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| Thursday, 26 August 2004 |
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Are vegetarians prone to develop anaemia? by Dr. D. P. Atukorale What is Anaemia? Anaemia literally means "lack of blood" More precisely the word is used to denote reduction in oxygen - carrying capacity of the blood which can be caused in 3 main ways: (a) loss of blood (e.g. haemorrhoids, heavy menstrual periods); (b) excessive red cell destruction; (c) defective red blood formation. Oxygen is held within the red cell (RBC) by the pigment haemoglobin (Hb) which transports oxygen from the lungs to body cells and returns waste carbondioxide (Co2) from the cells to the lungs.
About 20 percent of oxygen used each day is used by the human brain. Fatigue and mental dullness occur when the brain does not get enough oxygen. If the Hb level drops the heart rate will speed up and you will start panting on mild exertion. Replacement of the Hb requires iron in the diet as well as vitamin B12 and folic acid. If any of these are inadequately present or are inadequately absorbed, anaemia will result. There are many kinds of anaemia, but the commonest type of anaemia is iron deficiency anaemia which is thought to be a nutritional problem. How can vegetarian diet prevent anaemia? After all vegetarians don't eat red meat do they? You may be surprised to know that despite the meat industry propaganda, the facts reveal that a healthy vegetarian diet is an excellent way to get all the iron and folic acid and vitamin C you need. Since anaemia can result from an inadequate intake of iron, vitamin B 12 and folic acid it is alleged that vegetarians are risking their health and are condemned to become anaemic. But is this true? Iron deficiency anaemia is uncommon in men but more widespread in women especially during child bearing period i.e. before menopause. Blood loss due to excessive bleeding during menstrual periods is the most common cause of iron - deficiency anaemia among the women and iron deficiency anaemia is a problem affecting both vegetarians and non vegetarians alike in all countries including Sri Lanka. Other primates such as chimpanzees eat vegetarian diet and these animals don't get anaemia. Vegetarian and vegan diet is well capable of providing normal iron requirements which are normally obtain from dark green leafy vegetables and whole grain. Radical new evidence suggests that over-consumption of iron-rich foods such as red meat may in fact be a health hazard and that people with elevated blood iron (serum ferritin) are prone to heart attacks. There are large number of research studies such as the British Vegetarian Study, The British Vegan Report, studies done in Israel, Holland, Sweden, Canada and China comparing the haemoglobin (Hb) levels of vegetarians and meat eaters to show that vegetarians are not prone to anaemia. The Chinese study which involved 6,500 vegetarians, showed that meat eating is by no means necessary to prevent iron deficiency anaemia. In 1988, the American Dietetic Association (ADA) concluded "With both Vegetarian and non vegetarian diet, iron and folate supplements are usually necessary during pregnancy although vegetarians frequently have greater intake of those nutrients than do non-vegetarians". All the research studies disprove the fallacy that a meat free diet cant provide enough iron. It certainly can. Other dietary anaemias Besides iron, folic acid (vitamin B9) and vitamin B12 play an essential part in regular replacement of Hb in the blood. Folic acid deficiency is widespread globally and body does not store folic acid unlike iron. The good news for vegetarians is that folic acid is present in many common green leafy vegetarian foods and it is not present in most meat, fish, milk and root vegetables. For all practical purposes, folic acid deficiency anaemia does not occur in vegetarians although folic acid supplements are given to both vegetarians and meat eaters during pregnancy to prevent neural tube defects in the foetus. Almost all Sri Lankan vegetarians are lacto-vegetarians who take milk, curd and milk products which contain vitamin B12. The amount of B12 needed in the diet is 1.5 micrograms (one million of a gram) per day. B12 deficiency does not exist in lacto-vegetarians. Vegan do not consume milk but B12 deficiency has not yet been documented in our vegetarians and vegan as far as I am aware. B12 is almost always manufactured by bacteria. The bacteria in our gut, mouth, around teeth and gums, nasal passages and around tonsils may all produce B12. But it is advisable for vegans to take a vitamin tablet containing B12 periodically. The commonest type of B12 deficiency anaemia is pernicious anaemia which is caused by an inability to absorb vitamin B12 from our gut. Pernicious anaemia which is a relatively common haematological problem in the West,is extremely rare in Sri Lanka. In the West pernicious anaemia occurs among both vegetarians and non vegetarians and is not due to vegetarian diet. Science of nutrition just like any other branch of human knowledge is full of its own folklore. Majority of laymen and doctors both in Sri Lanka and abroad believe that vegetarians are likely to be anaemic and these fallacies are passed down from one generation of practitioners to another because they should plausible, because no one bothers to check or question the original research in the field and if they do, they would be in for quite a shock. A computer search reveals that in the period 1966 to 1994 a total of 7,618,328 major medical journals (Medline database published by the US National Library of Medicine) were published. Of these just sixty two mentioned the world anaemia in connection with the worlds vegetarians or vegan. That is just under 0.000814 per cent of the medical literature in 28 years. Not very much is it? Most of the above 62 reports dealt with iron deficiency anaemia in impoverished Indians and their anaemia was found to be due to poverty. As mentioned earlier that vegetarians are prone to anaemia is a common myth among laymen and doctors including specialists. Anaemia in both vegetarian and non-vegetarian women is more common before menopause as mentioned earlier. In any middle aged or elderly vegetarian with anaemia, before diagnosing anaemia due to vegetarian diet, an underlying disease such as cancer has to be excluded. I know of an elderly vegetarian lady with anaemia who has been pumped with iron and vitamin B12 injections and given vitamin B9 (folic acid), pyridoxine and vitamin C with no response to above treatment. Ultimately this lady was brought to me by a friend as she had dyspnoea and as her cardiovascular system was normal I referred her to a general surgeon who subjected her to endoscopy and diagnosed a growth in her large gut. She was subjected to surgery and after removal of the growth she recovered from anaemia and now she is active and normal and continues to take her vegetarian diet. In summary: (a) Iron deficiency anaemia is a widespread problem particularly in women (both vegetarian and non vegetarian) and commonly occurs before menopause. (b) Eating a vegetarian diet does not increase the risk of anaemia and a healthy meat free diet includes several source of iron such as lentils (dhal), spinach "gotukola", sesame seed (gingili), beet, cashew nuts, cabbage, molasses, soya, pumpkin, cocoa, wheat, lima beans and ginger root. (c) The body naturally regulates absorption of dietary iron according to our needs. Taking too much iron can cause disease. (d) Eating foods rich in vitamin C (such as fresh vegetables and fruits) will enhance iron-bio-availability. Vit C is available only in vegetarian diet and is not found in fish and meat. (e) Plant-based foods are superior to meat-based ones because they furnish us with all the iron normally necessary which naturally protects us from health hazards associated with iron overload such as coronary heart disease. |
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