Vegetarianism
Description	A vegetarian diet is derived from plants, with or without eggs or dairy.[1]
Origins	Ancient India, ancient Greece; 6th century BCE and earlier
Varieties	Ovo, lacto, ovo-lacto, veganism, raw veganism, fruitarianism, Buddhist vegetarianism

Vegetarianism encompasses the practice of following plant-based diets (fruits, vegetables, etc.), with or without the inclusion of dairy products or eggs, and with the exclusion of meat (red meat, poultry, and seafood). Abstention from by-products of animal slaughter, such as animal-derived rennet and gelatin, may also be practiced.^[2][3]

Vegetarianism can be adopted for different reasons. Many object to eating meat out of respect for sentient life. Such ethical motivations have been codified under various religious beliefs, along with the concept of animal rights. Other motivations for vegetarianism include health, political, environmental, cultural, aesthetic or economic. There are varieties of the diet as well: an ovo-vegetarian diet includes eggs but not dairy products, a lacto-vegetarian diet includes dairy products but not eggs, and an ovo-lacto vegetarian diet includes both eggs and dairy products. A vegan diet excludes all animal products, including eggs, dairy, and honey.

Various packaged or processed foods, including cake, cookies, chocolate and marshmallows, often contain unfamiliar animal ingredients, and may be a special concern for vegetarians due to the likelihood of such additions.^[4] Often, products are scrutinized by vegetarians for animal-derived ingredients prior to purchase or consumption.^[4] Vegetarians vary in their feelings regarding these ingredients, however. For example, while some vegetarians may be unaware of animal-derived rennet's role in the usual production of cheese and may therefore unknowingly consume the product,^[5][6] other vegetarians may not be bothered by its consumption.^[3] The results of a 2009 International survey suggest the standard definition of vegetarianism is different in different nations. Vegetarians in some nations consume more animal products than those in others.^[7]

Semi-vegetarian diets consist largely of vegetarian foods, but may include fish or poultry, or sometimes other meats on an infrequent basis. Those with diets containing fish or poultry may define "meat" only as mammalian flesh and may identify with vegetarianism.^[8][9][10] A pescetarian diet, for example, includes "fish but no meat".^[11] The common use association between such diets and vegetarianism has led vegetarian groups such as the Vegetarian Society to state that diets containing these ingredients are not vegetarian, due to fish and birds being animals.^[12]

Etymology[link]

The Vegetarian Society, founded in 1847, says that the word "vegetarian" is derived from the Latin word vegetus meaning lively or vigorous.^[13] Despite this, the Oxford English Dictionary (OED) and other standard dictionaries state that the word was formed from the term "vegetable" and the suffix "-arian".^[14] The OED writes that the word came into general use after the formation of the Vegetarian Society at Ramsgate in 1847, though it offers two examples of usage from 1839 and 1842.^[15]

History[link]

The earliest records of (lacto) vegetarianism come from ancient India and ancient Greece in the 6th century BCE.^[16] In the Asian instance the diet was closely connected with the idea of nonviolence towards animals (called ahimsa in India) and was promoted by religious groups and philosophers.^[17] Among the Hellenes, Egyptians and others, it had medical or Ritual purification purposes.

Indian emperor Ashoka asserted protection to fauna:

Vegetarian label used in India on packed foodstuff

Following the Christianisation of the Roman Empire in late antiquity, vegetarianism practically disappeared from Europe as it was in other Continents, except India.^[18] Several orders of monks in medieval Europe restricted or banned the consumption of meat for ascetic reasons, but none of them eschewed fish.^[19] (The medieval definition of "fish" included such animals as seals, porpoises, dolphins, barnacle geese, puffins, and beavers.)^[20]

It re-emerged during the Renaissance,^[21] becoming more widespread in the 19th and 20th centuries. In 1847, the first Vegetarian Society was founded in the United Kingdom;^[22] Germany, the Netherlands, and other countries followed. The International Vegetarian Union, a union of the national societies, was founded in 1908. In the Western world, the popularity of vegetarianism grew during the 20th century as a result of nutritional, ethical, and more recently, environmental and economic concerns.

Varieties of vegetarianism[link]

Roadside café near Kullu, India.

There are a number of types of vegetarianism, which exclude or include various foods.

• Ovo vegetarianism includes eggs but not dairy products.
• Lacto vegetarianism includes dairy products but not eggs.
• Ovo-lacto vegetarianism (or lacto-ovo vegetarianism) includes animal/dairy products such as eggs, milk, and honey.
• Veganism excludes all animal flesh and animal products, including milk, honey, and eggs, and may also exclude any products tested on animals, or any clothing from animals.^[23]
• Raw veganism includes only fresh and uncooked fruit, nuts, seeds, and vegetables. Vegetables can only be cooked up to a certain temperature.^[24]
• Fruitarianism permits only fruit, nuts, seeds, and other plant matter that can be gathered without harming the plant.^[25]
• Buddhist vegetarianism (also known as su vegetarianism) excludes all animal products as well as vegetables in the allium family (which have the characteristic aroma of onion and garlic): onion, garlic, scallions, leeks, or shallots.
• Jain vegetarianism includes dairy but excludes eggs and honey, as well as root vegetables.
• Macrobiotic diets consist mostly of whole grains and beans.

Within the 'ovo-' groups, there are many who refuse to consume fertilized eggs (with balut being an extreme example), however such distinction is typically not specifically addressed.

Some vegetarians also avoid products that may use animal ingredients not included in their labels or which use animal products in their manufacturing; for example, sugars that are whitened with bone char, cheeses that use animal rennet (enzymes from animal stomach lining), gelatin (derived from the collagen inside animals' skin, bones and connective tissue), some cane sugar (but not beet sugar) and apple juice/alcohol clarified with gelatin or crushed shellfish and sturgeon, while other vegetarians are unaware of such ingredients.^[4][5][6]

Individuals may describe themselves as "vegetarian" while practicing a semi-vegetarian diet,^[10][26][27] as some dictionary definitions pertaining to vegetarianism vary and include the consumption of fish,^[9] while other definitions exclude fish and all animal flesh.^[12] In other cases, individuals may describe themselves as "flexitarian".^[26] These diets may be followed by those who reduce animal flesh consumed as a way of transitioning to a complete vegetarian diet or for health, environmental, or other reasons. Semi-vegetarian diets include:

• pescetarianism, which includes fish and some other forms of seafood;
• pollotarianism, which includes poultry;
• "pollo-pescetarian", which includes poultry and fish, or "white meat" only;
• macrobiotic diets consisting mostly of whole grains and beans, but may sometimes include fish.

Semi-vegetarianism is contested by vegetarian groups who state that vegetarianism excludes all animal flesh.^[12]

Health benefits and concerns[link]

Scientific endeavors in the area of vegetarianism have shifted from concerns about nutritional adequacy to investigating health benefits and disease prevention.^[28] The American Dietetic Association and Dietitians of Canada have stated that at all stages of life, a properly planned vegetarian diet is "healthful, nutritionally adequate, and provides health benefits in the prevention and treatment of certain diseases." Large-scale studies have shown that mortality from ischaemic heart disease was 30% lower among vegetarian men and 20% lower among vegetarian women than in non-vegetarians.^[29][30][31] Necessary nutrients, proteins, and amino acids for the body's sustenance can be found in vegetables, grains, nuts, soymilk, eggs and dairy.^[32] Vegetarian diets offer lower levels of saturated fat, cholesterol and animal protein, and higher levels of carbohydrates, fibre, magnesium, potassium, folate, and antioxidants such as vitamins C and E and phytochemicals.^[33][34]

Vegetarians tend to have lower body mass index,^[35] lower levels of cholesterol, lower blood pressure, and less incidence of heart disease, hypertension, type 2 diabetes, renal disease, metabolic syndrome,^[36] dementias such as Alzheimer’s disease and other disorders.^[37] Non-lean red meat, in particular, has been found to be directly associated with increased risk of cancers of the esophagus, liver, colon, and the lungs.^[38] Other studies have shown no significant differences between vegetarians and non-vegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, breast cancer, or prostate cancer.^[30] A 2010 study compared a group of vegetarian and meat-eating Seventh Day Adventists in which vegetarians scored lower on depression tests and had better mood profiles.^[39] However, vegetarians are more likely to be deficient in vitamin B12, leading to increased incidence of osteoporosis^[40] and depression.^[41]

The 2010 version of Dietary Guidelines for Americans, a report issued by the U.S. Department of Agriculture and the U.S. Department of Health and Human Services every five years states:

In prospective studies of adults, compared to non-vegetarian eating patterns, vegetarian-style eating patterns have been associated with improved health outcomes—lower levels of obesity, a reduced risk of cardiovascular disease, and lower total mortality. Several clinical trials have documented that vegetarian eating patterns lower blood pressure.

On average, vegetarians consume a lower proportion of calories from fat (particularly saturated fatty acids); fewer overall calories; and more fiber, potassium, and vitamin C than do non-vegetarians. Vegetarians generally have a lower body mass index. These characteristics and other lifestyle factors associated with a vegetarian diet may contribute to the positive health outcomes that have been identified among vegetarians.^[42]

Nutrition[link]

A fruit stall in Barcelona

Western vegetarian diets are typically high in carotenoids, but relatively low in long-chain n-3 fatty acids and vitamin B₁₂. Vegans can have particularly low intake of vitamin B and calcium if they do not eat enough items such as collard greens, leafy greens, tempeh and tofu (soy). High levels of dietary fiber, folic acid, vitamins C and E, and magnesium, and low consumption of saturated fat are all considered to be beneficial aspects of a vegetarian diet.^[43][44]

Protein[link]

Protein intake in vegetarian diets is only slightly lower than in meat diets and can meet daily requirements for any person, including athletes and bodybuilders.^[45] Studies at Harvard University as well as other studies conducted in the United States, United Kingdom, Canada, Australia, New Zealand and various European countries, confirmed vegetarian diets provide sufficient protein intake as long as a variety of plant sources are available and consumed.^[46] Proteins are composed of amino acids, and a common concern with protein acquired from vegetable sources is an adequate intake of the essential amino acids, which cannot be synthesised by the human body. While dairy and egg products provide complete sources for ovo-lacto vegetarians, the only vegetable sources with significant amounts of all eight types of essential amino acids are lupin beans, soy, hempseed, chia seed, amaranth, buckwheat, peanut butter, and quinoa. However, the essential amino acids can also be obtained by eating a variety of complementary plant sources that, in combination, provide all eight essential amino acids (e.g. brown rice and beans, or hummus and whole wheat pita, though protein combining in the same meal is not necessary). A 1994 study found a varied intake of such sources can be adequate.^[47]

Iron[link]

Vegetarian diets typically contain similar levels of iron to non-vegetarian diets, but this has lower bioavailability than iron from meat sources, and its absorption can sometimes be inhibited by other dietary constituents.^{[citation needed]} Vegetarian foods rich in iron include black beans, cashews, hempseed, kidney beans, lentils, oatmeal, raisins, spinach, black-eyed peas, soybeans, many breakfast cereals, sunflower seeds, chickpeas, tomato juice, tempeh, molasses, thyme, and whole-wheat bread.^[48] The related vegan diets can often be higher in iron than vegetarian diets, because dairy products are low in iron.^[44] Iron stores often tend to be lower in vegetarians than non-vegetarians, and a few small studies report very high rates of iron deficiency (up to 40%,^[49] and 58%^[50] of the respective vegetarian or vegan groups). However, the American Dietetic Association states that iron deficiency is no more common in vegetarians than non-vegetarians (adult males are rarely iron deficient); iron deficiency anaemia is rare no matter the diet.^[51]

[edit] Vitamin B₁₂

Plants are not sources of vitamin B₁₂. According to the United States National Institutes of Health, natural food sources of vitamin B₁₂ are limited to foods that come from animals.^[52] Lacto-ovo vegetarians can obtain B₁₂ from dairy products and eggs, and vegans can obtain it from fortified foods (including some soy products and some breakfast cereals) and dietary supplements.^{[53][54][55][56]} Vitamin B₁₂ can also be obtained from yeast extract products.^[57] The research on vitamin B₁₂ sources has increased in recent years.^[58]

The recommended dietary allowance of B₁₂ in the United States is, per day, 0.4 mcg (0–6 months), rising to 1.8 mcg (9–13 years), 2.4 mcg (14+ years), and 2.8 mcg (lactating female).^[52] The body can preserve stores of B₁₂ for up to 30 years,^[59] and reuses the vitamin without destroying the substance. Clinical evidence has shown a deficiency of B₁₂ in vegans and, to lesser degree, vegetarians.^[40][60]

Fatty acids[link]

Plant-based, or vegetarian, sources of Omega 3 fatty acids include soy, walnuts, pumpkin seeds, canola oil, kiwifruit and especially hempseed, algae, chia seed, flaxseed, echium seed and purslane. Purslane contains more Omega 3 than any other known leafy green. Plant foods can provide alpha-linolenic acid but not the long-chain n-3 fatty acids EPA and DHA, which are found in low levels in eggs and dairy products. Vegetarians, and particularly vegans, have lower levels of EPA and DHA than meat-eaters. While the health effects of low levels of EPA and DHA are unknown, it is unlikely that supplementation with alpha-linolenic acid will significantly increase levels.^{[61][clarification needed]} Recently, some companies have begun to market vegetarian DHA supplements containing seaweed extracts. Similar supplements providing both DHA and EPA have also begun to appear.^[62] Whole seaweeds are not suitable for supplementation because their high iodine content limits the amount that may be safely consumed. However, certain algae such as spirulina are good sources of gamma-linolenic acid (GLA), alpha-linolenic acid (ALA), linoleic acid (LA), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA).^[63][64]