their carrier's lifestyle and history of the disease. While they increased the chance of suffering from five types of cancer the genes were not linked to an increased risk of another nine cancers for which the scientists could test, including breast cancer, the most commonly diagnosed form of the disease in women, the findings revealed.

The study has been published in the latest edition of the Nature Genetics journal.