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© 2005 Oxford University Press
NEWS |
Studies Seek Molecular Clues on Alcohol's Role in Cancer
| The first 10% of the full text of this article appears below. |
Dozens of epidemiologic studies in the last several decades have shown an association between alcohol consumption and increased cancer risk. Now, laboratory studies are beginning to tease out the molecular mechanisms that may be at work.
Chronic alcohol consumption increases risk for cancers of the upper gastrointestinal tract. Alcohol is also associated with an increased risk of breast, colon, and liver cancer. Although many theories abound to explain the alcohol–cancer connection, alcohol metabolism is emerging as one of the main culprits.
Alcohol is broken down primarily in the liver by two enzymes. Alcohol dehydrogenase (ADH) converts ethanol into acetaldehyde, which collects in the blood, saliva, gastric juice, and large intestines. Acetaldehyde dehydrogenase (ALDH) then converts acetaldehyde into acetate, which is metabolized by tissues outside the liver.
In cell cultures and animal models, acetaldehyde is toxic, mutagenic, and carcinogenic. A recent study by