Vegetarian Diets : Can Veggies Prevent Cancer? Part 2

by Food and Drug Administration (FDA)

(Page 3 of 3)

Because vegans and ovo-vegetarians face the greatest potential nutritional risk, the Institute of Food Technologists recommends careful diet planning to include enough calcium, riboflavin, iron, and vitamin D, perhaps with a vitamin D supplement if sunlight exposure is low. (Sunlight activates a substance in the skin and converts it into vitamin D.)

For these two vegetarian groups, the institute recommends calcium supplements during pregnancy, infancy, childhood, and breast-feeding. Vegans need to take a vitamin B12 supplement because that vitamin is found only in animal food sources. Unless advised otherwise by a doctor, those taking supplements should limit the dose to 100 percent of the National Academy of Sciences' Recommended Dietary Allowances.

Vegans, and especially children, also must be sure to consume adequate calories and protein. For other vegetarians, it is not difficult to get adequate protein, although care is needed in small children's diets.

Nearly every animal food, including egg whites and milk, provides all eight of the essential amino acids in the balance needed by humans and therefore constitutes "complete" protein. Plant foods contain fewer of these amino acids than animal foods.

The American Dietetic Association's position paper on vegetarian diets, published in its journal in 1988 and co-authored by Dwyer and Suzanne Havala, R.D., states that a plant-based diet provides adequate amounts of amino acids when a varied diet is eaten on a daily basis. The mixture of proteins from grains, legumes, seeds, and vegetables provide a complement of amino acids so that deficits in one food are made up by another. Not all types of plant foods need to be eaten at the same meal, since the amino acids are combined in the body's protein pool.

Frances Lappe, in Diet for a Small Planet, writes that to gain the greatest use of all the amino acids, it's best to consume complementary proteins within three to four hours. High amounts of complete proteins can be gained by combining legumes with grains, seeds or nuts.

Also available are various protein analogs. These substitute "meats" — usually made from soybeans — are formed to look like meat foods such as hot dogs, ground beef, or bacon. Many are fortified with vitamin B12.

The accompanying chart lists sources of the nutrients of greatest concern for vegetarians who don't eat animal foods.

As with any diet, it's important for the vegetarian diet to include many different foods, since no one food contains all the nutrients required for good health. "The wider the variety, the greater the chance of getting the nutrients you need," says FDA's Stephenson.

The American Dietetic Association recommends:

• minimizing intake of less nutritious foods such as sweets and fatty foods
• choosing whole or unrefined grain products instead of refined products
• choosing a variety of nuts, seeds, legumes, fruits, and vegetables, including good sources of vitamin C to improve iron absorption
• choosing low-fat varieties of milk products, if they are included in the diet
• avoiding excessive cholesterol intake by limiting eggs to two or three yolks a week
• for vegans, using properly fortified food sources of vitamin B12, such as fortified soy milks or cereals, or taking a supplement
• for infants, children and teenagers, ensuring adequate intakes of calories and iron and vitamin D, taking supplements if needed
• consulting a registered dietitian or other qualified nutrition professional, especially during periods of growth, breast-feeding, pregnancy, or recovery from illness
• if exclusively breast-feeding premature infants or babies beyond 4 to 6 months of age, giving vitamin D and iron supplements to the child from birth or at least by 4 to 6 months, as your doctor suggests
• usually, taking iron and folate (folic acid) supplements during pregnancy.

With the array of fruits, vegetables, grains, and herbs available in U.S. grocery stores and the availability of vegetarian cookbooks, it's easy to devise tasty vegetarian dishes.

People who like their entr}es on the hoof also can benefit from adding more plant foods to their diets. You don't have to be a vegetarian to enjoy dishes from a vegetarian menu.

Vegetarian Varieties

The Institute of Food Technologists, in the July 1991 issue of its journal, Food Technology, describes six types of vegetarians. They are listed here by degree of exclusion of animal foods and by the foods included in the diet:

• semi-vegetarian — dairy foods, eggs, chicken, and fish, but no other animal flesh
• pesco-vegetarian — dairy foods, eggs, and fish, but no other animal flesh
• lacto-ovo-vegetarian — dairy foods and eggs, but no animal flesh
• lacto-vegetarian — dairy foods, but no animal flesh or eggs
• ovo-vegetarian — eggs, but no dairy foods or animal flesh
• vegan — no animal foods of any type.

Replacing Animal Sources of Nutrients

Vegetarians who eat no meat, fish, poultry, or dairy foods face the greatest risk of nutritional deficiency. Nutrients most likely to be lacking and some non-animal sources are:

• vitamin B12 — fortified soy milk and cereals
• vitamin D — fortified margarine and sunshine
• calcium — tofu, broccoli, seeds, nuts, kale, bok choy, legumes (peas and beans), greens, calcium-enriched grain products, and lime-processed tortillas
• iron — legumes, tofu, green leafy vegetables, dried fruit, whole grains, and iron-fortified cereals and breads, especially whole wheat (absorption is improved by vitamin C, found in citrus fruits and juices, tomatoes, strawberries, broccoli, peppers, dark-green leafy vegetables, and potatoes with skins)
• zinc — whole grains (especially the germ and bran), whole-wheat bread, legumes, nuts, and tofu.

As all plant foods — including fruit — contain some protein, by eating a variety of fruits, vegetables and grains, even vegans probably can get enough of this nutrient. To improve the quality of protein and ensure getting enough: Combine legumes such as black-eyed peas, chickpeas, peas, peanuts, lentils, sprouts, and black, broad, kidney, lima, mung, navy, pea, and soy beans with grains such as rice, wheat, corn, rye, bulgur, oats, millet, barley, and buckwheat.

There are also foods made to look like meats (protein analogs) such as hot dogs, sausage, and bacon.

About the Author

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