What is vegetarianism?

• Vegetarianism is the term used by Britons in 1842 to describe their practice of avoiding meat.

• Probable reasons for the practice:

• Religion • Compassion • Parental influence • Respect for the dignity of animal life, Dislike the taste • Body image • Health related (hormone, chemicals, saturated fat, diseases etc.) • Cost incurred • Fashion Variety of vegatarianism

• Different types of vegetarianism could be described on the basis of the degree of dietary restrictions as follows.

1. Fruitarianism:

The practice of restricting food intake to raw or dried fruits, nuts and honey.

2. Strict vegetarian (vegan):

A person whose food intake is limited only to plant foods. Variety of vegetarianism (contd)…

3. Lacto-vegetarian: A person who consumes milk and dairy products in addition to plant foods.

4. Ovo-vegetarian: A person who consumes eggs and egg products in addition to plant foods.

5. Lacto-ovo vegetarian:

A person who takes dairy products and eggs in addition to plant foods. Variety of Vegatarianism (contd)…

6. Semi-vegetarian:

A person who eats fish with or without restriction of dairy and eggs products.

Nutritional Considerations: In general more restrictive the diet is, the greater the chance that a deficiency will develop.

• Because of the bulkiness of vegetarian diet, young children may have a difficulty in obtaining enough energy before they becomes full.

• Consequently, proteins may be inefficiently used. Nutritional Considerations

• Hence careful planning is essential. • Cases have been reported of vegetarian children

with rickets, vitamin B12 deficiency, Ca imbalance and general under-nutrition.

The Vegan diet:

• Vegan diet tends to be low in calcium, Vitamin D,

Vitamin B12, riboflavin and Zn.

• Dairy foods are the major source for Ca and riboflavin. Ca absorption from vegan diet is low due to the presence of phytic acid (cereals), oxalic acid (vegetables), fibre and low intake of vitamin D. Nutritional Considerations

• Zn from plants is also poorly absorbed.

Protein:

• The amount and quality of protein could be low.

• Some non-meat protein sources are not well digested because of high fibre content. E.g. young children do not digest beans well

• Pulses contain anti-nutritional factors

• Infants wean on to vegan diets may not be able to consume enough energy due to their small stomach capacity and the limits on the kind of food. Nutritional Considerations

• Small children should not be put on a strict vegetarian diet unless medical and nutritional expertise is available to supervise the diet and monitor the child’s health.

• If the diet is carefully planned, however, the energy and protein requirement can be met.

• Vitamin B12 is available with only animal products (meat, milk, eggs) and is required for:

• maturation of RBC. • Synthesis of myelin sheath of nerve cells. Nutritional Considerations

• Vegans are at-risk of vitamin B12 deficiency. But very few vegans have shown the deficiency.

• Human body can store vitamin B12 sufficient to last for 5 years.

• Vitamin B12 requirement is very low • When stores are depleted body is more efficient in reabsorbing the vitamin • Deficiency could be masked by high intake of folic acid

• Some non-animal origin foods also contain Vit. B12

However, it is safer to recommend Vit. B12 fortified foods or Vit. B12 supplements (5 μg/d) for strict vegetarians. Nutritional Considerations Lacto-ovo vegetarianism:

• Offers no risk to children or adults with regard to protein or energy. • Iron may present a problem.

In a study, the nutrient intake of lacto-ovo vegetarians, fish eaters and meat eaters was compared.

• Fish eaters and lacto-ovo vegetarians consumed many foods of high nutrient density • The energy intake was similar in all 3 groups but vegetarians had a higher intake of carbohydrates vitamin C, vitamin B1, Ca, P, and Fe. • Meat eaters had more obesity. Health Considerations

• Vegetarianism, if practiced intelligently, can be a healthy way to eat.

• Young children on strict vegetarian diets may grow slow (low heights and weights)

• On the other hand vegetarianism can promote health in many ways.

• The health promoting properties of vegetarian diets have been universally accepted. Health Considerations (contd..)

• Consumption of a diet of whole grains, legumes, vegetables, fruits and nuts with avoidance of meat and high fat animal products, along with a regular exercise program is consistently associated with:

• Low blood cholesterol • Low blood pressure • Less cancer • Less obesity • Less heart disease and stroke • Less diabetes • Less overall mortality Cancer Protection World Cancer Research Fund Report (1997):

• Risk of cancer is lowered by plant based diets rich in a variety of vegetables and fruits, legumes and minimally processed starchy foods and limiting the intake of grilled, cured and smoked meat or fish.

• Grilling, curing and smoking produce polycyclic aromatic hydrocarbons and heterocyclic amines which are carcinogenic.

• About three-dozen plant foods have been identified as possessing cancer preventive phytochemicals.

• They include carrots, celery, citrus, tomato, cucumber, grapes, soya beans, berries, brown rice, whole wheat, oats, flax seed, nuts: hazel nut, almonds, walnuts, macademia nuts, peanuts, herbs: garlic, onions, cloves, ginger, turmeric, dill, thyme, basil, oregano, rosemary etc Cancer Protection

The anti-cancer phytochemicals include: carotenoids, flavanoids, isothiocyanates, isoflavones, catechins, ellagic acid, curcumins, lignans, liminoids, phenolic acids, pthalides, saponins, phytosterols, sulfide compounds, terpenoids, tocotrienols etc.

These phytochemicals might:

• alter metabolic pathways and hormonal actions associated with development of cancer

• stimulate immune system

• have anti-oxidant activity. Heart disease protection Italian study found that regular fruit and vegetable consumption reduces the risk of ischemic heart diseases;

• 21% reduction in myocardial infarction • 11% reduction in angina (Am J Clin Nutr 1997)

A British study found that the daily consumption of fresh fruits was associated with:

• 24% reduction in mortality from CHD • 32% reduction in mortality from CVD compared with less frequent fruit consumption (BMJ 1996) Heart disease protection

Healthy volunteers who consumed a vegetarian diet (25% calories as fat) that was rich in green leafy vegetables, other low calorie vegetables, beans, fruits, and nuts experienced, after two weeks,

• 25% reduction in total cholesterol • 33% reduction in LDL cholesterol • 20% reduction in triglycerides • 21% reduction in total / HDL cholesterol ratio (Metabolism 1997) Heart disease protection

• Factors in fruit and vegetable that protect against CHD include dietary fibre, folic acid, K, Mg, carotenoids, phytosterols,flavonoids, and polyphenolic antioxidants.

• Vegetarian diets are low in saturated fat and cholesterol, and are rich in soluble fibre.

Flavonoids are potent antioxidants which can: – prevent LDL cholesterol from oxidation – inhibit formation of blood clots – have hypolipidemic properties – have anti-inflammatory action Heart disease protection • Carotenoids are powerful antioxidants that can quench free radicals and protect against cholesterol oxidation, suppress cholesterol synthesis and increase LDL receptor activity

• Anthocyanin pigments found in fruits are very effective in scavenging free radicals, inhibiting LDL oxidation and platelet aggregation.

• Various terpenoids in fruits and vegetables and tocotrienols in nuts and seeds facilitate lower blood cholesterol levels by inhibiting HMG CoA reductase (cholesterol synthesis)

• Nuts are high in fat but low in saturated fat and rich in monounsaturates. Heart disease protection

• Nuts contain vitamins, minerals and other substances necessary for CV health. E.g. K, Mg, Cu, fibre, Vitamin E, folic acid, phytosterols, flavonoids, tocotrienols etc.

• Frequent consumption of nuts are associated with 30-60% reduction in CHD. They lower LDL cholesterol (Nutr Rev 2001)

• Research done in University of Peradeniya also confirms that vegan diet has a less risk of CHD compared to omnivorous diet. Lipid profile of people around Peradeniya

TC LDL HDL TC/HDL Group No (mg/dl) (mg/dl) (mg/dl) ratio

Omnivores 73 208 141 42 5.2

Lacto-ovo 17 195 131 44 4.8 vegetarians

Lacto- 41 194 125* 42 4.7 vegetarians

Vegans 19 186* 127* 42 4.4* Vegetarian diet and other diseases

• Higher consumption of nuts (JAMA 2002) and whole grains (Am J Clin Nutr 2002) have been associated with lower rates of diabetes

• An increased consumption of fruits and vegetables appear to reduce diabetes (Eur J Clin Nutr 2001)

• Osteoporosis condition is low among vegetarians. Lacto-ovo vegetarians have only half of the bone loss seen in 60-90 year-old meat eaters How to plan a vegetarian diet ? Meat alternatives:

• Major concern is planning a vegetarian diet is to allow enough high quality protein.

Two criteria have to be met.

• The amount of protein provided by meat and the plant foods has to be the same (protein quantity criteria).

• The pattern of 8 EAA must be similar to those required by human beings (protein quality criteria).

Ways to replace flesh protein

1. Direct substitution of flesh foods with other high quality animal proteins (e.g. milk, cheese, eggs). Excellent in quality, better used than meat.

2. Small quantity of high quality animal proteins (milk, eggs) with a larger quantity of plant proteins (beans, grains).

3. Combination of different plant protein foods with mutually complementary AA paterns. E.g. legumes and cereals (soyabean + rice; beans + bread)