1. 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

2. 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

3. 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.

4. 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.

5. 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

6. Types of Vegetarian Diets

7. 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.

8. 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.

9. 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.

10. 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.

11. 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.

12. Recommendations to Reduce the Risk of Cancer

13. 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.

14. 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.

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

16. 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

17. Examples of Phytochemicals, Their Sources, and Their Benefits

21. 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.

22. 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.

23. 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

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

25. 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

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

27. 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.

28. Make a Nutritional Plan

29. 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

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

31. 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

32. 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

33. 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

34. 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.

35. Mediterranean Diet

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

37. 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

38. 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

39. 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