喝酒臉紅是有人性？容易把酒精揮發出來不入骨？

如果喝了酒臉紅，中國人流傳下來的説法一般都會說臉紅代表這個人有血性，有人性酒精容易揮發出來不入骨是好事，但原來事實並非如此！

根據美國N.I.A.A.A.（National Institute on Alcohol Abuse and Alcoholism 國家酒精濫用及中毒研究所）研究酒精對人體代謝和健康的影響結果，亞洲人喝酒出現臉汎紅（Asian Flush) 可能是由於身體缺乏分解酒精毒素的酵素，患有先天性乙醛脫氫酵素（ALDH2）缺乏症，主要發生在日本、中國和韓國血統人種身上，酒精進入身體後由於缺乏酒精脫氫酵素及乙醛脫氫酵素，酒後有毒物質無法正常分解引致酒後瞬間面紅、惡心及心跳加速，患者若繼續習慣性每天喝兩杯啤酒（或等同），患上食道癌的機會將較普通可以分解酒精有毒物質的人高達十倍！

以後喝酒後如果臉紅的上述亞裔人仕，不要以爲自己是好人酒精容易揮發可以多喝幾杯，反過來應該馬上減少喝酒降低患癌的機會！

Source 節錄自：NBC News http://www.nbcnews.com/health/body-odd/asian-flush-red-flag-risk-cancer-f1C6437432

Between the brisk cold and the holiday cheer, many of us get a little red in the face this time of year. But for some people of Asian descent, a New Year’s toast – or even a few beers after work – will trigger a bright red blush known as the “Asian flush,” which can also increase their risk of deadly esophageal cancer.

“When I drink, the skin in my face and even all the way down to my waist will start to turn red,” says Patrick McMahon, a 30-year-old education director from Seattle, who’s half-Japanese. “I think the blood vessels dilate and I get very flushed. It’s often mistaken for a sunburn.”

That response is typical for about a third of people from East Asian descent, says Philip J. Brooks, an investigator with the Division of Metabolism and Health Affects at the National Institute on Alcohol Abuse and Alcoholism.

       

“It happens predominantly in individuals of Japanese, Chinese or Korean descent,” he says. “People who have this will get a facial flush and a headache and will feel nauseous at the time they’re drinking. And it’s not just flushing. They’ll also get an increased heart rate. It’s a pretty unpleasant experience.”

       

What causes this reaction?

Brooks says it’s basically a genetic inability to properly metabolize alcohol (or ethanol) which, thanks to enzymes in the liver, is normally metabolized first into the toxic chemical acetaldehyde – an animal carcinogen that causes DNA damage and other cancer-promoting effects -- and then into the harmless substance acetate. People with the flushing response have a genetic deficiency in the alcohol-metabolizing enzyme ALDH2, which can lead to an accumulation of the toxic substance acetaldehyde.

       

“Individuals with this particular genetic disposition can’t metabolize it to the acetate,” says Brooks. “So it builds up in their body and causes the vasodilation which causes the flushing response.”

In some people – those with two copies of the deficient gene -- the symptoms are so severe they can’t tolerate alcohol at all. Those with only one copy of the gene often learn to live with the heart palpitations and the flushing, though.

And that’s where things get risky.   

     

“People with this ALHD2 deficiency have a really high risk of getting esophageal cancer when they drink alcohol,” says Brooks, who wrote about the link between the Asian flush and esophageal cancer in a 2009 paper in PLoS Medicine, a journal published by the Public Library of Science. “Anyone who drinks is at risk, but the more you drink, the more your risk goes up. And when you’re ADLH2-deficient, your risk goes up much more dramatically.”

       

According to studies, a person with a single copy of the deficient gene who drinks just two beers a day is up to 10 times more likely to develop esophageal cancer than a person who’s able to metabolize the alcohol properly.

       

Unfortunately, while many people of Asian descent are familiar with the flush, Brooks says too few realize it’s not just an inconvenience, but a red flag for one of the deadliest cancers worldwide.

“It’s not just an issue that affects appearance, but an indication that they’re at increased risk of esophageal cancer if they drink heavily,” says Brooks. ”You have to think about the production of acetaldehyde throughout the body. We want people to discuss this with their doctor and be sure their doctor is aware of the data that’s out there.”