This factsheet was completed by People for the Ethical Treatment of Animals (PETA)  . Please direct any questions or comments to PETA directly at 757-622-7382 or info@peta.org.

Vegan Protein

Can the vegan (strict vegetarian) diet provide enough protein for sound human health? The medical community agrees about the distinct health advantages of a vegan diet, but the protein question stays with us because animal products have been promoted by the industries that produce them, sell them, and want people to think of them as the best source of protein. This assumption is wrong and can 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. 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 20 amino acids may constitute a protein. In much the same way that the 26 letters of our alphabet serve to form millions of different words, the 20 amino acids serve to form different proteins.

Amino acids are a fundamental part of our diet. While half of the 20 can be manufactured by the human body, the other 10 cannot.¹ These “essential amino acids” can easily be provided by a balanced vegan diet.

How Much Protein?
As babies, our mothers’ milk provided the protein we needed to grow healthy and strong. Cow’s milk has about three times the amount of protein found in human breast milk. Once we start eating solid foods, non-animal sources can easily provide us with all the protein we need. Only 10 percent of the total calories consumed by the average human being need be in the form of protein.² The Recommended Dietary Allowance for both men and women is 0.8 grams of protein for every kilogram (2.2 pounds) of body weight.³ People with special needs (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. Protein deficiency, or “kwashiorkor,” is very rare in the U.S. and is usually diagnosed in people living in countries suffering from famine.⁴

By contrast, eating too much animal protein has been directly linked to the formation of kidney stones and has been associated with cancer of the colon and liver.^5,6 By replacing animal protein with vegetable protein, you can improve your health while enjoying a wide variety of delicious foods.

Protein Sources
While just about every vegetarian food contains some protein, the soybean deserves special mention, for it contains all the essential amino acids and surpasses all other food plants in the amount of protein that it can deliver to the human system. In this regard, it is nearly equal to meat. The human body is able to digest 92 percent of the protein found in meat and 91 percent of that found in soybeans.⁷ The many different and delicious soy products (such as tempeh, soy “hot dogs” and “burgers,” Tofutti brand “ice cream,” soy milk, 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, yeast, 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 get about 50 percent of their calories from protein.⁸

Percentage of Calories From Protein
(Value per 100 Grams Edible Portion, From USDA National Nutrient Database for Standard Reference, 2003)⁹

As the above chart demonstrates, protein deficiency need not be a concern for vegans. If we ate nothing but wheat, oatmeal, or potatoes, we would easily take in more than enough protein.

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. Call 1-888-VEG-FOOD for some recipes and cooking tips to get you and your family started.

References

¹ University of Arizona, Department of Biochemistry and Molecular Biophysics, “Amino Acids Problem Set,” The Biology Project, 25 Aug. 2003.
² Paula Kurtzweil, “‘Daily Values’ Encourage Healthy Diet,” U.S. Food and Drug Administration, 2003.
³ Food and Nutrition Board, “Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids (Macronutrients),” National Academy of Sciences (2002): 10-1.
⁴ U.S. National Library and the National Institutes of Health, “Kwashiorkor,” MEDLINEplus Medical Encyclopedia, 11 Jul. 2002.
⁵ Gary C. Curhan et al., “A Prospective Study of Dietary Calcium and Other Nutrients and the Risk of Symptomatic Kidney Stones,” The New England Journal of Medicine 328 (1993): 833-8.
⁶ Kathleen M. Stadler, “The Diet and Cancer Connection,” Virginia Tech, Nov. 1997.
⁷ Gertjan Schaafsma, “The Protein Digestiblity-Corrected Amino Acid Score,” Journal of Nutrition 130 (2000):1865S-1867S.
⁸ USDA National Nutrient Database for Standard Reference, “Leavening Agents, Yeast, Baker’s, Active Dry,” 16 Jul. 2003.
⁹ Agricultural Research Service, “Nutrient Data Laboratory,” United States Department of Agriculture, 29 Aug. 2003.