Vegetarian Nutrition Information
One of the largest obstacles to becoming vegetarian (or vegan) is a fear of getting inadequate amounts of protein (and to a lessor extent, calcium, iron and B-12). In general, we would do well to have a greater fear of getting too much of a good thing. With the possible exception of pregnant women and impoverished individuals, western adults (and some children) tend to suffer from excess nutrition--not malnutrition. For instance, most everyone in this country consumes too much protein--even vegetarians!
Let's look at the nutritional fears. The materials below are exerts from "Position of The American Dietetic Association: Vegetarian diets" published in the Journal of the ADA, Nov. 1993, Vol. 93, Number 11. It should be noted that the ADA is one of the most conservative and respected dietary organizations in the world. Medical and dietary policy is greatly influenced by ADA positions (although meat industry money often has a greater influence). The ADA report is widely considered to be the most authoritative document on vegetarian nutrition.
Plant sources of protein alone can provide adequate amounts of the essential and nonessential amino acids, assuming that dietary protein sources from plants are reasonably varied and that caloric intake is sufficient to meet energy needs. Whole grains, legumes, vegetables, seeds, and nuts all contain essential and nonessential amino acids. Conscious combining of these foods within a given meal, as the complementary protein dictum suggests, is unnecessary. Additionally, soy protein has been shown to be nutritionally equivalent in protein value to proteins of animal origin and, thus, can serve as the sole source of protein intake if desired.
Although most vegetarian diets meet or exceed the Recommended Dietary Allowances for protein, they often provide less protein than nonvegetarian diets. This lower protein intake may be associated with better calcium retention in vegetarians and improved kidney function in individuals with prior kidney damage. Further, lower protein intakes may result in a lower fat intake with its inherent advantages, because foods high in protein are frequently high in fat also. . . . Reduced consumption of meat and animal protein has also been associated with decreased colon cancer in some, but not all, studies of omnivores.
CALCIUM (Also see above.)
Certain plant constituents appear to inhibit the absorption of dietary calcium, but within the context of the total diet, this effect does not appear to be significant. Calcium from low-oxalate vegetable greens, such as kale, has been shown to be absorbed as well or better than calcium from cow's milk. Calcium deficiency in vegetarians is rare, and there is little evidence to show that calcium intakes below the Recommended Dietary Allowance cause major health problems in the vegetarian population. The relatively high US recommendations for calcium intake, compared with those for populations consuming a more plant based diet, are designed to compensate for the calciuric effect of high intakes of animal protein, which are customary in the United States. Studies have shown that vegetarians, on the other hand, absorb and retain more calcium from foods than do nonvegetarians.
Vegetarians are not at greater risk of iron deficiency than nonvegetarians, but Western vegetarians generally have better iron status than those in developing countries. Western vegetarians generally have an adequate intake of iron from plant products. They also consume greater amounts of ascorbic acid, an important enhancer of nonheme iron absorption. See also Iron and a Vegetarian Diet.
. . . a [dietary] pattern that includes animal products such as milk and milk products is unlikely to be deficient in vitamin B-12.
Vegans should include a reliable source [of vitamin B-12] in their diets. [Note: Some would disagree with the ADA on this, but why take chances?] . . . Cyanocobalamin, the form of vitamin B-12 that is physiologically active for human beings, is available from vitamin supplements or fortified foods such as some commercial breakfast cereals, soy beverages, some brands of nutritional yeast, and other products.
In Western countries . . . where sanitary practices are better [than developing countries where people receive B-12 from microbes and organisms on the surfaces of unwashed fruits or vegetables], the risk of vitamin B-12 deficiency for vegans may be greater.
Lack of intrinsic factor in the stomach, rather than diet . . . is the most common cause of vitamin B-12 deficiency.
A vitamin D supplement may be indicated [for vegans] if exposure to sunlight is limited.
Western vegetarians usually have satisfactory zinc status. . . . Good plant sources include grains, nuts and legumes.
Infants, children, and adolescents who consume well-planned vegetarian diets can generally meet all of their nutritional requirements for growth. . . . Calcium, iron, and zinc intakes may . . . deserve special attention, although intakes are usually adequate when reasonable variety and adequate energy are consumed. . . . Well-planned vegetarian diets can be adequate for pregnant and lactating women. Vegetarians and nonvegetarians alike are generally advised to take iron and folic acid supplements during pregnancy, although vegetarians frequently have greater intakes of those nutrients than do nonvegetarians. [For infants, children, adolescents, pregnant women and lactating women, the ADA paper generally reiterates the previous information, adds the concern of sufficient caloric intake for vegan infants and weaning children, and extends sunlight/vitamin D concerns to certain nonvegetarians as well.]
How does the common concern about malnutrition compare to the risk or overnutrition? Let's use some common sense by asking: How many people do we know who have died from or suffered from any type of malnutrition? How many friends, loved ones and acquaintances have we lost from heart disease, stroke, cancer and diabetes? It's no contest. Again, quoting the ADA: A considerable body of scientific data suggests positive relationships between vegetarian diets and risk reduction for several chronic degenerative diseases and conditions, including obesity, coronary artery disease, hypertension, diabetes mellitus, and some types of cancer.
. . . vegetarians' high intake of complex carbohydrates, which are often relatively high in fiber content, improves carbohydrate metabolism and may lower basal blood glucose levels.
. . . animal products . . . are devoid of fiber. Fiber has been shown to be important in the prevention and treatment of certain conditions and diseases.
Vegetarians have lower rates of hypertension and non-insulin-dependent diabetes mellitus than do nonvegetarians. . . . Vegetarians may be at lower risk for non-insulin-dependent diabetes because they are leaner than nonvegetarians . . . Vegetarians, especially vegans, often have weights that are closer to desirable weights than do nonvegetarians.
Vegetarian diets that are low in animal products are typically lower than nonvegetarian diets in total fat, saturated fat, and cholesterol, factors associated with reduced risk of coronary artery disease and some forms of cancer. . . . dietary differences, especially in vegans, may produce physiologic changes that may inhibit the causal chain for colon cancer. . . . Lung cancer rates are lower in vegetarians, chiefly because they usually do not smoke, but possibly also because of diet. Research suggests that vegetarians are also at decreased risk for breast cancer.
Mortality from coronary artery disease is lower in vegetarians than in nonvegetarians. . . . Studies of vegetarians indicate that they often have lower mortality rates from several chronic degenerative diseases than do nonvegetarians.
Vegetarian diets are very safe, have real benefits, and generally require very little planning for maximum health. In contrast, diets that include meat must include careful, extremely complex planning to reduce the risks of the most prevalent diseases. For more information, please see the journal article and other ADA literature.
David Lee Winston Miller -- Winston Miller is a past president of ETVS and a lifetime member. He now lives in upstate New York.