Search the Community
Showing results for tags 'vegetarianism'.
Found 1 result
Note: this guide was written over an extended period of time in 2009, and with one exception (the sections on choline and carnitine) has not been updated since. It is therefore probably in significant ways outdated on both current science and my own evolving understanding. Also, I am not a doctor or health professional. Information in this article is just that: information — not advice. Before taking up CR, veg(etari)anism, or using dietary supplements, consult a doctor or other licensed health professional. Neither I nor the CR Society provides any warranty is given or implied in relation to the information supplied in this article or on the website, and neither I nor CR Society accepts any liability in the event that a user suffers loss as a result of reliance upon the information. Finally: this is a multi-part article, and unlike posts on the old CR Society email distribution lists, it can be periodically updated thanks to the fine editability of the Forums. To avoid cluttering up the article, please post ask any questions or comments about the contents of this article in a new thread, rather than by hitting "reply" to posts in this one. I will make a good-faith effort to answer such and to update this article as appropriate. Part I: Principles and Strategies Records of groups practicing vegetarianism go back to ancient times, and while animal cruelty or religious purity have clearly been the dominant motivations, the belief that diets free of animal flesh were healthier has been and continues to be a common belief amongst practitioners and advocates. And clearly there are reasons to expect that they might be. Vegetarian diets are lower in saturated fat and cholesterol, and vegetarians tend to have lower LDL (“bad”) cholesterol; they are free of the risks of the carcinogens present in highly-processed or overcooked meat; vegetarians tend to be slimmer; and the benefits of increasing one’s intake of fruits, vegetables, and whole grains are endorsed not only by academics and public health professionals, but by nearly every popular diet, from Atkins to Ornish. And yet, large-scale, prospective studies, in which the health of vegetarians is tracked over time with reference to the general population (and, more clearly, compared with other groups that include meat and/or seafood in their diets, but who otherwise lead similarly health-conscious lifestyles), fail to find an overall difference in the ultimate balance sheet of the health of a biological system: its life expectancy. Surprisingly, despite enjoying a reduction in risk of ischemic heart disease, vegetarians live about as long as similar omnivores do,[ii],[iii],[iv] – and, even when it comes to heart health, vegans (whose diets are the most restrictive of animal fat (and thus saturated fatty acids and cholesterol)) actually seem to have risks similar to have those of people who eat meat a few times a month, and are actually at higher risk than either ovolacto vegetarians (who get these nutrients from most dairy products and egg yolk), or eaters of fish but not terrestrial meat.4 And this is despite a lower rate of smoking and lighter bodies even in comparison with health-conscious omnivores.1 These findings are even more surprising when you consider one of its minor implications. Aside from the fact that the effects on heart disease are more modest than most of us would expect from the considerable reduction in the single most well-established dietary determinant of disease incidence, or the more surprising finding of a lack of overall benefit in cancer deaths, the only way that a group with a lower risk of death from one thing (heart disease) can wind up having no lower a risk of dying overall than members of another group, is if that group simultaneously suffers a commensurate increase in risk of death from one or more other causes. In other words, for every omnivore who dies early clutching hir heart and sprawled over the dining room table, there is a vegetarian out there dying from one of an unidentified spectrum of less common diseases than heart disease or major cancers. This should not trigger a massive research campaign to attempt to tease out the mystery illnesses cutting a swath through the ranks of vegetarians: most vegetarians are dying of exactly what’s killing the rest of the population, and as a corollary, an individual vegetarian’s risks of other diseases, even amongst vegetarians, remain low, and are more likely related to the biology of aging (which tends to dilute out the effects of risk factors for disease over time, as the intrinsic molecular decay that accumulates in the tissues of the body makes the organism more susceptible to insults of all kinds) than to some specific disease process. The more immediate question is, what’s wrong with a vegetarian diet that doesn’t allow us to reap the expected benefits of low intake of saturated fat and charred meat and high intake of plant-based foods? A number of certain and probable weaknesses of typical vegetarian diets have been identified in epidemiological and small cross-sectional studies, and for a number of them the potential health risks are reasonably clear, though the degree to which any of them actually contribute to risk of death and disease in vegetarians specifically has not been systematically tested with intervention trials (where one group of vegetarians would eat their normal, but typically nutritionally imperfect, diet, while another would have their diets improved in a way that actually brought one or more of these parameters more in line with typical omnivorous diets, and long-term health outcomes in the two groups would be compared). In addition to such limited information about the health effects that come somewhat inherently to a ‘default’ self-selected plant-based diet compared with one including a substantial amount of meat (and, for vegans, dairy and eggs), there is also the problem of failure, even by well-meaning vegetarian advocates, to correct these default deficiencies, for fear of making eating a healthy vegetarian diet seem more difficult and burdensome for most people to take up. And on top of that, there is a much higher level of sheer food faddism amongst vegetarians, resulting from a mixture of the perverse effect of many vegetarians being more health-conscious than the general population, but no more scientifically literate in nutrition (hence the widespread citation of John Robbins, John MacDougall, and even the authors of Skinny Bitch on the health benefits of vegetarianism), leading to a dangerous susceptibility to convincing-sounding but scientifically groundless arguments on the subject. Additionally, I personally suspect that, once immersed into a subculture (including online vegetarian communities) where an already-unusual dietary practice is the norm, vegetarians find it all the easier to begin walking down a slippery slope into increasingly unsafe or untested dietary practices. A recent study[v] finding that current and former adolescent vegetarians and semivegetarians are more prone to clearly pathological eating patterns (such as binge eating, use of laxatives for weight control) may support this idea, although it’s possible that some of this represents young people using “vegetarianism” as a camouflage for an eating disorder, or that all of their food relationships were in an unhealthy flux during their teen years. But there is a fair bit that we can say about the composition of meat-centered vs. plant-centered diets, and about observations of the nutritional statuses of vegetarians in the real world. And so we can say a fair amount about some of the more common deficiencies and imbalances built into typical vegetarian lifestyles – and, therefore, of what dietary adjustments or (as necessary) dietary supplements might at least help to correct them. So most of this article will be devoted to the well-established weaknesses in typical vegetarian diets, and some of the known or probable risks associated with letting those problems go uncorrected – but I emphatically do not intend this to be a boilerplate set of supplements and dietary modifications that should be adopted ‘as is’ by all vegetarians. Instead, the focus of the article will be on getting a handle on your own, unique dietary patterns and needs, and then giving some further insight on problems you’re likely to encounter, and the whys and hows of getting around them. Know Thy Diet In order to know what changes and additions are needed to your existing pattern, you’ll have to have a good handle on what, exactly, that pattern is, how it breaks down nutritionally, and where its weaknesses lie. Broad-stroke dietary advice inevitably misses this factor: even eating diets that are otherwise very healthy, almost everyone has a variety of mild deficiencies and imbalances in their day-to-day eating pattern, and the special strictures of a vegetarian diet tend to take away some of the wiggle room that omnivores have to fill in gaps in their nutritional pattern. Moreover, people’s understanding and characterization of their own diets tend to be quite mistaken: they come into their dietary habits by a lifelong mixture of culture, habit, availability, and taste that they’ve never deeply analyzed and haven’t compared to any Platonic standard, with the result that they really don’t know what they’re eating or how it compares to average diets or dietary guidelines. Worse, when they try to evaluate what they’re eating, they still get it wrong:[vi] they usually aren’t fully paying attention as they grab small snacks here and there through the day, can’t eyeball serving sizes (and indeed don’t really grasp what a ‘serving’ of a given food is), and frankly sometimes engage in self-deception, telling themselves white lies about the amount of poor-quality food they eat or (less commonly) indulging a tendency toward self-flagellation by exaggerating minor dietary infractions. So I’m going to strongly recommend that you spend a few dollars and some time doing something that my fellow practitioners of Calorie restriction do every day, which is to record and quantitate everything you eat for a few typical days – not days when you’re ‘being good,’ but a genuinely representative sample. If you don’t have them already, pick up a set of measuring cups (for liquids and solids) and spoons; also spend some money on a digital food scale accurate to 1 gram (postal scales are an easier-to-find and usually less expensive route to the same end). When you make food for yourself, weigh or measure it out; when you eat pre-packaged foods, carefully record the relevant information; keep a PDA or small pad of paper with you, and carefully evaluate small snacks and drinks eaten out. Plug all this information into nutritional software, such as CRON-O-Meter (on whose design I consulted), which is an excellent tool for nutritional analysis, is free (though the developer takes donations, and there are some nifty features for the inexpensive upgrade to "Gold" membership), or NutritionData.com. If a food isn’t on the list, you can use the Command-F (or Food > New Food) function to enter it, from the package or online sources like The Daily Plate and Calorie King; Google searches for the food name plus “nutrition facts” or (calories protein calcium) are also often successful. One significant challenge here is restaurants. Studies show that almost nobody – including postgraduate academic and professional nutritionists[viii] – can accurately estimate the Caloric or saturated fat content of restaurant meals, and almost always underestimate these values.[ix],[x] My anecdotal experience as an individual vegetarian with a fair number of vegetarian friends suggests that this was once less of a problem for vegetarians than for the general population, as they long seemed to eat relatively few meals out for the unpleasant reason of sheer lack of options, beyond vegetable side-dishes, salads, and a few pasta dishes. But times have changed, and for better and for worse, it’s become easier and easier for vegetarians to find real meals out at the same moment that there has been a significant increase in the percentage (and total!) of Calories eaten out in the culture at large, and a ballooning of portion sizes and Caloric densities of restaurant meals. The result is that most vegetarians have a reasonable range of restaurant meals available to them, and appear, anecdotally, to be taking advantage of the changes in the industry – and it is taking advantage of them. Certainly, there is always coffee (which can run 800 Calories at Starbucks these days) and bagels and cream cheese (or mustard and tomato for the vegans). If you mostly eat in major chain restaurants, you can likely get nutritional information online; if not, and if the Mysore Masala Dosai at the local Indian place is a part of your Friday ritual with your lover, you can’t just pretend it isn’t. Do your best to find a comparable dish at a large restaurant chain with nutritional information, or at least enter in a recipe for the same dish from online or other sources. Yes, this is a lot of work! But most people’s diets are fairly well-worn, happy ruts, and eating food you prepare yourself is a good and increasingly-rare pattern to be in, so you ought to be able to get away with doing it for a week or so, and then perhaps once a weeks or so for a few weeks thereafter. Again, I guarantee you that you will find some significant holes and ‘overgrowths’ in your diet, no matter how fundamentally healthy it may be. Do yourself the favor of investing the time and trouble: knowledge is power, and your health really shouldn’t rely on guesswork. The Benchmarks Now that you know what you’re eating, how do you identify and correct the imbalances? What are the standards? Most people, if they think about it at all, would first turn to the government’s nutrition experts, but such bodies are viewed with great suspicion by many health-conscious people. Advocates of vitamin and mineral supplementation believe that the RDAs only protect against frank, acute deficiency state, and don’t take account of the long-term impacts of a kind of chronic, low-level, suboptimal intake, whose correction requires supplemental intakes anywhere from a few to a hundred multiples of the RDA. Supporters of organic agriculture argue that our soils have become so depleted, and our plants first bred to be convenient for agribusiness production and distribution chains, and then forced to grow so quickly by synthetic fertilizers and ‘spoiled’ by pesticides that prevent the formation of secondary metabolites, that it has drained them dramatically of nutritional content. And vegetarians often point to the institutional conflict-of-interest inherent to having the USDA both make dietary recommendations and be responsible for supporting American agrobusiness as leading to flawed nutritional advice – especially when it comes to the consumption of animal products. But while there is some truth in all of these critiques, over time a healthy suspicion of authority has for many people slowly slid over time into uncritical, blanket derision, or closed-system conspiracy theory, to the point that no such guidance can be taken seriously. Worse, too many people concerned about their health have simply replaced highly-qualified government and academic authorities with alternative ‘authorities’ that are actually far less qualified, less grounded in the body of nutritional science, and more driven by outside agendas – and too often, by sheer nutritional superstition. While it’s heresy to say so in many health-driven communities, the government’s nutrition experts really do know what they’re talking about, and when they do make mistakes, they tend to be based on drawing conservative conclusions in the face of a limited amount of high-quality information, instead of making Olympian leaps from a few evidential straws – and such errors tend to work themselves out over time and with scientific peer-review. This is particularly true when we turn away from the intentionally vague and highly politicized guidance offered by the USDA in the form of the ‘Food Pyramid’ (now ‘My Pyramid’) and similar efforts[xi] to the much more specific and independent guidance on nutritional science embodied in the National Academies of Science’s Institute of Medicine (IOM) reports on nutrient requirements, which for the basis for later Dietary Reference Intakes (DRIs), a panel of parameters that includes the Recommended Dietary Allowances (RDAs) by age, and which are different from the values promulgated by the FDA and USDA in the form of the US RDA (perversely, not the same as the IOM RDA) and such complementary indexes as the Daily Value and Reference Daily Intakes (RDIs). Broadly speaking, nearly all of the current DRIs are excellent, or at least within the right ballpark, especially for the general populace to which they are primarily addressed. There is a large (but fortunately shrinking) constituency in the life extension community whose knee-jerk reaction is assume that everything that Authority says about nutrition is wrong, and in particular that the RDAs are orders of magnitude too low; these opinions are largely based in honest ignorance, by folks who have been convinced by sloppy arguments, mostly advanced by supplement pushers (I speak as a notorious, but hopefully relatively intellectually honest and sophisticated, former supplement pusher myself), and who (crucially) have simply not read the enormous and normally quite well-presented documentation that form the basis of the IOM's recommendations, and usually lack the scientific background to do so. For those interested, the mammoth tomes that summarize the evidence underlying the IOM's current RDAs are available for free online[xii]; click on the photo of a given volume, and then scroll down to read the individual chapters (you have to go page-by-page, alas). But for bottom-line purposes, the latest iteration of the DRIs are also tabulated on the IOM website.[xiii] In addition to these guidelines for essential nutrients, there are a variety of ‘conditionally essential’ nutrients whose intake is much lower in vegetarians than in omnivores. “Conditionally essential” nutrients are substances that play an essential role in physiological function, are available in (and absorbable from) the diet, but are not strictly ‘essential’ because they can be biosynthesized from their precursors in the body. Many of these nutrients are present in animal products and not plant-based ones, so vegetians certainly have a lower intake of these nutrients, but because people can in principle synthesize these substances from other nutrients that are in their diets, and because experimental animals given diets free of these nutrients don’t suffer any obvious impairments in growth or fertility, long led to the assumption that there was no need to get them from the diet. However, as we’ll see, there are many cases where vegetarians’ levels of these nutrients are, in fact, lower than those of omnivores, and where evidence exists that their health is not as good as it could be because of it. How’s That Workin’ for you? In many health-conscious circles, it’s a commonplace that everyone has hir own unique nutritional needs: that genetic, age, and lifestyle variations in absorption, utilization, biotransformation, storage, enzymatic affinity, etc. ensure that the RDA will not provide the right dose for many people. And indeed, despite my previously-stated confidence in the RDAs, the fact is that even a benchmark set to cover the nutritional requirements for 95% of the population will, by mathematical necessity, mean that 5% of the population will actually not have their needs met at that level – even if the original RDA were set in perfect scientific knowledge of the range of needs and long-term impacts of a given dose of a particular nutrient, which of course it is not. But too often, this emphasis of “biochemical individuality” is ironically used to justify blanket, population-wide recommendations that everyone should engage in high-dose supplementation of everything, as if no essential nutrient (or combination of such nutrients) could be harmful in high doses. As we’ve learned from the miserable history of supplement trials for everything except vitamin D for fractures, this advice has turned out to be unhelpful at best, and occasionally fatal at worst, with multiple large, long-term, carefully-controlled trials of megadose supplements documenting possible marginal increases in cancer rates from ‘antioxidants,’ heart disease from B vitamins, and in diabetes from selenium. No, you want to determine and meet your particular needs – no more, no less. To do this, you’ll certainly want to start with the IOM RDAs – but where you can, you won’t want to stay there. Instead, it’s best to get yourself functionally tested, to see if the enzymes and biochemical pathways that rely on a given nutrient are functioning as they would if the supply of that nutrient were adequate. Many people (including many health providers, especially in the ‘alternative’ medicine fields) rely on blood levels to determine adequacy, but these are almost never a good guide to functional status. For some nutrients, blood levels are held within strict limits that are maintained by either furiously working to metabolize the excess away in a not-always-helpful way, or by drawing down long-term body stores to make up a deficiency, which if not replaced by future dietary intake creates (and masks) a creeping systemic deficiency. In other cases, blood levels fluctuate with recent intake, and tell you more about what you had for dinner the night before than about your day-to-day health status. And in still other cases, a level in the blood that would be quite adequate to saturate enzyme activity in most people is insufficient for you as an individual, because a minor typo in your genetic code makes the enzyme require a bit higher concentration of the nutrient to squeeze a molecule of it into a slightly resistant binding site. And in the end, most blood level guidance is based on the level that is ‘normal’ in the population, or (in a closed-loop) on people already following a given nutritionally-minded health care provider’s dietary recommendations, and not on any evidence that the target level actually meets metabolic demand. Unfortunately, for many essential nutrients (especially minerals), no reliable test exists, or is only available in a few research labs instead of from commercial testing laboratories. But where your own body’s biochemical soup can tell you how you’re doing, you’ll want to hear what its saying. Another Tool As we go along, and as you find the need to boost intake of some nutrients and avoid overdosing on others, you’ll often want to find foods high in some nutrient – and generally, low in others. Lists of ‘foods rich in …’ are often misleading, because they’re based on a serving size that can be quite arbitrary, and because they don’t help you to tailor a food in to other priorities, such as keeping Calories low or avoiding common ‘fellow traveller’ nutrients (such as high copper levels in most zinc-rich vegan foods). A good tool for this is the "Oracle" function on CRON-O-Meter; NutritionData.com’s Nutrient Search tool can also allow you to look for foods high in one or more nutrients, but high or low in other nutrients at the same time. Combined with an analysis of your full diet, good guidance for intake, and testing where good functional assays are available, this will let you bring your diet closer to its health-supporting best. In Part II of this article, we’ll tackle the essential vitamins, minerals, and amino acids, with a focus on nutrients typically lacking or overrepresented in a vegetarian diet; in Part III, we’ll more gingerly approach the more limited information about the ‘conditionally essential’ nutrients. Next: Part II: Essential Nutrients Remember, please post ask any questions or comments about the contents of this article in a new thread, rather than by hitting "reply" to posts in this one. 1: Bor MV, Lydeking-Olsen E, Møller J, Nexø E. A daily intake of approximately 6 microg vitamin B-12 appears to saturate all the vitamin B-12-related variables in Danish postmenopausal women. Am J Clin Nutr. 2006 Jan;83(1):52-8. Eussen SJ, de Groot LC, Clarke R, Schneede J, Ueland PM, Hoefnagels WH, van Staveren WA. Oral cyanocobalamin supplementation in older people with vitamin B12 deficiency: a dose-finding trial. Arch Intern Med. 2005 May 23;165(10):1167-72. “Daily doses of 647 to 1032 mug of cyanocobalamin were associated with 80% to 90% of the estimated maximum reduction in the plasma methylmalonic acid concentration.” ,[xxvi],[xxvii], McDougall J. Optimal diets to prevent heart disease. JAMA. 2003 Mar 26;289(12):1509. Key TJ, Appleby PN, Spencer EA, Travis RC, Roddam AW, Allen NE. Mortality in British vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). Am J Clin Nutr. 2009 Mar 18. doi:10.3945/ajcn.2009.26736L [ii] 1: Singh PN, Sabaté J, Fraser GE. Does low meat consumption increase life expectancy in humans?. Am J Clin Nutr. 2003 Sep;78(3 Suppl):526S-532S. [iii] 1: Chang-Claude J, Hermann S, Eilber U, Steindorf K. Lifestyle determinants and mortality in German vegetarians and health-conscious persons: results of a 21-year follow-up. Cancer Epidemiol Biomarkers Prev. 2005 Apr;14(4):963-8. [iv] Key TJ, Fraser GE, Thorogood M, Appleby PN, Beral V, Reeves G, Burr ML, Chang-Claude J, Frentzel-Beyme R, Kuzma JW, Mann J, McPherson K. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr. 1999 Sep;70(3 Suppl):516S-524S. [v] Robinson-O'Brien R, Perry CL, Wall MM, Story M, Neumark-Sztainer D. Adolescent and young adult vegetarianism: better dietary intake and weight outcomes but increased risk of disordered eating behaviors. J Am Diet Assoc. 2009 Apr;109(4):648-55. [vi] The foibles of our self-monitoring are cataloged extensively and entertainingly in Cornell University Professor of Consumer Behavior Brian Wansink’s excellent and revealing Mindless Eating: Why We Eat More Than We Think (2006; Bantam books, ISBN: 0-553-80434-0). [vii] http://spaz.ca/cronometer/ [viii] Food Commission. Which fast food meals are healthiest? Anyone’s guess! The Food Magazine. 2008 Jul/Aug:82. [ix] Burton S, Creyer EH, Kees J, Huggins K. Attacking the obesity epidemic: the potential health benefits of providing nutrition information in restaurants. Am J Public Health. 2006 Sep;96(9):1669-75. [x] Wansink B, Chandon P. Meal size, not body size, explains errors in estimating the calorie content of meals. Ann Intern Med. 2006 Sep 5;145(5):326-32. [xi] The corrupting influence of business interests on the media and much government (especially USDA) nutrition communication is very well covered in Marion Nestle’s excellent Food Politics: How the Food Industry Influences Nutrition and Health (2007; Univ of California Press, ISBN-10: 0520254031). [xii] http://www.nap.edu/catalog/dri/ [xiii] Food and Nutrition Board, Institute of Medicine, National Academies. Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Vitamins. Online at http://www.iom.edu/File.aspx?ID=21372 ; accessed 2009-04-09. [xiv] McDougall J. Vitamin B12 Deficiency—the Meat-eaters’ Last Stand. McDougall Newsletter. 2007 Nov;6(11). Online at http://www.drmcdougall.com/misc/2007nl/nov/b12.htm , accessed 2009-04-06. [xv] McDougall J. Vegetarianism - An Offensive Stand. Pamphlet, ND. Box 14039, Santa Rosa, CA 95402. Copies posted online at http://old.animalsong.org/mcdougal.html , http://www.thisiscool.com/mohan/mcdougal.html , http://www.vegetarian1.net/Page2.htm#Vegetarianism%20-%20An%20Offensive%20Stand , and elsewhere. Accessed 200-04-06. [xvi] Herbert V. Vitamin B-12: plant sources, requirements, and assay. Am J Clin Nutr. 1988 Sep;48(3 Suppl):852-8. [xvii] Elmadfa I, Singer I. Vitamin B-12 and homocysteine status among vegetarians: a global perspective. Am J Clin Nutr. 2009 Apr 8. [Epub ahead of print] [xviii] Majchrzak D, Singer I, Männer M, Rust P, Genser D, Wagner KH, Elmadfa I. B-vitamin status and concentrations of homocysteine in Austrian omnivores, vegetarians and vegans. Ann Nutr Metab. 2006;50(6):485-91. [xix] Koebnick C, Hoffmann I, Dagnelie PC, Heins UA, Wickramasinghe SN, Ratnayaka ID, Gruendel S, Lindemans J, Leitzmann C. Long-term ovo-lacto vegetarian diet impairs vitamin B-12 status in pregnant women. J Nutr. 2004 Dec;134(12):3319-26. [xx] Herrmann W, Schorr H, Obeid R, Geisel J. Vitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians. Am J Clin Nutr. 2003 Jul;78(1):131-6. [xxi] Krajcovicová-Kudlácková M, Blazícek P, Kopcová J, Béderová A, Babinská K. Homocysteine levels in vegetarians versus omnivores. Ann Nutr Metab. 2000;44(3):135-8. [xxii] Mann NJ, Li D, Sinclair AJ, Dudman NP, Guo XW, Elsworth GR, Wilson AK, Kelly FD. The effect of diet on plasma homocysteine concentrations in healthy male subjects. Eur J Clin Nutr. 1999 Nov;53(11):895-9. [xxiii] Mezzano D, Muñoz X, Martínez C, Cuevas A, Panes O, Aranda E, Guasch V, Strobel P, Muñoz B, Rodríguez S, Pereira J, Leighton F. Vegetarians and cardiovascular risk factors: hemostasis, inflammatory markers and plasma homocysteine. Thromb Haemost. 1999 Jun;81(6):913-7. [xxiv] Kumar J, Garg G, Sundaramoorthy E, Prasad PV, Karthikeyan G, Ramakrishnan L, Ghosh S, Sengupta S. Vitamin B12 deficiency is associated with coronary artery disease in an Indian population. Clin Chem Lab Med. 2009 Mar; 47(3): 334-8. [xxv] Geisel J, Schorr H, Bodis M, Isber S, Hübner U, Knapp JP, Obeid R, Herrmann W. The vegetarian lifestyle and DNA methylation. Clin Chem Lab Med. 2005;43(10):1164-9. [xxvi] Karabudak E, Kiziltan G, Cigerim N. A comparison of some of the cardiovascular risk factors in vegetarian and omnivorous Turkish females. J Hum Nutr Diet. 2008 Feb;21(1):13-22. [xxvii] Chen CW, Lin YL, Lin TK, Lin CT, Chen BC, Lin CL. Total cardiovascular risk profile of Taiwanese vegetarians. Eur J Clin Nutr. 2008 Jan;62(1):138-44.