Vegetarian Diets: Health Benefits and Associated Risks

Vegetarian Diets: Health Benefits and Associated Risks ISSN: 2394-0026 (P)Review Article ISSN: 2394-0034 (O)Vegetarian Diets: Health Benefits and Associated RisksNavneet Kumar Kaushik1*, Anup Aggarwal2, Mohita Singh1, Shelja Deswal1, Priyanka Kaushik1 1Junior Resident, Department of Physiology, PGIMS, Rohtak, India 2Senior Resident, Department of Physiology, PGIMS, Rohtak, India *Corresponding author email: [email protected] to cite this article: Navneet Kumar Kaushik, Anup Aggarwal, Mohita Singh, Shelja Deswal,Priyanka Kaushik. Vegetarian Diets: Health Benefits and Associated Risks. IAIM, 2015; 2(3): 206-210. Available online at www.iaimjournal.comReceived on: 28-01-2015 Accepted on: 09-02-2015AbstractRecently, vegetarian diets have experienced an increase in popularity. A growing body of scientificevidence indicates that wholesome vegetarian diets offer distinct advantages compared to dietscontaining meat and other foods of animal origin. A vegetarian diet may be adopted for variousreasons that can include ecological, economic, religious, ethical, and health considerations. In thelatter case they arise from the desire to lose weight, in tackling obesity, improving physical fitnessand/or in reducing the risk of acquiring certain diseases. It has been shown that properly appliedvegetarian diet is the most effective way of reducing body mass (expressed as BMI), improving theplasma lipid profile and in decreasing the incidence of high arterial blood pressure, cardiovasculardisease, stroke, metabolic syndrome and arteriosclerosis. In addition, improved insulin sensitivitytogether with lower rates of diabetes and cancer has been observed. Some studies have howeverfound that a vegetarian diet may result in changes adversely affecting the body. These include:hyperhomocysteinemia, protein deficiency, anemia, decreased creatinine content in muscles andmenstrual disruption in women who undertake increased physical activity. Some of these changesmay decrease the ability for performing activities that require physical effort. Nevertheless, onbalance it can be reasonably concluded that the beneficial effects of a vegetarian diet significantly,by far, outweigh the adverse ones. It should also be noted that the term ‘vegetarian diet’ is notalways clearly defined in the literature and it may include many dietary variations.Key wordsVegetarian diet, BMI (Body Mass Index), Hyperhomocysteinemia.International Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 206Copy right © 2015, IAIM, All Rights Reserved.

Vegetarian Diets: Health Benefits and Associated Risks ISSN: 2394-0026 (P)Introduction ISSN: 2394-0034 (O) evidence within the literature on the impact thatVegetarian diets are the one that are based on such diets have on the human body.foodstuffs of plant origin such as cereals, Table – 1: Classification of the different types oflegumes, oilseeds, fruits, vegetables, nuts and vegetarian diet.mushrooms. The many types of vegetarian dietsdevised all share the same characteristic in the Type of Definitionelimination of meat, fish and poultry vegetarianconsumption, while some also eliminate egg, Excludes all types of fleshmilk and dairy products (Vegan Diets). diet foodstuffs (meat, poultry, fish),Classification of the different types of vegetarian Lacto-ovo- but permits eating all otherdiet is as per Table – 1. vegetarianVegetarian diets are usually rich in Lacto- animal products (e.g. eggs, milk,carbohydrates, n-6 fatty acids, dietary fibre, vegetarian honey).carotenoids, folic acid, vitamin C, vitamin E, Excludes flesh foodstuffs andmagnesium and phytochemicals, and relatively Ovo- eggs but allows dairy products,low in proteins, calories, saturated fat, long vegetarian honey, etc.chain n-3 fatty acids, choline, retinol, vitamin D, Excludes consumption of allvitamin B12, calcium, iron, zinc and iodine. Vegan animal products with theAmerican Dietetic Association states that well- exception of eggs.balanced vegetarian diets can meet Excludes all animal products.recommended daily requirements of all the Vitarian Permits consumption of organic,nutrients and are appropriate for all stages of raw and fresh foods only.the life cycle including pregnancy, lactation, Excludes coffee and tea.infancy, childhood, adolescence, and for Liquidarian Consumption of vegetarian foodathletes. Such plant-based foodstuffs are in the form of juices.unfortunately now also contaminated with Fruitarian Excludes flesh foodstuffs, animalmany industrial toxins that include nitrates. It is products and vegetables.however very well recognised that such Sproutarian Eating foods in the form offoodstuffs contain ingredients beneficial to sprouted plant seedlings, such ashealth. Moreover, non-dietary factors may also grains, vegetables, fruits.contribute towards the efficacy of a vegetarian Semi- Transitional form betweendiet such as following a healthy lifestyle, which vegetarian vegetarian and meat based diets;includes physical activity and the avoidance of limited amount of meat eaten.harmful practices, particularly smoking andalcohol consumption. It has been shown that Methodvegetarians possess good health and sufferfewer from illnesses and have a higher self- In order to identify relevant articles, werespect concerning their proper eating habits conducted an independent literature review viathan those eating a traditional diet [1]. However, internet using PubMed/Medline and Googlemany controversies have arisen over the efficacy databases through 1990 to 2014. The followingof adopting a vegetarian diet and thus the aim of search terms were used: vegetarian diets, veganthis study was to investigate and review the diets, beneficial effects of vegetarian diets, harmful effects of vegetarian diets. For theInternational Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 207Copy right © 2015, IAIM, All Rights Reserved.

Vegetarian Diets: Health Benefits and Associated Risks ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)purpose of this study, articles reporting relevant Eating large amounts of vegetables and fruits,health outcomes (either beneficial or harmful) which form a major part of all vegetarian dietassociated with vegetarian diets were included. types, also has a beneficial effect on theAnimal studies and case studies with small size cardiovascular system. Plant based foodstuffswere excluded. provide the body with multiple antioxidants. A study by Somannavar and KodliwadmathDiscussion confirmed that vegetarians have significantlyThe obsession of modern society with weight higher antioxidant levels compared to thosereduction is reflected by the creation of eating a mixed diet (p<0.001) [6]. The mostnumerous and varied diets. Many indeed active of these include the antioxidant vitaminsdemonstrate real effectiveness in tackling (α-tocopherol, ascorbic acid), flavonoids andobesity and overweight with the proviso that carotenoids (lycopene, lutein, β-carotene,success can only be guaranteed if a given diet is cryptoxanthin, zeaxanthin). Their biologicalstrictly adhered in conjunction with performing activity is based on inhibiting the oxidation ofadditional physical activity. Numerous studies LDL cholesterol (LDL-C), increasing HDLhave demonstrated lower Body mass index cholesterol and reducing total cholesterol (T-C)(BMI) values in people adopting a vegetarian concentration in circulation. This results in adiet. In the Sabate and Wien study, the mean lower risk of developing arteriosclerosis.body mass of males and females was The plasma lipid profiles of vegetarians andrespectively 7.6 kg (p<0.001) and 3.3 kg those eating a traditional diet was studied by(p<0.005) lower compared to those consuming Dourado, et al. which demonstrated that themeat in their diets [2]. A study by Spencer, et al. latter group had significantly higher average T-Cshowed that meat-eating subjects, aged 20–97 (207.11 mg/dl) and LDL-C (143.79 mg/dl) bloodyears, had a mean BMI higher by 1.92 kg/m2 concentrations compared to the former at(p<0.05) in men and 1.54 kg/m2 (p<0.05) in respectively T-C; 160.06 mg/dl, LDL-C; 87.40women compared to vegans [3]. mg/dl (p<0.001). The aforementioned study alsoThe potential effectiveness of vegetarian diets showed that meat eaters have a significantlyfor dealing with obesity was observed in a study higher systolic blood pressure (123.76 mmHg)by Tonstad, et al. conducted on a group of compared to vegetarians (114.86 mmHg)22,434 men and 38,469 women where BMI was (p<0.05) [7]. In conclusion, it is clear that ameasured in six treatment groups (vegetarians, properly applied vegetarian diet can effectivelyvegans, lacto-ovo-vegetarians, semi-vegetarians, protect against high blood pressure and reducefish eaters, and meat eaters). The mean BMI was the risk of heart disease, stroke andfound lowest in the vegans (23.06 kg/m2) and arteriosclerosis.gradually increased as follows, lacto-ovo- The authors take the view that the high amountsvegetarians (25.7 kg/m2), fish eaters (26.3 of carbohydrates and low amounts of fat as seenkg/m2), semi-vegetarians (27.3 kg/m2) and meat in vegetarian diets increases cellular insulineaters (28.8 kg/m2, p<0.001) [4]. A study by sensitivity thereby affording some protectionNewby, et al. confirmed that the BMI was against diabetes. This hypothesis was checked insignificantly lower in vegetarians of all types [5]. a study by Tonstad, et al. conducted on a groupThe data thus suggest that adopting a vegetarian of 38,469 women and 22,434 men. It was founddiet can be an effective means for reducing body that the incidence of type 2 diabetes occurred inmass.International Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 208Copy right © 2015, IAIM, All Rights Reserved.

Vegetarian Diets: Health Benefits and Associated Risks ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)the following groups in descending order of The viewpoints expressed concerning themagnitude; meat eaters (7.6%), semi- benefits of a vegetarian diet and its effect onvegetarians (6.1%), fish eaters (4.8%), lacto-ovo- exercise capacity are not sufficientlyvegetarians (3.2 %) and vegans (2.9%), (p<0.05). documented in power sports, endurance sportsA related study by Wolfram and Ismail-Beigi or even in everyday life to permit anything moresuggested a correlation between increased than a tentative conclusion to be drawn at thecellular insulin sensitivity with the consumption moment. Further research is essential in thisof vegetables and whole grains [8]. Indeed, the regard.lower risk of metabolic syndrome in vegetariansas compared to semi-vegetarians and meat Conclusioneaters (p<0.001) has been documented by Rizzo, It can be reasonably concluded that theet al. whose data showed that it is reasonable to beneficial effects of a vegetarian diethypothesise that a vegetarian diet can also be significantly outweigh the adverse ones. Theused in tackling metabolic syndrome [9]. published studies paint a consistent pictureImproperly applied vegetarian diets can lead to associating vegetarian diets with lower bodylowered levels of vitamin B12, producing an mass index, coronary heart disease,increase in blood levels of homocysteine, which hypertension, type 2 diabetes, and metabolicis associated with increased risk of syndrome. Vegetarians also have lower risks forcardiovascular morbidity, a reduction in the colon, gastrointestinal tract, prostate and overallblood levels of sex hormones and disruption of cancer. The lower risk among vegetarians ofthe menstrual cycle. The problem of vitamin B12 several high prevalent chronic diseases results indeficiency in vegetarians was confirmed by a greater life-expectancy compared to non-Herrmann, et al. [10]. vegetarians. The reasons for choosing a vegetarian diet often go beyond health and well-Controversies remain concerning the safety of a being and include economical, ecological andvegetarian diet when adopted by athletes. The social concerns which are the subject of the newconcerns relate to a sufficient supply of proteins, field of nutritional ecology that is concernediron and creatinine together with the occurrence with sustainable life styles and humanof irregular menstrual cycles, especially in hard- development.training women. However, study by Barr, et al. Referencesdemonstrated that a vegetarian diet can providelarge amounts of proteins if dairy products and 1. Pilis W, Stec K, Zych M, Pilis A. Healtheggs are included [11]. Vegetarians can benefits and risk associated withadditionally supplement their diet with proteins adopting a vegetarian diet. Rocz Panstwderived from legumes, nuts, seeds and whole Zakl Hig, 2014; 65(1): 9-14.grains. In most cases, vegetarian athletes canadjust the level of iron by eating foods rich in 2. Sabaté J, Wien M. Vegetarian diets andvitamin C, citric acid, malic acid, tartaric acid, childhood obesity prevention. Am J Clinfructose and sorbitol. Lower creatinine levels Nutr, 2010; 91(5): 1-5.found in vegetarian athletes can be increased byadministering creatinine as a dietary 3. Spencer EA, Appleby PN, Davey GK, Keysupplement improving physical performance TJ. Diet and body mass index in 38,000and muscle strength. EPIC-Oxford meat eaters, fish eaters, vegetarians and vegans. Int J Obes, 2003; 27: 728-34.International Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 209Copy right © 2015, IAIM, All Rights Reserved.

Vegetarian Diets: Health Benefits and Associated Risks ISSN: 2394-0026 (P)4. Tonstad S, Butler T, Ru Y, Fraser GE. ISSN: 2394-0034 (O) 8. Wolfram T, Ismail-Beigi F. Efficacy ofType of vegetarian diet, body weight, high fiber diets in the management ofand prevalence of type 2 diabetes. type 2 diabetes mellitus. Endocr Pract,Diabet Care, 2009; 32: 791-6. 2011; 17(1): 132-42.5. Newby PK, Tucker KL, Wolk A. Risk of 9. Rizzo NS, Sabate J, Jaceldo SK, Fraser GE.overweight and obesity among semi- Vegetarian dietary patterns arevegetarian, lacto-vegetarian and vegan associated with a lower risk of metabolicwomen. Am J Clin Nutr, 2005; 81(6): syndrome. Diab Care, 2011; 34: 1225-7.1267-74. 10. Herrmann W, Schorr H, Purschwitz K,6. Somannavar MS, Kodliwadmath MV. Rassoul F, Richter V. TotalCorrelation between oxidative stress homocysteine, vitamin B12, and totaland antioxidant defense in South Indian antioxidant status in vegetarians. Clinurban vegetarians and non-vegetarians. Chem, 2001; 47(6): 1094-101.Eur Rev Med Pharmacol Sci, 2011; 16: 11. Barr SI, Rideout CA. Nutritional351-4. considerations for vegetarian athletes.7. Dourado KF, Arruda CF, Sakugava NK. Nutrition, 2004; 20: 696-703.Relation between dietary and circulatinglipids in lacto-ovo-vegetarians. NutrHosp, 2011; 26(5): 959-64.Source of support: Nil Conflict of interest: None declared.International Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 210Copy right © 2015, IAIM, All Rights Reserved.