To
most people in the industrialized world a vegetarian lifestyle conjures
up images of carrots and lettuce leaves, but nothing could be further
from the truth. Vegetarian
diets
can be very satisfying indeed, as underscored by most of mankind that
has subsisted for much of human
history on vegetarian or near-vegetarian diets. Even in this modern
age, the vast majority of the people who inhabit this planet subsist
on a largely vegetarian diet.[i] A
prime example are the Hunzas of the Himalayas who are known for their
disease-free society and longetivity of life. The Tarahumara Indians
of Mexico are also renowned for their stamina and vibrant health, yet
both these tribes subsist on largely vegetarian whole-food diets.[ii] Vegetarian
lifestyles are becoming more and more popular, and many people are adopting
the vegetarian diet for reasons of health, religious beliefs, philosophical
considerations or environmental convictions. However, not all the
vegetarian practices dictated by some of these convictions are equally
beneficial, and some of them, particularly those dictated by religious
or metaphysical beliefs, can place severe restrictions on the utilization
of certain foods. Moreover, some groups, in addition to following
restrictive diets, shun the expertise of nutritional science and the
medical profession, and run the risk of suffering malnutrition and associated
diseases.
Vegetarians can be divided into various categories, depending on the range of foods which are included in the diet.
Vegan vegetarians: Avoid all animal products
Lacto vegetarians: Include dairy products in their diet
Lacto-ovo-vegetarians: Include dairy products and eggs in their diet
Dairy products should, if possible, not be included in the human diet, and the other animal products also have their health risks, particularly in view of modern husbandry practices and the rising incidence of animal food-borne diseases. However, a diet that excludes all animal products might seem restrictive, and indeed can be, if certain criteria are not met. The more restrictive one’s diet the greater the chance of developing deficiencies and nutrient-deficiency related diseases. Risks will increase if single plant food regimes are adopted such as diets consisting only of fruit or only of legumes or only of cereals. The higher diet levels of the Zen macrobiotic diet are, for example, made up entirely of cereals, and cases of scurvy, anemia, hypo-proteinaemia, hypocalcaemia and even death from malnutrition have resulted from this lifestyle.[iii],[iv]
Vegan vegetarian diets must be well planned, and special attention must be given to nutrients which occur in low levels or are absent from plant foods. Moreover, pregnant or lactating women and infants and growing children also need specific dietary consideration. However, if due consideration to these points is given, a total plant-based diet can supply all our dietary needs. At this point it can be emphasized again that a variety of plant foods, incorporating grains, nuts, seeds, legumes, fruits and vegetables, will supply ample nutrients for healthful living. Nutritionists often express skepticism as to the adequacy of a vegetarian diet, and their main concerns revolve around adequacy of proteins, calcium, iron, riboflavin and vitamin B-12.
If combinations of cereals and legumes are used, protein-deficiency is extremely unlikely, and numerous studies have proved not only the adequacy, but even the superiority of plant proteins over those of animal origin.[v] Indeed, the reverse is true in that it is difficult not to exceed recommended protein allowances on a varied vegetarian diet. It is only when calorie needs are not met that the body will preferentially utilize proteins as an energy source, and this may result in deficiencies. Such conditions are mostly found in populations where malnutrition is a common phenomenon. Regarding the other nutrients listed, all these nutrient requirements can be met by plant foods, except for vitamin B-12, but his can be supplied through fortified soybean milk, nutritional yeast grown on a B-12 medium, or through supplementation.[vi],[vii] Even without supplementation, reports of vegans suffering from vitamin B-12 deficiency are extremely rare.
The above has been excerpted from the book Diet and Health by Professor Walter J. Veith available through our webstore.
Resources:
[i] American Dietetic Association. 1980. Position paper on the vegetarian approach to eating. Am.Diet.Assoc. 77:61-69.
[ii] Balke, B., Snow, C. 1965. Anthropological and physiological observations on Tarahumara endurance runners. A.J.Phys. Anthropol. 23: 293-301.
[iii] Register, U.D. and Sonnenberg, L.M. 1973. The vegetarian diet. J.Am.Diet.Assoc. 62: 253-261.
[iv] Council on foods and Nutrition. 1971. Zen Macrobiotic diets. J.A.M.A. 218:397.
[v] Snowdon, D.A. 1988. Animal product consumption and mortality of all causes combined, coronary heart disease, stroke, diabetes and cancer in Seventh-day Adventists. Am. J. Clin. Nutr. 48: 739-48.
[vi] Mutch, P.B. 1988. Food guides for the vegetarian. Am. J. Clin. Nutr. 48:913-9
[vii] Nieman, D.C. 1988. Vegetarian dietary practices and endurance performance. Am.J.Clin. 48:754-61
by Professor Walter J. Veith Phd.