Tuesday, March 31, 2009
Gimme a Drink--But Hold the Acetaldehyde
Another look at alcohol and cancer.
If beverage alcohol were a new drug, it would face an uphill battle to make it through the Food and Drug Administration (FDA) pipeline. Why? Because the amount of acetaldehyde in alcoholic drinks—combined with acetaldehyde from other sources—might be too carcinogenic to pass muster under existing regulations.
When drinkers drink, the first thing that happens is that enzymes convert the alcohol into acetaldehyde. Previous research has shown that this common organic chemical is implicated in certain cancers, particularly cancers of the digestive tract. Studies at the National Institutes of Health (NIH) showed that the concentration of acetaldehyde measured in human saliva during drinking episodes was sufficient to produce the kind of damage to DNA that can result in cancer.
In a study published recently in the journal Addiction, researchers from Canada and Germany showed that heavy drinkers ingest enough acetaldehyde to raise their lifetime cancer risk to as high as 1 in 1,000. The study concludes: “The life-time cancer risks from acetaldehyde from alcoholic beverages greatly exceed the usual limits for cancer risks from the environment.”
The real problem comes when alcohol is used in combination with acetaldehyde from other sources, such as tobacco, food flavorings, pesticides, and perfume. Heavy drinkers “face a magnitude of risk requiring intervention.” According to Dr. Jurgen Rehm at Canada’s Centre for Addiction and Mental Health (CAMH), quoted in Science Daily: “Most risk assessments to date were based on one source of exposure only. This has led to a negligence of the overall risk.”
According to the Science Daily article, “Alone, the risks associated with surpassing limits of acetaldehyde from the air may not yet be alarming, but for heavy drinkers and smokers, it adds to the acetaldehyde levels already received from these sources. This overall risk then surpasses established safety limits.” To make matters worse, acetaldehyde is a common substance in tobacco smoke—and alcoholics are often heavy cigarette smokers.
A Finnish drug company is currently conducting clinical trials of a time-release capsule of the amino acid cysteine, which can bind with acetaldehyde and render it inactive.
In a related development, a study in PLoS Medicine appeared to demonstrate that people who suffer from the so-called alcohol flush reaction—primarily Japanese, Chinese, and Koreans—are at increased risk for throat cancer. The culprit? An excess of acetaldehyde.
Photo Credit: National Institute of Standards and Technology