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    from the association

    Position of the American Dietetic Association:

    Vegetarian Diets







    BSTRACTt is the position of the American Di-tetic Association that appropriatelylanned vegetarian diets, includingotal vegetarian or vegan diets, areealthful, nutritionally adequate, anday provide health benefits in the

    revention and treatment of certainiseases. Well-planned vegetarian di-ts are appropriate for individualsuring all stages of the life cycle, in-luding pregnancy, lactation, infancy,hildhood, and adolescence, and forthletes. A vegetarian diet is defineds one that does not include meat (in-luding fowl) or seafood, or productsontaining those foods. This articleeviews the current data related toey nutrients for vegetarians includ-ng protein, n-3 fatty acids, iron, zinc,odine, calcium, and vitamins D and-12. A vegetarian diet can meet cur-

    ent recommendations for all of theseutrients. In some cases, supplementsr fortified foods can provide usefulmounts of important nutrients. An ev-dence-based review showed that veg-tarian diets can be nutritionally ad-quate in pregnancy and result inositive maternal and infant healthutcomes. The results of an evidence-ased review showed that a vegetar-an diet is associated with a lower riskf death from ischemic heart disease.egetarians also appear to have lower

    ow-density lipoprotein cholesterol lev-ls, lower blood pressure, and lowerates of hypertension and type 2 diabe-es than nonvegetarians. Furthermore,egetarians tend to have a lower bodyass index and lower overall cancer

    ates. Features of a vegetarian diethat may reduce risk of chronic diseasenclude lower intakes of saturated fatnd cholesterol and higher intakes ofruits, vegetables, whole grains, nuts,oy products, fiber, and phytochemi-


    edoi: 10.1016/j.jada.2009.05.027


    als. The variability of dietary practicesmong vegetarians makes individualssessment of dietary adequacy essen-ial. In addition to assessing dietary ad-quacy, food and nutrition profession-ls can also play key roles in educatingegetarians about sources of specificutrients, food purchase and prepara-ion, and dietary modifications to meetheir needs.

    Am Diet Assoc. 2009;109:266-1282.

    OSITION STATEMENTt is the position of the American Di-tetic Association that appropriatelylanned vegetarian diets, includingotal vegetarian or vegan diets, areealthful, nutritionally adequate, anday provide health benefits in the pre-

    ention and treatment of certain dis-ases. Well-planned vegetarian dietsre appropriate for individuals duringll stages of the lifecycle, includingregnancy, lactation, infancy, child-ood, and adolescence, and for athletes.

    EGETARIAN DIETS IN PERSPECTIVEvegetarian is a person who does not

    This American Dietetic Associatiauthors’ independent review of thereview conducted using the ADA’s Etion from the Evidence Analysis LibrLibrary are clearly delineated. Theprovides important added benefitsadvantage of the approach is the mcriteria, which minimizes the likelihease with which disparate articles mtion of the methods used in the evEvidence Analysis Process at http://

    Conclusion Statements are assibased on the systematic analysis andevidence. Grade I�Good; GradeIV�Expert Opinion Only; and Gradno evidence to support or refute the

    Evidence-based information for thttps://www.adaevidencelibrary.comavailable for purchase at https://ww

    at meat (including fowl) or seafood, d

    ON © 2009

    r products containing these foods.he eating patterns of vegetariansay vary considerably. The lacto-ovo-

    egetarian eating pattern is based onrains, vegetables, fruits, legumes,eeds, nuts, dairy products, and eggs.he lacto-vegetarian excludes eggss well as meat, fish, and fowl. Theegan, or total vegetarian, eating pat-ern excludes eggs, dairy, and othernimal products. Even within theseatterns, considerable variation mayxist in the extent to which animalroducts are excluded.Evidence-based analysis was used

    o evaluate existing research on typesf vegetarian diets (1). One questionor evidence-analysis was identified:

    hat types of vegetarian diets arexamined in the research? The com-lete results of this evidence-basednalysis can be found on the Ameri-an Dietetic Association’s Evidencenalysis Library (EAL) Web site

    www.adaevidencelibrary.com) andre summarized below.EAL Conclusion Statement: The twoost common ways of defining vege-

    arian diets in the research are vegan

    (ADA) position paper includes theterature in addition to systematicence Analysis Process and informa-. Topics from the Evidence Analysisse of an evidence-based approachearlier review methods. The majorrigorous standardization of reviewof reviewer bias and increases the

    be compared. For a detailed descrip-nce analysis process, access ADA’seal.com/eaprocess/.

    ed a grade by an expert work groupaluation of the supporting researchFair; Grade III�Limited; Grade�Not Assignable (because there isclusion).and other topics can be found at

    d subscriptions for nonmembers aredaevidencelibrary.com/store.cfm.




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    iets: Diets devoid of all flesh foods;

    by the American Dietetic Association


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    nd vegetarian diets: Diets devoid ofll flesh foods, but also include eggovo) and/or dairy (lacto) products.

    However, these very broad cat-gories mask important variationsithin vegetarian diets and dietaryractices. These variations withinegetarian diets make absolute cat-gorization of vegetarian dietaryractices difficult and may be one ofhe sources of unclear relationshipsetween vegetarian diets and otheractors. Grade II�Fair.

    In this article, the term vegetarianill be used to refer to people choosinglacto-ovo-, lacto-, or vegan vegetarianiet unless otherwise specified.Whereas lacto-ovo-, lacto-, and

    egan-vegetarian diets are thoseost commonly studied, practitionersay encounter other types of vegetar-

    an or near-vegetarian diets. For ex-mple, people choosing macrobioticiets typically describe their diet asegetarian. The macrobiotic diet isased largely on grains, legumes, andegetables. Fruits, nuts, and seedsre used to a lesser extent. Some peo-le following a macrobiotic diet areot truly vegetarian because they eat

    imited amounts of fish. The tradi-ional Asian-Indian diet is predomi-antly plant based and is frequently

    acto-vegetarian although changes of-en occur with acculturation, includ-ng greater consumption of cheesend a movement away from a vege-arian diet. A raw foods diet may be aegan diet, consisting mainly or ex-lusively of uncooked and unproc-ssed foods. Foods used include fruits,egetables, nuts, seeds, and sproutedrains and beans; in rare instancesnpasteurized dairy products andven raw meat and fish may be used.ruitarian diets are vegan dietsased on fruits, nuts, and seeds. Veg-tables that are classified botanicallys fruits like avocado and tomatoesre commonly included in fruitarianiets; other vegetables, grains, beans,nd animal products are excluded.Some people will describe them-

    elves as vegetarian but will eat fish,hicken, or even meat. These self-de-cribed vegetarians may be identifiedn research studies as semivegetarians.ndividual assessment is required toccurately evaluate the nutritionaluality of the diet of a vegetarian or aelf-described vegetarian.

    Common reasons for choosing a

    egetarian diet include health consid- a

    rations, concern for the environ-ent, and animal welfare factors.egetarians also cite economic rea-ons, ethical considerations, worldunger issues, and religious beliefs asheir reasons for following their cho-en eating pattern.

    onsumer Trendsn 2006, based on a nationwide poll,pproximately 2.3% of the US adultopulation (4.9 million people) consis-ently followed a vegetarian diet,tating that they never ate meat, fish,r poultry (2). About 1.4% of the USdult population was vegan (2). In005, according to a nationwide poll,% of 8- to 18-year-old children anddolescents were vegetarian; close to% were vegan (3).Many consumers report an interest

    n vegetarian diets (4) and 22% reportegular consumption of meatless sub-titutes for meat products (5). Addi-ional evidence for the increasing in-erest in vegetarian diets includes themergence of college courses on vege-arian nutrition and on animal rights;he proliferation of Web sites, period-cals, and cookbooks with a vegetar-an theme; and the public’s attitudeoward ordering a vegetarian mealhen eating away from home.Restaurants have responded to this

    nterest in vegetarian diets. A surveyf chefs found that vegetarian dishesere considered “hot” or “a perennial

    avorite” by 71%; vegan dishes by 63%6). Fast-food restaurants are begin-ing to offer salads, veggie burgers,nd other meatless options. Most uni-ersity foodservices offer vegetarianptions.

    ew Product Availabilityhe US market for processed vegetar-

    an foods (foods like meat analogs,ondairy milks, and vegetarian en-rees that directly replace meat orther animal products) was estimatedo be $1.17 billion in 2006 (7). Thisarket is forecast to grow to $1.6 bil-

    ion by 2011 (7).The availability of new products, in-

    luding fortified foods and convenienceoods, would be expected to have anmpact on the nutrient intake of vege-arians who choose to eat these foods.ortified foods such as soy milks, meatnalogs, juices, and breakfast cereals

    re continually being added to the mar- f

    July 2009 ● Journal

    etplace with new levels of fortifica-ion. These products and dietary sup-lements, which are widely available inupermarkets and natural foods stores,an add substantially to vegetarians’ntakes of key nutrients such as cal-ium, iron, zinc, vitamin B-12, vitamin, riboflavin, and long-chain n-3 fattycids. With so many fortified productsvailable today, the nutritional statusf the typical vegetarian today woulde expected to be greatly improvedrom that of a vegetarian 1 to 2 decadesgo. This improvement would benhanced by the greater awarenessmong the vegetarian population ofhat constitutes a balanced vegetarianiet. Consequently older research dataay not represent the nutritional sta-

    us of present-day vegetarians.

    ealth Implications of Vegetarian Dietsegetarian diets are often associatedith a number of health advantages,

    ncluding lower blood cholesterol levels,ower risk of heart disease, lower bloodressure levels, and lower risk of hy-ertension and type 2 diabetes. Vege-arians tend to have a lower body massndex (BMI) and lower overall cancerates. Vegetarian diets tend to be lowern saturated fat and cholesterol, andave higher levels of dietary fiber, mag-esium and potassium, vitamins C and, folate, carotenoids, flavonoids, andther phytochemicals. These nutri-ional differences may explain some ofhe health advantages of those follow-ng a varied, balanced vegetarian diet.owever, vegans and some other vege-

    arians may have lower intakes of vita-in B-12, calcium, vitamin D, zinc, and

    ong-chain n-3 fatty acids.Recently, outbreaks of food-borne ill-

    ess associated with the consumptionf domestically grown and importedresh fruits, sprouts, and vegetableshat have been contaminated by Sal-onella, Escherichia coli, and othericro-organisms have been seen.ealth advocacy groups are calling for

    tricter inspection and reporting proce-ures and better food-handling prac-ices.

    UTRITION CONSIDERATIONS FOREGETARIANSroteinlant protein can meet protein re-uirements when a variety of plant

    oods is consumed and energy needs


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    re met. Research indicates that anssortment of plant foods eaten overhe course of a day can provide allssential amino acids and ensure ad-quate nitrogen retention and use inealthy adults; thus, complementaryroteins do not need to be consumedt the same meal (8).A meta-analysis of nitrogen bal-

    nce studies found no significant dif-erence in protein needs due to theource of dietary protein (9). Based onhe protein digestibility-correctedmino acid score, which is the stan-ard method for determining proteinuality, other studies have found thatlthough isolated soy protein caneet protein needs as effectively as

    nimal protein, wheat protein eatenlone, for example, may result in aeduced efficiency of nitrogen utiliza-ion (10). Thus, estimates of proteinequirements of vegans may vary, de-ending to some degree on dietaryhoices. Food and nutrition profes-ionals should be aware that proteineeds might be somewhat higherhan the Recommended Dietary Al-owance in those vegetarians whoseietary protein sources are mainlyhose that are less well digested, suchs some cereals and legumes (11).Cereals tend to be low in lysine, an

    ssential amino acid (8). This may beelevant when evaluating diets of in-ividuals who do not consume animalrotein sources and when diets areelatively low in protein. Dietary ad-ustments such as the use of moreeans and soy products in place ofther protein sources that are lowern lysine or an increase in dietary pro-ein from all sources can ensure andequate intake of lysine.Although some vegan women have

    rotein intakes that are marginal,ypical protein intakes of lacto-ovo-egetarians and of vegans appear toeet and exceed requirements (12).thletes can also meet their proteineeds on plant-based diets (13).

    -3 Fatty Acidshereas vegetarian diets are gener-

    lly rich in n-6 fatty acids, they maye marginal in n-3 fatty acids. Dietshat do not include fish, eggs, or gen-rous amounts of algae generally areow in eicosapentaenoic acid (EPA)nd docosahexaenoic acid (DHA),atty acids important for cardiovascu-

    ar health as well as eye and brain

    268 July 2009 Volume 109 Number 7

    evelopment. The bioconversion of-linolenic acid (ALA), a plant-based-3 fatty acid, to EPA is generally lesshan 10% in humans; conversion ofLA to DHA is substantially less (14).egetarians, and particularly vegans,

    end to have lower blood levels of EPAnd DHA than nonvegetarians (15).HA supplements derived from mi-

    roalgae are well absorbed and posi-ively influence blood levels of DHA,nd also EPA through retroconver-ion (16). Soy milk and breakfastars, fortified with DHA, are nowvailable in the marketplace.The Dietary Reference Intakes rec-

    mmend intakes of 1.6 and 1.1 g ALAer day, for men and women, respec-ively (17). These recommendationsay not be optimal for vegetariansho consume little if any DHA andPA (17) and thus may need addi-

    ional ALA for conversion to DHA andPA. Conversion rates for ALA tend

    o improve when dietary n-6 levelsre not high or excessive (14). Vege-arians should include good sources ofLA in their diet, such as flaxseed,alnuts, canola oil, and soy. Thoseith increased requirements of n-3

    atty acids, such as pregnant and lac-ating women, may benefit fromHA-rich microalgae (18).

    ronhe iron in plant foods is nonheme

    ron, which is sensitive to both inhibi-ors and enhancers of iron absorption.nhibitors of iron absorption includehytates, calcium, and the polypheno-ics in tea, coffee, herb teas, and cocoa.iber only slightly inhibits iron absorp-ion (19). Some food preparation tech-iques such as soaking and sproutingeans, grains, and seeds, and the leav-ning of bread, can diminish phytateevels (20) and thereby enhance ironbsorption (21,22). Other fermentationrocesses, such as those used to makeiso and tempeh, may also improve

    ron bioavailability (23).Vitamin C and other organic acids

    ound in fruits and vegetables canubstantially enhance iron absorp-ion and reduce the inhibitory effectsf phytate and thereby improve irontatus (24,25). Because of lower bio-vailability of iron from a vegetarianiet, the recommended iron intakesor vegetarians are 1.8 times those ofonvegetarians (26).

    Whereas many studies of iron ab- v

    orption have been short term, theres evidence that adaptation to low in-akes takes place over the long term,nd involves both increased absorp-ion and decreased losses (27,28). In-idence of iron-deficiency anemiamong vegetarians is similar to thatf nonvegetarians (12,29). Althoughegetarian adults have lower irontores than nonvegetarians, their se-um ferritin levels are usually withinhe normal range (29,30).

    inche bioavailability of zinc from vege-

    arian diets is lower than from nonveg-tarian diets, mainly due to the higherhytic acid content of vegetarian diets31). Thus, zinc requirements for someegetarians whose diets consist mainlyf phytate-rich unrefined grains and le-umes may exceed the Recommendedietary Allowance (26). Zinc intakes ofegetarians vary with some researchhowing zinc intakes near recommen-ations (32) and other research findinginc intakes of vegetarians signifi-antly below recommendations (29,33).vert zinc deficiency is not evident inestern vegetarians. Due to the diffi-

    ulty in evaluating marginal zinc sta-us, it is not possible to determine theossible effect of lower zinc absorptionrom vegetarian diets (31). Zinc sourcesnclude soy products, legumes, grains,heese, and nuts. Food preparationechniques, such as soaking andprouting beans, grains, and seeds asell as leavening bread, can reduceinding of zinc by phytic acid and in-rease zinc bioavailability (34). Organiccids, such as citric acid, can also en-ance zinc absorption to some extent


    odineome studies suggest that vegansho do not consume key sources of

    odine, such as iodized salt or sea veg-tables, may be at risk for iodine de-ciency, because plant-based dietsre typically low in iodine (12,35). Seaalt and kosher salt are generally notodized nor are salty seasonings suchs tamari. Iodine intake from sea veg-tables should be monitored becausehe iodine content of sea vegetablesaries widely and some contain sub-tantial amounts of iodine (36).Foods such as soybeans, cruciferous

    egetables, and sweet potatoes con-

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    ain natural goitrogens. These foodsave not been associated with thyroid

    nsufficiency in healthy people pro-ided iodine intake is adequate (37).

    alciumalcium intakes of lacto-ovo-vegetar-

    ans are similar to, or higher than,hose of nonvegetarians (12), whereasntakes of vegans tend to be lowerhan both groups and may fall belowecommended intakes (12). In the Ox-ord component of the European Pro-pective Investigation into Cancernd Nutrition (EPIC-Oxford) study,he risk of bone fracture was similaror lacto-ovo-vegetarians and meataters, whereas vegans had a 30%igher risk of fracture possibly due toheir considerably lower mean cal-ium intake (38). Diets rich in meat,sh, dairy products, nuts, and grainsroduce a high renal acid load,ainly due to sulfate and phosphate

    esidues. Calcium resorption fromone helps to buffer this acid load,esulting in increased urinary lossesf calcium. A high sodium intake canlso promote urinary calcium losses.n the other hand, fruits and vegeta-les rich in potassium and magne-ium produce a high renal alkalineoad which slows bone calcium resorp-ion, and decreases calcium losses inhe urine. In addition, some studieshow that the ratio of dietary calciumo protein is a better predictor of boneealth than calcium intake alone.ypically, this ratio is high in lacto-vo-vegetarian diets and favors boneealth, whereas vegans have a ratiof calcium to protein that is similar tor lower than that of nonvegetarians39). Many vegans may find it is eas-er to meet their calcium needs if cal-ium-fortified foods or dietary supple-ents are utilized (39).Low-oxalate greens (eg, bok choy,

    roccoli, Chinese cabbage, collards,nd kale) and fruit juices fortifiedith calcium citrate malate are good

    ources of highly bioavailable calcium50% to 60% and 40% to 50%, respec-ively), while calcium-set tofu, andow’s milk have good bioavailabilityf calcium (about 30% to 35%), andesame seeds, almonds, and driedeans have a lower bioavailability21% to 27%) (39). The bioavailabilityf calcium from soy milk fortified withalcium carbonate is equivalent to

    ow’s milk although limited research e

    as shown that calcium availability isubstantially less when tricalciumhosphate is used to fortify the soyeverage (40). Fortified foods such asruit juices, soy milk, and rice milk,nd breakfast cereals can contributeignificant amounts of dietary cal-ium for the vegan (41). Oxalates inome foods, such as spinach andwiss chard, greatly reduce calciumbsorption, making these vegetablespoor source of usable calcium. Foods

    ich in phytate may also inhibit cal-ium absorption

    itamin Ditamin D has long been known tolay a role in bone health. Vitamin Dtatus depends on sunlight exposurend intake of vitamin D–fortifiedoods or supplements. The extent ofutaneous vitamin D production fol-owing sunlight exposure is highlyariable and is dependent on a num-er of factors, including the time ofay, season, latitude, skin pigmenta-ion, sunscreen use, and age. Low vi-amin D intakes (42), low serum 25-ydroxyvitamin D levels (12), andeduced bone mass (43) have been re-orted in some vegan and macrobioticroups who did not use vitamin Dupplements or fortified foods.Foods that are fortified with vita-in D include cow’s milk, some

    rands of soy milk, rice milk, and or-nge juice, and some breakfast cere-ls and margarines. Both vitamin D-2nd vitamin D-3 are used in supple-ents and to fortify foods. Vitamin-3 (cholecalciferol) is of animal ori-in and is obtained through the ultra-iolet irradiation of 7-dehydrocholes-erol from lanolin. Vitamin D-2ergocalciferol) is produced from theltraviolet irradiation of ergosterolrom yeast and is acceptable to veg-ns. Although some research sug-ests that vitamin D-2 is less effectivehan vitamin D-3 in maintaining se-um 25-hydroxyvitamin D levels (44)ther studies find that vitamin D-2nd vitamin D-3 are equally effective45). If sun exposure and intake ofortified foods are insufficient to meeteeds, vitamin D supplements areecommended.

    itamin B-12he vitamin B-12 status of some veg-

    tarians is less than adequate due to e

    July 2009 ● Journal

    ot regularly consuming reliableources of vitamin B-12 (12,46,47).acto-ovo-vegetarians can obtain ad-quate vitamin B-12 from dairy foods,ggs, or other reliable vitamin B-12ources (fortified foods and supple-ents), if regularly consumed. For

    egans, vitamin B-12 must be ob-ained from regular use of vitamin-12-fortified foods, such as fortifiedoy and rice beverages, some break-ast cereals and meat analogs, or Redtar Vegetarian Support Formula nu-ritional yeast; otherwise a daily vita-in B-12 supplement is needed. No

    nfortified plant food contains anyignificant amount of active vitamin-12. Fermented soy products cannote considered a reliable source of ac-ive B-12 (12,46).

    Vegetarian diets are typically richn folacin, which may mask the hema-ological symptoms of vitamin B-12eficiency, so that vitamin B-12 defi-iency may go undetected until aftereurological signs and symptomsay be manifest (47). Vitamin B-12

    tatus is best determined by measur-ng serum levels of homocysteine,

    ethylmalonic acid, or holotransco-alamin II (48).

    EGETARIAN DIETS THROUGHOUT THEIFE CYCLEell-planned vegan, lacto-vegetarian,

    nd lacto-ovo-vegetarian diets are ap-ropriate for all stages of the life cycle,ncluding pregnancy and lactation. Ap-ropriately planned vegan, lacto-vege-arian, and lacto-ovo-vegetarian dietsatisfy nutrient needs of infants, chil-ren, and adolescents and promote nor-al growth (49-51). Figure 1 provides

    pecific suggestions for meal planningor vegetarian diets. Lifelong vegetari-ns have adult height, weight, andMIs that are similar to those who be-ame vegetarian later in life, suggest-ng that well-planned vegetarian dietsn infancy and childhood do not affectnal adult height or weight (53). Vege-arian diets in childhood and adoles-ence can aid in the establishment ofifelong healthful eating patterns andan offer some important nutritionaldvantages. Vegetarian children anddolescents have lower intakes of cho-esterol, saturated fat, and total fat andigher intakes of fruits, vegetables, andber than nonvegetarians (54,55). Veg-

    tarian children have also been re-


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    orted to be leaner and to have lowererum cholesterol levels (50,56).

    regnant and Lactating Womenhe nutrient and energy needs ofregnant and lactating vegetarianomen do not differ from those ofonvegetarian women with the excep-ion of higher iron recommendationsor vegetarians. Vegetarian diets cane planned to meet the nutrient needsf pregnant and lactating women. Ev-dence-based analysis of the researchiterature was used to evaluate exist-ng research on vegetarian pregnancy57). Seven questions for evidence-nalysis were identified:

    How do macronutrient and energyintake in pregnant vegetarians dif-fer from intakes in pregnant omni-vores?Are birth outcomes different formothers who maintain a vegetarianvs an omnivorous diet during preg-nancy?How do macronutrient and energyintake in pregnant vegans differfrom intakes in pregnant omnivores?Are birth outcomes different formothers who maintain a vegan vsan omnivorous diet during preg-nancy?What are patterns of micronutrientintake among pregnant vegetarians?What is the bioavailability of differ-ent micronutrients in pregnant veg-etarians?What are birth outcomes associatedwith the micronutrient intake ofmaternal vegetarian diets?

    The complete results of this evidence-ased analysis can be found on the EALeb site (www.adaevidencelibrary.com)

    A variety of menu planning approaches caThe Dietary Reference Intakes are a valuable rVarious food guides (41,52) can be used whenfollowing guidelines can help vegetarians plan

    ● Choose a variety of foods, including whoand, if desired, dairy products, and eggs

    ● Minimize intake of foods that are highlyespecially saturated fat and trans-fatty ac

    ● Choose a variety of fruits and vegetables● If animal foods such as dairy products an

    and use both eggs and dairy products in● Use a regular source of vitamin B-12 and

    igure 1. Suggestions for planning vegetarian

    nd are summarized below. v

    270 July 2009 Volume 109 Number 7

    acronutrient and Energy Intake. Fourrimary research studies were identi-ed that examined maternal macro-utrient intake during lacto-ovo- or

    acto- vegetarian pregnancy (58-61).one focused on pregnant vegans.EAL Conclusion Statement: Limited re-

    earch on non-US populations indi-ates that the macronutrient intakef pregnant vegetarians is similar tohat of nonvegetarians with the fol-owing exceptions (as percentages ofnergy intake):

    pregnant vegetarians receive statis-tically lower levels of protein thanpregnant nonvegetarians; andpregnant vegetarians receive statis-tically higher levels of carbohydratesthan pregnant nonvegetarians.

    It is important to note, however,hat none of the studies report a clin-cally significant difference in macro-utrient intake. In other words, nonef the studies report a protein defi-iency in pregnant vegetarians.rade III�Limited.EAL Conclusion Statement: No researchas identified that focused on macro-utrient intakes among pregnant veg-ns. Grade V�Not Assignable.

    irth Outcomes. Four cohort studiesere identified that examined the rela-

    ionship between maternal macronu-rient intake during pregnancy andirth outcomes such as birth weightnd length (59-62). None of the studiesocused on pregnant vegans.

    EAL Conclusion Statement: Limited re-earch on non-US populations indi-ates that there are no significantealth differences in babies born toonvegan vegetarian mothers vs non-

    rovide adequate nutrition for vegetarians.urce for food and nutrition professionals.rking with vegetarian clients. In addition, thelthful diets:rains, vegetables, fruits, legumes, nuts, seeds,

    etened, high in sodium, and high in fat,.

    ggs are used, choose lower-fat dairy productsderation.sunlight exposure is limited, of vitamin D.


    egetarians. Grade III�Limited. f

    EAL Conclusion Statement: No researchas identified that focused on the birthutcomes of vegan vs omnivorousothers. Grade V�Not Assignable.

    icronutrient Intake. Based on 10 stud-es (58-60,63-69), two of which wereonducted in the United States (64,65),nly the following micronutrients hadower intake among vegetarians thanonvegetarians:

    vitamin B-12;vitamin C;calcium; andzinc.

    Vegetarians did not meet dietarytandard (in at least one country) for:

    vitamin B-12 (in the United King-dom);iron (in the United States, for bothvegetarians and omnivores);folate (in Germany, though lowerrate of deficiency than among omni-vores); andzinc (in the United Kingdom).

    EAL Conclusion Statement: Grade III�imited.

    icronutrient Bioavailability. Six studiesfive non-US, one with combined USnd non-US samples; all but one of pos-tive quality) were identified that ex-mined the bioavailability of differenticronutrients in vegetarian vs non-

    egetarian pregnant women (58,63,64,6,67,69). Of the micronutrients exam-ned in the research, only serum B-12evels were significantly lower in non-egan-vegetarians than nonvegetar-ans. In addition, one study reportedhat lower B-12 levels are more likelyo be associated with high serum totalomocysteine in lacto-ovo-vegetarianshan low meat eaters or omnivores.

    hereas zinc levels were not signifi-antly different between nonvegan-egetarians and nonvegetarians, vege-arians who have a high intake ofalcium may be at risk for zinc defi-iency (because of the interaction be-ween phytate, calcium, and zinc).ased on limited evidence, plasma fo-

    ate levels may actually be highermong some vegetarian groups thanonvegetarians.EAL Conclusion Statement: Grade III�


    icronutrients and Birth Outcome EAL Con-lusion Statement: Limited evidence

    n pesowo

    heale g.sweids

    .d emo, if

    rom seven studies (all outside the


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    nited States) indicated that the mi-ronutrient content of a balanced ma-ernal vegetarian diet does not haveetrimental outcomes for the healthf the child at birth (58-63,69). Thereay be, however, a risk for a false

    ositive diagnosis of Down syndromen the fetus when maternal serumree beta-human chorionic gonadotro-in and alpha fetoprotein levels aresed as markers in vegetarian moth-rs. Grade III�Limited.utrition Considerations. Results of evi-ence-based analysis suggest thategetarian diets can be nutritionallydequate in pregnancy and can leado a positive birth outcome (57).

    Key nutrients in pregnancy includeitamin B-12, vitamin D, iron, andolate whereas key nutrients in lacta-ion include vitamin B-12, vitamin D,alcium, and zinc. Diets of pregnantnd lactating vegetarians should con-ain reliable sources of vitamin B-12aily. Based on recommendations forregnancy and lactation, if there isoncern about vitamin D synthesisecause of limited sunlight exposure,kin tone, season, or sunscreen use,regnant and lactating women shouldse vitamin D supplements or vita-in D–fortified foods. No studies

    ncluded in the evidence-analysis ex-mined vitamin D status during veg-tarian pregnancy. Iron supplementsay be needed to prevent or treat

    ron-deficiency anemia, which is com-on in pregnancy. Women capable of

    ecoming pregnant as well as womenn the periconceptional period are ad-ised to consume 400 �g folate dailyrom supplements, fortified foods, oroth. Zinc and calcium needs can beet through food or supplement

    ources as identified in earlier sec-ions on these nutrients.

    DHA also plays a role in pregnancynd lactation. Infants of vegetarianothers appear to have lower cord

    nd plasma DHA than do infants ofonvegetarians (70). Breast milkHA is lower in vegans and lacto-ovo-egetarians than in nonvegetarians71). Because of DHA’s beneficial ef-ects on gestational length, infant vi-ual function, and neurodevelopment,regnant and lactating vegetariansnd vegans should choose foodources of DHA (fortified foods or eggsrom hens fed DHA-rich microalgae)r use a microalgae-derived DHA sup-

    lement (72,73). Supplementation m

    ith ALA, a DHA precursor, in preg-ancy and lactation has not beenhown to be effective in increasing in-ant DHA levels or breast milk DHAoncentration (74,75).

    nfantsrowth of young vegetarian infants

    eceiving adequate amounts of breastilk or commercial infant formula is

    ormal. When solid foods are intro-uced, provision of good sources of en-rgy and nutrients can ensure normalrowth. The safety of extremely re-trictive diets such as fruitarian andaw foods diets has not been studiedn children. These diets can be veryow in energy, protein, some vita-

    ins, and some minerals and cannote recommended for infants and chil-ren.Breastfeeding is common in vege-

    arian women, and this practicehould be supported. The breast milkf vegetarian women is similar inomposition to that of nonvegetariansnd is nutritionally adequate. Com-ercial infant formulas should be

    sed if infants are not breastfed orre weaned before 1 year of age. Soyormula is the only option for non-reastfed vegan infants. Other prep-rations including soymik, rice milk,nd homemade formulas should note used to replace breast milk or com-ercial infant formula.Solid foods should be introduced in

    he same progression as for nonveg-tarian infants, replacing strainedeat with mashed or pureed tofu, le-

    umes (pureed and strained if neces-ary), soy or dairy yogurt, cooked eggolk, and cottage cheese. Later,round 7 to 10 months, foods such asubed tofu, cheese, or soy cheese andite-size pieces of veggie burgers cane started. Commercial, full-fat, forti-ed soy milk or pasteurized cow’silk can be used as a primary bever-

    ge starting at age 1 year or older forchild who is growing normally and

    ating a variety of foods (51). Foodshat are rich in energy and nutrientsuch as legume spreads, tofu, andashed avocado should be used when

    he infant is being weaned. Dietaryat should not be restricted in chil-ren younger than 2 years.Guidelines for dietary supplements

    enerally follow those for nonvegetar-an infants. Breastfed infants whose

    others do not have an adequate in- K

    July 2009 ● Journal

    ake of vitamin B-12 should receive aitamin B-12 supplement (51). Zincntake should be assessed and zincupplements or zinc-fortified foodssed when complementary foods are

    ntroduced if the diet is low in zinc orainly consists of foods with low zinc

    ioavailability (76).

    hildrenrowth of lacto-ovo-vegetarian chil-ren is similar to that of their nonveg-tarian peers (50). Little informationbout the growth of nonmacrobioticegan children has been published.ome studies suggest that vegan chil-ren tend to be slightly smaller butithin the normal ranges of the stan-ards for weight and height (58). Poorrowth in children has primarily beeneen in those on very restrictediets (77).Frequent meals and snacks and the

    se of some refined foods (such as for-ified breakfast cereals, breads, andasta) and foods higher in unsatur-ted fats can help vegetarian childreneet energy and nutrient needs. Av-

    rage protein intakes of vegetarianhildren (lacto-ovo, vegan, and macro-iotic) generally meet or exceed rec-mmendations (12). Vegan childrenay have slightly higher protein

    eeds because of differences in pro-ein digestibility and amino acid com-osition (49,78) but these proteineeds are generally met when dietsontain adequate energy and a vari-ty of plant foods.Food guides for vegetarian children

    ave been published elsewhere (12).

    dolescentsrowth of lacto-ovo-vegetarian andonvegetarian adolescents is similar50). Earlier studies suggest that veg-tarian girls reach menarche slightlyater than nonvegetarians (79); moreecent studies find no difference inge at menarche (53,80).Vegetarian diets appear to offer

    ome nutritional advantages for ado-escents. Vegetarian adolescents areeported to consume more fiber, iron,olate, vitamin A, and vitamin C thanonvegetarians (54,81). Vegetariandolescents also consume more fruitsnd vegetables, and fewer sweets,ast foods, and salty snacks comparedo nonvegetarian adolescents (54,55).

    ey nutrients of concern for adoles-


  • ct














    ent vegetarians include calcium, vi-amin D, iron, zinc, and vitamin B-12.

    Being vegetarian does not causeisordered eating as some have sug-ested although a vegetarian dietay be selected to camouflage an ex-

    sting eating disorder (82). Because ofhis, vegetarian diets are somewhatore common among adolescentsith eating disorders than in the gen-ral adolescent population (83). Foodnd nutrition professionals should beware of young clients who greatlyimit food choices and who exhibitymptoms of eating disorders.With guidance in meal planning,

    egetarian diets can be appropriatend healthful choices for adolescents.

    lder Adultsith aging, energy needs decrease

    ut recommendations for several nu-rients, including calcium, vitamin D,nd vitamin B-6 are higher. Intakesf micronutrients, especially calcium,inc, iron, and vitamin B-12, declinen older adults (84). Studies indicatehat older vegetarians have dietaryntakes that are similar to nonveg-tarians (85,86).Older adults may have difficultyith vitamin B-12 absorption from

    ood, frequently due to atrophic gas-ritis, so vitamin B-12-fortified foodsr supplements should be used be-ause the vitamin B-12 in fortifiedoods and supplements is usuallyell-absorbed (87). Cutaneous vita-in D production decreases with ag-

    ng so that dietary or supplementalources of vitamin D are especiallymportant (88). Although current rec-mmendations for protein for healthylder adults are the same as those forounger adults on a body weight basis17), this is a controversial area (89).ertainly older adults who have lownergy requirements will need to con-ume concentrated sources of protein.lder adults can meet protein needsn a vegetarian diet if a variety ofrotein-rich plant foods, including le-umes and soy products, are eatenaily.

    thletesegetarian diets can also meet theeeds of competitive athletes. Nutri-ion recommendations for vegetarianthletes should be formulated with con-

    ideration of the effects of both vegetar- d

    272 July 2009 Volume 109 Number 7

    an diets and exercise. The position ofmerican Dietetic Association and Di-titians of Canada on nutrition andthletic performance provides addi-ional information specific to vegetar-an athletes (90). Research is needed onhe relation between vegetarian dietnd performance. Vegetarian diets thateet energy needs and contain a vari-

    ty of plant-based protein foods, suchs soy products, other legumes, grains,uts, and seeds, can provide adequaterotein without the use of special foodsr supplements (91). Vegetarian ath-etes may have lower muscle creatineoncentration due to low dietary creat-ne levels (92,93). Vegetarian athletesarticipating in short-term, high-inten-ity exercise and resistance trainingay benefit from creatine supplemen-

    ation (91). Some, but not all researchuggests that amenorrhea may be moreommon among vegetarian than non-egetarian athletes (94,95). Femaleegetarian athletes may benefit fromiets that include adequate energy,igher levels of fat, and generousmounts of calcium and iron.

    EGETARIAN DIETS AND CHRONICISEASEardiovascular Disease (CVD)vidence-based analysis of the re-earch literature is being used tovaluate existing research on the re-ationship between vegetarian di-tary patterns and CVD risk factors96). Two evidence analysis questionsave been completed:

    What is the relationship between avegetarian diet and ischemic heartdisease?How is micronutrient intake in avegetarian diet associated withCVD risk factors?

    schemic Heart Disease. Two large co-ort studies (97,98) and one meta-nalysis (99) found that vegetariansere at lower risk of death from isch-mic heart disease than nonvegetar-ans. The lower risk of death was seenn both lacto-ovo-vegetarians and veg-ns (99). The difference in risk per-isted after adjustment for BMI,moking habits, and social class (97).his is especially significant becausehe lower BMI commonly seen in veg-tarians (99) is one factor that mayelp to explain the lower risk of heart

    isease in vegetarians. If this differ- v

    nce in risk persists even after adjust-ent for BMI, other aspects of a veg-

    tarian diet may be responsible forhe risk reduction, above and beyondhat which would be expected due toower BMI.

    EAL Conclusion Statement: A vegetar-an diet is associated with a lower riskf death from ischemic heart disease.rade I�Good.

    lood Lipid Levels. The lower risk ofeath from ischemic heart diseaseeen in vegetarians could be ex-lained in part by differences in bloodipid levels. Based on blood lipid lev-ls in one large cohort study, the in-idence of ischemic heart disease wasstimated to be 24% lower in lifelongegetarians and 57% lower in lifelongegans compared to meat eaters (97).ypically, studies find lower total cho-

    esterol and low-density lipoproteinLDL) cholesterol levels in vegetari-ns (100, for example). Interventiontudies have demonstrated a reduc-ion in total and LDL-cholesterol lev-ls when subjects switched from theirsual diet to a vegetarian diet (101,or example). Although evidence isimited that a vegetarian diet is asso-iated with higher high-density li-oprotein cholesterol levels or withigher or lower triglyceride levels, aegetarian diet is consistently associ-ted with lower LDL cholesterol lev-ls. Other factors such as variationsn BMI and foods eaten or avoidedithin the context of a vegetarian diet

    r lifestyle differences could partiallyxplain the inconsistent results withegard to blood lipid levels.Factors in a vegetarian diet that

    ould have a beneficial effect on bloodipid levels include the higher amountsf fiber, nuts, soy, and plant sterols andower levels of saturated fat. Vegetari-ns consume between 50% and 100%ore fiber than nonvegetarians and

    egans have higher intakes than lacto-vo-vegetarians (12). Soluble fiber haseen repeatedly shown to lower totalnd LDL cholesterol levels and to re-uce risk of coronary heart disease (17).diet high in nuts significantly lowers

    otal and LDL cholesterol levels (102).oy isoflavones may play a role in re-ucing LDL cholesterol levels and ineducing the susceptibility of LDL toxidation (103). Plant sterols, found inegumes, nuts and seeds, whole grains,

    egetable oils, and other plant-based

  • fl













    oods reduce cholesterol absorption andower LDL cholesterol levels (104).

    actors Associated with Vegetarian Dietshat May Affect Risk of CVD. Other fac-ors in vegetarian diets may impactVD risk independent of effects on

    holesterol levels. Foods that featurerominently in a vegetarian diet thatay offer protection from CVD in-

    lude soy protein (105), fruits andegetables, whole grains, and nuts106,107). Vegetarians appear to con-ume more phytochemicals than doonvegetarians because a greaterercentage of their energy intakeomes from plant foods. Flavonoidsnd other phytochemicals appear toave protective effects as antioxi-ants, in reducing platelet aggrega-ion and blood clotting, as anti-in-ammatory agents, and in improvingndothelial function (108,109). Lacto-vo-vegetarians have been shown toave significantly better vasodilationesponses, suggesting a beneficial ef-ect of vegetarian diet on vascular en-othelial function (110).Evidence analysis was conducted

    o examine how the micronutrientakeup of vegetarian diets might be

    elated to CVD risk factors.EAL Conclusion Statement: No re-

    earch meeting inclusion criteriaere identified that examined the mi-

    ronutrient intake of a vegetarianiet and CVD risk factors. Grade�Not Assignable.Not all aspects of vegetarian diets

    re associated with reduced risk foreart disease. The higher serum ho-ocysteine levels that have been re-

    orted in some vegetarians, appar-ntly due to inadequate vitamin B-12ntake, may increase risk of CVD111,112) although not all studiesupport this (113).Vegetarian diets have been suc-

    essfully used in treatment of CVD. Aegimen that used a very low-fat�10% of energy) near vegan (limitedonfat dairy and egg whites allowed)iet along with exercise, smoking ces-ation, and stress management, washown to reduce blood lipid levels,lood pressure, and weight, and im-rove exercise capacity (114). A near-egan diet high in phytosterols, vis-ous fiber, nuts, and soy protein haseen shown to be as effective as aow-saturated fat diet and a statin forowering serum LDL-cholesterol lev-

    ls (115). h

    ypertensioncross-sectional study and a cohort

    tudy found that there was a lowerate of hypertension among vegetari-ns than nonvegetarians (97,98).imilar findings were reported ineventh-day Adventists (Adventists)

    n Barbados (116) and in preliminaryesults from the Adventist Healthtudy-2 cohort (117). Vegans appearo have a lower rate of hypertensionhan do other vegetarians (97,117).

    Several studies have reportedower blood pressure in vegetariansompared to nonvegetarians (97,118)lthough other studies reported littleifference in blood pressure betweenegetarians and nonvegetarians100,119,120). At least one of thetudies reporting lower blood pres-ure in vegetarians found that BMIather than diet accounted for muchf the age-adjusted variation in bloodressure (97). Vegetarians tend toave a lower BMI than nonvegetar-

    ans (99); thus, vegetarian diets’ in-uence on BMI may partially accountor reported differences in blood pres-ure between vegetarians and non-egetarians. Variations in dietary in-ake and lifestyle within groups ofegetarians may limit the strength ofonclusions with regard to the rela-ionship between vegetarian dietsnd blood pressure.Possible factors in vegetarian diets

    hat could result in lower blood pres-ure include the collective effect ofarious beneficial compounds foundn plant foods such as potassium,

    agnesium, antioxidants, dietary fat,nd fiber (118,121). Results from theietary Approaches to Stop Hyper-

    ension study, in which subjects con-umed a low-fat diet rich in fruits,egetables and dairy, suggest thatubstantial dietary levels of potas-ium, magnesium, and calcium playn important role in reducing bloodressure levels (122). Fruit and vege-able intake was responsible for aboutne-half of the blood pressure reduc-ion of the Dietary Approaches totop Hypertension diet (123). In ad-ition, nine studies report that con-umption of five to 10 servings of fruitnd vegetables significantly lowerslood pressure (124).

    iabetesdventist vegetarians are reported to

    ave lower rates of diabetes than Ad- l

    July 2009 ● Journal

    entist nonvegetarians (125). In thedventist Health Study, age-adjustedisk for developing diabetes was two-old greater in nonvegetarians, com-ared with their vegetarian counter-arts (98). Although obesity increaseshe risk of type 2 diabetes, meat androcessed meat intake was found toe an important risk factor for diabe-es even after adjustment for BMI126). In the Women’s Health Study,he authors also observed positive as-ociations between intakes of redeat and processed meat and risk of

    iabetes after adjusting for BMI, totalnergy intake, and exercise (127). Aignificantly increased risk of diabe-es was most pronounced for frequentonsumption of processed meats suchs bacon and hot dogs. Results re-ained significant even after further

    djustment for dietary fiber, magne-ium, fat, and glycemic load (128). Inlarge cohort study, the relative risk

    or type 2 diabetes in women for everyne-serving increase in intake was.26 for red meat and 1.38 to 1.73 forrocessed meats (128).In addition, higher intakes of vege-

    ables, whole-grain foods, legumes,nd nuts have all been associatedith a substantially lower risk of in-

    ulin resistance and type 2 diabetes,nd improved glycemic control in ei-her normal or insulin-resistant indi-iduals (129-132). Observationaltudies have found that diets rich inhole-grain foods are associated with

    mproved insulin sensitivity. This ef-ect may be partly mediated by signif-cant levels of magnesium and cerealber in the whole-grain foods (133).ersons with elevated blood glucoseay experience an improvement in

    nsulin resistance and lower fastinglood glucose levels after they haveonsumed whole grains (134). Peopleonsuming about three servings peray of whole-grain foods are 20% to0% less likely to develop type 2 dia-etes than low consumers (�3 serv-ngs per week) (135).

    In the Nurses’ Health Study, nutonsumption was inversely associ-ted with risk of type 2 diabetes afterdjustment for BMI, physical activ-ty, and many other factors. The riskf diabetes for those consuming nutsve or more times a week was 27%

    ower than those almost never eatinguts, whereas the risk of diabetes forhose consuming peanut butter at

    east five times a week (equivalent to


  • 5tn













    oz peanuts/week) was 21% lowerhan those who almost never ate pea-ut butter (129).Because legumes contain slowly di-

    ested carbohydrate and have a highber content, they are expected to im-rove glycemic control and reduce in-ident diabetes. In a large prospectivetudy, an inverse association waseen between the intake of total le-umes, peanuts, soybeans, and otheregumes by Chinese women, and thencidence of type 2 diabetes mellitus,fter adjustment for BMI and otheractors. The risk of type 2 diabetesas 38% and 47% lower, for those

    onsuming a high intake of total le-umes and soybeans, respectively,ompared to a low intake (132).

    In a prospective study, the risk ofype 2 diabetes was 28% lower foromen in the upper quintile of vege-

    able, but not fruit intake, comparedo the lower quintile of vegetable in-ake. Individual vegetable groupsere all inversely and significantlyssociated with the risk of type 2 di-betes (131). In another study, con-umption of green leafy vegetablesnd fruit, but not fruit juice, was as-ociated with a lower risk of diabetes136).

    Fiber-rich vegan diets are charac-erized by a low glycemic index and aow to moderate glycemic load (137).n a 5-month randomized clinicalrial, a low-fat vegan diet was showno considerably improve glycemic con-rol in persons with type 2 diabetes,ith 43% of subjects reducing diabe-

    es medication (138). Results wereuperior to those obtained from fol-owing a diet based on American Dia-etes Association guidelines (individ-alized based on body weight and

    ipid concentrations; 15%-20% pro-ein; �7% saturated fat; 60% to 70%arbohydrate and monounsaturatedat; �200 mg cholesterol).

    besitymong Adventists, about 30% ofhom follow a meatless diet, vegetar-

    an eating patterns have been associ-ted with lower BMI, and BMI in-reased as the frequency of meatonsumption increased in both mennd women (98). In the Oxford Vege-arian Study, BMI values were highern nonvegetarians compared withegetarians in all age groups for both

    en and women (139). In a cross-sec- c

    274 July 2009 Volume 109 Number 7

    ional study of 37,875 adults, meat-aters had the highest age-adjustedean BMI and vegans the lowest,ith other vegetarians having inter-ediate values (140). In the EPIC-xford Study, weight gain over a-year period, among a health-con-cious cohort, was lowest amonghose who moved to a diet containingewer animal foods (141). In a largeross-sectional British study, it wasbserved that those people who be-ame vegetarian as adults did not dif-er in BMI or body weight comparedo those who were life-long vegetari-ns (53). However, those who haveeen following a vegetarian diet for ateast 5 years typically have a lowerMI. Among Adventists in Barbados,

    he number of obese vegetarians, whoad followed the diet for more than 5ears, was 70% less than the numberf obese omnivores whereas recentegetarians (following the diet �5ears) had body weights similar tomnivores (116). A low-fat vegetarianiet has been shown to be more effec-ive in long-term weight loss for post-enopausal women than a more

    onventional National Cholesterolducation Program diet (142). Vege-

    arians may have a lower BMI due toheir higher consumption of fiber-ich, low-energy foods, such as fruitnd vegetables.

    anceregetarians tend to have an overallancer rate lower than that of theeneral population, and this is notonfined to smoking-related cancers.ata from the Adventist Healthtudy revealed that nonvegetariansad a substantially increased risk foroth colorectal and prostate cancerompared with vegetarians, but thereere no significant differences in riskf lung, breast, uterine, or stomachancer between the groups after con-rolling for age, sex, and smoking98). Obesity is a significant factor in-reasing the risk of cancer at a num-er of sites (143). Because the BMI ofegetarians tends to be lower thanhat of nonvegetarians, the lighterody weight of the vegetarians maye an important factor.A vegetarian diet provides a variety

    f cancer-protective dietary factors144). Epidemiologic studies haveonsistently shown that a regular

    onsumption of fruit and vegetables is c

    trongly associated with a reducedisk of some cancers (108,145,146). Inontrast, among survivors of earlytage breast cancer in the Women’sealthy Eating and Living trial, thedoption of a diet enhanced by addi-ional daily fruit and vegetable serv-ngs did not reduce additional breastancer events or mortality over a-year period (147).Fruit and vegetables contain a com-

    lex mixture of phytochemicals, pos-essing potent antioxidant, antiprolif-rative, and cancer-protective activity.he phytochemicals can display addi-

    ive and synergistic effects, and areest consumed in whole foods148-150). These phytochemicals inter-ere with several cellular processes in-olved in the progression of cancer.hese mechanisms include the inhibi-

    ion of cell proliferation, inhibition ofNA adduct formation, inhibition ofhase 1 enzymes, inhibition of signalransduction pathways and oncogenexpression, induction of cell cycle arrestnd apoptosis, induction of phase 2 en-ymes, blocking the activation of nu-lear factor-kappaB, and inhibiting an-iogenesis (149).According to the recent World Can-

    er Research Fund report (143), fruitnd vegetables are protective againstancer of the lung, mouth, esophagus,nd stomach, and to a lesser degreeome other sites. The regular use ofegumes also provides a measure ofrotection against stomach and pros-ate cancer (143). Fiber, vitamin C,arotenoids, flavonoids, and other phy-ochemicals in the diet are reported toxhibit protection against various can-ers. Allium vegetables may protectgainst stomach cancer and garlic pro-ects against colorectal cancer. Fruitsich in the red pigment lycopene areeported to protect against prostateancer (143). Recently, cohort studiesave suggested that a high intake ofhole grains provided substantial pro-

    ection against various cancers (151).egular physical activity provides sig-ificant protection against most of theajor cancers (143).Although there is such a variety of

    otent phytochemicals in fruit andegetables, human population studiesave not shown large differences inancer incidence or mortality ratesetween vegetarians and nonvegetar-ans (99,152). Perhaps more detailedood consumption data are needed be-

    ause the bioavailability and potency

  • opeomooaptfi














    f phytochemicals depends on foodreparation, such as whether the veg-tables are cooked or raw. In the casef prostate cancer, a high dairy intakeay lessen the chemoprotective effect

    f a vegetarian diet. Use of dairy andther calcium-rich foods have beenssociated with an increased risk ofrostate cancer (143,153,154), al-hough not all studies support thisnding (155).Red meat and processed meat con-

    umption is consistently associatedith an increase in the risk of colorec-

    al cancer (143). On the other hand,he intake of legumes was negativelyssociated with risk of colon cancer inonvegetarians (98). In a pooled anal-sis of 14 cohort studies, the adjustedisk of colon cancer was substantiallyeduced by a high intake of fruit andegetable vs a low intake. Fruit andegetable intakes were associatedith a lower risk of distal colon can-

    er, but not with proximal colon can-er (156). Vegetarians have a sub-tantially greater intake of fiber thanonvegetarians. A high fiber intake ishought to protect against colon can-er, although not all research sup-orts this. The EPIC study involving0 European countries reported a5% reduction in risk of colorectalancer in the highest quartile of di-tary fiber intake compared to theowest. Based upon these findings,ingham and colleagues (157) con-

    luded that in populations with a lowber intake, doubling the fiber intakeould reduce the colorectal cancer by0%. On the other hand, a poolednalysis of 13 prospective cohorttudies reported a high dietary fiberntake was not associated with a de-reased risk of colorectal cancer afterccounting for multiple risk factors158).

    Soy isoflavones and soy foods haveeen shown to possess anti-cancerroperties. Meta-analysis of eighttudies (one cohort, and seven caseontrol) conducted in high-soy-con-uming Asians showed a significantrend of decreasing risk of breast can-er with increasing soy food intake. Inontrast, soy intake was unrelated toreast cancer risk in studies con-ucted in 11 low-soy-consumingestern populations (159). However,

    ontroversy remains regarding thealue of soy as a cancer-protectivegent, because not all research sup-

    orts the protective value of soy to- a

    ards breast cancer (160). On thether hand, meat consumption haseen linked in some, but not all, stud-es with an increased risk of breastancer (161). In one study, breast can-er risk increased by 50% to 60% forach additional 100 g/day of meat con-umed (162).

    steoporosisairy products, green leafy vegeta-les, and calcium-fortified plant foodsincluding some brands of ready-to-at cereals, soy and rice beverages,nd juices) can provide ample calciumor vegetarians. Cross-sectional andongitudinal population-based studiesublished during the past 2 decadesuggest no differences in bone min-ral density (BMD), for both trabecu-ar and cortical bone, between omni-ores and lacto-ovo-vegetarians (163).Although very little data exist on

    he bone health of vegans, some stud-es suggest that bone density is lowermong vegans compared with non-egetarians (164,165). The Asianegan women in these studies hadery low intakes of protein and cal-ium. An inadequate protein and lowalcium intake has been shown to bessociated with bone loss and frac-ures at the hip and spine in elderlydults (166,167). In addition, vitaminstatus is compromised in some veg-

    ns (168).Results from the EPIC-Oxford study

    rovide evidence that the risk of boneractures for vegetarians is similar tohat of omnivores (38). The higher riskf bone fracture in vegans appeared toe a consequence of a lower calciumntake. However, the fracture rates ofhe vegans who consumed over 525 mgalcium/day were not different from theracture rates in omnivores (38). Otheractors associated with a vegetarianiet, such as fruit and vegetable con-umption, soy intake, and intake of vi-amin K-rich leafy greens must be con-idered when examining bone health.

    Bone has a protective role in main-aining systemic pH. Acidosis is seeno suppress osteoblastic activity, withhe gene expression of specific matrixroteins and alkaline phosphatase ac-ivity diminished. Prostaglandin pro-uction by the osteoblasts increasesynthesis of the osteoblastic receptorctivator of nuclear factor kappaB li-and. The acid induction of receptor

    ctivator of nuclear factor kappaB li- y

    July 2009 ● Journal

    and stimulates osteoclastic activitynd recruitment of new osteoclasts toromote bone resorption and buffer-ng of the proton load (169).

    An increased fruit and vegetableonsumption has a positive effect onhe calcium economy and markers ofone metabolism (170). The high po-assium and magnesium content ofruits, berries, and vegetables, withheir alkaline ash, makes these foodsseful dietary agents for inhibitingone resorption (171). Femoral necknd lumbar spine BMD of premeno-ausal women was about 15% to 20%igher for women in the highest quar-ile of potassium intake comparedith those in the lowest quartile

    172).Dietary potassium, an indicator of

    et endogenous acid production andruit and vegetable intake, was showno exert a modest influence on mark-rs of bone health, which over a life-ime may contribute to a decreasedisk of osteoporosis (173).High protein intake, especially an-

    mal protein, can produce increasedalciuria (167,174). Postmenopausalomen with diets high in animal pro-

    ein and low in plant protein revealedhigh rate of bone loss and a greatly

    ncreased risk of hip fracture (175).lthough excessive protein intakeay compromise bone health, evi-

    ence exists that low protein intakesay increase the risk of low bone in-

    egrity (176).Blood levels of undercarboxylated

    steocalcin, a sensitive marker of vi-amin K status, are used to indicateisk of hip fracture (177), and predictMD (178). Results from two large,rospective cohort studies suggest annverse relationship between vitamin

    (and green, leafy vegetable) intakend risk of hip fracture (179,180).Short-term clinical studies suggest

    hat soy protein rich in isoflavones de-reases spinal bone loss in postmeno-ausal women (181). In a meta-analy-is of 10 randomized controlled trials,oy isoflavones demonstrated a signifi-ant benefit on spine BMD (182). In aandomized controlled trial, postmeno-ausal women receiving genistein ex-erienced significant decreases in uri-ary excretion of deoxypyridinoline (aarker of bone resorption), and in-

    reased levels of serum bone-specific al-aline phosphatase (a marker of boneormation) (183). In another meta-anal-

    sis of nine randomized controlled tri-


  • avrt












    ls on menopausal women, soy isofla-ones significantly inhibited boneesorption and stimulated bone forma-ion compared to placebo (184).

    To promote bone health, vegetari-ns should be encouraged to consumeoods that provide adequate intakesf calcium, vitamin D, vitamin K, po-assium, and magnesium; adequate,ut not excessive protein; and to in-lude generous amounts of fruits andegetables and soy products, withinimal amounts of sodium.

    enal Diseaseong-term high intakes of dietaryrotein (above 0.6 g/kg/day for a per-on with kidney disease not undergo-ng dialysis or above the Dietary Ref-rence Intake for protein of 0.8 g/kg/ay for people with normal kidneyunction) from either animal or vege-ables sources, may worsen existinghronic kidney disease or cause renalnjury in those with normal renalunction (185). This may be due to theigher glomerular filtration rate as-ociated with a higher protein intake.oy-based vegan diets appear to beutritionally adequate for peopleith chronic kidney disease and may

    low progression of kidney disease185).

    ementiane study suggests that vegetariansre at lower risk of developing demen-ia than nonvegetarians (186). Thiseduced risk may be due to the lowerlood pressure seen in vegetarians oro the higher antioxidant intake ofegetarians (187). Other possible fac-ors reducing risk could include aower incidence of cerebrovascularisease and possible reduced use ofostmenopausal hormones. Vegetari-ns can, however, have risk factorsor dementia. For example, poor vita-in B-12 status has been linked to an

    ncreased risk of dementia apparentlyue to the hyperhomocysteinemiahat is seen with vitamin B-12 defi-iency (188).

    ther Health Effects of Vegetarian Dietsn a cohort study, middle-aged vege-arians were found to be 50% lessikely to have diverticulitis comparedith nonvegetarians (189). Fiber was

    onsidered to be the most important a

    276 July 2009 Volume 109 Number 7

    rotective factor, whereas meat in-ake may increase the risk of divertic-litis (190). In a cohort study of 800omen aged 40 to 69 years, nonveg-tarians were more than twice asikely as vegetarians to suffer fromallstones (191), even after control-ing for obesity, sex, and aging. Sev-ral studies from a research group ininland suggest that fasting, followedy a vegan diet, may be useful in thereatment of rheumatoid arthritis192).

    ROGRAMS AND AUDIENCES AFFECTEDpecial Supplemental Nutrition Programor Women, Infants, and Childrenhe Special Supplemental Nutritionrogram for Women, Infants, andhildren is a federal grant program

    hat serves pregnant, postpartum,nd breastfeeding women; infants;nd children up to age 5 years whore documented as being at nutri-ional risk with family income belowederal standards. This program pro-ides vouchers to purchase someoods suitable for vegetarians includ-ng infant formula, iron-fortified in-ant cereal, vitamin C–rich fruit oregetable juice, carrots, cow’s milk,heese, eggs, iron-fortified ready-to-at cereal, dried beans or peas, andeanut butter. Recent changes to thisrogram promote the purchase ofhole-grain breads and cereals, allow

    he substitution of canned beans forried beans, and provide vouchers forurchasing fruits and vegetables193). Soy-based beverages and cal-ium-set tofu that meet specificationsan be substituted for cow’s milk foromen and for children with medicalocumentation (193).

    hild Nutrition Programshe National School Lunch Programllows nonmeat protein products in-luding certain soy products, cheese,ggs, cooked dried beans or peas, yo-urt, peanut butter, other nut or seedutters, peanuts, tree nuts, and seedso be used (194). Meals served musteet the 2005 Dietary Guidelines formericans and provide at least one

    hird of the Recommended Dietaryllowance for protein, vitamins A and, iron, calcium, and energy. Schoolsre not required to make modifica-ions to meals based on food choices of

    family or a child although they are i

    ermitted to provide substitute foodsor children who are medically certi-ed as having a special dietary need195). Some public schools regularlyeature vegetarian choices, includingegan, menu items and this seems toe more common than in the past al-hough many school food programstill have limited options for vegetar-ans (196). Public schools are allowedo offer soy milk to children who bringwritten statement from a parent or

    uardian identifying the student’special dietary need. Soy milks musteet specified standards to be ap-

    roved as substitutes and schoolsust pay for expenses that exceed

    ederal reimbursements (197).

    eeding Programs for Elderly Adultshe federal Elderly Nutrition Pro-ram distributes funds to states, ter-itories, and tribal organizations for aational network of programs thatrovide congregate and home-deliv-red meals (often known as Meals onheels) for older Americans. Meals

    re often provided by local Meals onheels agencies. A 4-week set of veg-

    tarian menus has been developed forse by the National Meals on Wheelsoundation (198). Similar menusave been adapted by individual pro-rams including New York City’s De-artment for the Aging which hasreapproved a 4-week set of vegetar-an menus (199).

    orrections Facilitiesourt rulings in the United Statesave granted prison inmates the righto have vegetarian meals for certaineligious and medical reasons (200).n the federal prison system, vegetar-an diets are only provided for in-

    ates who document that their diet ispart of an established religious

    ractice (201). Following review andpproval by the chaplaincy team, thenmate can participate in the Alterna-ive Diet Program either through self-election from the main line that in-ludes a nonflesh option and access tohe salad/hot bar or through provisionf nationally recognized, religiouslyertified processed foods (202). Ifeals are served in prepared trays,

    ocal procedures are developed for therovision of nonflesh foods (201). Inther prisons, the process for obtain-

    ng vegetarian meals and the type of

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    eal available varies depending onhere the prison is located and the

    ype of prison (201). Although somerison systems provide meatless al-ernatives, others simply leave meatff the inmate’s tray.

    ilitary/Armed Forceshe US Army’s Combat Feeding Pro-ram, which oversees all food regula-ions, provides a choice of vegetarianenus including vegetarian Meals,eady-to-Eat (203,204).

    ther Institutions and Quantity Foodervice Organizationsther institutions, including colleges,niversities, hospitals, restaurants,nd publicly funded museums andarks, offer varying amounts andypes of vegetarian selections. Re-ources are available for vegetarianuantity food preparation.

    OLES AND RESPONSIBILITIES OF FOODND NUTRITION PROFESSIONALSutrition counseling can be highlyeneficial for vegetarian clients whoanifest specific health problems re-

    ated to poor dietary choices and foregetarians with existing clinical con-itions that require additional di-tary modifications (eg, diabetes, hy-erlipidemia, and kidney disease).epending on the client’s knowledge

    evel, nutrition counseling may beseful for new vegetarians and for in-ividuals at various stages of the lifeycle including pregnancy, infancy,hildhood, adolescence, and for the el-erly. Food and nutrition profession-ls have an important role in provid-ng assistance in the planning ofealthful vegetarian diets for thoseho express an interest in adoptingegetarian diets or who already eat aegetarian diet, and they should beble to give current accurate informa-ion about vegetarian nutrition. In-ormation should be individualizedepending on type of vegetarian diet,ge of the client, food preparationkills, and activity level. It is impor-ant to listen to the client’s own de-cription of his or her diet to ascertainhich foods can play a role in meallanning. Figure 1 provides meallanning suggestions. Figure 2 pro-ides a list of Web resources on vege-

    arian diets.

    Qualified food and nutrition profes-ionals can help vegetarian clients inhe following ways:

    Provide information about meetingrequirements for vitamin B-12, cal-cium, vitamin D, zinc, iron, and n-3fatty acids because poorly plannedvegetarian diets may sometimesfall short of these nutrients.Give specific guidelines for plan-ning balanced lacto-ovo-vegetarianor vegan meals for all stages of thelife cycle.Supply information about generalmeasures for health promotion anddisease prevention.Adapt guidelines for planning bal-anced lacto-ovo-vegetarian or veganmeals for clients with special dietaryneeds due to allergies or chronic dis-ease or other restrictions.Be familiar with vegetarian optionsat local restaurants.Provide ideas for planning optimal

    Vegetarian Nutrition Dietetic PracticeGrouphttp://vegetariannutrition.net

    Andrews University Nutrition Departmenthttp://www.vegetarian-nutrition.info

    Center for Nutrition Policy and Promotionhttp://www.mypyramid.gov/tips_resources/vegetarian_diets.html

    Food and Nutrition Information Centerhttp://www.nal.usda.gov/fnic/pubs/bibs/gen/vegetarian.pdf

    Mayo Clinichttp://www.mayoclinic.com/health/vegetarian-diet/HQ01596

    Medline Plus, Vegetarian Diethttp://www.nlm.nih.gov/medlineplus/vegetariandiet.html

    Seventh-day Adventist DieteticAssociationhttp://www.sdada.org/plant.htm

    The Vegan Society (vitamin B-12)http://www.vegansociety.com/food/nutrition/b12/

    The Vegetarian Resource Grouphttp://www.vrg.org

    The Vegetarian Society of the UnitedKingdomhttp://www.vegsoc.org/health

    igure 2. Useful Web sites concerning vege-arian diets.

    vegetarian meals while traveling. f

    July 2009 ● Journal

    Instruct clients about the prepara-tion and use of foods that frequentlyare part of vegetarian diets. Thegrowing selection of products aimedat vegetarians may make it impos-sible to be knowledgeable about allsuch products. However, practitio-ners working with vegetarian cli-ents should have a basic knowledgeof preparation, use, and nutrientcontent of a variety of grains,beans, soy products, meat analogs,and fortified foods.Be familiar with local sources forpurchase of vegetarian foods. Insome communities, mail ordersources may be necessary.Work with family members, partic-ularly the parents of vegetarianchildren, to help provide the bestpossible environment for meetingnutrient needs on a vegetarian diet.If a practitioner is unfamiliar withvegetarian nutrition, he/she shouldassist the individual in findingsomeone who is qualified to advisethe client or should direct the clientto reliable resources.

    Qualified food and nutrition profes-ionals can also play key roles in ensur-ng that the needs of vegetarians are

    et in foodservice operations, includ-ng child nutrition programs, feedingrograms for the elderly, corrections fa-ilities, the military, colleges, universi-ies, and hospitals. This can be accom-lished through development ofuidelines specifically addressing theeeds of vegetarians, creation and im-lementation of menus acceptable toegetarians, and the evaluation ofhether or not a program meets theeeds of its vegetarian participants.

    ONCLUSIONSppropriately planned vegetarian dietsave been shown to be healthful, nutri-ionally adequate, and may be benefi-ial in the prevention and treatment ofertain diseases. Vegetarian diets areppropriate for all stages of the life cy-le. There are many reasons for the ris-ng interest in vegetarian diets. Theumber of vegetarians in the Unitedtates is expected to increase duringhe next decade. Food and nutritionrofessionals can assist vegetarian cli-nts by providing current, accurate in-ormation about vegetarian nutrition,

    oods, and resources.



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from the association Position of the American Dietetic Association: Vegetarian Diets ABSTRACT It is the position of the American Di- etetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian di- ets are appropriate for individuals during all stages of the life cycle, in- cluding pregnancy, lactation, infancy, childhood, and adolescence, and for athletes. A vegetarian diet is defined as one that does not include meat (in- cluding fowl) or seafood, or products containing those foods. This article reviews the current data related to key nutrients for vegetarians includ- ing protein, n-3 fatty acids, iron, zinc, iodine, calcium, and vitamins D and B-12. A vegetarian diet can meet cur- rent recommendations for all of these nutrients. In some cases, supplements or fortified foods can provide useful amounts of important nutrients. An ev- idence-based review showed that veg- etarian diets can be nutritionally ad- equate in pregnancy and result in positive maternal and infant health outcomes. The results of an evidence- based review showed that a vegetar- ian diet is associated with a lower risk of death from ischemic heart disease. Vegetarians also appear to have lower low-density lipoprotein cholesterol lev- els, lower blood pressure, and lower rates of hypertension and type 2 diabe- tes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates. Features of a vegetarian diet that may reduce risk of chronic disease include lower intakes of saturated fat and cholesterol and higher intakes of fruits, vegetables, whole grains, nuts, soy products, fiber, and phytochemi- cals. The variability of dietary practices among vegetarians makes individual assessment of dietary adequacy essen- tial. In addition to assessing dietary ad- equacy, food and nutrition profession- als can also play key roles in educating vegetarians about sources of specific nutrients, food purchase and prepara- tion, and dietary modifications to meet their needs. J Am Diet Assoc. 2009;109: 1266-1282. POSITION STATEMENT It is the position of the American Di- etetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the pre- vention and treatment of certain dis- eases. Well-planned vegetarian diets are appropriate for individuals during all stages of the lifecycle, including pregnancy, lactation, infancy, child- hood, and adolescence, and for athletes. VEGETARIAN DIETS IN PERSPECTIVE A vegetarian is a person who does not eat meat (including fowl) or seafood, or products containing these foods. The eating patterns of vegetarians may vary considerably. The lacto-ovo- vegetarian eating pattern is based on grains, vegetables, fruits, legumes, seeds, nuts, dairy products, and eggs. The lacto-vegetarian excludes eggs as well as meat, fish, and fowl. The vegan, or total vegetarian, eating pat- tern excludes eggs, dairy, and other animal products. Even within these patterns, considerable variation may exist in the extent to which animal products are excluded. Evidence-based analysis was used to evaluate existing research on types of vegetarian diets (1). One question for evidence-analysis was identified: What types of vegetarian diets are examined in the research? The com- plete results of this evidence-based analysis can be found on the Ameri- can Dietetic Association’s Evidence Analysis Library (EAL) Web site (www.adaevidencelibrary.com) and are summarized below. EAL Conclusion Statement: The two most common ways of defining vege- tarian diets in the research are vegan diets: Diets devoid of all flesh foods; This American Dietetic Association (ADA) position paper includes the authors’ independent review of the literature in addition to systematic review conducted using the ADA’s Evidence Analysis Process and informa- tion from the Evidence Analysis Library. Topics from the Evidence Analysis Library are clearly delineated. The use of an evidence-based approach provides important added benefits to earlier review methods. The major advantage of the approach is the more rigorous standardization of review criteria, which minimizes the likelihood of reviewer bias and increases the ease with which disparate articles may be compared. For a detailed descrip- tion of the methods used in the evidence analysis process, access ADA’s Evidence Analysis Process at http://adaeal.com/eaprocess/. Conclusion Statements are assigned a grade by an expert work group based on the systematic analysis and evaluation of the supporting research evidence. Grade IGood; Grade IIFair; Grade IIILimited; Grade IVExpert Opinion Only; and Grade VNot Assignable (because there is no evidence to support or refute the conclusion). Evidence-based information for this and other topics can be found at https://www.adaevidencelibrary.com and subscriptions for nonmembers are available for purchase at https://www.adaevidencelibrary.com/store.cfm. 0002-8223/09/10907-0019$36.00/0 doi: 10.1016/j.jada.2009.05.027 1266 Journal of the AMERICAN DIETETIC ASSOCIATION © 2009 by the American Dietetic Association
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