"Drinking alcohol can damage DNA in stem cells and increase a person's risk of cancer, according to a new study."
These are mouth, upper throat (pharynx), voice box (laryngeal), esophageal, breast, liver, and bowel cancer. The rodents that were engineered to lack the enzymes were four times more likely to have their DNA damaged by alcohol than regular mice.
Their study, which was funded by Cancer Research U.K., is published this week in the journal Nature.
The scientists made use of chromosome analysis and DNA sequencing of mice to examine what happens when they were given diluted alcohol.
Blood stem cells, found in blood and bone marrow, are immature blood cells that can develop into any type of blood cell, including white blood cells, platelets, and red blood cells.
Magdalena Zernicka-Goetz, who is Professor of Mammalian Development and Stem Cell Biology at the University of Cambridge, but not involved in the study, was impressed with the research. This is of significance because when the genetic code of stem cells gets scrambled, the changes can lead to the cells mutating and causing cancer.
They found that acetaldehyde can break and damage DNA within blood stem cells leading to rearranged chromosomes and permanently altering the DNA sequences within these cells.
Lead study author Prof.
"This is handsome work, which puts our finger on the molecular basis for the link between alcohol and increased cancer risk and stem cells". However, acetaldehyde doesn't always have such a destructive effect on the body thanks to two saving mechanisms.
Enzymes called aldehyde dehydrogenases (ALDHs) form the first line of defense against alcohol-related damage.
Millions of people - particularly from Southeast Asia - either lack these enzymes or carry faulty versions, said the team. This byproduct is acetaldehyde, which is toxic. These individuals will experience tell-tale flushed cheeks and potentially feel ill. "But it's important to remember that alcohol clearance and DNA fix systems are not flawless and alcohol can still cause cancer in different ways, even in people whose defence mechanisms are intact".
The study also examined how the body tries to protect itself against damage caused by alcohol. "This is lovely work which puts our finger on the molecular basis for the link between alcohol and increased cancer risk and stem cells", she commented.