Vegetarianism probably originated in India. It is certainly in India that most vegetarians live nowadays. In the 3rd century BC the great Indian emperor Ashoka was one of the first to promote vegetarianism on a large scale.
Types of vegetarian
In general a vegetarian can be considered as someone who avoids all red and white meat as well as fish and offal. Ethically this is basically not eating something that requires an animal to be killed. However many vegetarians will eat products that use by-products of animal slaughter.
In terms of increasing levels of restriction:
These people will eat perhaps fish and white meat. Often the restriction will be for health reasons. Ethically some may avoid mammals and accept that more distant genetic relations like birds and fish may be on the menu.
Vegetarians can be lacto- (eating dairy), ovo- (eating eggs) or lacto-ovo (eating eggs and dairy) depending on their attitude to dairy produce and eggs. Most vegetarians I come across in the UK are lacto-ovo. Eggs contain chicken embryos, and so ethically a distinction is drawn between unborn and born animal life. Dairy produce involves animal husbandry and is considered to cause suffering and premature death.
Products derived from the slaughter of animals such as rennet (typically from cows intestinal linings), and gelatin (typically from animal bones) may be avoided by some vegetarians.
Vegans do not consume dairy produce or eggs. They will also avoid honey (food destined for baby bees). Vegans and many vegetarians will also avoid any products tested on animals, clothes produced from animals (silk, leather and wool) and oppose animals being used in sport, research and entertainment.
Like vegans only nuts, seeds, vegetables and fruit will be eaten. However there is a restriction on cooking temperatures also. Ethically it is hard to see a rationale for not cooking plants. The main reasons for following a raw vegan diet seem to be based on health considerations.
Fruitarians consume nuts seeds and fruit only. Ethically the motivation is not to kill the plant, and so only fruit, nuts and seeds that don't require a plant to be uprooted are consumed.
Certain religions, such as Jainism (founder pictured to the left), Bhuddism and subsets of Hinduism have dietary restrictions. Jains are basically lacto-vegetarians that exclude root vegetables also. Bhuddists often prefer not to kill animals and this may lead to various forms of vegetarianism. Some in Taiwan avoid plants of the allium family (onions and garlic).
Some Hindus may stick to foods that are sattvic, which equates perhaps to pure and uncontaminated. The diet is basically lacto-vegetarian with avoidance of stimulants such as tea, coffee and chocolate as well as mushrooms, fermented foods and alcohol.
Is it healthy to be vegetarian?
A question with a big qualification. It depends what you are already eating. For those with a poor diet and lifestyle vegetarianism may extend lifespan. However the biggest factor linking vegetarianism and increased life expectancy is likely to be that vegetarians smoke and drink less than non-vegetarians, while consuming more vegetables.
For perfect health
Ultimately, by restricting your available food groups you are restricting the potential health benefits you can get from foods. Animal products contain nutrients that are very similar in make up to our own bodies. There are a number of key nutrients that are better consumed in an omnivorous diet. Iron, vitamin B12, long chain fatty acids and fat soluble vitamins are not available in optimal amounts in vegetarian and vegan diets, and supplementation should be given consideration with the help of a qualified nutrtional expert.
Heme iron, the most absorbable form of iron is not found in plants. Plant iron is harder to absorb as it can be bound to other substances such as phytate in the gut. For vegetarians, especially menstruating women and runners it is important to avoid eating rich sources of iron with inhibitors of its absorption. Inhibitors include phytate, found in nuts, seeds and grains, tannins found in tea and oxylates found in spinach and rhubarb.
It is also a good idea to consume sources of iron with nutrients such as vitamins, A and C, found in green leafy vegetables, which can help with its absorption. Cooking with iron cookware can also help build up iron levels over time. Curry powder and tomato juice are good sources of iron.
This is another substance that is not found in plants. Vegans, but also vegetarians are at substantially increased risk of vitamin B12 deficiency(1). This can lead to elevated levels of homocysteine, which is associated with cognitive decline and risk of heart attack. It is commonly thought in vegetarian circles that spirulina, seaweed and brewer's yeast contain B12. They do, but not very much of it in an active form(2). I would advise taking a supplement or fortified foods rather than relying on spirulina, seaweed and brewer's yeast.
If consuming shellfish such as clams or oysters is acceptable, then you can top up on B12 and zinc once per month from these B12 rich creatures.
Long chain fatty acids and cholesterol
The anti-inflammatory effects of omega 3 fatty acids are well known. While an omega 3 fatty acid called linolenic acid is found in flax seeds and other plants, the much more effective and longer chain versions, called EPA (eicosapentanoic acid) and DHA (docosahexanoic acid), are found in animal tissues, and in particular in oily fish.
For some vegans a lack of cholesterol could be problematic. While we make our own, a few people do not make enough cholesterol and could be at risk of pschological problems if they do not eat eggs.
Fat soluble vitamins
For vegans, avoiding eggs and dairy reduces the amount of vitamins A, D, E and K in the diet. This is potentially serious as these vitamins are vital for health and most people do not consume enough of them anyway. Vitamin D you get from the sun, so there is not so much of concern if you get outside a lot. Vitamin E is present in nuts and seeds and their oils. However vitamin K2 is not so easy to obtain. I recommend that you consider consuming the fermented soybean product called natto if you do not eat dairy produce.
Adequate amounts of protein are available in a vegetarian diet so long as it is properly constructed. There are two main issues. Firstly is there enough protein and secondly is the mix of amino acids that makes up the protein adequate to enable your body to produce its own proteins.
To ensure you get enough protein it is worth emphasizing high protein foods such as nuts seeds, eggs and dairy.
For those not eating many calories the mix of amino acids in foods should be considered. Ther are 20 amino acids used to build protein in our body 8-10 of these are essential in the diet as we cannot create them ourselves. When we make our own proteins it is like writing a book using letters. The amino acids are the letters and the book is the protein. If any amino acid is not available when needed we will be in trouble as we will not be able to produce the protein. For vegans lysine is the amino acid most likely to be in short supply(3). Eat plenty of lentils, nuts and beans to ensure you are getting enough of this.
Is being vegetarian good for the planet?
Despite the claims of many vegetarians and vegans there is no clear cut answer to this. The way you produce your meat or crops is the critical factor. Some methods are unsustainable, while others are fully sustainable. The average vegetarian may cause less environmental degradation than the average carnivore, but clearly there are ways to eat meat sustainably, and equally to be a vegetarian and indirectly cause environmental destruction.
A far better approach to saving the environment is to source food as locally as possible and reduce food miles, eat minimally processed food and avoid foods that are known to cause environmental damage.
There are many problems with fishing practices throughout the world. One problem is the needless destruction of fish through bycatch - where unwanted fish are caught in the net and then dumped back in the sea after perishing. Another problem is the virtual complete destruction of the seabed through bottom trawling.
Fish consumption needn't entail these damaging methods however. It all depends on how they are caught and the health of the fishery from which they come.
While meat may require land resources to sustain it, the amount needed need not be as great as some think. For instance the claim that livestock produce more carbon dioxide than cars(4), producing 18% of the worlds emissions is highly suspect. The truth may be nearer to 3%(5).
The impact on water levels in red meat production also depend on the area in which the meat is produced, for instance if it rains a lot no additional water may be used at all. Also the production method has an impact, with the less intensive systems being less water hungry(6).
Soy and Palm
Soya plantations are associated with massive rainforest destruction in the Amazon(7), and palm oil production is associated with the same in the Indonesian rainforests(8).
There are plenty of examples of vegetarian foods that are associated with environmental destruction. Again, like the meat and fish above, they needn't be, it is just a case of ensuring that they are sourced in an environmentally friendly manner.
I eat meat and fish. I do so because I believe it is healthier for me. I also believe that by eating this meat and fish I'm not harming the environment irreparably. As such I do try and buy my food from local suppliers rather than supermarkets.
What do I think of vegetarians? Well, I respect their views. The value of life is a philosophical issue, and even the fruitarian argument of not killing plants I understand. Unfortunately for fruitarians though, it clearly is a diet that is almost impossible to stay healthy with. Lacto-ovo vegetarians however can live healthy lives, especially if they construct their diet carefully. The same is also true for meat eaters of course.
I do get annoyed by vegetarians arguing that it is inherently healthier or better for the environment to be vegetarian. They are wrong. However, if I was a vegetarian I would probably make the very arguments I object to. It would make a lot of sense if I was trying to save the lives of innocent animals!