Photo by Rick Geary

Adam and Eve were the first vegetarians, and it was all downhill after that.

Recently my four grown children (who all seem to be older than I am) were visiting me, and we got into a discussion on vegetarian food. One daughter commented that the human being was never "designed" to eat meat. My argument (unsupported by any evidence) centers on the apparent success human beings have had for generations to adapt to whatever conditions are required to be fruitful and multiply. Eating meat seems to have contributed to this success.

Besides, why else would human beings have canine eye-teeth if not for tearing into flesh, just like other carnivores, who probably served as a model for primitive people? One son argued that the human digestive system is not capable of dealing with meat. But then how have we survived, lo these many millennia, by processing meat just as so many other animals do? — Ric Gravagno, San Diego

You’ve raised quite a brood, there, Ric. Fully able to ignore evidence right before their eyes, in the service of...what? Religion? Philosophy? The odd satisfaction of sneering at carnivores? Cultural history may be on their side, but not nutrition science.

If we humans were not “designed” to eat meat, we would have stopped doing so long ago. See many people savoring com cobs, palm fronds, cotton swabs, two-by-fours? All perfectly “vegetarian.” All perfectly indigestible except by cows, sheep, goats, or termites. Cellulose, a major component of plant matter, is one of the most indigestible things we can eat. So, using the logic of the offspring, we shouldn’t eat plants. Cellulose provides necessary bulk in our diet but no nutrients.

Of course, plants can’t look up at you with big, sad eyes that say, “Eat me? You 're going to eat me? Whadd’I ever do to you?” This has always been one thorny element of the carnivore-herbivore standoff.

Mankind — personkind, whatever — has been, since the time of Homo erectus (1-1/2 million years ago), an omnivore. Fruits, nuts, plants, bugs, and the occasional small mammal or bird were all potential people-food. Meat was probably an opportunistic menu item, though, and not the main course every night. Homo habilus and all the predecessors of our Homeboy erectus were most likely fruit and plant eaters, according to anthropologists who’ve examined tooth-wear patterns in fossil remains. (We’ll give the Gravagno kids a half-point for that one, I guess.) But that’s not because we weren’t “designed” to digest protorodents or whatever else scurried around at the time.

“Meat" in its current definition (the flesh of animals) has had a vaguely sinister rep through most of modem history, partly from biblical stories and references. Adam and Eve, after all, were the first vegetarians, and it was all downhill after that. Our continuing slide to Hell, apparently, has been upon a rack of lamb and pork hot links. Maybe Eve served serpentburgers the night of the Fall. Anyway, with few exceptions, throughout most of history and in most places on the globe, meat has been the indulgence of the (wicked? thieving? despotic?) rich, and grains and legumes the fodder of the (honest? hard-working? downtrodden?) poor. The makings of an image problem. I’d say.

One interesting reference to the sinful image of meat-eating came during the American Colonial era, when wild game and pasturage were abundant and the human population small. Americans rich and poor could have meat virtually every day. European visitors sent home postcards saying, “Having a wonderful time, but these colonists sure eat a revolting amount of meat.” Our guests were quite disgusted at the display, according to historians of the era. Worldwide, meat-eating is still today largely influenced by economics, not philosophy. And certainly not by our digestive enzymes.

Because the biochemistry of lower animals is so similar to that of humans, meat supplies us with the most concentrated and complete form of protein (amino acids) available. And the average healthy human bean doesn’t have to grab for the Maalox after downing a T-bone. Moderation (as usual) is the watchword — boring old moderation.

Obviously, meat’s not absolutely necessary; well-balanced vegetable proteins will keep us ticking along nicely — and without those nightmares about the apocalyptic revenge of the veal chops. But I don’t expect my saying this to appease the ranks of militant vegans out there, so I’ve cleared off a spot on my desk to hold all the insulting correspondence. Then I’m going to toss in some snow peas and cloud ear mushrooms and make a quick, high-fiber, all-vegetable stir-fry. Mail is best when cooked unopened

April 29 update

A brief review of the sniper fire following the “Are humans designed to eat meat?” question. As predicted, the vegans got pretty huffy. Many of the Grazers, as they’re affectionately known here at the Matthew Alice Bar-B-Q & Science Center, rightly (jointed out that a cow, for instance, is an inefficient middleman between us and grain. The number of people who could be fed from the grain it takes to raise one cow is much greater than the number that can be fed from the resulting cow. That observation has nothing to do with the original question, but as far as it goes, it’s correct. Of course, the cow converts the grain into nutrients that we couldn’t get from the plant, and cow meat is much more concentrated and easily extracted by the human digestive system than is the nutrition in plants. That’s why plant-eating animals must feed more or less continuously during their waking hours, while meat eaters can go unfed for long stretches. The elephant probably represents the outer size limits for a pure herbivore; any larger animal would never be able to consume enough to keep itself alive.

This contribution by one (anonymous) “Friendly Local Militant Vegan” makes the point quite well. “Look at the digestive tract of a vegetarian such as the gorilla. It’s 12 times the height of the gorilla’s body. Now take a look at the digestive tract of a carnivore such as the lion. It’s only three times the length of the lion’s body. The human digestive tract is (you guessed it) 12 times the height of the human body. That means when...you eat a chunk of meat, it stays in the digestive tract for weeks merrily rotting away.”

To F.L.M. Vegan I can only say, if the last burger you ate was “rotting” in your digestive tract for “weeks,” then no wonder you eat nothing more lively than tofu. Weeks? Transit time for the burger probably wasn’t any more than 36 hours max, barring some physiological problem. The meat itself was virtually a liquid by the time it left your stomach. And doctors once thought food went through a process similar to “rotting” inside our bodies, but the differences between “digestion” and “rotting” were delineated about 300 years ago. In fact, herbivores rely on bacteria and protozoa (not chemicals) to break down tough plant matter in their complicated stomachs, so if there’s any “rotting” going on, it’s probably inside the cow, not the farmer. A herbivore’s digestive tract is longer than a carnivore’s because it takes longer to extract the food value from plants.

Gorilla and lion guts aside, if F.L.M. Vegan’s digestive tract is 12 times his/her height, then our correspondent must check in at a diminutive two-and-a-half or three feet. A six-foot-tall man does not have 72 feet of esophagus, stomach, and intestine.

Mr./Ms. Vegan signed off, leaving me to my “simmering morsel of dead flesh.” People, please, can’t we all just...get along?