human nut final part 1 Flashcards
(176 cards)
1
Q
What percentage of women and men suffer from anorexia nervosa, bulimia nervosa, and binge eating disorder according to large national surveys?
A
Anorexia nervosa: 0.9% women, 0.3% men; Bulimia nervosa: 0.5% women, 0.1% men; Binge eating disorder: 3.5% women, 2% men.
2
Q
According to the passage, what are the multiple factors that experts believe contribute to the development of eating disorders?
A
Sociocultural, psychological, and neurochemical factors.
3
Q
Why are athletes, such as Suzanne, mentioned as being among those most likely to develop eating disorders?
A
Athletes, including gymnasts, may face excessive pressure to maintain a specific weight for their sport, leading to disordered eating patterns.
4
Q
What is relative energy deficiency, and how does it develop in athletes like David?
A
Relative energy deficiency occurs when an athlete’s diet provides insufficient energy for their physical activity. David experiences this by drastically restricting food and fluid intake to make weight for wrestling matches.
5
Q
Why might athletes engage in disordered eating, and what are some risk factors mentioned in the passage?
A
Athletes may engage in disordered eating due to unsuitable weight standards. Risk factors include young age, pressure to excel, focus on an “ideal” body weight, and participation in sports that emphasize a lean appearance.
6
Q
What are some physical consequences of prolonged inadequate energy intake discussed in relation to anorexia nervosa?
A
Consequences include nutrient deficiencies, chronic fatigue, increased risk of infections, heart disease, amenorrhea, bone losses, and stress fractures.
7
Q
What is the multidisciplinary approach recommended for the treatment of anorexia nervosa, and what are the key objectives of dietary interventions?
A
The approach involves teams of professionals. Dietary objectives include stopping weight loss, establishing regular eating patterns, and tailoring diets to individual needs. The ultimate goal is to achieve recovery and prevent relapse.
8
Q
According to the passage, what is the general outcome for individuals treated for anorexia nervosa, and what factors influence the success of treatment?
A
About half of women treated can maintain their body weight at 85% or more of a healthy weight. Success is influenced by factors such as response to treatment, relapse into abnormal eating behaviors, and overall mortality rates.
9
Q
How does the passage describe the distorted body image characteristic of anorexia nervosa, using Julie as an example?
A
Anorexia nervosa involves a distorted body image where individuals, like Julie, overestimate their body fatness, seeing themselves as fat even when dangerously underweight.
10
Q
What is orthorexia nervosa, and why is it mentioned in the context of disordered eating?
A
Orthorexia nervosa is disordered eating in the name of health, characterized by obsessive focus on diet and exercise. It is mentioned to highlight the potential negative consequences of obsessive health-related behaviors.
11
Q
What percentage of US adults are underweight?
A
Fewer than 2 percent of US adults are underweight.
12
Q
What are some potential causes of being underweight mentioned in the passage?
A
Underweight may be due to malnutrition, smoking habits, substance abuse, or illnesses.
13
Q
Why is a complete assessment necessary for underweight individuals?
A
Weight and fat measures alone would not reveal underlying causes, and a complete assessment, including a diet and medical history, physical examination, and laboratory tests, is required.
14
Q
How does underweight affect individuals facing wasting diseases like cancer?
A
Underweight individuals may struggle to preserve lean tissue during the fight against wasting diseases, increasing mortality risks.
15
Q
What health risks are associated with underweight women?
A
Underweight women may experience menstrual irregularities, infertility, and an increased risk of giving birth to unhealthy infants.
16
Q
What is the financial cost of obesity-related illnesses to the nation annually?
A
Obesity-related illnesses cost the nation $147 billion annually, comparable to or exceeding the medical costs of smoking.
17
Q
What is the relationship between obesity and cardiovascular disease risk?
A
Obesity is strongly linked to elevated blood cholesterol and hypertension, increasing the risk of heart attack and stroke.
18
Q
What diseases are associated with chronic inflammation in obesity?
A
Chronic inflammation in obesity contributes to diseases like diabetes, hypertension, and atherosclerosis, forming a cluster known as the metabolic syndrome.
19
Q
How does weight loss affect insulin resistance and inflammation in obese individuals?
A
Weight loss can effectively reverse atherosclerosis and lower both blood cholesterol and blood pressure in overweight and obese people, improving inflammation and the metabolic syndrome.
20
Q
How does weight gain after the age of 18 influence the risk of developing diabetes?
A
A weight gain of more than 10 pounds after the age of 18 doubles the risk of developing diabetes, even in adults of average weight.
21
Q
What is the relationship between inflammation and the metabolic syndrome?
A
Chronic inflammation in obesity contributes to the metabolic syndrome, increasing the risks for diabetes, hypertension, and atherosclerosis.
22
Q
How does obesity influence the risk of developing some cancers?
A
The duration and severity of overweight or obesity increase the risk of developing some cancers, possibly due to elevated levels of hormones or chronic inflammation.
23
Q
What is “healthy obesity,” and how stable is this condition over time?
A
Healthy obesity refers to obese individuals with normal blood pressure, blood glucose, and blood lipids. It appears to be a relatively unstable condition, transitioning to unhealthy over time.
24
Q
Does BMI alone provide a complete picture of health risks?
A
No, BMI and weight gains/losses do not tell the whole story. Physical activity and fitness also play major roles in health and longevity.
25
hat limitations do weight measures have in assessing disease risk, according to the passage?
Weight measures fail to reveal how much of the weight is fat and where the fat is located.
26
What factors determine the ideal amount of body fat for athletes? Provide the recommended percentage range for young men and young women athletes.
The ideal amount of body fat for athletes depends on providing fuel, insulation, protection, nerve impulse transmission, and hormone support. For young men, the recommended percentage is 7 to 16 percent, and for young women, it is 15 to 22 percent.
27
How does body fat distribution impact health, and what health risks are associated with central obesity independently of BMI?
Excessive visceral fat stored around abdominal organs contributes significantly to heart disease, cancers, diabetes, and related deaths independently of BMI.
28
Explain the differences in body fat distribution between men and women.
Men typically have more visceral fat, especially past menopause, while women, during their reproductive years, commonly have lower body fat around the hips and thighs.
29
What is waist circumference, and how is it related to central obesity? Provide the recommended measurements for women and men indicating a high risk of central obesity-related health problems.
Waist circumference is an anthropometric measurement used to assess abdominal fat. Women with a waist circumference greater than 35 inches and men with a waist circumference greater than 40 inches have a high risk of central obesity–related health problems.
30
* what is the expected waist circumfrence to a perosn height?
* Explain the significance of the waist-to-height ratio in assessing disease risks.
Waist circumference should be less than half of a person’s height, and the waist-to-height ratio is a useful measure of disease risks. As waist circumference increases, disease risks also increase.
31
What are some other methods mentioned in the passage for estimating body fat and its distribution, apart from BMI and waist circumference?
Other methods include total body water, radioactive potassium count, near-infrared spectrophotometry, ultrasound, computed tomography, and magnetic resonance imaging.
32
How does the passage describe the correlation between body weight, body fat, and disease risks?
Body weight and body fat correlate with disease risks, suggesting a greater likelihood of developing chronic diseases and shortening life expectancy for those with a higher BMI and waist circumference.
33
What is the relationship between BMI and mortality, and what does the J-shaped curve describe?
The J-shaped curve describes the relationship between BMI and mortality, indicating that both underweight and overweight present risks of premature death. Mortality risks are lowest when BMI ranges between about 20 and 30.
34
What independent factors, mentioned in the passage, can influence health risks irrespective of BMI? Provide examples.
Factors such as smoking habits raise health risks, while physical fitness lowers them. The passage provides an example of a man with a BMI of 22 who smokes and a woman with a BMI of 32 who engages in brisk walking.
35
What percentage of US adults are underweight?
: Fewer than 2 percent of US adults are underweight.
36
Q: What are some potential causes of being underweight mentioned in the passage?
A: Underweight may be due to malnutrition, smoking habits, substance abuse, or illnesses.
37
Q: Why is a complete assessment necessary for underweight individuals?
A: Weight and fat measures alone would not reveal underlying causes, and a complete assessment, including a diet and medical history, physical examination, and laboratory tests, is required.
38
Q: How does underweight affect individuals facing wasting diseases like cancer?
A: Underweight individuals may struggle to preserve lean tissue during the fight against wasting diseases, increasing mortality risks.
39
Q: What health risks are associated with underweight women?
A: Underweight women may experience menstrual irregularities, infertility, and an increased risk of giving birth to unhealthy infants.
40
What is the financial cost of obesity-related illnesses to the nation annually?
Obesity-related illnesses cost the nation $147 billion annually, comparable to or exceeding the medical costs of smoking.
41
Q: What is the relationship between obesity and cardiovascular disease risk?
A: Obesity is strongly linked to elevated blood cholesterol and hypertension, increasing the risk of heart attack and stroke.
42
Q: What diseases are associated with chronic inflammation in obesity?
A: Chronic inflammation in obesity contributes to diseases like diabetes, hypertension, and atherosclerosis, forming a cluster known as the metabolic syndrome.
43
Q: How does weight loss affect insulin resistance and inflammation in obese individuals?
A: Weight loss can effectively reverse atherosclerosis and lower both blood cholesterol and blood pressure in overweight and obese people, improving inflammation and the metabolic syndrome.
44
How does weight gain after the age of 18 influence the risk of developing diabetes?
A weight gain of more than 10 pounds after the age of 18 doubles the risk of developing diabetes, even in adults of average weight.
45
Q: What is the relationship between inflammation and the metabolic syndrome?
A: Chronic inflammation in obesity contributes to the metabolic syndrome, increasing the risks for diabetes, hypertension, and atherosclerosis.
46
How does obesity influence the risk of developing some cancers?
: possibly due to elevated levels of hormones or chronic inflammation.
47
Q: What is "healthy obesity," and how stable is this condition over time?
A: "Healthy obesity" refers to obese individuals with normal blood pressure, blood glucose, and blood lipids. It appears to be a relatively unstable condition, transitioning to unhealthy over time.
48
Q: Does BMI alone provide a complete picture of health risks?
: No, BMI and weight gains/losses do not tell the whole story. Physical activity and fitness also play major roles in health and longevity.
49
According to the passage, what are the multiple factors that experts believe contribute to the development of eating disorders?
Sociocultural, psychological, and neurochemical factors.
50
Why are athletes, such as Suzanne, mentioned as being among those most likely to develop eating disorders?
A: Athletes, including gymnasts, may face excessive pressure to maintain a specific weight for their sport, leading to disordered eating patterns.
51
What is relative energy deficiency, and how does it develop in athletes like David?
A: Relative energy deficiency occurs when an athlete's diet provides insufficient energy for their physical activity. David experiences this by drastically restricting food and fluid intake to make weight for wrestling matches.
52
Why might athletes engage in disordered eating, and what are some risk factors mentioned in the passage?
A: Athletes may engage in disordered eating due to unsuitable weight standards. Risk factors include young age, pressure to excel, focus on an "ideal" body weight, and participation in sports that emphasize a lean appearance.
53
According to the passage, what is the general outcome for individuals treated for anorexia nervosa, and what factors influence the success of treatment?
A: About half of women treated can maintain their body weight at 85% or more of a healthy weight. Success is influenced by factors such as response to treatment, relapse into abnormal eating behaviors, and overall mortality rates.
54
How does the passage describe the distorted body image characteristic of anorexia nervosa, using Julie as an example?
A: Anorexia nervosa involves a distorted body image where individuals, like Julie, overestimate their body fatness, seeing themselves as fat even when dangerously underweight.
55
What is orthorexia nervosa, and why is it mentioned in the context of disordered eating?
A: Orthorexia nervosa is disordered eating in the name of health, characterized by obsessive focus on diet and exercise. It is mentioned to highlight the potential negative consequences of obsessive health-related behaviors.
56
What is the multidisciplinary approach recommended for the treatment of anorexia nervosa, and what are the key objectives of dietary interventions?
A: The approach involves teams of professionals. Dietary objectives include stopping weight loss, establishing regular eating patterns, and tailoring diets to individual needs. The ultimate goal is to achieve recovery and prevent relapse.
57
What percentage of women and men suffer from anorexia nervosa, bulimia nervosa, and binge eating disorder according to large national surveys?
A: Anorexia nervosa: 0.9% women, 0.3% men; Bulimia nervosa: 0.5% women, 0.1% men; Binge eating disorder: 3.5% women, 2% men.
58
What are some physical consequences of prolonged inadequate energy intake discussed in relation to anorexia nervosa?
A: Consequences include nutrient deficiencies, chronic fatigue, increased risk of infections, heart disease, amenorrhea, bone losses, and stress fractures.
59
What is the role of chromium in the body?
Chromium participates in carbohydrate and lipid metabolism.
60
How does chromium help maintain glucose homeostasis?
Chromium enhances the activity of the hormone insulin.
61
What happens when chromium is lacking in the diet?
A diabetes-like condition may develop, characterized by elevated blood glucose, impaired glucose tolerance, insulin response, and glucagon response.
62
Do chromium supplements benefit people with type 2 diabetes?
Research suggests that chromium supplements provide little or no benefit to people with type 2 diabetes.
63
Where is chromium found in the diet?
Chromium is present in a variety of foods, with the best sources being unrefined foods, liver, brewer’s yeast, and whole grains.
64
What is the function of molybdenum in the body?
Molybdenum acts as a working part of several metalloenzymes.
65
Are dietary deficiencies of molybdenum common?
No, dietary deficiencies of molybdenum are unknown because the amounts needed are very small.
66
What are molybdenum-rich foods?
Molybdenum-rich foods include legumes, breads, other grain products, leafy green vegetables, milk, and liver.
67
Is molybdenum toxicity common in humans?
Molybdenum toxicity in people is rare and is characterized by kidney damage and reproductive abnormalities.
68
How do contaminant minerals enter the food supply?
what are some Contaminant minerals and how do like lead, mercury, and cadmum enter the food supply through soil, water, and air pollution.
69
What is the main focus regarding lead in this context?
The section focuses on lead poisoning as it is a serious environmental threat to young children, and reducing blood lead levels is a goal of the Healthy People initiative.
70
How does lead disrupt body processes?
Lead competes with essential minerals like iron and calcium, displacing them from metabolic sites, disrupting body processes, and impairing nutrition status.
71
Why are children with iron deficiency vulnerable to lead toxicity?
Children with iron deficiency are particularly vulnerable to lead toxicity.
72
What is the general impact of contaminant minerals on health?
Contaminant minerals impair the body’s growth, work capacity, and general health.
73
What are phytochemicals, and where are they found?
Phytochemicals are compounds in plant-derived foods with biological activity. They are found in fruits, vegetables, and other plant-based foods.
74
How do phytochemicals defend against chronic diseases?
Phytochemicals may act as antioxidants, mimic hormones, stimulate enzymes, interfere with DNA replication, suppress inflammation, destroy bacteria, and bind to cell walls, preventing chronic diseases.
75
What is the definition of functional foods?
Functional foods include those with potentially beneficial effects on health beyond their nutrient contributions.
76
Give examples of functional foods rich in phytochemicals.
Examples include whole grains, oily fish, fresh fruits, orange juice fortified with calcium, and margarine with plant sterols.
77
What are some examples of phytochemicals defending against specific diseases?
Soy may protect against breast and prostate cancers, while lycopene in tomatoes may offer protection against some cancers.
78
What is the concept of functional foods?
Functional foods naturally contain biologically active phytochemicals and offer health benefits.
79
How do functional foods blur the distinctions between foods and drugs?
Functional foods have characteristics of both foods and drugs, acting like drugs with ingredients that alter body functions.
80
What are some examples of foods acting like drugs?
Margarine enhanced with plant sterols that lower blood cholesterol is an example of a food acting like a drug.
81
What are the challenges in using functional foods as drugs?
Unanswered questions include whether functional foods work, their safety, effectiveness, dosage, and whether they are a healthy choice.
82
What are the potential future developments in the field of functional foods?
Future developments may involve designing specific eating patterns based on individual health needs, merging knowledge of the human genome and nutrition, and creating foods to meet specific health requirements.
83
What percentage of an adult's body weight is water?
bout 60 percent.
84
How does body composition influence the proportion of water in the body?
Water makes up about 75 percent of the weight of lean tissue and less than 25 percent of the weight of fat. The proportion of water is generally smaller in females, obese people, and the elderly due to their smaller proportion of lean tissue.
85
List some functions of water in the body fluids.
Carries nutrients and waste products throughout the body, Maintains the structure of large molecules such as proteins and glycogen., Participates in metabolic reactions.,Serves as a solvent for minerals, vitamins, amino acids, glucose, and other small molecules.
86
Define intracellular fluid and extracellular fluid.
ntracellular fluid: Fluid inside cells, usually high in potassium and phosphate. , Extracellular fluid: Fluid outside cells, includes interstitial fluid (between cells) and intravascular fluid (inside blood vessels).
87
What are electrolytes, and why are they important?
Electrolytes are salts that dissolve in water and dissociate into charged particles called ions. They are important because they can conduct electricity and play a crucial role in various physiological processes.
88
Explain osmosis and its relationship to electrolytes.
Osmosis is the movement of water across a membrane toward the side where solutes are more concentrated. Electrolytes attract water, so when electrolytes move across a membrane, water follows.
89
How do proteins influence fluid movement in and out of cells?
Proteins attract water and regulate fluid movement. When proteins leak out of blood vessels, fluids follow, causing swelling. Transport proteins in cell membranes regulate the passage of ions, and water flows toward more concentrated solutions.
90
What is the role of antidiuretic hormone (ADH) in fluid regulation?
ADH is a water-conserving hormone that stimulates the kidneys to reabsorb water. It is released when blood volume or pressure falls too low, helping to retain fluids and trigger thirst.
91
Describe the three systems that defend the body against fluctuations in pH.
Buffers in the blood: Bicarbonate, carbonic acid, and proteins neutralize acids or bases., Respiration in the lungs: Controls carbonic acid concentration by adjusting respiration rate., Excretion in the kidneys: Controls bicarbonate concentration by reabsorbing or excreting it.
92
What is the minimum daily water excretion, and how is it related to maintaining balance?
The minimum daily water excretion, about 500 milliliters, helps dispose of metabolic wastes. Excretion adjusts to balance intake, and maintaining this balance requires healthy kidneys and adequate fluid intake.
93
How do thirst and satiety influence water intake?
Thirst signals inadequate water intake, while stretch receptors in the stomach and signals from the heart influence satiety, signaling when to stop drinking.
94
What are the symptoms and consequences of dehydration?
Symptoms include thirst, dry skin, rapid heartbeat, low blood pressure, weakness. Consequences can progress from fatigue to delirium and, if uncorrected, death.
95
Explain water intoxication and its causes.
Water intoxication is rare but can occur with excessive water intake and reduced urine production, leading to hyponatremia. Guidelines suggest limiting fluid intake during heavy sweating to prevent this condition.
96
How is the recommended daily water intake determined?
Recommendations vary based on diet, activity, temperature, and humidity. A general guideline is 1.0 to 1.5 milliliters per kilocalorie expended, with the average adult recommended to consume 2 to 3 liters of water per day.
97
Why is water considered the best choice for most people?
Water meets fluid needs without contributing to weight gain. Other acceptable choices include tea, coffee, nonfat and low-fat milk, soymilk, artificially sweetened beverages, fruit and vegetable juices, and sports drinks.
98
What health effects does water have on the body?
Water supports physical and mental performance, optimal functioning of body systems, and is essential for maintaining health. The kind of water consumed may also impact health, with considerations for hard and soft water.
99
What are the main roles of zinc in the body?
Zinc supports the work of proteins in metabolic processes, stabilizes cell membranes and DNA, strengthens antioxidant defenses, assists in immune function, growth, and development. It participates in hormone synthesis, blood clotting, thyroid function, and influences behavior and learning.
100
How does zinc absorption vary with dietary intake?
The rate of zinc absorption varies from 15 to 40 percent. As zinc intake increases, the absorption rate decreases, and as zinc intake decreases, the absorption rate increases. Dietary factors like phytates can influence absorption, limiting bioavailability.
101
What is the enteropancreatic circulation of zinc?
After absorption, zinc circulates between the small intestine and the pancreas. Some zinc reaches the pancreas to be incorporated into digestive enzymes, providing a dual source of zinc for the small intestine. This circulation is known as the enteropancreatic circulation of zinc.
102
What are the symptoms of zinc deficiency?
Zinc deficiency can lead to impaired growth, immature sexual development, digestion issues, diarrhea, compromised immune response, central nervous system damage, poor motor development, cognitive performance, altered taste, loss of appetite, and slowed wound healing.
103
What are the potential side effects of zinc toxicity?
High doses of zinc (more than 50 milligrams) can cause vomiting, diarrhea, headaches, exhaustion, and interfere with copper metabolism, leading to heart muscle degeneration. The UL for adults is set at 40 milligrams.
104
In which foods is zinc most abundant?
Zinc is highest in protein-rich foods such as shellfish (especially oysters), meats, poultry, milk, and cheese. Plant-based diets tend to be low in zinc, but legumes and whole-grain products can be good sources if consumed in large quantities.
105
What essential role does iodine play in the body?
Iodine is integral to thyroid hormones that regulate body temperature, metabolic rate, reproduction, growth, blood cell production, nerve and muscle function. It influences energy expenditure during basal metabolism by controlling cellular oxygen use.
106
What is the primary cause of goiter?
Goiter is primarily caused by iodine deficiency. In iodine deficiency, the thyroid gland enlarges as it attempts to trap more iodine. Some foods containing goitrogens, like collards and kale, can also contribute to goiter by interfering with iodine uptake by the thyroid.
107
How does iodine deficiency impact mental health?
Iodine deficiency is the most common cause of preventable mental impairment. It can lead to poor performance in school, and severe deficiency during pregnancy can result in irreversible mental impairment and stunted physical growth, known as cretinism.
108
What is the UL for iodine intake in adults?
The UL for iodine intake in adults is 1100 micrograms per day. Excessive iodine intake during pregnancy can be especially damaging to the developing infant, potentially causing goiter severe enough to block airways and lead to suffocation.
109
What are the major sources of selenium in the diet?
Selenium is found in soil and crops, with reliable sources being meats, milk, and eggs. Eating as few as two Brazil nuts a day can effectively improve selenium status. Average intakes in the United States exceed the RDA, which is based on maximizing glutathione peroxidase activity.
110
What are the roles of copper in the body?
Copper serves as a constituent of enzymes involved in various metabolic roles, including iron metabolism, collagen manufacturing, inactivation of histamine, degradation of serotonin, and participation in energy metabolism reactions.
111
How can copper deficiency and toxicity occur?
Copper deficiency is rare in typical US diets and is associated with genetic disorders. Excessive copper intake from foods is unlikely, but supplements may cause liver damage. Genetic disorders like Menkes disease and Wilson's disease can lead to copper deficiency or toxicity.
112
What is the role of manganese in the body?
Manganese acts as a cofactor for enzymes facilitating carbohydrate, lipid, and amino acid metabolism. It is essential for bone formation, the conversion of pyruvate to a TCA cycle compound, and maintaining healthy nerves.
113
How does fluoride contribute to oral health?
Fluoride, by forming fluorapatite in teeth, strengthens enamel and makes teeth more resistant to decay. Drinking water, usually the best source of fluoride, helps protect against dental caries. However, excessive fluoride intake can lead to fluorosis, causing tooth damage.
114
What factors influence the trace mineral contents of foods?
The trace mineral contents of foods depend on soil and water composition, food processing, diet, and the body's bioavailability.
115
Why is assessing trace mineral status challenging?
Assessing trace mineral status is challenging due to the complexity of their roles in various body systems, difficulty in diagnosing deficiencies, and the potential for mild deficiencies to be overlooked.
116
Explain the importance of avoiding excessive intake of trace minerals.
Most trace minerals can be toxic at intakes only two and a half to eleven times above current recommendations. Exceeding the Upper Level (UL) can lead to adverse effects, and dietary supplements make it easy to surpass recommended intakes.
117
What role do interactions among trace minerals play in the body?
Interactions among trace minerals are common and can be well-coordinated to meet the body’s needs, supporting various physiological functions. However, imbalances or excesses of one mineral can lead to deficiencies or toxicities of others.
118
Why is research on nonessential trace minerals challenging?
Research on nonessential trace minerals like nickel, bromine, vanadium, cobalt, and boron is challenging due to their small quantities in the body and the lack of clear understanding of their functions and deficiencies in humans.
119
What are the two ionic states of iron, and how do they function in the body?
Iron has two ionic states—ferrous iron (reduced state) and ferric iron (oxidized state). These states allow iron to serve as a cofactor for enzymes involved in oxidation-reduction reactions and as part of electron carriers in the electron transport chain.
120
How does the body regulate iron absorption and maintain balance?
The body regulates iron absorption primarily through ferritin and transferrin. Ferritin captures and stores iron in the cells of the small intestine, releasing it when needed. Transferrin transports iron to various tissues, and the body adapts absorption based on iron stores.
121
What are the dietary factors that enhance or inhibit nonheme iron absorption?
Factors that enhance nonheme iron absorption include vitamin C, MFP factor (found in meat, fish, and poultry), acids, and certain sugars. Inhibitors include phytates, vegetable proteins, calcium, and polyphenols.
122
Why is iron deficiency a significant concern worldwide?
Iron deficiency is the most common nutrient deficiency globally, affecting over 2 billion people. It can lead to anemia, particularly in preschool children and pregnant women.
123
What are the stages of iron deficiency, and how is it assessed?
Iron deficiency progresses through stages of diminishing iron stores, decreased transport iron, and limited hemoglobin production. Assessment involves measuring serum ferritin, transferrin, transferrin saturation, and erythrocyte protoporphyrin.
124
How does iron deficiency differ from iron-deficiency anemia?
Iron deficiency refers to depleted iron stores, while iron-deficiency anemia is a severe depletion that results in low hemoglobin concentration, leading to symptoms such as fatigue, weakness, and pale skin.
125
Why do premenopausal women often face challenges in meeting their iron needs?
Premenopausal women have higher iron needs but lower energy needs, making it challenging to obtain enough iron from their diets. They may need to consciously choose iron-rich foods at each meal.
126
What are some good sources of iron in the diet?
Meats, fish, poultry, legumes, eggs, fortified grains, and dark greens are good sources of iron. Enriched or fortified foods, especially in the form of bread and cereals, contribute significantly to iron intake.
127
What are the potential health risks associated with iron overload?
Iron overload can lead to toxic accumulation in tissues, causing free-radical damage, infections, cirrhosis, liver cancer, heart failure, and arthritis. Excess iron in the diet or supplements can contribute to iron overload.
128
What factors should be considered when recommending iron supplements?
Iron supplements should be prescribed by a physician after assessing iron deficiency. The dose, formulation, and schedule should be individualized, and supplements should be taken with consideration of potential side effects, such as constipation.
129
What is the role of chromium in the body?
Chromium participates in carbohydrate and lipid metabolism.
130
How does chromium help maintain glucose homeostasis?
Chromium enhances the activity of the hormone insulin.
131
What happens when chromium is lacking in the diet?
A diabetes-like condition may develop, characterized by elevated blood glucose, impaired glucose tolerance, insulin response, and glucagon response.
132
Do chromium supplements benefit people with type 2 diabetes?
Research suggests that chromium supplements provide little or no benefit to people with type 2 diabetes.
133
Where is chromium found in the diet?
Chromium is present in a variety of foods, with the best sources being unrefined foods, liver, brewer’s yeast, and whole grains.
134
What is the function of molybdenum in the body?
Molybdenum acts as a working part of several metalloenzymes.
135
Are dietary deficiencies of molybdenum common?
No, dietary deficiencies of molybdenum are unknown because the amounts needed are very small.
136
What are molybdenum-rich foods?
Molybdenum-rich foods include legumes, breads, other grain products, leafy green vegetables, milk, and liver.
137
Is molybdenum toxicity common in humans?
Molybdenum toxicity in people is rare and is characterized by kidney damage and reproductive abnormalities.
138
How do contaminant minerals enter the food supply?
Contaminant minerals like lead, mercury, and cadmium enter the food supply through soil, water, and air pollution.
139
What is the main focus regarding lead in this context?
The section focuses on lead poisoning as it is a serious environmental threat to young children, and reducing blood lead levels is a goal of the Healthy People initiative.
140
How does lead disrupt body processes?
Lead competes with essential minerals like iron and calcium, displacing them from metabolic sites, disrupting body processes, and impairing nutrition status.
141
Why are children with iron deficiency vulnerable to lead toxicity?
Children with iron deficiency are particularly vulnerable to lead toxicity.
142
What is the general impact of contaminant minerals on health?
Contaminant minerals impair the body’s growth, work capacity, and general health.
143
What are phytochemicals, and where are they found?
Phytochemicals are compounds in plant-derived foods with biological activity. They are found in fruits, vegetables, and other plant-based foods.
144
How do phytochemicals defend against chronic diseases?
Phytochemicals may act as antioxidants, mimic hormones, stimulate enzymes, interfere with DNA replication, suppress inflammation, destroy bacteria, and bind to cell walls, preventing chronic diseases.
145
What is the definition of functional foods?
Functional foods include those with potentially beneficial effects on health beyond their nutrient contributions.
146
Give examples of functional foods rich in phytochemicals.
Examples include whole grains, oily fish, fresh fruits, orange juice fortified with calcium, and margarine with plant sterols.
147
What are some examples of phytochemicals defending against specific diseases?
Soy may protect against breast and prostate cancers, while lycopene in tomatoes may offer protection against some cancers.
148
What is the concept of functional foods?
Functional foods naturally contain biologically active phytochemicals and offer health benefits.
149
How do functional foods blur the distinctions between foods and drugs?
Functional foods have characteristics of both foods and drugs, acting like drugs with ingredients that alter body functions.
150
What are some examples of foods acting like drugs?
Margarine enhanced with plant sterols that lower blood cholesterol is an example of a food acting like a drug.
151
What are the challenges in using functional foods as drugs?
Unanswered questions include whether functional foods work, their safety, effectiveness, dosage, and whether they are a healthy choice.
152
What are the potential future developments in the field of functional foods?
Future developments may involve designing specific eating patterns based on individual health needs, merging knowledge of the human genome and nutrition, and creating foods to meet specific health requirements.
153
What motivates supplement manufacturers to introduce new supplements?
The day's hot topics in nutrition and emerging research news lead supplement manufacturers to develop new supplements. Terms like antioxidants and lycopene become popular, and commercials claim magic in fighting aging and disease.
154
What is a free radical, and how does it become unstable?
A free radical is a molecule with one or more unpaired electrons. An electron without a partner makes the molecule unstable and highly reactive. To regain stability, a free radical steals an electron from a stable but vulnerable compound, initiating a chain reaction.
155
How do antioxidants neutralize free radicals, and why don't they become free radicals themselves?
Antioxidants neutralize free radicals by donating one of their own electrons, ending the chain reaction. Antioxidants do not become free radicals because they remain stable in either form.
156
What role do free radicals play in the immune system?
Cells of the immune system use free radicals in an "oxidative burst" to demolish disease-causing viruses and bacteria. However, free-radical attacks most often cause widespread damage, contributing to cell damage, disease progression, and aging.
157
What minerals and vitamins act as defense against free-radical damage?
Enzymes dependent on selenium, copper, manganese, and zinc, along with antioxidant vitamins (vitamin E, beta-carotene, and vitamin C), defend against free-radical damage.
158
How might antioxidants reduce the risk of cancer?
Antioxidants may reduce cancer risks by protecting DNA from free-radical damage. Diets rich in fruits and vegetables, especially those containing vitamin C, beta-carotene, and carotenoids, are associated with lower cancer rates.
159
How does oxidative stress contribute to atherosclerosis, and how can antioxidants protect against heart disease?
Oxidative stress contributes to atherosclerosis by oxidizing LDL cholesterol. Antioxidants, especially vitamin E and vitamin C, protect against LDL oxidation, inflammation, and arterial injuries, potentially reducing the risk of heart disease.
160
According to the passage, what dietary strategies are most effective in preventing heart disease?
Effective strategies include using unsaturated fats, selecting foods rich in omega-3 fatty acids, and consuming a diet high in fruits, vegetables, nuts, and whole grains while low in refined grain products.
161
Should antioxidants be replenished from foods or supplements, according to the passage?
The passage emphasizes that antioxidants are best obtained from foods, especially fruits and vegetables, which offer a range of nutrients and phytochemicals. Taking supplements is not recommended for disease prevention.
162
What does the passage suggest about the use of antioxidant supplements for cancer prevention?
The passage suggests that antioxidant supplements may not provide the same benefits as a diet rich in fruits and vegetables. Some studies even indicate potential risks associated with certain supplements, such as increased mortality.
163
What are the two subgroups of the vitamin E family, and how are they named?
The vitamin E family consists of two subgroups—tocopherols and tocotrienols. The members are designated by letters of the Greek alphabet (alpha, beta, gamma, and delta).
164
Why is alpha-tocopherol the only member of the vitamin E family that is maintained in the body to meet its needs?
Alpha-tocopherol is the only member maintained because the other members are not converted to alpha-tocopherol in the body, and they are not recognized by its transport protein.
165
What is the main action of vitamin E as an antioxidant?
Vitamin E's main action is to stop the chain reaction of free radicals, preventing the production of more free radicals and protecting cell components and membranes from destruction.
166
How may tocotrienols contribute to health besides preventing cancer?
Tocotrienols may also protect against osteoporosis, diabetes, heart disease, and neurological disorders.
167
What is the primary deficiency of vitamin E associated with, and what is a classic sign of this deficiency?
The primary deficiency of vitamin E is associated with diseases of fat malabsorption, such as cystic fibrosis. A classic sign is erythrocyte hemolysis, seen in premature infants.
168
What is the role of vitamin E in reducing the risk of heart disease?
Vitamin E may reduce the risk of heart disease by protecting low-density lipoproteins (LDL) against oxidation and reducing inflammation.
169
What is the UL for vitamin E, and what can extremely high doses of vitamin E potentially cause?
The UL for vitamin E is 1000 milligrams. Extremely high doses may interfere with the blood-clotting action of vitamin K and enhance the effects of anti-clotting drugs, causing hemorrhage.
170
Why is the RDA for vitamin E based only on alpha-tocopherol?
The RDA is based only on alpha-tocopherol because the other tocopherols and tocotrienols cannot be converted to alpha-tocopherol, and they do not perform the same metabolic roles.
171
In which foods is vitamin E found, and why is the intake of polyunsaturated fatty acids related to vitamin E needs?
Vitamin E is found in vegetable oils, margarine, salad dressings, and wheat germ oil. Higher intake of polyunsaturated fatty acids requires more vitamin E, and fortunately, they often occur together in the same foods.
172
What are the primary roles of vitamin K in the body?
Vitamin K is essential for blood clotting and is involved in the metabolism of bone proteins, including osteocalcin. It may also be associated with a reduced risk of heart disease and some cancers.
173
Under what circumstances may a secondary deficiency of vitamin K occur?
A secondary deficiency of vitamin K may occur when fat absorption falters (as in bile production failure) or due to certain drugs disrupting vitamin K synthesis and action.
174
How do vitamin K and vitamin D interact in relation to bone health?
Vitamin K helps synthesize a specific bone protein, and vitamin D regulates that synthesis. Both vitamins, along with vitamin A, play important roles in bone growth and remodeling.
175
What is the primary dietary source of vitamin K, and what are the forms of vitamin K found in foods?
Leafy green vegetables such as spinach and kale, fruits like avocado and kiwi, and some vegetable oils like soybean oil are primary sources. Phylloquinone and menaquinone are the two forms of vitamin K found in foods.
176
Why is it important for individuals on anticoagulant drugs to monitor their vitamin K intake?
High doses of vitamin K can reduce the effectiveness of anticoagulant drugs, so individuals on these drugs should maintain a consistent intake of vitamin K-rich foods and monitor their blood clotting times regularly.
