Veganism and the Issue of Protein
Can the vegan (strict vegetarian) diet provide protein adequate for sound human health? This question continues to be asked despite the fact that a "yes" answer was given some three decades ago in a study reported by Hardinge and Stare. The question stays with us largely because animal products (meat, milk, cheese, and eggs) have been promoted (usually by the industries that produce and sell them) as the best source of protein. This dietary assumption is wrong and can even be harmful, as a quick study of the facts about vegetable protein and nutrition shows.
The Importance of Protein
Protein is essential to human health. In fact, our bodies - hair, muscles, fingernails, and so on - are made up mostly of protein. As suggested by the differences between our muscles and our fingernails, not all proteins are alike. This is because differing combinations of any number of 22 known amino acids may constitute a protein. (In much the same way that the 26 letters of our alphabet serve to form different words, the 22 amino acids serve to form different proteins.)
Amino acids are a fundamental part of our diet. While most of the 22 can be manufactured in one way or another by the human body, eight (or, for some people, 10) cannot. These "essential amino acids" can easily be provided by a balanced vegan diet.
How Much Protein?
Non-animal foods can easily provide us with the necessary protein. Despite the claims of the meat and dairy industries, only 2.5-10 percent of the total calories consumed by the average human being needs to be in the form of protein. The rule of thumb used by the National Academy of Sciences Food and Nutrition Board is .57 grams of protein for every kilogram (2.2 pounds) of body weight. People under special circumstances (such as pregnant women) are advised to get a little more. Vegans should not worry about getting enough protein; if you eat a reasonably varied diet and ingest sufficient calories, you will undoubtedly get enough protein
Eating too much protein can result in osteoporosis and kidney stones. Meat and dairy products raise the acid level in human blood, causing calcium to be excreted from the bones to restore the body's natural pH balance. This calcium depletion results in osteoporosis, or weakening of the bones. The excreted calcium ends up in the kidneys, where it often forms painful stones. Kidney disease is far more common in meat-eaters than in vegans, and excessive protein consumption has also been linked to cancer of the colon, breast, prostate, and pancreas. By replacing animal protein with vegetable protein, you can improve your health while enjoying a wide variety of delicious foods.
While just about every vegetarian food contains some protein, the soybean deserves special mention, for it contains all eight essential amino acids and surpasses all other food plants in the amount of protein it can deliver to the human system. In this regard it is nearly equal to meat. The human body uses about 70 percent of the protein found in meat and 60 to 65 percent of that found in soybeans. The many different and delicious soy products (tempeh, soy "hot dogs," "burgers," Tofutti brand "ice cream," and tofu) available in health and grocery stores suggest that the soybean, in its many forms, can accommodate a wide range of tastes.
Other rich sources of non-animal protein include legumes, nuts, seeds, food yeasts and freshwater algae. Although food yeasts ("nutritional yeast" and "brewer's yeast") do not lend themselves to forming the center of one's diet, they are extremely nutritious additions to most menus (in soups, gravies, breads, casseroles, and dips). Most yeasts are 50 percent protein (while most meats are only 25 percent).
Freshwater algae contains a phenomenal percentage of protein. One type is the deep green spirulina, a food that is 70 percent protein. It is available in tablets, powders, and even candy bars.
Protein deficiency need not be a concern for vegans. If we ate nothing but wheat, oatmeal, or potatoes, we would easily have more than enough protein. Eating nothing but cabbage would provide more than twice as much protein as anyone would need!
Of course, an actual vegan would never want to be limited to just one food. The vegan diet can (and should) be full of a wide variety of delicious foods.