Excessive drinking promotes cellular changes, study finds.

Researchers say they've gained new insight into a link at the cellular level between alcohol consumption, aging and cancer.

The key appears to lie in telomeres, structures at the end of chromosomes that shorten as people get older. Telomeres are also thought to shorten because of excessive drinking.

Researchers thought that people with shorter telomeres due to heavy drinking would face a higher risk of cancer.

"Heavy alcohol users tend to look haggard, and it is commonly thought 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," lead researcher Dr. Andrea Baccarelli, head of a research center at the University of Milan, said in a statement.

In the study, researchers analyzed DNA in 59 people who drank heavily (nearly one in four consumed at least four alcoholic drinks a day) and 197 people who drank at various levels.

Researchers found that telomere lengths were much shorter in those who drank a lot of alcohol.

"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 study was to be presented Wednesday at the American Association for Cancer Research annual meeting, in Washington, D.C.