Opinions abound as to whether humans are "meant" to eat meat or not.
It's clear, however, that as a species we are omnivores, and our survival has depended on it. We put into our mouths just about anything catchable or remotely digestible, and can tolerate long stretches of starvation (up to seven months for normal weight people). No doubt our adaptable GI tracts and down-regulating metabolic systems have been key factors in our ability to thrive in the animal kingdom. Perhaps only the cockroach surpasses us in gastrointestinal ingenuity.
Most people say they'd like to eat less meat. Among my patients, ninety percent of whom have suboptimal lipid profiles, most should reduce animal protein in their diets for the sake of their health. Animal products are high in saturated fats, which clog small blood vessels and cause strokes and heart attacks. Twenty-first century animal products in the United States are loaded with chemicals, not least of which are adrenaline and its biological by-products.
Adrenalin is another term for cortisol, a stress hormone which skyrockets when animals are kept in close quarters, force-fed, denied access to the outdoors, and treated with cruelty. It is a sad consequence of our purposeful divorce from everything natural that Americans exercise unnecessary barbarism in the production of meat, and that most of us ignore this immorality as we gluttonize ourselves with meat--far too much meat.
Why do people get so hungry for meat, fish, and cheese? Patients who try to reduce their intake find themselves craving certain things: a big steak, bacon, cheeseburgers, chicken nuggets.
I think what they hanker for is glutamate. It's a taste that causes cravings as powerful as those for sugar, salt, and fat. There's nothing wrong with these cravings--they're built into our nature. Glutamate is an amino acid that's present in high quantities in meat, fish, and cheese. It's associated with the "fifth taste," known as umami.
Umami is a term that comes from the Japanese word for "deliciousness." Our taste buds are geared to pick it up, just as they register salty, sweet, sour and bitter flavors--but what they're registering is glutamate. In 1908 Professor Kikunae Ikeada "discovered" monosodium glutamate by isolating glutamic acid from a seaweed, kombu, and ionizing it. Thus, MSG was born and patented, and has been used in cooking in western countries ever since. It was the target of Chinese-restaurant syndrome, a constellation of symptoms including headache and dizziness unfairly attributed to MSG, and suffered a loss in popularity for many years. But it is probably very safe, since the body breaks down MSG into glutamic acid readily, and glutamic acid is present in many foods.
Which brings me to the point of this post. If you want to eat less meat, you have to increase your intake of foods that are high in glutamic acid, or glutamate. The modern American diet doesn't include many of these foods, hence our craving for meat and other animal products. You could simply add MSG to all your vegetables and non-meat foods, but it doesn't seem right to veer to far from traditional cooking lore, and MSG is a modern, laboratory-produced crystalline substance, unlike salt, which is found along seashores, or sugar, which is boiled down from cane or beets. Adding MSG to foods seems like something astronauts would do, because they have to, not earthbound humans with a long and well-documented history of cooking and eating wisdom.
The foods high in glutamate are those our ancestors made, preserved and ate. They are foods that are making their way back into the American diet, inch by inch, and they are high in nutritional substances not yet well understood, and not found in many other places. We all need to learn to make them, and cook with them, and think of them when we eat. It's easy to renounce meat, and even to become a complete vegetarian if you know how to include umami with the other four flavors in cooking. Glutamate stimulates brain receptors, and may promote a sense of well-being.
High amounts of umami are found in the following foods: tomatoes, tamari or soy sauce, anchovies, mushrooms (especially shiitake), nutritional yeast, olives, marmite, miso, kombu, umeboshi plums, ketchup, wasabi, vinegar, beer, wine, parmesan cheese, sauerkraut, tempeh, and all fermented foods. Traditional cooking from all cultures includes foods with umami.
Many of these products are loaded with probiotics--those all-important organisms that seed our GI tracts and help to boost our immune systems, and which is so often associated with yogurt. (In fact, most yogurt brands probably contain no probiotics--you have only to try to make your own yogurt with a "starter" of commercial yogurt to find that there aren't enough active lactobacilli in a store-bought yogurt to get a culture going, which is proof that they're a worthless source of probiotics.)
Any vegetarian cookbook worth the paper it's written on will include umami-containing ingredients in most of its recipes--or at least at every meal--otherwise a key flavor will be missing, and the cook's family and guests will leave the table feeling hungry, with a vague sense that something was missing. They'll blame it on the fact that the food was "vegetarian"--when the problem will have been: no umami. They'll leave your table to rush to the nearest fast-food joint and satisfy the craving for umami by gorging on a few burgers with ketchup.
If the concept of adding umami to your diet in forms besides meat seems daunting, go slowly. Learn to make a few things with one or more of the ingredients above, and eliminate meat from the meal. See if it makes a difference. The less meat you eat, the longer you're likely to live, if the regions with the longest life-expectancy (Okinawa; Sardinia; Ikaria; Loma Linda) are any clue.