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Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets The Comparative Anatomy of Eating So Much for the Hunter/Gatherer Theory Vegetarian & Vegan Related Quotes Fight Global Warming by Going Vegetarian
Staying a Healthy Vegan by Jack Norris, RD Updated April 18, 2003 Summary: * Introduction Introduction The vegan diet appears to be a relatively new experiment in the history of human eating. It has only been since the mid-1940s that it has been practiced in an organized fashion in the Western world. So far, the experiment appears to be successful: vegans in developed countries have been shown to have the same overall mortality rates as meat-eaters with healthy lifestyles (low smoking andalcohol intake).2 These mortality rates (deaths per year before age 90) are about 50% lower than those of the general population.2 However, there are areas where vegans' health can be improved. This article has three purposes: * To help people make the transition to a vegan diet. I also wrote this article to provide information that other Vegan Outreach members and I wish we had known when we became involved in promoting veganism. Vegan Outreach promotes a vegan diet in order to lessen the suffering of animals. Since the average American consumes thousands of animals over the course of a lifetime, each person who goes vegan makes a difference by removing their support from the factory farming and slaughtering of these animals. For this reason, I have been involved in vegan advocacy for over a decade. During my years of outreach, I have been told by many people that they tried to be vegetarian or vegan, but hadn't felt healthy. I found this troubling. How can we prevent animal suffering by promoting a vegan diet for our society if some people do not respond well to it? Finding an answer to this problem was a major motivation for my becoming a registered dietitian. In researching the subject, I discovered that some claims about the vegan diet include distortions or omissions which can lead to people having poor experiences. For example, some vegan advocates emphasize that humans need only small amounts of B12 and that it can be stored in the body for years. It is true that, at the time they become vegan, some people have enough B12 stored in their liver to prevent serious B12 deficiency for many years. However, people often misinterpret this to mean that you only need to consume a tiny amount of B12 once every few years. Actually, to build up such stores, it takes many years of consuming B12 beyond one's daily needs. Many people do not have large enough stores of B12 to be relied upon even for short periods. This is an easy problem to solve by simply eating B12-fortified foods or taking a supplement. Nutritional myths have a way of going from one extreme to the other. For example, people once believed that in order to rely on plant protein, you had to combine particular foods at every meal. We now know this is not true. But in countering this myth, statements have gone from "You don't need to combine proteins," to "It's easy to get enough protein on a vegan diet" to the harmful "It's impossible not to get enough protein!" On average, vegans get enough protein. In fact, many people trying a vegan diet may choose foods that are high in protein without knowing it. Others may randomly choose foods that are not high in protein. Personally, since I do not feel right when I'm not eating at least a few protein-rich foods each day, I can see how someone else might be ready to quit a vegan diet after a few days of not consuming some protein-rich foods. I fear that many people quickly give up on a vegan diet, thinking it made them feel bad, instead of realizing they might have felt differently had they eaten more protein-rich foods." Similarly, eating enough calories might be an issue for an uninformed person who decides to give the vegan diet a try for a few days. Someone on the standard Western diet may only be aware of vegan foods that are low in calories (e.g., salads, vegetables, fruits). Eating only these foods for a day will likely leave someone unsatisfied and thinking the vegan diet is to blame, when all they needed to do was eat more high-calorie foods. Of course, many advocacy groups are actively trying to educate people about the wide variety of satisfying vegan foods. In promoting the diet, each person could help prepare potential vegans for the real possibility that they won't feel good if they don't choose some calorie-dense foods. Less noticeable problems can arise due to misinformation. One can find certain studies that support the idea that meat, eggs, and dairy are the cause of osteoporosis, and that calcium intake is not important. Because the arguments can sound impressive, someone might take these claims as fact. Such a person might conclude that a vegan diet must protect against osteoporosis, and that there is no need for vegans to make sure they are getting plenty of calcium and vitamin D. However, selectively choosing such studies leaves out the majority of research published on the subject. Someone who evaluates more of the research will likely conclude that vegans, like nonvegans, should ensure good sources of calcium and vitamin D on a daily basis. The other nutritional issues of which vegans should be aware are addressed later in this article. Few long-term, scientific studies have looked at true vegans. A summary of the research on vegetarians and vegans is included in this article. The research has not overwhelmingly supported the idea that a vegan diet is vastly superior to a diet that includes meat or a lacto-ovo vegetarian diet, and some vegans have found this to contradict what they have always heard. How can this be explained? Popular vegan literature has sometimes presented studies on groups -- such as lacto-ovo vegetarians, semi-vegetarians, cultures that eat little meat, and people who have a high intake of fruits and vegetables -- as indications of the health status of vegans. Although this can provide some useful information about some aspects of the vegan diet, it cannot substitute for studying actual vegans. Additionally, certain risk factors, such as cholesterol levels, have been used to make projections about the health of vegans, but these do not necessarily tell the whole story. For example, while vegans' cholesterol levels tend to be very good, some vegans' low vitamin B12 status can potentially increase their risk for heart disease. Again, this is easily solved by ensuring a source of B12. For a concise explanation of the different types of studies and their pros and cons, please see the section "How are associations between diet and disease established?" in Stephen Walsh's Briefing Paper for the UK Vegan Society, Milk and Breast Cancer. There are real differences in how people respond to various diets. While many people thrive on a vegan diet, it may not be so easy for others. When someone is committed to reducing animal suffering, there are often solutions to these dilemmas. Affirming everyone's experience is the first step in working with people towards a more humane diet. I would like to see vegan advocates promote the diet in such a way that we minimize the chances of someone having a bad experience. In so doing, I hope that future, long-term studies on vegans will show us to have even better health than our meat-eating counterparts. Promoting veganism as though there are no nutritional concerns may initially attract more people; but we don't want people merely to go vegan -- we want them to stay vegan. Thanks Virginia Messina, MPH, RD, Brenda Davis, RD, and Stephen Walsh, PhD for their invaluable help in preparing this article. In their 1997 position paper on vegetarian diets, the American Dietetic Association states, "Scientific data suggest positive relationships between a vegetarian diet and reduced risk for several chronic degenerative diseases and conditions, including obesity, coronary artery disease, hypertension, diabetes mellitus, and some types of cancer.".…. Well-planned vegan and lacto-ovo-vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy and lactation. Appropriately planned vegan and lacto-ovo-vegetarian diets satisfy nutrient needs of infants, children, and adolescents and promote normal growth."(30) Health Benefits of a Vegetarian Diet, a 1999 paper co-authored by two experts on the mortality rates of vegetarians, concludes: Compared with non-vegetarians, Western vegetarians have a lower mean BMI (by about 1 kg/m(2)), a lower mean plasma total cholesterol concentration (by about 0.5 mmol/l [19 mg/dl]), and a lower mortality from IHD [ischemic heart disease] (by about 25%). They may also have a lower risk for some other diseases such as diverticular disease, gallstones and appendicitis. No differences in mortality from common cancers have been established. There is no evidence of adverse effects on mortality. Much more information is needed, particularly on other causes of death, osteoporosis, and long-term health in vegans.(35) Diet and Cancer It may come as a surprise that vegetarians have not been shown to have lower rates of mortality from cancer. There has not been enough data on vegans to determine their cancer rates. For a recent summary of the evidence regarding diet and cancer, see "The Effect of Diet on Cancer," by Key TJ, Allen NE, Spencer EA, and Travis RC of the Cancer Research UK Epidemiology Unit. * The only major, ongoing study on the general health and mortality of vegetarians in the U.S. men women *BMI is a measure of healthy body weight. Lower than 20 is underweight, while ≥ 25 is overweight. Compared to the non-vegetarians vegetarians had about: 1. 1/2 the high blood pressure and diabetes Life expectancies in the Adventist Health Study have recently been published.(27) They show that white, non-Hispanic Seventh-day Adventists live longer than other white Californians (7.28 years for men, 4.42 years for women). In fact, according to the researchers, this group of Seventh-day Adventists appears to be the longest-lived, formally studied population in the world (with an average life span of 78.5 years for men, 82.3 for women). The following variables were shown to increase life expectancy: * vegetarian diet The only other variable looked at was hormone replacement therapy for women which possibly contributed to increased life expectancy.(27) In 1999, data were published from the 4 largest studies (including the Adventist Health Study mentioned above) analyzing vegan mortality rates.(2) The data compared the risk of dying from various diseases between people with different diets but who had similar lifestyles. The standardized mortality ratios (SMR) in 3 of the studies showed less mortality in these groups than in the population at large (no SMR was calculated for the 4th study). Most of this difference was thought to be due to lower smoking rates in the study groups, but some difference may have been due to a generally healthier diet overall than in the population at large. Compared to 31,766 people who ate meat ≥ 1/week: * Occasional meat eaters (8,135 people who ate meat < 1/week) had a 20% reduced rate of dying of heart disease and a 10% reduced rate of overall mortality. Those who ate no meat other than fish (2,375 people) had a 34% reduced rate of dying from heart disease and an 18% reduced rate of overall mortality. Lacto-ovo vegetarians (23,265 people) had a 38% reduced rate of dying from lung cancer, a 34% reduced rate of dying from heart disease, and a 15% reduced rate of mortality. Vegans (753 people) had a 26% reduced rate of dying from heart disease (however the difference was not statistically significant, meaning that it could have been due to random chance) and their mortality was the same as the regular meat-eaters. This data, while not conclusive because of the small number of vegans in the study, indicates that vegans can probably do better in preventing heart disease and possibly other diseases. This handout addresses areas where many vegans can improve their health. Click here for the article "The Long Term Health of Western Vegetarians," by Paul Appleby. All diets must be appropriately planned in order to be healthy. In part because of government requirements intended to prevent nutritional deficiencies in the average American, the food industries in the U.S. fortify a wide variety of products with many different vitamins and minerals. However, since the government and food industries have generally not been concerned with meeting the needs of vegans (although this is changing), vegans must make an effort to ensure adequate intake of certain nutrients. Jump to Summary of Recommendations for Vegan Adults. * There are no reliable, unfortified plant sources of vitamin B12; therefore fortified foods and/or supplements are necessary for the optimal health of vegans.31 Recommendations Please see this page for B12 recommendations. You can download Vitamin B12: Are You Getting It? (1MB pdf) or read it on-line for more information. Fats The following quick summary about fats simply gives basic recommendations. For a more comprehensive discussion see The Challenge of Defining Optimal Fat Intake by Virginia Messina, MPH, RD, and Making Sense of Fats and Oils, by Brenda Davis, RD. Fats that generally increase heart disease risk: Saturated Fats * Many saturated fats raise the risk of heart disease. Trans Fats * Found mostly in foods made with hydrogenated or partially hydrogenated oils. Food sources include margarines, shortening, commercial frying fats, crackers, cookies, and other snacks. The ingredients will list whether these foods are made with hydrogenated oils. Butter and animal fat can also contain trans-fats from bacterial fermentation.(33) Monounsaturated Fats (MUFA) * Improve cholesterol levels. Polyunsaturated Fats (PUFA) * Building blocks for hormones that increase inflammation and blood clotting. Most vegans get too much and should limit these oils.(39) There are 3 important n-3 fatty acids: 1. alpha-Linolenic acid (LNA) - found mainly in flaxseeds and oil, hemp seeds and oil, walnuts and oil, canola oil, soybeans and oil. Also found in leafy green vegetables and other plant foods, but not in large enough amounts to contribute significantly. LNA reduces blood clotting, improves artery flexibility, and may also reduce heart arrhythmias. LNA shows a strong association with reduced cardiovascular mortality rates, including those from heart attack and stroke. 2. Eicosapentaenoic acid (EPA) - found mainly in fatty fish. Also in irish moss and wakame, but the ratio of iodine to EPA is much too high to make these foods a recommended source. EPA serves as a precursor for eicosanoids (hormone-like substances that act on local tissues) which reduce inflammation, blood clotting, and cholesterol. 3. Docosahexaenoic acid (DHA) - found mainly in fatty fish and seaweed. For some of its benefits, LNA must be converted to EPA which in turn must be converted to eicosanoids or DHA. DHA can also be retroconverted into EPA at a rate of about 10%.(37) Although there is no clear evidence that vegans require supplements of DHA or EPA, vegan supplements of DHA are also available: NuTru's O-Mega-Zen3 NuTru's Omega-3 DHA Formula from Pangea. Genestra Neurogen DHA Neuromins© DHA is available at most health food stores, but it comes in gelatin capsules. Notes About Flax & Hemp * Flaxseeds are the most concentrated source of LNA. Cooking flaxseed oil damages the LNA, but it can be put on warm food such as toast. Flaxseed oil should be kept in the refrigerator. PUFA Recommendations Many vegans do not get enough n-3 fatty acids.(15) This can result in higher blood clotting rates. A panel of experts recently recommended an n-3 intake for nonvegetarians of about 1.3% of calories.(38 )They recommended an additional 300 mg/d of DHA for pregnant and lactating nonvegetarians. Limiting n-6 intake and making intake of LNA 1.5% of calories will enhance conversion of LNA to EPA and DHA; however, it can sometimes take a few months of following these recommendations to build up DHA. Based on the RDA for caloric intake (and subtracting .5% of kcal for usual intake without any supplementation), the following amounts of LNA should be added to the diet: age (years) LNA (g/day) flaxseed oil (rounded teaspoons)
0.5-6 .9 - 2.0 .5 > 7 2.2 - 3.3 1
Pregnant(a)
2nd Trimester extra .3 extra .5 3rd Trimester extra .3 extra .5
Lactating(a) extra .6 extra .5 (a)Pregnant and lactating women should consider replacing the extra .5 teaspoon of flaxseed oil with 300 mg (.3 g) of DHA because infants have more difficulty converting n-3s. Limit n-6 Fats * Limiting n-6 intake is important for maximizing the conversion of n-3s into EPA and DHA. You should aim for an n-6:n-3 of 4:1 or less. The following sources of n-3s are followed by their approximate ratio of n-6:n-3: n-3s source approx. n-6:n-3 ratio * Flaxseed oil goes a long way in correcting the imbalance in a typical vegan diet, but you should only take the recommended amounts. If you prefer oils on foods such as bread, I recommend raw olive or raw canola oil to minimize your n-6:n-3 ratio as well as for other benefits. Diabetes Pre-Term Infants Recent, small studies have shown vegans to have the same or slightly worse bone mineral density as non-vegans.(5, 6, 7, 8, 9) Factors that can prevent osteoporosis: * Weight-bearing exercise throughout one's lifetime is one of the most important. Factors that can contribute to osteoporosis: * High sodium and caffeine intake * Plant foods that provide calcium offer other things that are good for bones: vitamin K in leafy greens; and vitamin C, potassium, and magnesium in fortified orange juice. Leafy greens also have folate which is good for the heart. Beans, nuts, leafy green vegetables, and non-citrus fruits are good sources of boron.10 * The Daily Value for calcium on food labels is 1,000 mg. Therefore, if a food label says it has 25% of the daily value, it means it has 250 mg of calcium per serving. * Recommended daily intakes for calcium: age mg Upper Limit* (*)Do not exceed the upper limit. (a)cooked Vitamin D * Regulates calcium absorption and excretion, especially when calcium intake is low. Dietary Reference Intake (DRI) for vitamin D: (a)Do not exceed the upper limit. Typical fortified soy, almond, or rice milk 2-3 mcg (80-120 IU) per Cup * Vitamin D-only Supplements Iodine * Needed for healthy thyroid function which regulates metabolism. Vegan iodine supplements can be found in most grocery or natural food stores. Most vegan multivitamins also contain iodine. 2001 recommendations for iodine: age (yrs) 1-3 > 18 pregnant ≤ 18 lactating ≤ 18 (a)Do not exceed the upper limit. It was once believed that vegetarians (and vegans) needed to combine protein sources at each meal to get "complete protein." Now we know that protein combining is not necessary. Experts recommend that adult vegans eat .4 g of protein per day for every pound of healthy body weight.(22) Protein (grams/day) recommendations for young vegans are:(26) * Vegan athletes interested in how much protein they need should see Vegetarian Diet for Exercise and Athletic Training and Performing: An Update by D. Enette Larson, MS, RD, LD.(11) serving protein (g) 1. Food intake does not enough to meet energy needs such as in cases of anorexia nervosa, depression, poverty, lack of appetite due to illness,(3 )or dieting. 2. Higher-protein plant foods are not included in sufficient amounts. This can happen when: * Most food eaten is junk food such as French fries, soda, etc. Amino Acids Taurine, carnitine, and creatine are found primarily or only in animal products. * Taurine and carnitine are non-essential amino acids. If you are eating enough protein, your body should make what you need. If you go an extended period of time without eating enough protein, or if you have a metabolic problem, you might benefit from a period of supplementation. In such cases, it is prudent to contact a health professional. There is no reason for most vegans to be concerned. Non-vegetarians typically eat 40-70 mg of taurine per day(42) and 100-300 mg of carnitine per day.(43) Country Life’s Vegetarian Support multi-vitamin contains 2.5 mg of carnitine and 50 mg of taurine per tablet. Iron * Iron-deficiency anemia is probably one of the most inaccurately self-diagnosed illnesses. It is a serious disease, and only a medical doctor can diagnose it. People who think they may be suffering from it should see a doctor.
Iron in vegan diets is a somewhat controversial topic for a number of reasons: 1. Although vegetarians' ferritin (the storage form of iron) levels are often lower than non-vegetarians, they are no more likely to have iron-deficiency anemia. * Hemochromatosis is a disease of increased iron absorption. Its most serious, homozygous form occurs in about 1 in 100 blacks and 1 in 200 nonblacks. Its less serious, heterozygous form occurs in 30% of blacks and 12% of nonblacks.(33) Most affected people do not know they have the disease.(33) People with hemochromatosis are at risk for cirrhosis,(33) liver cancer,(32) and other diseases. Alcoholic cirrhosis, other liver diseases, iron-loading abnormalities, and other rare diseases can also cause iron overload.(32) Thus, before someone actively tries to increase their iron absorption, they should have their ferritin levels checked to make sure they do not have one of these diseases. (Because of blood loss, menstruating vegan women do not need their serum ferritin levels checked; they can take steps to increase iron absorption.) Recommended Dietary Allowance for Iron: (a)Do not exceed the upper limit. Those who engage in regular, intense exercise may need an additional 30%.(21) Iron Content of Common Foods (a)cooked You probably do not need to worry about iron if you are otherwise healthy and eat a varied vegan diet. If you suspect an iron deficiency, see a doctor. If your doctor thinks your iron stores are too low, eating meat (which is unnecessary) or taking an iron supplement may be suggested. Taking a 100-mg vitamin C tablet with 2 meals a day for 60 days should improve the anemia. * Zinc is not found in large amounts in plant foods, but vegetarians tend to have adequate zinc status. Selenium Selenium intake is more related to the selenium content of the soil than to dietary pattern. U.S. and Canadian soil appears to be adequate in selenium. Studies of vegetarians and vegans in the U.S. have shown them to have adequate intakes. Selenium is found in many foods, but in higher amounts in Brazil nuts, whole grains (whole-wheat bread, oatmeal, barley), white rice, and beans.(22) Vitamin A Pre-formed vitamin A exists only in animal products. However, there are about 50 carotenoids that the body can convert into vitamin A; the most common is beta-carotene. The vitamin A content of foods is now stated as retinol activity equivalents (RAE). The RDA of 900 RAE for men and 700 RAE for women, can be met with: 1 medium carrot (1012 RAE), Other sources include kale, mango, spinach, butternut squash, and various greens. Some people may have specific problems absorbing or utilizing certain nutrients (regardless of their diet). There are certain nutrients that are normally provided adequately by a varied vegan diet, but can be low in some vegans' diets. Riboflavin (vitamin B2) and pyridoxine (vitamin B6) are two such nutrients. For example, while most vegans have no problem with vitamin B6, one vegan family showed symptoms of vitamin B6 deficiency.(24) * Symptoms of vitamin B2 deficiency are sores outside of the lips and in the corners of the mouth, swollen tongue and mouth cavity, and dermatitis.(23 )Vitamin B2 is found in a wide variety of plant foods in small amounts, including avocados, mushrooms, almonds, leafy green vegetables, and soybeans.(26) Young Vegans The American Dietetic Association and the American Academy of Pediatrics agree that well-planned vegan diets can satisfy nutrient needs and normal growth of infants.25 For more information on the needs of vegan infants, please see Becoming Vegan. If you need to feed your baby formula, soy formulas are available. Unfortunately, they all contain vitamin D3 which usually comes from sheep’s wool or fish. As of 2001, the following brands were vegan except for the vitamin D3: * Alsoy by Nestle Vegan parents should not try to make their own infant formulas as this often leads to poor child development. Instead, we recommend commercial infant formulas, even though they are not 100% vegan. (More thoughts on the subject of trying to be 100% vegan.) Infant soy formulas have been around for many years and used without apparent problems. However, there has recently been a concern that the isoflavones in soy could be harmful for infants. Click here for an abstract for the only long-term study comparing infants receiving cow’s milk formula to infants receiving soy formula. Click here for an abstract of a more recent review of the subject. So, while more research would be desirable, it appears that soy formulas are generally safe. Click here for more information on vegan infants from the Vegetarian Resource Group. The American Academy of Pediatrics recommends that children eat no more than .23 g of fiber per pound of body weight per day. Vegan children can easily exceed this limit. They might come closer to recommendations by eating half of their servings of grains as refined grains (e.g., white pasta, white rice, white bread).26 In addition to being excellent sources of protein, beans and nuts have many other benefits such as vitamins, minerals, fiber, and other chemicals that may prevent cancer and heart disease.28,29 Nuts also contain monounsaturated fats which are healthy for the heart. In one study, eating nuts (including peanuts34) 5 or more times per week reduced heart disease by about 50%!1 High fruit and vegetable consumption has been associated with a reduced risk for cardiovascular disease, several common cancers, and other chronic diseases (such as macular degeneration and cataracts). Whole-grain consumption has been associated with a reduced risk for heart disease, diabetes, hypertension, and stomach and colon cancer. Whole grains include brown rice, whole-wheat bread, barley, oatmeal, corn, quinoa, and millet. Recommended Daily Intakes(a) Vitamin B12 3-100 mcg (µg) Vitamin D 5-15 mcg (200-600 IU) General Health Plenty of green and yellow vegetables, other vegetables, fruits, nuts, legumes, and whole grains. General health: Plenty of green and yellow vegetables, other vegetables, fruits, nuts, legumes, and whole grains (a)See different sections for needs of other age groups. Vegan multivitamins Country Life In health food stores Freeda Pangea 800-340-1200 VegLife in health food stores, Vegan One Multiple (a)microgram = mcg = µg * A Recipe for Abundant Vegan Health by Dr Stephen Walsh and Dr Glynis Chapman. The Vegan, Autumn 2001, UK Vegan Society. Newsletters 1711 Nichol Hall 1. Fraser GE. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am J Clin Nutr. 1999 Sep;70(3 Suppl):532S-538S. © Jack Norris, 2002 May be photocopied.
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