Vegetarian and Vegan Diet
Does Being a Vegetarian Lower Cancer Risk? continued...
A 1998 Dutch survey of 150,000 vegetarians concluded that the benefit of a vegetarian diet comes not just from excluding meat but in eating more whole grains, fruits and vegetables, legumes, and nuts.
Researchers who conducted an 11-year study in Germany came to a similar conclusion. They examined the relationship between a vegetarian diet and colon cancer among 1,900 vegetarians. Researchers noted fewer deaths from cancers of the stomach and colon and even the lung in study participants -- particularly among those who practiced some form of vegetarianism for at least 20 years. They suggested, however, that other factors, like body weight and amount of exercise, likely affected mortality rates in the vegetarians they studied.
Vegetarianism and Nutrition
A vegetarian diet can be a healthy diet, but vegetarians -- especially vegans -- need to make sure they're getting enough vitamin B12, calcium, and iron.
The Academy of Nutrition and Dietetics warns of the risk of vitamin B12 deficiencies in strict vegetarians (vegans). Vitamin B12 is found naturally only in animal products. A lack of vitamin B12 can lead to anemia and blindness. It can also cause muscle weakness, tingling, and numbness.
Calcium is another nutrient that may be lacking in some vegetarian diets. Ovo-vegetarians, who eat eggs but not dairy, need to find foods that compensate for the missing calcium from their diets. Dark green vegetables are a good source of calcium.
Lacto-vegetarians (who don't eat eggs) also need to boost their intake of B12 and iron.
A vegan diet, in particular, may lead to an increased risk of deficiencies of vitamin B12, vitamin B2, calcium, iron, and zinc. To counteract the increased risk, vegans should include B12 supplements, or fortified cereals and veggie burgers in their diets.
Is a Vegan Diet Safe During Pregnancy?
The warnings are a bit more urgent for pregnant and lactating women who are vegan. Having a vitamin B12 deficiency, particularly, has been shown to impair neurological development in infants nursed by vegetarian mothers. A lack of vitamin D and calcium also can result in bone demineralization in breastfeeding women.
Similarly, young children (under 5) reared on vegetarian and vegan diets can suffer impaired growth. That's because of a vitamin B12 deficiency, which can also result in anemia and rickets. Yet a well planned diet can meet all the nutritional needs.
Absorbable calcium is critical, too, for vegans and ovo-vegetarians to protect against weak bones that can lead to osteoporosis.
Key Nutrients for Vegetarians and Vegans
The U.S. Department of Agriculture offers dietary guidelines for vegetarians of all stripes on its web site. The Academy of Nutrition and Dietetics (formerly the American Dietetic Association) is also a good source for dietary recommendations.
Regardless of the kind of meat-free diet practiced, vegetarians should focus on getting enough protein, iron, calcium, zinc, and vitamin B12. They also need riboflavin, linolenic acid, and vitamin D.
Here are some ways for vegetarians to incorporate these nutrients into their diets:
- Protein: Is found in tofu, tempeh, veggie burgers, beans, nuts and nut butters, eggs.
- Iron: Eggs, fortified breakfast cereals, soy-based foods, dried prunes and apricots, nuts beans, legumes, whole-wheat bread, and baked potatoes are rich in iron.
- Calcium, which builds bone, is plentiful in cheese, yogurt and milk. Ovo-vegetarians and vegans can get it in soy products, legumes, almonds, sesame tahini, calcium-fortified orange juice, and dark, leafy vegetables like collard greens and bok choy.
- Zinc, which boosts the immune system, is ample in soybeans and soymilk, veggie "meats," eggs, cheese and yogurt, fortified breakfast cereals, nuts, breads, mushrooms, and peas. Wheat germ and pumpkin seeds also have high zinc content
- Vitamin B12: Soy-based beverages, some breakfast cereals, and fortified veggie "meats" are all good sources of vitamin B12
- Riboflavin: Almonds, fortified cereals, cow's milk, yogurt, mushrooms, and soy milk are riboflavin-rich foods.
- Linolenic acid (omega-6): Canola oil and flaxseeds and flaxseed oil contain linolenic acid, along with soybeans, tofu, walnuts, and walnut oil.
- Omega-3 Fatty Acids: Cold-water fish, such as salmon and mackerel, are high in omega-3 fatty acids For vegetarians who do not eat fish, good sources of omega-3s are flaxseed, walnut, soy and canola oils. Supplements are fine, too.