Ovovegetarianism

Definition

Origins

Description

Function

Benefits

Precautions

Risks

Research and general acceptance

Resources

Definition

Ovovegetarianism is a subcategory of vegetarianism . Ovovegetarians, who are sometimes called eggetarians, are people who consume a plant-based diet with the addition of eggs. The ovo- part of the name comes from the Latin word for egg. Ovovegetarians do not eat red meat, poultry, fish, or use cow’s milk or milk-based products (cheese, yogurt, ice cream).

Origins

Vegetarianism in general has existed for thousands of years, although the anatomical and archaeological evidence indicates that prehistoric humans were not vegetarians. The pattern of human dentition (teeth adapted for tearing meat as well as grinding plant matter), the length of the human digestive tract, and the secretion of pepsin (an enzyme that is necessary for digesting meat) by the human stomach are all indications that humans evolved as omnivores, or animals that consume both plant and animal matter.

Religious faith is the oldest known motive for consuming a vegetarian diet. Hinduism is the earliest of the world’s major religions known to have encouraged a vegetarian lifestyle. As of the early 2000s, Hinduism accounts for more of the world’s practicing vegetarians—70 percent—than any other faith or political conviction. The Hindu religion does not, however, endorse ovovegetarianism, as strict Hindus avoid all of the following foods:

• Beef and cow products, including gelatin.
• Other types of meat; fish; and eggs.
• Onions, garlic and mushrooms.
• Alcohol.
• Red lentils.

Devout Hindus are also not allowed to eat food that has been cooked in the same pot or pan used for cooking meat, fish or eggs, even if the implement has been washed and cleaned after such use, or food that has been heated in the same oven or microwave in which meat, fish, or eggs are cooked or heated.

Most ovovegetarians in North America, however, are guided by health or ethical concerns rather than religion in the strict sense. Some people are ovovege-tarian because they suffer from lactose intolerance (a condition in which the body fails to produce enough lactase, an enzyme needed to digest the sugars in milk and dairy products) but do want to include eggs in their diet as a source of protein . They may also believe that eating eggs is more ethically acceptable than consuming dairy products, on the grounds that cows must have calves before giving milk; thus eating dairy products supports the meat industry indirectly through increasing the population of animals that cannot be sustained for any other purpose. Hens, however, can lay eggs for human consumption without being fertilized or reproducing.

Some ovovegetarians insist on purchasing eggs only from small farmers who raise free-range chickens, on the grounds that factory-farming of eggs is inhumane.

KEY TERMS

Albumen— The white of the egg. It can be separated from the yolk for cooking or to avoid the high fat and high cholesterol content of the yolk.

Factory farming— A term that refers to the application of techniques of mass production borrowed from industry to the raising of livestock, poultry, fish, and crops. It is also known as industrial agriculture.

Free-range— Allowed to forage and move around with relative freedom. Free-range chickens are typically raised on small farms or suburban back yards, and are often considered pets as well as egg producers.

Lactose intolerance— A condition in which the body does not produce enough lactase, an enzyme needed to digest lactose (milk sugar). Lactose intolerance is the reason why some vegetarians are ovovegetarians.

Ovolactovegetarian— A vegetarian who consumes eggs and dairy products as well as plant-based foods. The official diet recommended to Seventh-day Adventists is ovolactovegetarian.

Ovovegetarian— A vegetarian who eats eggs in addition to plant-based foods.

Pepsin— A protease enzyme in the gastric juices of carnivorous and omnivorous animals that breaks down the proteins found in meat. Its existence in humans is considered evidence that humans evolved as omnivores.

Vegan— A vegetarian who excludes all animal products from the diet, including those that can be obtained without killing the animal. Vegans are also known as strict vegetarians.

Yolk— The yellow spherical mass in the inner portion of an egg. It contains almost all the fat and cholesterol found in eggs.

Some factory farms contain as many as 100,000 chickens, typically crowded together in cages, de-beaked (which is painful and leads some hens to starve themselves to death), and killed after 12 months, when their egg-laying capacity starts to decline. In addition, all male chicks of egg-laying breeds are killed between one and three days after birth, as they are not suitable for meat production. Free-range chickens, on the other hand, are often kept as pets by small farmers; allowed to run outside, build nests, and scratch in the dirt; and are not killed automatically when they reach a certain age.

Description

There is no ‘typical’ ovovegetarian diet; however, several popular diets can be easily adapted by ovovegetarians.

Mediterranean diets

Mediterranean diets are not purely ovovegetarian. They are, however, sparing in their use of red meat and eggs, and low in their use of fish and poultry. Ovovegetarians can simply cut meat, fish, and dairy ingredients from Mediterranean recipes, or use almond or soy milk in place of cow’s milk. Mediterranean diets appeal to many people because of their wide choice of flavorful foods and their generous use of fresh vegetables and whole-grain breads.

Ornish diet

Developed by a medical doctor to reverse the signs of heart disease, the Ornish diet has also been popularized as a weight-loss program. It is a strict low-fat, high-fiber diet that excludes red meat, poultry, and fish, although ovovegetarians following this diet may use limited amounts of egg whites.

Seventh-day Adventist diet

Seventh-day Adventists (SDAs) have followed vegetarian dietary regimens since the denomination was first organized in 1863. The diet recommended by the church’s General Conference Nutrition Council (GCNC) in the early 2000s is an ovolactovegetarian diet high in whole-grain breads and pastas, fresh vegetables and fruits; moderate use of nuts, seeds, and low-fat dairy products; and limited use of eggs. Some SDAs prefer a vegan diet, however, which indicates that the GCNC diet can be easily modified for ovovegetarians as well. The church has its own professional organization for dietitians, which is affiliated with the ADA, and encourages all its members to follow the ADA guidelines for vegetarians.

Some ovovegetarian recipes

HUNGARIAN OMELET. Ingredients: 1 tbsp. olive oil; 1 small onion, sliced; 1/4 of a small red pepper, sliced and seeds removed; 2 medium tomatoes, peeled and sliced; 1 tsp. paprika; 2 beaten eggs; salt to taste; chopped fresh parsley or chives (garnish).

Cooking instructions: Heat 1 tsp. olive oil in a saucepan and saute the onion and pepper until soft. Add tomatoes and paprika and cook gently (about 5 minutes) until mixture is soft. Add salt to taste. Heat remaining olive oil in an omelet pan. Beat two tbsp. water into the eggs to lighten the mixture; cook eggs in the omelet pan. To serve: fill the omelet with the tomato mixture and top with parsley or chives.

SWEET POTATO SOUFFLE. Ingredients: 1 cup soy milk; 1/2 cup sugar; 1/2 tsp. salt; 3 tbsp. margarine; 1 tsp. nutmeg; 2 cups mashed sweet potatoes; 2 eggs, separated; 1/2 cup raisins; 1/2 cup chopped pecans; miniature marshmallows (topping).

Cooking instructions: Scald soy milk; add sugar, salt, margarine, nutmeg, and mashed sweet potatoes; beat until fluffy. Beat egg yolks and add to sweet potato mixture. Add raisins and pecans. Beat egg whites until stiff; fold into sweet potato mixture and pour into a greased baking dish. Bake in a moderate oven (350 °F) for 50 to 60 minutes or until firm. Top wit miniature marshmallows and brown in oven. Serves 8.

POTATO PANCAKES. Ingredients: 2 large white potatoes; 1/2 onion; 1 egg; pepper to taste; 1/2 tsp. salt; 1/3 cup flour; 1/2 cup water.

Cooking instructions: Peel potatoes and put in food processor with the onion and water. Process and drain through a paper towel placed in a colander. In a separate small bowl, beat the egg together with the salt and pepper, and add to the drained potato/onion mixture. Stir well; then stir in flour. Drop by 1/4-cupfuls into hot oil in a large frying pan, and flatten the mixture while frying over medium heat. Fry until golden-brown on the outside. May be served with applesauce, stewed apples, soy-based sour cream, or soy-based yogurt.

Function

Vegetarian diets in general, and ovovegetarian diets in particular, are adopted by people in developed countries primarily for ethical or religious reasons rather than economic necessity. Another more recent reason is the growing perception that plant-based diets are a form of preventive health care for people at increased risk of such diseases as heart disease, type 2 diabetes and some forms of cancer. According to a survey conducted by the editors of Vegetarian Journalin 1997, 82% of the respondents gave health concerns as their primary reason for becoming vegetarians, with animal rights a close second.

Benefits

The benefits of an ovovegetarian diet include those of vegetarian diets in general, namely lowered blood pressure, lower rates of cardiovascular disease and stroke, lower blood cholesterol levels, and lowered risks of colon and prostate cancer. There is also evidence that vegetarian diets lower the risk of developing type 2 (adult-onset) diabetes, and assist in weight reduction.

It is possible that ovovegetarianism is more beneficial to maintaining fertility in women than vegetarian diets allowing dairy foods. A group of researchers at the Harvard School of Public Health reported in early 2007 that a high intake of low-fat dairy foods is associated with infertility in women caused by failure to ovulate.

Precautions

The ADA strongly recommends that people consult a registered dietitian as well as their primary physician before starting any type of vegetarian diet. The reason for this precaution is the variety of vegetarian regimens as well as the variations in height, weight, age, genetic inheritance, food preferences, level of activity, geographic location, and preexisting health problems among people. A dietitian can also answer questions about the desirability of limiting egg consumption within an ovovegetarian diet; for example, the Seventh-day Adventist Dietetic Association (SDADA) recommends that people following the Adventist vegetarian diet limit their use of egg yolks to three or less per week.

Risks

The longstanding concern about all vegetarian diets is the risk of nutritional deficiencies, particularly for such important nutrients as protein, minerals (iron, calcium, and zinc), vitamins (vitamin D, ribo-flavin, vitamin B ₁₂, and vitamin A) , iodine, and n-3 fatty acids. Although the ADA food guide does not discuss ovovegetarians as a distinctive subgroup, their recommendations for vegans would apply to ovovegetarians, since eggs do not supply as much vitamin D or vitamin B₁₂ as milk. Moreover, ovovegetarians who remove the yolks from the eggs they consume would lose all the vitamin D content of the egg. The 2003 vegetarian food guide published by the ADA and DC recommends that vegans in all age groups should take supplements of vitamin B₁₂ and vitamin D, or use foods fortified with these nutrients.

It is particularly important for pregnant women to maintain an adequate intake of vitamin B₁₂, as a lack of this vitamin can cause irreversible neurological damage in the infant. A recent Canadian study reported that a reduced intake of milk during pregnancy, which would be characteristic of ovovegetarians as well as nonvegetarian women suffering from lactose intolerance, is associated with low birth weight in the infant. In addition, some studies indicate that vegans (and by implication ovovegetarians as well) are at increased risk of osteoporosis and bone fractures compared to either meat-eaters or less strict vegetarians because their average calcium intake is lower.

There is some disagreement among researchers regarding the cholesterol content of eggs as a health risk. Some maintain that the cholesterol in eggs actually raises high-density lipoprotein (‘good’ cholesterol) blood levels while lowering lowdensity lipoprotein (‘bad’ cholesterol) levels. Other researchers have noted wide variations among individuals in the effect of egg consumption on blood lipids. One Indian study of volunteers on a lacto-vegetarian diet found that the subjects’ blood lipid levels rose for a few weeks after adding one boiled egg per day to their diets, but that the levels fell to baseline values by the end of 8 weeks for two-thirds of the subjects. The remaining third were hyper-responsive to the addition of eggs to their diet. This finding suggests that a vegetarian who is concerned about blood cholesterol levels may wish to find out whether he or she is hyper-responsive before increasing their level of egg consumption. In any case, the cholesterol in chicken eggs is concentrated in the yolk, and can be minimized or eliminated by eating only part of the yolk or eating only the white (albumen) of the egg—which is 87% water, 13% protein, and very little fat.

Ovovegetarians should avoid eating raw or under-cooked eggs, however, because of the danger of contamination by Salmonella enteritidis and other Salmonella species associated with food poisoning. The shell of a chicken egg ordinarily acts as a barrier against bacterial contamination, but improper handling or an active infection in the hen producing the egg may allow Salmonella and other disease organisms to enter. According to a 2002 study produced by the U.S. Department of Agriculture, only one in every 30,000 eggs produced in the United States is contaminated, as most egg producers wash the eggs with a sanitizing solution shortly after they have been laid. It is best, however, to protect oneself and others by cooking eggs thoroughly and by not allowing containers or cutting boards that have held raw eggs to come into contact with food that is ready to eat. This precaution is particularly important for people with weakened immune systems or who are taking drugs that suppress the immune system.

QUESTIONS TO ASK YOUR DOCTOR

• Are any of your other patients ovovegetarians?
• Would you recommend an ovovegetarian diet? In your opinion, is it preferable to a vegan diet?
• What is your opinion of eggs as part of an adult’s diet? Should people limit their consumption of them even if they are ovovegetarians?

Research and general acceptance

Basic nutritional information about eggs

In order to evaluate the nutritional content of chicken eggs, the reader should note that eggs vary considerably in size and therefore in calorie or fat content. The following are the standard sizes as defined in the United States:

• Peewee: greater than 1.25 oz or 35 g
• Small (S): greater than 1.5 oz or 43 g
• Medium (M): greater than 1.75 oz or 50 g
• Large (L): greater than 2 oz or 57 g
• Extra Large (XL): Greater than 2.25 oz or 64 g
• Jumbo: Greater than 2.5 oz or 71 g

The nutrient content of a large egg (59 g) is as follows:

• Calories: 75 (17 in the white or albumen, 58 in the yolk)
• Cholesterol: 213 mg (all in the yolk)
• Protein: 6.25 g (3.5 g in the white, 2.78 g in the yolk)
• Carbohydrate: 0.61 g (0.34 g in the white, 0.27 g in the yolk)
• Fats: 5 g (all in the yolk)
• Vitamin A: 317 IU (all in the yolk)
• Vitamin D: 24.5 IU (all in the yolk)
• Vitamin B₁₂: 0.52 mcg (all in the yolk)
• Calcium: 25 mg (2 in the white, 23 in the yolk)
• Zinc: 0.55 mg (all in the yolk)

It will be evident from the foregoing list that ovovegetarians who omit all or part of the yolk from their egg consumption will be losing important vitamins and minerals along with the cholesterol and fats.

Evaluations ofovovegetarianism

Vegetarianism, including ovovegetarianism, is accepted by all mainstream medical associations and professional nutritionists’ societies, and positively recommended by some. The position statement jointly adopted by the ADA and DC in 2003 states: ‘‘It is the position of the American Dietetic Association and Dietitians of Canada that appropriately planned vegetarian diets are healthful, nutritionally adequate and provide health benefits in the prevention and treatment of certain diseases. . . . Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood and adolescence.’’

On the other hand, little research has been done on ovovegetarianism as a subtype of vegetarianism, whether of ovovegetarianism by itself or in comparison to other vegetarian diets. It is therefore difficult to determine whether the consumption of eggs (or egg yolks) by itself has a negative effect on the overall health benefits of a vegetarian diet. Further research in this area would be beneficial.

Ovovegetarians are a fairly small subgroup of vegetarians. As is sometimes pointed out in discussions of meal choices in restaurants, school cafeterias, and airline food service, most institutions interpret ‘vegetarian’ to mean ‘ovolactovegetarian.’ This fact requires ovovegetarians in many situations to ask whether a vegan meal or food choice is available. One website has a list of airlines that offer ovovegetarian (called ‘nondairy’ vegetarian) meals (as well as vegan, Hindu vegetarian, and raw vegetarian choices) provided the customer calls 48 hours in advance of departure. The URL is listed below.

It is difficult to estimate either how many people in the general North American population are ovovegetarians or how many people who consider themselves vegetarians fall into this subgroup. Charles Stahler reported in an article in Vegetarian Journal in 2006, however, that a poll conducted by Harris Interactive indicated that 7.6% of adults in the United States ‘never eat dairy products.’

Another factor that further confuses the issue is that vegetarians disagree among themselves as to how strictly their various subgroups should be defined; some ovove-getarians may be flexible about the occasional use of milk or other dairy products while others may not be. One registered dietitian who offers tutorials on vegetarian nutrition and food service has remarked, ‘Just as there are no culinary police that dictate how people eat or how food is prepared, there are no vegetarian police who oversee if people are adhering to their ‘declared’ vegetarian choice. This is a very hot topic for some people, who are adamant that their definitions or life-style choices are the only way. For the sake of these lectures, it will be easier for those people . . . with very strong feelings to park their dogma by the door.’

Resources

BOOKS

Rossier, Jay. Living with Chickens. Newton Abbot, UK: David & Charles, 2005. Explains the details of raising chickens for those interested in starting and maintaining a flock of free-range chickens.

Scully, Matthew. Dominion: The Power of Man, the Suffering of Animals, and the Call to Mercy. New York: St. Martin’s Press, 2002. The author’s focus is on kindness to animals rather than vegetarianism in the strict sense; however, he has been a vegetarian since the late 1970s, and his chapters on commercialized hunting, fishing, and factory farming are of particular interest to vegetarians.

Stuart, Tristan. The Bloodless Revolution: A Cultural History of Vegetarianism from 1600 to Modern Times. New York: W. W. Norton & Co., 2006.

PERIODICALS

American Dietetic Association and Dietitians of Canada. ‘Position of the American Dietetic Association and Dietitians of Canada: Vegetarian Diets.’ Canadian Journal of Dietetic Practice and Research 64 (Summer 2003): 62–81.

Chakrabarty, G., R. L. Bijlani, S. C. Mahapatra, et al. ‘The Effect of Ingestion of Egg on Serum Lipid Profile in Healthy Young Free-Living Subjects.’ Indian Journal of Physiology and Pharmacology 46 (October 2002): 492–498.

Chavarro, J. E., J. W. Rich-Edwards, B. Rosner, and W. C. Willett. ‘A Prospective Study of Dairy Foods Intake and Anovulatory Infertility.’ Human Reproduction 22 (May 2007): 1340–1347.

Mannion, C. A., K. Gray-Donald, and K. G. Koski. ‘Association of Low Intake of Milk and Vitamin D during Pregnancy with Decreased Birth Weight.’ Canadian Medical Association Journal 174 (April 25, 2006): 1273–1277.

Reader Survey Results. Vegetarian Journal 17, no. 1 (January-February 1998). Available online at

Stahler, Charles. ‘How Many Adults Are Vegetarian?’. Vegetarian Journal, no. 4 (2006). Available online at http://www.vrg.org/journal/vj2006issue4/vj2006issue4poll.htm.

Willett, Walter, MD. ‘Lessons from Dietary Studies in Adventists and Questions for the Future.’ American Journal of Clinical Nutrition 78 (September 2003): 539S–543S.

OTHER

American Egg Board (AEB) fact sheet. Nutrient Breakdown. Available online at http://www.aeb.org/LearnMore/NutrientBreakdown.htm (accessed April 24, 2007).

Berkoff, Nancy, RD, EdD. Introduction to Vegetarian Nutrition and Food Service. Online tutorial available at http://www.vrg.org/berkoff/introduction.htm(accessed April 25, 2007).

Green Kitchen. Ovo-Vegetarian Recipes. Available online at http://userwww.sfsu.edu/%7Ejohnw/dai_527_2/public_html/website/index/ovo/index.html (accessed April 24, 2007).

Mayo Clinic Staff. Vegetarian Diet: A Starter’s Guide to a Plant-Based Diet. Rochester, MN: Mayo Clinic Foundation, 2006. Available online at http://www.mayocli-nic.com/health/vegetarian-diet/HQ01596.

Pals, Bart. Helping Poultry Breeders Raise Birds in an Urban Area. Available online at http://www.amerpoultryassn.com/newcityhall.htm (accessed April 24, 2007).

Seventh-day Adventist Dietetic Association (SDADA). A Position Statement on the Vegetarian Diet. Orlando, FL: SDADA, 2005. Available online at http://www.sdada.org/position.htm.

U.S. Department of Agriculture (USDA), Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 18. Available online at http://www.nal.usda.gov/fnic/foodcomp/Data/SR18/sr18.html.

Vegetarians in Paradise website. Airline Vegetarian Meals. Available online at http://www.vegparadise.com/airline.html (updated April 23, 2007; accessed April 28, 2007).

ORGANIZATIONS

American Dietetic Association (ADA). 120 South Riverside Plaza, Suite 2000, Chicago, IL 60606-6995. Telephone: (800): 877-1600. Website: http://www.eatright.org.

American Egg Board (AEB). 1460 Renaissance Drive, Park Ridge, IL 60068. Telephone: (847) 296-7043. Website: http://www.aeb.org The AEB represents factory-farm egg producers.

American Poultry Association. P. O. Box 306, Burgetts-town, PA 15021. Telephone: (724) 729-3459. This organization is a good source of information about backyard and urban poultry raising.

Dietitians of Canada/Les dietetistes du Canada (DC). 480 University Avenue, Suite 604, Toronto, Ontario, Canada M5G 1V2. Telephone: (416) 596-0857. Website: http://www.dietitians.ca.

North American Vegetarian Society (NAVS). P.O. Box 72, Dolgeville, NY 13329. Telephone: (518) 568-7970. Website: http://www.navs-online.org.

Seventh-day Adventist Dietetic Association (SDADA). 9355 Telfer Run, Orlando, FL 32817. Website: http://www.sdada.org. SDADA is an official affiliate of the ADA.

Vegetarian Resource Group (VRG). P.O. Box 1463, Dept. IN, Baltimore, MD 21203. Telephone: (410) 366-VEGE. Website: http://www.vrg.org/index.htm Publishes Vegetarian Journal,1 a quarterly periodical.

Rebecca J. Frey, PhD