Science shows humans are “designed” to drink alcohol

Many nanny-state public health officials call for the prohibition of alcohol. But I stick to the science. And the science shows moderate alcohol consumption has many health benefits, as I often report.

Plus, a new report by my colleague, science reporter Faye Flam, explains how humans developed the ability to metabolize alcohol millions of years ago.

Let’s think about that finding for a moment. Animals develop genetic traits they are meant to use in Nature. So it certainly makes the case that drinking alcohol has a significant role in human biology, history and society.

How humans evolved to tolerate alcohol

Through the ages, humans all over the world have consumed alcohol in various forms. Archaeologists have found evidence of beer and wine consumption going back over 10,000 years. And my professor for my Ph.D. in Anthropology at Penn even found evidence that grains were first cultivated to make beer, not bread.

Modern research scientists now believe humans developed key genetic adaptations that allowed them to tolerate alcohol. Humans use enzymes — which belong to a family of metabolic factors called alcohol dehydrogenases — to digest the ethanol in alcohol.

It turns out, lots of animals (besides humans) also make these enzymes. Animals in the wild use them to metabolize certain yeasts that colonize fruits and naturally convert their sugar to alcohol. Have you been around a wild apple tree in the fall? The apples that fall to the ground become fermented, producing apple cider vinegar with its unmistakable pungent aroma.

Plus, humans, gorillas and chimps (known as the “great apes”) share another, more advanced genetic mutation. Dating back about 10 million years ago, humans, gorillas and chimps underwent a genetic mutation that improved the way their GI systems metabolize ethanol.

This change appeared to equip us with the ability to handle the relatively weak alcohol content of naturally fermenting fruits. It gave us the ability to metabolize alcohol about 40 times better than animals without this genetic adaptation. Of course, the ability to handle the naturally occurring alcohol was an important adaptation for animals living on fruit as an important dietary source.

This adaptation was probably made from necessity, if you think about it…

Animals that lived in trees had access to fresh (non-fermenting) fruit. But early human ancestors lived on the ground. They would have had more exposure to fruits that had fallen from the tree and begun to ferment.

Today, in Nature, biologists have observed that great apes, birds, and elephants naturally consume fermenting fruit and become intoxicated. Of course, there are big differences between naturally fermented fruit, at about one percent alcohol content, versus man-made brews, which are typically higher than three percent.

Another adaptation occurs

About 1,000 years ago, people in East and Southeast Asia began cultivating rice to make alcohol. After that, another mutation arose in another gene associated with alcohol metabolism — AHD1.

Those with this genetic mutation process alcohol faster than everyone else. They build up the toxic metabolite called acetaldehyde, which makes them become flushed and sick before becoming intoxicated. And they stop drinking sooner.

About 60 to 70 percent of Han Chinese now have this gene, protecting these people from alcoholism. Remember that, the next time you are toasting “Gan be” for the Chinese New Year.

Moderate drinking in a modern world

One could certainly argue consuming alcohol doesn’t make sense for survival in Nature. It impairs judgment, dulls the senses, impairs balance, and slows reflexes. Thus, inhibiting these faculties dulls the basic “fight-or-flight” response that helps humans avoid danger and survive longer.

Of course, we live in a modern world with chronic stress. And the human body responds to this modern stress by staying in a constant, harmful state of “fight or flight” arousal.

But moderate alcohol consumption lowers stress. In my view, this effect explains why modern studies show moderate drinking benefits health and longevity.

Overall, Flam’s report demonstrated two main points that I have long made:

The first is moderation in all things. The human body can metabolize tolerable levels of natural “toxins,” such as alcohol and smoke. At these moderate, tolerable levels, the human body even benefits from these natural “toxins.” Heavy alcohol use, on the other hand, can and does cause problems.

Second, people vary in their genetic susceptibility to alcohol. And we should treat people as individuals. “One size fits all” recommendations regarding your health simply miss the mark.

So — if drinking alcohol relaxes you — go ahead and enjoy a glass or two of wine with dinner. Your body is fully equipped to handle it in moderation.

Source:

  1. “Drunken Monkeys and the Evolution of Boozing,” Bloomberg (bloomberg.com) 12/30/2016

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