Nutrition
Decades of experience, culminating in more than a million vegans today, have shown that appropriate vegan diets support good health at all stages of life and reduce the risk of heart disease. This has been confirmed by independent scientific studies.
The Vegan Society recommends a highly varied diet including both cooked and raw foods as the proven basis for vegan health, particularly for infants. See Plant Based Nutrition and Health by Stephen Walsh for more detailed information. This and other books can be obtained from the Vegan Society, as can Liz Cook's useful and attractive nutrition wall chart. The Vegan Society also provides lots of useful information which can be found throughout the site - please use the search tool at the top of the page to find information and be sure to check the related links section on each page you visit.
Like any other form of diet, some vegan diets are more nutritionally complete than others. White bread, hydrogenated margarine and chips qualify as a vegan meal, but too many such meals will remove the usual benefit of a vegan diet in reducing risk of heart disease. Bananas are a healthful food in moderation, but anyone trying to live on bananas alone is headed for deficiency in about ten important nutrients.
The starting principle for health is to eat a wide variety of plant foods, including plenty of strongly coloured vegetables and fruits. Each food has different strengths, so the fewer foods you eat the less likely it is that all your needs will be met. Vegetables and fruits provide plenty of many vital vitamins and minerals along with a host of other beneficial plant chemicals. In general, the stronger the colour the better. Dark green leaves such as kale and spring greens leave white cabbage, iceberg lettuce and cucumber in the shade. In conjunction with HealthPlus, we've produced a multivitamin - Veg1 - which contains the essential nutrients required by vegans - taken as part of a healthy vegan diet, it will help to ensure vegans get adequate daily supplies of recommended nutrients.
Over-processed foods that have lost much of their nutrient content or have been transformed into unnatural and harmful forms should be used sparingly, if at all. Hydrogenating vegetable oils is one of the worst forms of processing as it produces unnatural trans-fats which have an even worse effect than ordinary saturated fat in raising cholesterol and increasing heart disease risk. Hydrogenated fat is found in most fast foods, hard margarines, doughnuts and biscuits, and in some vegan sausages and burgers. Prefer unprocessed foods and products stating that there is no hydrogenated fat. Refined grains should not be a major part of a vegan diet, but whole grains are associated with many health benefits. At the same time, especially for the very old or very young, it is important not to overtax the body with more fibre than it is comfortable with: some people will fare much better with brown rice rather than wheat as a main grain as it is lower in fibre and very rarely associated with food allergies or intolerances.
In conventional nutrition, animal products are seen as a key source of protein, iron, zinc and vitamin B12, while dairy products are seen as a key source of calcium. However, zinc and iron are found in useful amounts in many whole grains, nuts, seeds and legumes and vegans are no more likely to become anaemic than anyone else. Protein is found in adequate amounts in most plant foods: it is fairly low in fruit, potatoes and rice, but particularly high in legumes. With regard to calcium,100 grams of spring greens, kale, mustard greens or Chinese cabbage provide about the same amount of retained calcium as a cup of cow's milk. If you eat a lot of these vegetables, you can be confident about your bone health. If you totally avoid such vegetables, two cups of fortified soya milk (about 300 milligrams calcium per cup) would be adequate. It is probably best to use both, as each has other benefits as well as calcium: the greens provide folate, vitamin K and vitamin C and the fortified soya milk provides protein in a particularly healthful form, usually together with vitamins B12 and D. One large serving of calcium-rich dark green vegetables and a cup of fortified soya milk per day is an excellent foundation. Along with plenty of other vegetables and fruits and unrefined grains, you can be confident that such a diet is providing most nutrients in abundance, including intakes of vitamin C, vitamin K, folate, potassium and magnesium greatly exceeding most omnivorous diets.
A very few nutrients need more specific consideration to ensure optimal intakes. If you don't use fortified soya milk, you should include some other food fortified with B12 each day or take a supplement. B12 is not reliably available from modern unfortified plant foods in the amounts required for optimal health, so take no chances: use fortified foods or supplements and make sure you get at least 3 micrograms per day.
Certain other nutrients are best provided by specific plant foods:
Iodine is provided by iodised salt in many countries, but for most people in Britain and Ireland the main source is dairy produce because iodine is routinely added to cattle feed and also used to treat udder infections in dairy cattle. Iodine can be readily obtained from kelp (about 15 grams spread over a year, or two kelp tablets a week, is about right). Low iodine intake can cause hypothyroidism leading to tiredness, skin problems, tingling sensations and elevated cholesterol.
Selenium intake can be conveniently assured by 100 grams of Brazil nuts per month. Omega-3 fatty acids can be boosted by a teaspoon of flaxseed oil (culinary linseed oil) per day. In the UK winter, the body cannot make vitamin D from sunlight and it may be beneficial for bone health to include about 5 micrograms of vitamin D2 in your daily diet. This can be obtained from about 10 grams of dried shitake mushrooms or from fortified foods or supplements.
Kelp, Brazil nuts and flaxseed oil are highly concentrated sources of nutrients, so taking more than double the suggested amount is not recommended: more is not better.
If following a raw food diet, it is vital to include a B12 supplement as no fortified foods will be consumed and B12 deficiency is common in raw food vegans not using supplements. A diet based on modern cultivated fruits (a pale shadow of the wild fruits eaten by our ape cousins) is not nutritionally adequate. At least 500 grams per day of dark green leafy vegetables or broccoli and at least 50 grams per day of nuts and seeds would need to be added to improve nutritional content.
Fair Use Source:
http://www.vegansociety.com/food/nutrition/
Useful links:
http://www.vegansociety.com/food/nutrition/
http://www.goveg.com/celebs.asp
http://www.youtube.com/watch?v=TAaFhKuMRgw&feature=related - Famous Vegetarians