00:00He trained for three years, going from a single shot of Baijiu to drinking half a bottle without
00:03flinching. He thought he'd built up a tolerance. He's wrong. And you might be too. You've heard
00:10that turning red when you drink means you're allergic, or that your body is weak. Neither is
00:15true. That red face is your body screaming a warning, a class 1 carcinogen is piling up in
00:19your blood vessels, and you can't flush it out. The truly dangerous people are the ones who don't
00:24turn red. They carry the exact same broken part. It just never goes off. Scientists in
00:30Beijing followed more than 510,000 Chinese people for a decade. Their conclusion is blunt,
00:36the person to watch at the table was never the one turning red. Nearly 600 million people
00:40worldwide carry this broken part, almost all in East Asia, and scientists still don't fully
00:45understand why it was never eliminated. Let's start with the basics. Your body breaks down
00:51alcohol in two steps. Step 1, alcohol becomes acetaldehyde. Step 2, acetaldehyde becomes acetate,
00:58then it leaves the body. Two steps, two enzymes. And here's the catch. The problem sits in the
01:05second step. The enzyme is called aldehyde dehydrogenase 2, ALDH2 for short. In some people,
01:12this enzyme is defective. Step 1 runs fine, alcohol rapidly becomes acetaldehyde. But step 2 gets stuck.
01:19The acetaldehyde can't get out. So it starts accumulating in the body. It pries open your
01:25capillaries, and your face flushes bright red. So flushing isn't an allergy. Flushing is a pileup.
01:31What is acetaldehyde? The International Agency for Research on Cancer lists it as a group 1 carcinogen.
01:38Same class as asbestos. Same class as tobacco. Every drink you take adds another batch of
01:44unflushable carcinogens bathing your mouth, your throat, your esophagus. Your red face is just the
01:49visible progress. Bar of that process. Whether this enzyme is broken is decided by your genes.
01:56Everyone carries two copies, one from each parent. Two good copies, and it works at full strength.
02:02One good and one broken, and activity drops to between 17 and 38% of normal. Two broken,
02:08and it's basically zero. People with the full working pair don't turn red, they genuinely process it.
02:13People with two broken copies turn bright red from a single cup, heart pounding, miserable.
02:18That's not grit. That's a severe toxic reaction. And the middle group, one good, one broken,
02:25is who this video is really about. Because what comes next is the strangest part of the whole story.
02:30Back to the man who trained for 3 years. In China, people say drinking ability is something you build up.
02:36That's true, but not the way people understand it. He went from one shot to half a bottle. He.
02:43Doesn't even flush anymore. He thinks his enzyme got stronger. It didn't. That gene was written by
02:49your parents. It will never change. Your enzyme activity today is the same 17-38% as 3 years ago.
02:57What changed is your nervous system's sensitivity to acetaldehyde. The poison is still there,
03:02every drop. It still damages the same organs. Your body just stopped complaining. After 3 years of
03:09screaming and getting no response, it gave up. What you built isn't the ability to process alcohol.
03:14It's the ability to tolerate poison. You took out the fire alarm,
03:18then congratulated yourself that the house isn't burning. That's why the guy who used to turn red at
03:23one glass and now drinks half a bottle without blinking is the highest risk person at the table.
03:27His part is broken. His dashboard is broken too. And because he can hold his liquor,
03:32everyone cheers him on. By now you might think, fine, just.
03:37Watch who turns red. That's exactly the myth this study was designed to break.
03:41The Peking University team gave more than 510,000 people a genetic test, asked whether they flush when
03:47they drink, then match the answers. Here's what they found. Among people with a genuine ALDH2 defect,
03:53only about 57% said they flush quickly. The other 40 plus percent have the broken gene but don't turn
03:59red.
03:59So using flushing as a screening tool misses almost half the high risk group. And the half you miss is
04:05exactly the half that drinks the most, because they don't feel sick, they can drink, so they get praised
04:09and pushed. And here's the darker conclusion. The people who turn bright red from a single sip,
04:15who could never finish a small glass, they're actually the safest at the table.
04:19Not because their genes are good, but because their genes are the worst. So bad they physically
04:24can't drink. Their own bodies protect them by force. Now, a puzzle even scientists haven't solved.
04:31This mutation is a plain bad gene. It raises your risk of esophageal, stomach and liver cancer,
04:37and it's linked to cardiovascular disease. By cold evolutionary logic, it should have been eliminated.
04:43It wasn't. It spread to 560 million people in East Asia. Why? No firm answer. One guess, in ancient
04:51times, alcohol was rare, so the defect rarely showed itself, natural selection never saw it.
04:57Another hypothesis is more interesting. The high frequency zone of this gene overlaps suspiciously
05:02well with the high infection zone of hepatitis virus, southeastern China, Korea, Japan are high for
05:07both, northwestern China and Europe are low for both. Some researchers suspect this broken enzyme might be
05:12an advantage against certain viruses. Nobody has proven it. That's the most honest answer science has,
05:18we know how toxic it is, but not why it survived. By. The way, that geographic pattern also explains an
05:25old
05:25stereotype, northerners can hold their liquor, southerners can't. It's not true as a blanket statement,
05:31but it does have a genetic shadow. The RS671 variant is much more common in southeastern coastal China
05:37than in the northwest or north. It's not drinking culture. It's heredity. Finally, two pieces of
05:43advice you can actually use. First, whatever you drink. In that study, risk clearly starts climbing
05:49at 30 grams of pure alcohol per day, about one small cup of 52% by Joe, or 750 milliliters
05:55of beer.
05:56More than that, long term, and your esophageal cancer risk climbs. Carry the gene defect,
06:02and that curve climbs even faster. Second, something few people know.
06:07ALDH2 also processes nitroglycerin, the pill slipped under the tongue during a heart attack.
06:12Carry the defect, and it may work noticeably worse. If you or your parents have heart problems,
06:17tell a doctor. As for which group you're in, don't guess from a red face.
06:22Top-tier hospitals can run an ALDH2 gene test, usually for a modest fee, once, lasting a lifetime.
06:29So next time someone insists flushing means fast metabolism and you should drink more,
06:33tell them the truth, flushing means your metabolism has stalled.
06:36People who truly process alcohol fast stay pale. I know what some of you are thinking.
06:41The logic is clear, but at a real table there's a boss, a client, a father-in-law.
06:46Refuse a drink, and you might not have a project by morning.
06:49That one I can't solve. Science can tell you what's in a cup,
06:53not control the hand pushing it toward you. The comments are open.
06:57What's the wildest thing anyone ever said to get you to drink?
07:00I'll start. Cheers.
