Is there any truth to 'Asian Glow' being a real genetic thing?

Yes, this one is well-documented. The "Asian flush" or "Asian glow" is a real genetic phenomenon caused by a variant in the ALDH2 gene.

The mechanism: when your body breaks down alcohol, it first converts ethanol to acetaldehyde (a toxic intermediate), and then converts acetaldehyde to acetate (which is harmless). The second step is performed by an enzyme called aldehyde dehydrogenase 2, encoded by the ALDH2 gene.

Roughly 30 to 50% of people of East Asian descent (Chinese, Japanese, Korean, and others) carry a variant called ALDH2*2, which produces a slower, less functional enzyme. After drinking, acetaldehyde builds up faster than it can be cleared, and the result is facial flushing, increased heart rate, sometimes nausea and headache.

The variant is much rarer in South Asian, European, and African populations, though it does occur.

What is medically important about this is not the flushing itself but the long-term consequence. People who carry ALDH2*2 and continue to drink heavily face significantly elevated risks of esophageal cancer and other alcohol-related cancers, because acetaldehyde is a known carcinogen and they are exposed to it at higher concentrations for longer.

The flush is a warning signal, not a quirk. If you reliably flush from alcohol and you also drink heavily, that combination warrants attention. Cutting back is meaningful preventive medicine.