Chapter 9: Plant-Based Diets
What vegetable is a good source of both iron and calcium? Why is vitamin B12 intake not a concern for lacto-ovo-vegetarians?
Broccoli is a good source of iron and calcium. Vitamin B12 is not a concern for lacto-ovo-vegetarians because they consume animal products.
Cancer Risk Factors (Lifestyle choices)
Dietary choices can both increase and decrease risk. For example, eating a diet rich in vegetables, fruits, and legumes has been linked with a reduced risk of mouth, esophageal, stomach, and colon cancer. In contrast, alcohol consumption is associated with an increased risk of several types of cancer.
Semi-Vegetarian Diets
Diets which restrict consumption of some meats. This includes diets which exclude only red meat but eat all other animal products (quasi-vegetarians), pescatarians, and those who eat a mostly plant-based diet but who occasionally eat meat too (flexitarians).
Stages of Cancer - Metastasis (Step Four)
Mutated cells acquire additional mutations that allow the cancer cells to migrate to, and invade, other tissues. These new tumors disrupt the normal function of body organs and tissues.
Do vegetarian diets guarantee better health?
Some vegetarians eat primarily grain-based foods or legumes without much attention to variety or overall nutrition, which is not necessarily good for them. The quality of the diet depends significantly on the distribution of the nutrients being consumed and the types of food choices being made.
All of the following are true about complementary protein foods, EXCEPT:
They must be consumed at the same meal or snack to support protein synthesis.
Resveratrol
A polyphenol found in grapes and red wine.
Pescatarian Diet
A semi-vegetarian diet that excludes meats and poultry, but includes plant foods, dairy foods, eggs, fish, and shellfish.
Lacto-ovo Vegetarian Diet
A vegetarian diet consisting of plant foods plus dairy (lacto) and egg (ovo) products.
Vegan Diet
A vegetarian diet that eliminates all foods of animal origin.
Carotenoids
Another important class of phytochemicals. Although more than 700 types of these pigments have been identified, only about 50 of them are common in our diet, where they are responsible for the yellow, orange, and red colors of apricots, watermelons, sweet potatoes, red peppers, and tomatoes.
Flavonoids
Are the largest family of phenolic compounds. Flavonoids are further divided into subclasses, including anthocyanins (abundant in berries), isoflavones (abundant in soy products and licorice), and flavanols (abundant in dark chocolate and cocoa).
Beta-carotene, Lycopene, Lutein, and Zeaxanthin are important examples of:
Carotenoids
Vegetarians Diets for Children & Adolescents
Children and adolescents can be vegetarians, too, but given their higher nutrient needs to support growth and development, they may be at more risk than adults for nutrient inadequacies. Lacto-ovo-vegetarian kids grow similarly to their nonvegetarian peers, but some studies suggest that vegan children tend to be slightly smaller than nonvegetarian children, although they do tend to be within the normal range for their height and weight.
What are the two ways you could incorporate more flavonoids into your diet?
Flavonoids can easily be incorporated into the diet by the consumption of green teas, citrus fruits, berries, and soy products.
Organic Foods
Foods produced through approved methods that integrate cultural, biological, and mechanical practices that foster the recycling of resources, promote ecological balance, and conserve biodiversity.
What do you think may be the most common difference in the reasons given for why people chose to be vegetarians versus semi-vegetarians?
For some people, consuming animals may be against their moral or religious beliefs. These people will choose to be vegetarian over being semi-vegetarian.
Why it is beneficial to "eat a rainbow"?
Fruits, vegetables, and whole grains can contain thousands of these compounds, which give them their color, aroma, and flavor. Because phytochemicals are often color-specific, similarly colored foods, such as carrots and sweet potatoes, often contain similar types of phytochemicals—hence the recommendation to "eat a rainbow" of foods to ensure the consumption of a variety of phytochemicals.
Vegetarians that emphasize whole plant foods tend to have higher intakes of all of the following, EXCEPT:
Riboflavin
Plant-based diets and cancer:
Studies find that plant-based diets reduce the risk of cancer, the second leading cause of death in the United States, ranking just below cardiovascular disease.
Vegetarian diets and health outcomes (diseases)
Studies show that vegetarians have lower total blood cholesterol, low-density lipoprotein levels, and blood pressure, all of which reduce their cardiovascular risks; indeed, research suggests that vegetarians have a lower risk of obesity, heart disease, hypertension, cancer, type 2 diabetes, and mortality than those consuming a typical western diet.
Vegetarian Pattern
The Vegetarian Pattern is similar to the Healthy U.S.-Style Pattern (see chapter 2), but is higher in calcium and fiber and lower in vitamin D. Also, the Vegetarian Pattern increases consumption of soy products, legumes, nuts and seeds, and whole grains and eliminates meats, poultry, and seafood.
Vegetarians tend to have a higher intake of nutrients including:
Vitamins C and E, magnesium, potassium, folate, antioxidants, and phytochemicals.
What category of food is eaten daily by most individuals living in the United States but is consumed only occasionally by those who adhere to a Mediterranean diet?
Most individuals living in the United States consume meats daily. Those who adhere to a Mediterranean diet eat meat only occasionally.
Characteristics of the polyphenols include:
- They are the most abundant and diverse category of phytochemicals. - They are found in coffee, tea, and red wine. - They include flavonoids and isoflavones. - Many have anti-inflammatory effects.
Recommendations to Reduce Risk of Cancer
-Achieve or maintain healthy body weight - Limit consumption of energy-dense and sugary drinks that contribute to weight gain - Limit consumption of red and processed meat - Limit salt intake - Encourage infant breastfeeding - Be physically active - Eat mostly foods of plant origin - Limit alcoholic drinks - Aim to meet nutritional needs through diet alone - Avoid consuming moldy grains, legumes, and other foods [as some molds produce aflatoxins that are potent cancer-causing compounds]
Four Stages of Cancer Progression
1) Initiation 2) Promotion 3) Progression 4) Metastasis
Iron found in plant foods (non-heme iron) is lower in bioavailability than the heme iron found in animal foods. Thus, the U.S. Dietary Reference Intake of non-heme iron is _________ higher for vegetarians than the iron recommendation for nonvegetarians.
80%
Vegetarian Diet
A diet consisting of plant-based foods, which excludes all meats, fish, and shellfish, but may include dairy products and eggs.
Phytochemicals
Compounds found in plant foods that are physiologically active and beneficial to human health; they are not considered to be essential nutrients.
Why does the protein in corn not complement the protein in rice?
Corn and rice are low in the same amino acid; their proteins are not "complementary."
Organic vs Conventional Foods
Current evidence does not support any meaningful nutritional benefits associated with eating organic foods compared with conventional foods, and there are no well-powered human studies that directly demonstrate health benefits or disease protection as a result of consuming an organic diet.
Stages of Cancer - Initiation (Step One)
DNA inside a cell undergoes a mutation that alters the DNA sequence permanently. Any cells produced from the division of the mutated cell will also carry the mutation. Once a cell has been mutated, it is susceptible to the effects of promoters.
Effect of Polyphenols
Many polyphenols have anti-inflammatory effects, and diets rich in polyphenols are associated with a reduced risk of chronic diseases such as cardiovascular disease, diabetes, osteoporosis, and neurological-related disorders. Polyphenols may reverse, suppress, or prevent the development of cancer. There are thought to be many mechanisms of action—for example, polyphenols may be able to interrupt or reverse cancer development by interrupting cellular communication systems, thus stopping the initiation or promotion of cancer. Some polyphenols can also trigger cell death (apoptosis) in cancer cells. In addition to having antioxidant and anti-inflammatory effects, phytochemicals can also have hormone-like effects. In particular, two groups of polyphenols, isoflavones and lignans (found in flaxseed), are believed to mimic the actions of the female hormone estrogen.
Health Benefits Associated with the Mediterranean Diet
Mediterranean diet is associated with a reduced risk of diabetes, Parkinson's disease, allergies (in children), and cancer. The mechanism by which it reduces cancer risk may have something to do with the fact that the Mediterranean diet provides a healthy ratio of omega-6 to omega-3 fats and that it is high in fiber, antioxidants, and polyphenols. The diet also involves a "Mediterranean way of drinking," which means regular, moderate consumption of wine, mainly with food, which has been associated with a reduced risk of chronic disease.
Mediterranean Diet Study Results
Mediterranean dieters who were given olive oil had a 30% reduced risk of heart problems over the five-year period compared with the low-fat dieters, while those who had been given mixed nuts had a 28% reduced risk of heart problems or heart-related death compared with the low-fat dieters.
Common Features of Mediterranean Diets
More than half of the fat calories in a Mediterranean diet come from monounsaturated fats (mainly from olive oil), which appears to have beneficial blood lipid and other cardioprotective effects. In addition, the Mediterranean dietary pattern emphasizes a high intake of vegetables, legumes, fruits, nuts, whole grains, cheese or yogurt, fish, and healthy oils.
Stages of Cancer - Progression (Step Three)
Mutated cells acquire additional mutations that allow the cancer cells to migrate to, and invade, other tissues.
Are vegetarian diets nutritionally balanced?
Not only can vegetarians meet the recommended intakes for various nutrients with a bit of dietary planning, but they can also benefit from a reduced incidence of chronic disease and lower mortality rates compared with people eating a typical Western diet of high meat intake, and refined grains.
What is the "French paradox"?
The fact that the French, who consume many rich and high-fat foods but drink a lot of red wine, tend to die less often of coronary heart disease than individuals from other Western countries. ***More research is necessary as wine and other dietary sources of resveratrol may not provide the health benefits suggested, or the benefits may stem from other chemical constituents.
Polyphenols
The most abundant and diverse phytochemicals in our diet. Found in a wide variety of foods, polyphenols are particularly rich in berries, coffee, tea, red wine, cocoa powder, nuts, and spices; numerous fruits and vegetables are also good sources.
Iron Consumption Recommendations for Vegetarians
The recommended non-heme iron (plant based form of iron) intake for vegetarians, particularly vegans, is 80% higher than the iron recommendation for nonvegetarians. Iron-containing plant foods are soybeans, legumes, dried fruit, as well as fortified grains and cereals.
Stages of Cancer - Promotion (Step Two)
Various factors (like inflammation or some chemicals) selectively promote these mutated cells to divide and proliferate more quickly than they should.
Jason follows a vegan diet and avoids all animal foods. He consumes a wide variety of vegetables, fruits, grains, beans, and other whole plant-based foods. Despite his nutrient-rich diet, supplementation or use of foods fortified with ____________ is recommended.
Vitamin B12
Vitamin & Mineral Concerns for Vegetarians
Zinc, found in soy products, legumes, grains, and nuts, is less well-absorbed from plant foods than it is from animal foods, though vegetarians typically get enough of this mineral. Calcium, vitamin D, and riboflavin (vitamin B2) are nutrients of concern for vegetarians. Plant foods do provide the omega-3 ALA (alpha-linolenic acid), but less than 10% of ALA in plant foods is converted to EPA and DHA. EPA and DHA can also be found in foods such as soy milk, margarine, and eggs. Vegetarians who avoid animal sources of DHA and EPA should maximize their intake of ALA through walnuts, flaxseeds, soy, and algae.
