Vegetarian and Vegan Dietary Patterns

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November 4, 2021

Varalakshmi Niranjan, MD, MBA, Dip ABOM

Introduction

A large variety of dietary patterns exist throughout the world. Over the years, vegetarian and vegan diets have gained popularity for various reasons.⁸ Many follow these dietary patterns for personal or religious choices. Some follow these dietary patterns for health benefits.³ Some are trying to adopt more holistic whole food plant-based meals in their lifestyle even though they may not be strict vegetarians or vegans.⁴ Though we know dietary patterns are associated with healthcare outcomes, it is extremely difficult to disentangle a particular nutrient from a dietary pattern and show its contribution to increasing or decreasing the risk of disease.⁸ The bulk of evidence on dietary patterns and associations with health are from observational studies, mainly prospective cohort studies.⁸ In the age of information and Google searches, there are many resources and articles about these diets that can be confusing and misleading. In this article, we will discuss some of the health benefits of vegetarian and vegan dietary patterns. This article will try to debunk some of the myths about these dietary patterns and highlight the facts with resources that are useful in clinical practice.

Health benefits of vegetarian /vegan diet

Compared with non-vegetarians, Western vegetarians have a lower Body Mass Index (BMI).^1,2
Vegetarians, and in particular vegans, have lower total and low-density lipoprotein (LDL) cholesterol levels than non-vegetarians. Observational studies suggest vegetarians have lower triglyceride levels, but evidence from randomized controlled trials is inconclusive.²
Blood pressure is lower in vegetarians (more so in vegans) compared to non-vegetarians^1,4
People who eat a vegetarian diet seem to have a lower risk of developing type 2 diabetes. A vegetarian diet also seems to be effective in the treatment of type 2 diabetes.^1,4
Overall cancer risk is decreased in vegetarians when compared with non-vegetarians in both genders.⁵
Vegans have decreased risk in overall cancer in both genders and decreased risk in female-specific cancer.⁵
Lacto-ovo vegetarians showed decreased risk in cancers of the gastrointestinal tract.⁶
Vegetarian diets are associated with an overall lower incidence of colorectal cancers and in particular, pesco vegetarians had much a lower risk.⁶
Vegetarian diets, replacing meat and fish with soy, and replacing refined carbohydrates with whole grains, may be inversely associated with nonalcoholic fatty liver-related to BMI.⁷
Vegetarians may also have a lower risk for some other diseases such as diverticular disease, gallstones, and appendicitis.^5,6
Vegetarians have lower mortality from chronic degenerative diseases.⁴

Nomenclature ⁸

Vegan: This solely plant-based diet is the strictest form of vegetarianism and excludes all animal products such as meat, eggs, and dairy products.

Vegetarian (Lacto vegetarian): The vegetarian diet excludes all animal meat, fish, and seafood. It includes animal by-products such as milk, and cheese as well as honey.

Lacto-Ovo vegetarian: The lacto-vegetarian diet is a vegetarian diet that includes dairy products such as cheese, butter, milk, and eggs.

Semi Vegetarian: Animal products are included but more selectively. Many semi-vegetarians eat chicken and fish but not red meat.

Seasonal or occasional Vegetarian: Meat or animal products are not consumed on certain days for religious reasons.

Pescatarian: The pescatarian diet is a diet that excludes animal products, with exceptions for fish/seafood

Whole Food Plant-based diet: The Whole-Food, Plant-Based (WFPB) diet is a plant-based diet that eliminates processed foods. In addition, white rice, white bread, refined flour, grains, sugars, processed oils, fake meats, and cheese are excluded

Myths and Facts

Myths	Facts	Resources
Vegan/Vegetarian diets do not include enough protein.	Depending upon the requirement of protein for active weight loss or weight maintenances, vegan/vegetarians diets can provide adequate protein.	Position Paper on vegetarian diets Whole Food, Plant-Based Diet Guide – Center for Nutrition Studies
Vegan diets are too high in carbohydrates.	Vegan /vegetarian diets can be made low carbohydrate by choosing whole grains and plant-based protein sources.	Vegetarian Low-Carb Inspiration – Diet Doctor The Complete Guide to a Low-Carb Vegan Diet — Diet Doctor Low-Carb Vegan Recipes \| EatingWell
Vegan diets are healthy.	A vegan diet is not inherently “healthier”. It can be high in refined carbohydrates, saturated fats, and less nutritious if, foods are not chosen properly.	Plant-Based Recipes, A Comprehensive Archive \| Forks Over Knives 10 Vegan Foods That AREN’T Healthy—And What to Eat Instead \| Cooking Light
Vegan diets are not healthy for children.	With careful monitoring and some modification to accommodate the growing needs of children vegan and vegetarian diets can be followed by children safely.	Is a Vegan Diet Safe for Growing Children? – Cleveland Clinic Life stages \| The Vegan Society
A vegan diet makes you weaker.	A whole food plant-based diet with fruits and vegetables provides enough strength for the body when consumed properly. Many strong sports celebrities and athletes choose a vegan and vegetarian lifestyle.	World Class Vegan Athletes – Great Vegan Athletes Health effects of vegan diet- The American journal of clinical nutrition

Healthy Food Sources for Vegetarians and Vegans⁹

Carbohydrates	Proteins	Fats	Vegetables	Fruits
Brown rice Whole wheat Oats Quinoa Millet Spelt	Tofu Tempeh Edamame Lentils Legumes Moth beans Chickpeas Horse gram Nuts Plant-based milk Plant-based Yogurt Hemp Chia seeds	Avocados Peanut Butter Almond butter Olives Olive oil Coconut oil	Asparagus Beets Broccoli Brussels Sprouts Cabbage Carrots Cauliflower Celery Cucumber Eggplant Radishes Scallions Green beans Lettuce Mushrooms Spinach Sprouts Summer Squash Okra Tomato Onions Turnips Pea Pods Watercress Peppers Zucchini	Strawberries Blackberries Blueberries Raspberries Apple Banana Grapefruit Melon Orange Peach Pear Plum

Low-carb vegan substitutions⁹

Ingredients	Plant-based, low-carb substitute
Milk	Coconut milk Almond Milk Hazelnut Milk Other nut milks
Heavy Cream	Coconut cream
Butter	Coconut oil Vegan butter
Cheese	Vegan cheese Nutritional yeast
Greek Yogurt	Coconut cream
Gelatin	Agar flakes or powder
Chicken or beef broth	Vegetable broth Vegetable bouillon cubes
Eggs	Soaked chia seeds

References

Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet. 2016 Dec;116(12):1970-1980. doi: 10.1016/j.jand.2016.09.025. PMID: 27886704.
Key, T., Davey, G., & Appleby, P. (1999). Health benefits of a vegetarian diet. Proceedings of the Nutrition Society, 58(2), 271-275. doi:10.1017/S0029665199000373
Agnoli C, Baroni L, Bertini I, Ciappellano S, Fabbri A, Papa M, Pellegrini N, Sbarbati R, Scarino ML, Siani V, Sieri S. Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition. Nutr Metab Cardiovasc Dis. 2017 Dec;27(12):1037-1052. doi: 10.1016/j.numecd.2017.10.020. Epub 2017 Oct 31. PMID: 29174030.
Leitzmann C. Vegetarian diets: what are the advantages? Forum Nutr. 2005;(57):147-56. doi: 10.1159/000083787. PMID: 15702597.
Tantamango-Bartley Y, Jaceldo-Siegl K, Fan J, Fraser G. Vegetarian diets and the incidence of cancer in a low-risk population. Cancer Epidemiol Biomarkers Prev. 2013 Feb;22(2):286-94. doi: 10.1158/1055-9965.EPI-12-1060. Epub 2012 Nov 20. PMID: 23169929; PMCID: PMC3565018.
Orlich MJ, Singh PN, Sabaté J, et al. Vegetarian dietary patterns and the risk of colorectal cancers. JAMA Intern Med. 2015;175(5):767-776. doi:10.1001/jamainternmed.2015.59
Chiu TH, Lin MN, Pan WH, Chen YC, Lin CL. Vegetarian diet, food substitution, and nonalcoholic fatty liver. Tzu chi Medical Journal. 2018 Apr-Jun;30(2):102-109. DOI: 10.4103/tcmj.tcmj_109_17. PMID: 29875591; PMCID: PMC5968737.
Elisabeth Weichselbaum, PhD, MSc Background paper- Dietary patterns and the heart Aug 2013.
Spritzler, Franziska., Tamber, Michael MD. How to eat Low carb as a vegan. 2021, Sept. 14. Diet Doctor. https://www.dietdoctor.com/low-carb/vegan