Red face when you drink alcohol?
The following is an interesting and slightly horrifying article by Dr. Emily Willingham, Assistant Professor at St. Edward’s University. It’s something to read and ponder for any person who experiences flushing reponse to alcohol consumption.
“Just about every drug or toxin we ingest must pass through our liver before it goes anywhere else in the body. This “first-pass” metabolism takes the drug through the hepatic portal, where important enzymes await the most recognizable compounds, such as alcohol, and disable them to the best of their ability. When it comes to alcohol, one enzyme in particular can make or break the liver’s effectiveness. This enzyme, aldehyde dehydrogenase 2 (ALDH2), is responsible for metabolizing a breakdown product of alcohol, aldehyde. Too much aldehyde is toxic, so if the compound accumulates, the body will respond accordingly.
What is accordingly? I once worked with a man who found out the hard way. He was preparing to defend his dissertation in graduate school and thought it would be entertaining to spike the refreshments he had brought with some vodka. But one of the members of his committee almost immediately had a negative response to the spiked refreshment, becoming violently ill. Needless to say, the dissertation defense did not go all that well.
That committee member was of East Asian descent. East Asians—from China, Japan, and Korea—are far more likely to have that kind of a response to consuming alcohol. The reason is that about a third of the population carry a gene for ALDH2 that doesn’t work right—it encodes an inactive protein that does not break down aldehyde. For people who carry two genes coding the inactive form, their response to even a little bit of alcohol is like that of the man on my colleague’s dissertation committee. In other words, throwing up.
But for some people, only one copy of the gene encodes an inactive protein, and the other codes a perfectly good ALDH2. These folks do react to alcohol consumption, primarily with cheeks flushed bright red, a rapid heartbeat, and maybe a bit of nausea. In time, however, many people with this response continue drinking and build up a tolerance to the aldehydes that accumulate. In fact, some of them become heavy drinkers. And that may be the most dangerous scenario of all.
The reason is that researchers have recently identified a strong link between the flushing response to alcohol consumption and esophageal cancer, more specifically squamous cell carcinoma of the esophagus. This malignancy is one of the most deadly worldwide, with five-year survival rates of 35% in Japan, 16% in the United States, and only around 12% in Europe. Those rates indicate the number of people still alive five years after diagnosis. Looked at another way, 88% of people in Europe who receive a diagnosis of esophageal cancer will be dead in five years. Now we know there is a simple biomarker—probably one of the simplest ever detected—for identifying this risk: a red face after drinking alcohol.
One of the main risk factors for this cancer is smoking, but alcohol is also a known risk factor. What researchers previously did not know was that in people who carry a deficient ALDH2 gene and drink a couple of beers a day, the risk of esophageal cancer increases by as much as 10 times. As one researcher put it, “That’s a pretty serious risk.” Usually, the fold-increase in risk is not as dramatic because something with that level of risk would be more obvious, a raging mutagen like X rays.
The irony is that this recent research suggests that identifying this risk is obvious. Doctors don’t have to sequence a person’s genes to determine which variant of ALDH2 they carry. All they have to do is give the patient about half a beer. If the telltale bright red flush appears, that’s a sign that the person is a carrier of the inactive form of the protein. More important, that’s a strong signal that the person should try to avoid drinking alcohol altogether. It they must continue to drink, researchers have calculated that in a population of Japanese men carrying one inactive ALDH2, limiting their alcohol consumption to fewer than nine drinks a week would prevent 53% of the cancers that would develop if they drank more.”
