Excessive alcohol intake increases cancer risk

Excessive alcohol intake may increase the risk of cancer and even lead to premature aging, research shows.

This is due to shortening of telomeres, a region of DNA sequences at the end of a chromosome which is important for the genetic stability of cells. As people age, telomere length shortens progressively.

Excessive use of alcohol has been linked to oxidative stress and inflammation, two mechanisms that accelerate telomere shortening.

Since telomere shortening is thought to increase cancer risk, the researchers speculated that those with shorter telomeres due to heavy alcohol consumption would have an increased risk of cancer.

"Heavy alcohol users tend to look haggard, and it is commonly thought that heavy drinking leads to premature aging and earlier onset of diseases of aging. In particular, heavy alcohol drinking has been associated with cancer at multiple sites," said Andrea Baccarelli, who led the research.

"All the cells in our body have a biological clock in telomeres," noted Baccarelli, who heads the Centre of Molecular and Genetic Epidemiology, Ca' Granda Hospital Foundation, University of Milan, Italy.

The researchers measured serum DNA among 59 participants who abused alcohol (22 per cent consumed four or more alcoholic drinks per day) and 197 participants with variable alcohol consumption habits (4 per cent consumed four or more alcoholic drinks per day).

The two groups were similar in age and other factors that might affect telomere length, such as diet, physical exercise, work-related stress and environmental exposures, a Milan release said.

Results showed that telomere length was dramatically shortened in those who consumed heavy amounts of alcohol -- it was nearly half as long as that in the non-abusers (0.41 v/s 0.79 relative units).

"The decrease we found in telomere length is very sharp, and we were surprised to find such a strong effect at the cellular level," Baccarelli said.

The results were presented at the American Association for Cancer Research's 101st annual meeting.