As you may already know from my previous post about the “Asian glow,” the red flushing that Asians commonly experience after drinking alcohol is a result of a deficiency in the enzyme acetaldehyde dehydrogenase (ALDH2), which breaks down the chemicals in alcohol. But put aside the scientific mumbo jumbo and consider this—what if I told you that the flushing gene is evolutionary and resulted from East Asians eating rice? Apparently, it’s true.
According to a new study in the BMC Evolutionary Biology, the reason many Asians lack the enzyme to digest alcohol dates back to about 10,000 years ago in Southern China; the people who first started farming rice near the Yangtze River started to develop facial flushing after enjoying the alcohol that was found in fermented rice.
Sound far-fetched? The researchers from the study tested the DNA of 38 Asian populations in different provinces in China. Results showed that the flushing gene was mostly found in populations that farmed rice from the very beginning. While 70 percent of Han Chinese tested positive for the flushing gene, only 14 percent of Tibetans have it because they started farming rice much later.
So what does this all mean for us? Researchers believe that the “Asian glow” may have evolved as a survival tool to allow the ancient populations to enjoy the benefits of alcohol from fermented rice (as a disinfectant and preservative) when drinking in moderation. Furthermore, the gene may also be an evolutionary advantage for populations on the whole, as the flush seems to be associated with lower rates of alcoholism. So if you glow, don’t fret, it may actually be beneficial for you! (Or, you can blame our ancestors and their obsession with rice.)
Last modified: January 28, 2010