Jamie Pope, Steven Nizielski, and Alison McCook NUTRITION for a Changing World FIRST EDITION Chapter 9 Plant-Based Diets Pass the Plants, Please © 2016 by W. H. Freeman and Company & Scientific American

Chapter 9 Objectives Compare and contrast the types of vegetarian and semi-vegetarian diets Describe the steps that occur during the development of cancer List the recommendations that reduce the risk of cancer Provide examples of two specific phytochemicals and their significant dietary sources Identify challenges that vegetarians may experience in meeting their requirements for specific nutrients, and provide strategies to alleviate these concerns Compare and contrast the dietary recommendations and potential benefits of a vegetarian and Mediterranean diet

Benefits of a Mediterranean Diet Rich in fruits, vegetables, nuts, olive oil, and whole grains Low in processed and red meats, dairy products, and sweets Lowers heart problems As potent as modern drugs to reduce cardiovascular risk A randomized, controlled clinical trial published in 2013 based in Spain investigated the impact of a Mediterranean-like diet on the risk of heart attack, stroke, and death from heart disease compared with the effect of a traditional low-fat diet. Researchers assigned 7,500 people at high risk of heart disease to either a Mediterranean-diet group given high-quality olive oil (who subsequently had a 30% reduced risk of heart problems) or to a Mediterranean-diet group given nuts (who had a 28% reduction in heart problems); a third group told to reduce their intake of all fats was the control group over a 5-year period.

Plant-Based Diet Vegetarian diets Consume Limit or omit Fresh fruits and vegetables Limit or omit Animal foods Processed or refined foods Plant-based diets are similar to the Mediterranean diet, except that the Mediterranean diet includes fish and occasional consumption of lean meats, like skinless poultry. Individuals that follow a plant-based diet are oftentimes called vegetarians.

Types of Vegetarian Diets Lacto-vegetarian Plant foods plus diary Lacto-ovo vegetarian Plant foods plus dairy products and eggs Vegan Semi-vegetarian (quasi-vegetarian) Only exclude red meats but eat other animal products Pescatarians Plant based with fish and shell fish Flexitarian Mostly plant based but occasionally eat meat

Types of Vegetarian Diets

Benefits of a Plant-Based Diet High intake of Dietary fiber Vitamins C, E, and folate Magnesium and potassium Antioxidants and phytochemicals Fewer overall calories Lower proportion of calories from fat Decreased consumption of processed meats There are many reasons for following a vegetarian diet, such as cultural, ethical, environmental, religious, and even health reasons, but vegetarian diets that are unplanned can be unhealthy. Those that include a variety of foods tend to have lots of health benefits.

Benefits of a Plant-Based Diet Health benefits Lower total blood cholesterol levels Lower low-density lipoprotein levels Lower blood pressure Reduced cardiovascular risk Lower risk of obesity, heart disease, cancer, type 2 diabetes, and mortality Research has shown many health benefits of a plant-based diet.

Cancer Second leading cause of death in the United States Multistep process Initiation Mutation Promotion Progression Metastasis Cancer develops in a multistep process. First there is initiation, during which DNA inside a cell undergoes a mutation that alters the DNA sequence permanently. During promotion, various factors, like inflammation or some chemicals, selectively promote these mutated cells to divide and proliferate more quickly. Progression is last. During this phase, the mutated cells acquire additional mutations that allow the cancer cells to migrate to and invade other tissues in a process of metastasis.

Cancer develops in a multistep process Cancer develops in a multistep process. First there is initiation, during which DNA inside a cell undergoes a mutation that alters the DNA sequence permanently. During promotion, various factors, like inflammation or some chemicals, selectively promote these mutated cells to divide and proliferate more quickly. Progression is last. During this phase, the mutated cells acquire additional mutations that allow the cancer cells to migrate to and invade other tissues in a process of metastasis.

Cancer Risk Genetic factors Environmental factors Lifestyle choices like diet can increase or decrease risk Diet rich in fruits, vegetables, legumes, and whole grains decrease risk Rich in phytochemicals Plants are rich in phytochemicals or phytonutrients.

Recommendations to Reduce the Risk of Cancer

Benefits of Phytochemicals Provide color, aroma, and flavor Eat a rainbow of foods Health benefits Chemicals have antioxidant, anti-inflammatory, or hormone-like actions Plant pigments are a rich source of phytochemicals Color-specific, similarly colored foods often contain similar phytochemicals, hence the recommendation to eat a variety of foods in a rainbow of colors.

Many Types of Phytochemicals Polyphenols Associated with reduced risk of chronic diseases May reverse, suppress, or prevent cancer Phytochemicals are associated with a reduced risk of cardiovascular disease, diabetes, osteoporosis, and neurological-related disorders.

Many Types of Phytochemicals Phytochemicals are associated with a reduced risk of cardiovascular disease, diabetes, osteoporosis, and neurological-related disorders.

Some Types of Polyphenols Resveratrol In grapes and red wine Isoflavones and lignans In soy and flaxseed Hormone-like effects Carotenoids Lutein and zeaxanthin in spinach and kale are important to eye health Lycopene in tomatoes and watermelon lowers risk of prostate and ovarian cancer

Examples of Phytochemicals, Their Sources, and Their Benefits

Nutritional Considerations with Plant-Based Diets Nutrients of possible concern Protein Iron Vitamin D Riboflavin Vitamin B12 Omega-3 fatty acids Iodine Vegetarians must choose their foods carefully as some nutrients are less abundant and others are less bioavailable in plant foods compared to animal foods.

Protein Complete protein Incomplete protein Complementary proteins Provides all nine essential amino acids in amounts to support protein synthesis Includes meat, dairy, eggs, soy products, and quinoa Incomplete protein Includes most plant foods Complementary proteins Beans and grains Beans and nuts Most plant foods do not contain the right proportion of the nine essential amino acids needed to synthesis protein in the body, so one must combine two foods with different amino acid profiles to get all nine essential amino acids for protein synthesis.

Iron Heme iron Non-heme iron Found in animal foods Less bioavailable Vitamin C–rich foods enhance absorption Plant foods rich in iron Soybeans, beans, legumes, dried fruit, spinach, fortified whole grain cereals

Zinc Less bioavailable in plant foods Found in soy products, legumes, grains, and nuts

Calcium, Vitamin D, and Riboflavin All rich in dairy products Vegans at risk of deficiency Calcium plant sources Leafy greens, broccoli, fortified soy, rice, and almond milks or beverages Vitamin D plant sources Fortified soy, rice, almond milks, or foods Riboflavin plant sources Almonds, mushrooms, and spinach

Vitamin B12 Only in food of animal origin Vegans must obtain from Fortified foods Fortified nutritional yeasts B12 supplements

Iodine and Omega-3 Fatty Acids Rich in fish and seafood Iodine non-animal sources Iodized salt Omega-3 fatty acids non-animal sources No source of EPA and DHA in plants, but they are in some fortified foods ALA (alpha-linolenic acid) is found in walnuts, flaxseeds, soy, and algae Only about 10% of ALA is converted to EPA or DHA in the body. Vegetarians get plenty of omega-6 fatty acids from plant foods.

Make a Nutritional Plan

Vegetarian Guidelines The Academy of Nutrition and Dietetics Recommendations Choose a variety of foods Whole grains, vegetables, legumes, nuts, seeds, and if desired, low-fat dairy products and eggs in moderation Minimize intake of highly sweetened, fatty, and heavily refined foods Strict vegans may need supplements or fortified foods to get adequate nutrients, especially vitamin B12 and vitamin D Consult with a health provider or registered dietitian for dietary planning and advice on dietary supplement needs

Vegetarian Resources USDA’s www.ChooseMyPlate.gov Vegetarian/Vegan Diet Pyramid

Children and Adolescents Higher-nutrient needs to support growth and development Vegan children tend to be slightly smaller than children on lacto-ovo vegetarian diet or non-vegetarian diet Poor growth when deficient in protein, calories, or other nutrients Health benefits of plant-based diets can reduce risk of obesity and chronic disease later in life

Organic Foods USDA’s specifications for organic regulations Foods labels 100% organic Organic Must be 95% organic Made with organic ingredients At least 70% organic Some organic ingredients Composed of less than 70% organic ingredients

Organic Diets Expose consumers to less antibiotic-resistant bacteria and fewer pesticides Positive environmental impact Organic farmers Still allowed to use certain pesticides Current evidence No human studies demonstrating meaningful nutrition or health benefits or disease protection

Mediterranean Diet Different lifestyle and different diets High in monounsaturated fats Healthy ratio of omega-6 to omega-3 fats High in fiber, antioxidants, and polyphenols Moderate consumption of wine with food Consumption of fish and less other meat Lower incidence of heart disease, diabetes, Parkinson’s disease, allergies in children, cancer, and maybe Alzheimer’s disease It is impossible to know how much of a role diet plays and how much can be attributed to lifestyle.

Mediterranean Diet

Which Diet Is Best? No one knows for sure Plant-based diets and Mediterranean diets have health benefits

Summary Plant-based diets can vary significantly by including differing types and amounts of animal foods, and they can have varying degrees of healthfulness, depending on the quality and distribution of the nutrients being consumed and the types of food choices being made A vegan diet consists only of plant foods, while other types of vegetarianism may include dairy foods and eggs; semi-vegetarian diets may include limited amounts of fish, poultry, and red meats

Summary (Cont’d) Plant-based vegetarian diets are associated with numerous health benefits; research suggests that vegetarians have lower risk of obesity, heart disease, hypertension, cancer, type 2 diabetes, and overall mortality Cancer is a group of conditions that result from the uncontrolled growth or division of abnormal cells that invade a part or parts of the body; develops in multistep process that includes initiation, promotion, and profession; dietary choices can both increase and decrease risk of cancer Phytochemicals are chemical constituents in plants that have antioxidant or hormone-like actions and are associated with many benefits to human health

Summary (Cont’d) Vegetarian diets that exclude all or most animal foods require planning in order to meet nutrient needs; nutrients of potential concern include protein, iron, calcium, vitamin D, riboflavin, vitamin B12, omega-3 fatty acids, and iodine Complementary protein foods are incomplete protein plant foods that when consumed together or during the course of a day provide all essential amino acids to help meet protein needs Organic is a labeling term that indicates that a food or other agricultural product has been produced through approved methods and follows USDA specifications for organic regulations The traditional Mediterranean diet has unique characteristics and multiple health benefits