Download Perspectives in Nutrition, 8th Edition

Perspectives in Nutrition, 8th Edition
Chapter 15 Outline: Trace Minerals
After studying this chapter, you will be able to:
1.
2.
3.
4.
5.
6.
15.1
Discuss the major functions of each trace mineral.
List 3 important food sources for each trace mineral.
Describe how each trace mineral is absorbed, transported, stored, and excreted.
Describe the deficiency symptoms of trace minerals.
Describe the toxicity symptoms from the excess consumption of certain trace minerals.
Describe the development of cancer and the effect of genetic, environmental, and dietary
factors on the risk of developing cancer.
Iron (Fe)
A.
General
1.
In developing nations, 2/3 of children and women of childbearing age have iron
deficiency
2.
Even in developed countries, iron deficiency is a public health concern in
children and young women
B.
Iron in foods
1.
Heme iron: iron that is part of hemoglobin and myoglobin, found in animal flesh
a.
Beef
b.
Pork
c.
Seafood
d.
Poultry
2.
Non-heme iron: found in animal flesh and plant foods
a.
Animal products
b.
Vegetables (spinach and other leafy greens)
c.
Legumes
d.
Grains (enriched in refined flours)
e.
Supplements
3.
Bioavailability of iron from animal sources is higher than from plant foods
4.
Leaching of iron into foods from iron cookware contributes to iron intake,
especially with acidic foods
C.
Iron needs
1.
RDA (assumes ~18% absorption efficiency from typical Westernized diet)
a.
Adult women up to age 51: 18 mg
b.
Adult women after age 51: 8 mg
c.
Adult men: 8 mg
2.
DV:18 mg
3.
Average intake: 6 mg/1000 kcal
a.
17 mg for men
D.
E.
F.
G.
H.
I.
b.
12 mg for women
Absorption of Iron
1.
Factors that increase iron absorption
a.
Increased requirements (35 - 40% efficiency when iron status is low)
b.
Meat factor protein (MFP)
c.
Heme form (in ferrous form)
d.
Vitamin C and other organic acids increase absorption of non-heme iron
by keeping iron in ferrous form
e.
Gastric acid reduces ferric iron to ferrous form
2.
Factors that decrease iron absorption
a.
Decreased requirements (5% efficiency when iron needs are low and
stores are saturated)
b.
Phytic acid in whole grains and legumes
c.
Oxalic acid in leafy green vegetables
d.
High fiber intake
e.
Polyphenols (e.g., tannins found in tea)
f.
Excessive intakes of zinc, manganese, and possibly calcium
Transport of Iron
1.
Hemoglobin in blood
Storage of Iron
1.
Very little free iron is found in the body because high reactivity leads to
production of free radicals that damage DNA and cell membranes
2.
Hemoglobin
3.
Myoglobin
Excretion of Iron
1.
Body has limited ability to excrete iron, so absorption, cellular uptake, and
storage are tightly regulated
Functions of Iron
1.
Participates in oxidation/reduction reactions
2.
Component of hemoglobin
3.
Component of myoglobin: protein that transports oxygen from RBCs to muscle
cells
4.
Energy metabolism
5.
Drug and alcohol metabolism
6.
Excretion of organic compounds
7.
Component of cytochromes in electron transport chain
8.
Required for first step in citric acid cycle
9.
Synthesis of neurotransmitters, essential for normal early cognitive development
and lifelong brain function
10.
Immune function: production of lymphocyte cells and natural killer cells
Iron Deficiency
1.
Most common trace mineral deficiency worldwide
2.
Early stages: stores are still available
J.
a.
Compromised immune function
b.
Decreased work capacity
3.
Iron-deficiency anemia: stores become depleted
a.
Low hemoglobin synthesis, impaired oxygen transport in blood
b.
Fatigue
c.
Decreased work capacity
d.
Compromised immune function
e.
Impaired energy metabolism
f.
Delayed cognitive development
4.
Diagnosis
a.
RBCs: small (microcytic), pale (hypochromic)
b.
Hematocrit: percent of total blood volume comprised of RBCs
c.
Hemoglobin
d.
RBCs, hematocrit, and hemoglobin are not sensitive measures of iron
status because they are unchanged in early stages of deficiency and are
affected by disease, inflammation, blood loss, other nutrient deficiencies
e.
Transferrin receptor number reflects cellular iron need and is unaffected
by other conditions
5.
High-risk populations
a.
Premature infants: iron stores are deposited near end of pregnancy
b.
Young children: rapid growth, low dietary intake
c.
Teenage girls and women of childbearing age: menstrual losses and
insufficient dietary intake
d.
Pregnant women
e.
Vegetarians
f.
Frequent blood donors: 1 pint = 200- 250 mg Fe
Iron Overload and Toxicity
1.
UL: 45 mg
2.
Consequences
a.
Nausea/vomiting
b.
Stomach irritation
c.
Diarrhea
d.
Impaired absorption of other trace minerals
3.
Accidental iron overdose is leading cause of accidental poisoning in children
under age 6
4.
In adults, iron toxicity results from hemochromatosis: genetic condition in which
mucosal block is ineffective
a.
Defect in normal degradation cycle of ferroportin, absorption and
transport of iron across enterocyte are high
b.
With lack of excretion mechanism for excess iron, iron accumulates and
causes tissue injury (e.g., iron deposits in liver, heart, and other organs)
5.
High-risk populations
a.
Hemochromatosis
6.
15.2
b.
Excessive supplementation
c.
Frequent blood transfusions
Treatment
a.
Decrease supplemental intake
b.
Periodic blood removal
c.
Administration of chelator that binds iron and increases its excretion
(also binds other trace minerals)
Zinc (Zn)
A.
Zinc in Foods
1.
Animal-based foods
a.
Beef
b.
Lamb
c.
Pork
d.
Seafood
2.
Plant-based foods
a.
Nuts
b.
Beans
c.
Wheat germ
d.
Whole grains (if leavened)
e.
Fortified breakfast cereal
3.
Phytic acid in wheat products may decrease zinc bioavailability, but yeast
fermentation frees zinc
B.
Dietary Needs for Zinc
1.
RDA
a.
Adult men: 11 mg
b.
Adult women: 8 mg
2.
DV:15 mg
3.
Average intake meets RDA
C.
Absorption of Zinc
1.
Factors that increase zinc absorption
a.
Increased body needs
b.
High intake of animal protein
2.
Factors that decrease zinc absorption
a.
Excessive intake of zinc or non-heme iron
b.
Excessive intake of fiber and phytic acid
c.
Adequate zinc status
D.
Transport of Zinc
1.
Binds to blood proteins (e.g., albumin) for transport to liver
E.
Storage of Zinc
1.
No storage site
2.
Exchangeable pool of zinc in liver, bone, pancreas, kidney, and blood
F.
Excretion of Zinc
G.
H.
I.
1.
Feces
2.
Urine
3.
Sweat
Functions of Zinc
1.
Required by 300 enzymes
2.
DNA and RNA synthesis
3.
Alcohol metabolism
4.
Heme synthesis
5.
Bone formation
6.
Acid-base balance
7.
Immune function
8.
Reproduction
9.
Growth and development
10.
Antioxidant defenses (superoxide dismutase)
11.
Stabilizes structures of cell membrane proteins
12.
Stabilizes gene transcription fingers (“zinc fingers”)
13.
Stabilizes receptor proteins for vitamin A, vitamin D, and thyroid hormone
14.
May shorten duration of common cold, but evidence on supplementation is not
conclusive
Zinc Deficiency
1.
Consequences
a.
Loss of appetite
b.
Delayed growth
c.
Delayed sexual maturation
d.
Dermatitis
e.
Impaired vitamin A function
f.
Alopecia
g.
Decreased taste sensitivity
h.
Poor wound healing
i.
Immune dysfunction
j.
Severe diarrhea
k.
Birth defects
l.
Infant mortality
2.
High-risk populations
a.
Young children
b.
Malabsorptive diseases
c.
Kidney dialysis
d.
Low intake of animal-based foods
e.
Acrodermatitis enteropathica: genetic condition that impairs intestinal
absorption
3.
Marginal zinc deficiencies are difficult to detect due to lack of assessment
methods
Zinc Toxicity
1.
2.
15.3
UL: 40 mg
Consequences
a.
Loss of appetite
b.
Nausea/vomiting
c.
Intestinal cramps
d.
Diarrhea
e.
Impaired immune function
f.
Reduced copper absorption and activity of copper-containing enzymes
Copper (Cu)
A.
Copper in Foods
1.
Liver
2.
Shellfish
3.
Nuts
4.
Seeds
5.
Mushrooms
6.
Soy products
7.
Dark chocolate
8.
Legumes
9.
Whole grain products
10.
Some tap water sources
11.
Meat protein may promote copper absorption
B.
Dietary Needs for Copper
1.
RDA: 900 µg
2.
DV: 2 mg
3.
Average adult intake: 1000 - 1600 µg/d
C.
Storage of Copper
1.
Very little storage
2.
Liver is main storage site
D.
Excretion of Copper: bile
E.
Functions of Copper
1.
Component of many enzymes due to ability to alternate between 2 oxidation
states (Cu1+ and Cu2+)
2.
Ceruloplasmin (ferroxidase I) oxidizes ferrous to ferric iron for incorporation into
transferrin; copper deficiency can lead to development of anemia
3.
Superoxide dismutase: antioxidant enzyme system that eliminates superoxide
free radicals
4.
Cytochrome C oxidase: catalyzes last step in electron transport chain
5.
Monoamine oxidase: regulates neurotransmitters
6.
Lysyl oxidase: connective tissue formation
F.
Copper Deficiency
1.
Rare
2.
High-risk populations
G.
15.4
a.
Premature infants fed milk-based formulas
b.
Infants recovering from malnutrition
c.
Long-term TPN without added copper
d.
Menkes disease
3.
Consequences
a.
Anemia
b.
Decreased WBC counts (leukopenia and neutropenia)
c.
Skeletal abnormalities (osteopenia)
d.
May increase risk of neurological disorders (e.g., Lou Gehrig’s disease
and Alzheimer’s disease)
e.
Marginal intakes may lead to weakened immune function, glucose
intolerance, elevated cholesterol, and cardiac abnormalities
f.
Determining marginal copper deficiency is difficult due to lack of
reliable indicators
Copper Toxicity
1.
Not common
2.
Potential causes
a.
Accidental overdoses among children
b.
Consumption of copper-contaminated food or water
c.
Wilson’s disease: genetic disorder of excess copper storage
3.
Consequences
a.
Abdominal pain
b.
Nausea/vomiting
c.
Diarrhea
d.
Cirrhosis
e.
Neurological damage
4.
UL: 10 mg
Manganese (Mn)
A.
Manganese in Foods
1.
Whole grain cereals
2.
Nuts
3.
Legumes
4.
Tea
B.
Dietary Needs for Manganese
1.
AI
a.
Adult men: 2.3 mg
b.
Adult women: 1.8 mg
2.
DV: 2 mg
3.
Average intake: 2 - 6 mg/d
C.
Absorption of Manganese
a.
High absorption efficiency with low manganese intake and adequate iron
status
b.
D.
E.
F.
G.
H.
15.5
Decreased absorption with high intakes of manganese and possibly
calcium, iron, and phytates
Storage of Manganese: bone (possibly)
Excretion of Manganese
1.
Bile
2.
Primary regulation of manganese
Functions of Manganese
1.
Cofactor for many enzymes due to ability to alternate between oxidation states
(Mn2+, Mn3+, and Mn7+)
2.
Nitrogen metabolism
3.
Carbohydrate metabolism
4.
Cholesterol synthesis
5.
Urea synthesis
6.
Cartilage formation
7.
Antioxidant defense (Mn superoxide dismutase)
Manganese Deficiency
1.
Deficiency is not well documented in humans
2.
Consequences
a.
Poor growth
b.
Skeletal abnormalities
c.
Impaired glucose metabolism
d.
Abnormal reproductive function
3.
Potential causes
a.
Long-term TPN
b.
Inhalation of airborne industrial and automotive emissions
Manganese Toxicity
1.
Consequences
a.
Severe neurological impairment
b.
Similar to Parkinson’s disease (muscle stiffness, tremors)
2.
UL: 11 mg
Iodine (I)
A.
General
1.
Present in food as iodide (I-) and other non-elemental forms
2.
Heaviest element needed for human health
B.
Iodine in Foods
1.
Natural content of most foods is low
2.
Saltwater seafood
3.
Seaweed
4.
Iodized salt
5.
Molasses
6.
Dairy products (added to cattle feed and sanitizing solutions used on dairy
equipment)
7.
8.
9.
C.
D.
E.
F.
G.
Breads and cereals (if prepared with iodized salt and/or dough conditioners)
Plant foods (if soil is rich in iodine; usually in coastal regions)
Bioavailability and use by thyroid gland are affected by goitrogens in raw
vegetables (e.g., turnips, cabbage, Brussels sprouts, cauliflower, broccoli,
rutabagas, potatoes, and cassava), peanuts, soy, peaches, and strawberries;
activity of goitrogens is decreased by cooking
Dietary Needs for Iodine
1.
RDA: 150 µg
2.
DV: 150 µg
3.
Average intake: 190 - 300 µg, not accounting for iodized salt used at the table
Storage of Iodine: thyroid gland, used to support thyroid hormone synthesis
Excretion of Iodine: urine
Functions of Iodine
1.
Essential component of thyroxine (T4) and triiodothyronine (T3)
2.
Transported as T4, converted toT3 (active form) in body cells by deiodinase
enzymes, all of which require selenium
3.
Functions of thyroid hormones
a.
Regulation of basal energy expenditure
b.
Macronutrient metabolism
c.
Growth
d.
Brain development
e.
Organ maturation
Iodine Deficiency Disorders (IDD)
1.
Endemic: habitual presence of a disease within a given geographic area
2.
Goiter
a.
With lack of iodine, plasma T4 drops, causing secretion of thyroidstimulating hormone (TSH)
b.
TSH leads to enlargement of thyroid gland, allowing temporary
maintenance of thyroid hormone synthesis
c.
Goiter is not harmful, but may put pressure on esophagus and trachea
3.
Iodine deficiency during pregnancy may lead to problems in offspring
a.
Congenital abnormalities
b.
Low birth weight
c.
Cretinism
i.
Severe mental retardation
ii.
Loss of hearing and speech abilities
iii.
Short stature
iv.
Muscle spasticity
d.
Death
4.
1/3 of world population is at risk of iodine deficiency, particularly in South
America, Asia, Africa, and Middle East
5.
Although fortification of table salt with iodine is effective at eradicating goiter,
many countries have not yet adopted the practice
WHO calls iodine deficiency the “greatest single cause of preventable brain
damage and mental retardation”
Iodine Toxicity
1.
UL: 1100 µg
2.
Consequences
a.
Enlargement of thyroid gland
b.
Decreased thyroid hormone synthesis
c.
Autoimmune thyroid disease
d.
Thyroid cancer
3.
Potential causes
a.
High consumption of iodine-rich seaweed
b.
High levels of environmental iodine
c.
Increased use of iodine in water purification
d.
Excessive fortification of salt
6.
H.
15.6
Selenium (Se)
A.
Selenium in Foods
1.
Varies depending on soil content where plant or animal was grown/raised
2.
Most selenium in foods is bound to methionine (selenomethionine) and cysteine
(selenocysteine)
3.
Grains
4.
Seafood
5.
Meats
6.
Cereals
7.
Nuts
B.
Dietary Needs for Selenium
1.
RDA: 55 µg
2.
DV: 70 µg
3.
Average intakes exceed the RDA
C.
Storage of Selenium
1.
Blood
2.
Liver
3.
Muscle
4.
Kidneys
5.
Skeleton
6.
Selenomethionine is storage pool
7.
Selenocysteine is biologically active form
D.
Excretion of Selenium
1.
Urine
2.
Primary means of regulating selenium homeostasis
E.
Functions of Selenium
1.
Component of at least 25 enzymes and proteins
2.
Antioxidant defenses, spares vitamin E for use in other antioxidant functions
F.
G.
15.7
a.
Glutathione peroxidase (GPX) enzymes
b.
Thioredoxin reductase enzymes
c.
Selenoprotein P
3.
Thyroid metabolism: iodothyronine deiodinase converts T4 to T3
4.
Immune function; may inactivate a virus linked to the development of Keshan
disease
5.
Protection against prostate, lung, or other cancers
Selenium Deficiency
1.
No specific deficiency disease
2.
Consequences
a.
Changes in thyroid metabolism
b.
Possible increased risk of certain cancers
c.
Development of Keshan disease (insufficient cardiac function)
Selenium Toxicity
1.
Potential causes: excess supplementation
2.
Consequences
a.
Nausea
b.
Diarrhea
c.
Fatigue
d.
Hair loss
e.
Changes in nails
f.
Skin rashes
3.
UL: 400 µg
Chromium (Cr)
A.
Chromium in Foods
1.
Nutrient content information is lacking, so nutrient databases are incomplete
2.
Processed meats
3.
Liver
4.
Eggs
5.
Whole-grain products
6.
Broccoli
7.
Mushrooms
8.
Dried beans
9.
Nuts
10.
Dark chocolate
11.
Because chromium is used to manufacture steel, small amounts of the mineral are
transferred to food by processing
B.
Dietary Needs for Chromium
1.
AI
a.
Adult men (19 - 50 years): 35 µg
b.
Adult women (19 - 50 years): 25 µg
c.
Adult men (50+years): 30 µg
C.
D.
E.
F.
G.
15.8
d.
Adult women (50+ years): 20 µg
2.
DV: 120 µg
3.
Average intake generally meets AI
Storage of Chromium
1.
Bones
2.
Liver
3.
Kidneys
4.
Spleen
Excretion of Chromium: most dietary chromium is excreted in feces
Functions of Chromium
1.
Not fully known
2.
May enhance insulin action, promote glucose uptake into cells, and normalize
blood sugar levels; supplementation for type 2 diabetes has not proven effective
3.
Used to enhance muscle mass and strength among athletes; evidence for
effectiveness is poor
Chromium Deficiency
1.
Lack of sensitive indicators of chromium status
2.
Potential causes: TPN that lacks chromium
3.
Consequences
a.
Weight loss
b.
Glucose intolerance
c.
Nerve damage
Chromium Toxicity
1.
No UL
2.
High doses of chromium supplements are cause for concern
Fluoride (F)
A.
General
1.
May not be essential nutrient because all basic body functions can occur without
it
2.
Link between fluoride content of water and prevention of dental caries led to
controlled water fluoridation in some areas
3.
Controversy exists over fluoridation of public water supply; some argue that
excess exposure is a concern
B.
Fluoride in Foods
1.
Fluoridated water (0.2 mg/8 oz); not all public or private water sources are
fluoridated
2.
Tea
3.
Seafood
4.
Seaweed
5.
Fluoridated toothpastes, mouth rinses, and dental treatments
C.
Dietary Needs for Fluoride
1.
AI
15.9
a.
Adult women: 3 mg
b.
Adult men: 4 mg
c.
Infants up to 6 months: 0.01 mg
d.
Infants 6 - 12 months: 0.5 mg
e.
Children and adolescents: 0.7 - 3 mg
D.
Storage of Fluoride (most storage occurs during infancy, childhood, and adolescence)
1.
Teeth
2.
Skeleton
E.
Excretion of Fluoride: urine
F.
Functions of Fluoride
1.
Supports deposition of calcium and phosphorus in teeth and bones
2.
Protection against dental caries
a.
Hydroxyfluoroapatite crystals are resistant to bacteria and acids in the
mouth
b.
Remineralization of enamel lesions
c.
Reduces net loss of minerals from tooth enamel
G.
Fluoride Deficiency
1.
Consequences
a.
Increased risk of dental caries
b.
No specific deficiency disease
H.
Toxicity
1.
Consequences
a.
Nausea/vomiting
b.
Diarrhea
c.
Sweating
d.
Spasms
e.
Convulsions
f.
Coma
g.
Mottling (fluorosis) of tooth enamel
2.
UL:
a.
For infants and children up to 8 years: 0.1 mg/kg body weight/d
b.
For children older than 8 years and adults: 10 mg/d
Molybdenum (Mo) and Ultratrace Minerals
A.
Ultratrace minerals: daily requirements are low, but vital for health
B.
Molybdenum
1.
Functions: enzyme cofactor
2.
Food sources
a.
Amount of Mo varies depending on soil content
b.
Grains
c.
Legumes
d.
Nuts
3.
Dietary requirements
a.
RDA: 45 µg
C.
b.
DV: 75 µg
c.
Average intakes meet or exceed RDA
4.
Deficiencies and toxicities are rare, but UL: 2000 µg
Other ultratrace minerals with incomplete data on needs and functions
1.
Arsenic
a.
Functions
i.
Amino acid metabolism
ii.
DNA function
b.
Requirements
i.
Estimated needs: 12 -25 µg
ii.
UL: none set
iii.
Average intake: 30 µg
c.
Dietary sources
i.
Fish
ii.
Grains
iii.
Cereals
2.
Boron
a.
Functions:
i.
Ion transport across cell membranes
ii.
Steroid hormone metabolism
b.
Requirements
i.
Estimated needs: 1 - 13mg
ii.
UL: 20 mg
iii.
Average intake: 0.75 - 1.35 mg
c.
Dietary sources
i.
Legumes
ii.
Fruits
iii.
Vegetables
iv.
Potatoes
v.
Wine
3.
Nickel
a.
Functions
i.
Metabolism of amino acids
ii.
Metabolism of fatty acids
iii.
Metabolism of vitamin B-12
iv.
Metabolism of folic acid
b.
Requirements
i.
Estimated needs: 25 - 35 µg
ii.
UL: 1 mg
iii.
Average intake: 69 - 162 µg
c.
Dietary sources
i.
Chocolate
ii.
Nuts
4.
5.
iii.
Legumes
iv.
Whole grains
Silicon
a.
Functions: bone formation
b.
Requirements
i.
Estimated needs: 35 - 40 µg
ii.
UL: none set
iii.
Average intake: 19 - 40 µg
c.
Dietary sources
i.
Root vegetables
ii.
Whole grains
Vanadium
a.
Functions: mimics insulin action
b.
Requirements
i.
Estimated needs: 10 µg
ii.
UL: 1.8 mg
iii.
Average intake: 6 - 18 µg
c.
Dietary sources
i.
Shellfish
ii.
Mushrooms
iii.
Parsley
iv.
Dill
15.10
Global Perspective: The Micronutrient Initiative
A.
Global health problems of vitamin A and zinc deficiencies compromise immune function
and contribute to millions of preventable deaths each year, especially among children
B.
Micronutrient Initiative is a Canadian-based international organization formed in 1990 to
eliminate worldwide vitamin and mineral deficiencies
1.
Local food fortification programs
a.
Iron and folic acid fortification of flour in Middle East and North Africa
b.
Expansion of salt iodization
c.
Global Vitamin A Initiative
2.
Working partnerships with governments, food industries, international agencies,
and private sector to improve global health
15.11
Medical Perspective: Nutrients, Diet, and Cancer
A.
What is Cancer?
1.
Variety of diseases that affect a variety of tissues, but all forms are united by the
abnormal and uncontrolled division of altered cells
2.
Benign tumors are non-cancerous; enclosed in a membrane that prevents them
from spreading; only harmful if they interfere with normal function
3.
Malignant tumors: capable of invading surrounding structures and spreading to
other parts of the body (metastasis)
4.
B.
C.
Types of tumors
a.
Carcinomas: 80 - 90% of all cancers; develop from epithelial cells; affect
secretory organs
b.
Sarcomas: affect connective tissues (e.g., bone)
c.
Lymphomas: malignant tumors in lymph nodes and lymphoid tissues
d.
Leukemias: cancers of precursor WBCs in bone marrow
Development of Cancer (carcinogenesis)
1.
In normal cells:
a.
Cell replication is regulated by protooncogenes
b.
Tumor suppressor cells prevent uncontrolled growth
c.
Repair mechanisms look for and correct errors in DNA
2.
In cancer, oncogenes promote unregulated cell replication
3.
Carcinogenesis
a.
Initiation
i.
Relatively short stage: minutes to days
ii.
Spontaneous
iii.
Exposure of cell to carcinogen (e.g., tobacco, radiation, alcohol,
occupational toxins, food contaminants, dietary factors, drugs)
b.
Promotion
i.
May take months or years
ii.
Mutation is locked into DNA
iii.
Promoters (e.g., excess alcohol, estrogen, H. pylori) encourage
uncontrolled replication of altered DNA
c.
Progression
i.
Cells grow autonomously, proliferate, invade surrounding tissue,
metastasize to other sites
ii.
Progression may be stopped if immune system destroys
cancerous cells or if cancerous cells are so defective, they cannot
grow
Genetic, Environmental, and Dietary Factors
1.
Genetic factors account for 1 - 15% of cancer incidence
2.
Environmental factors play a large role
a.
Exposure to carcinogens
b.
Lack of physical activity
c.
Obesity
d.
Diet
3.
Dietary factors that influence cancer risk
a.
Diets low in fruits and vegetables are associated with increased risk for
certain cancers
b.
Excessive energy intake and obesity increase risk of breast cancer, likely
due to increased production of estrogen and insulin and availability of
excess energy to support tumor growth
c.
4.
High intakes of meats, especially red meat and grilled meat, increase risk
of colorectal, kidney, pancreatic, and stomach cancers, likely due to
saturated fat content, polyaromatic hydrocarbons, or nitrosamine
compounds
d.
Fried foods may increase cancer risk due to high calorie and fat content
as well as presence of acrylamide (produced when starches are fried at
high temperatures)
e.
Excess alcohol intake risk of mouth, throat, esophagus, breast, colon, and
liver cancer
f.
Low intakes of calcium and vitamin D may increase risk of colorectal
cancer
i.
Calcium may bind free fatty acids and bile acids to prevent them
from reacting with potential cancer cells
ii.
Vitamin D may inhibit progression of cancer growth from
malignant polyps
AICR Diet and Health Guidelines for Cancer Prevention
a.
Choose a diet rich in a variety of plant-based foods
b.
Eat plenty of vegetables and fruits
c.
Maintain a healthy weight and be physically active
d.
Drink alcohol only in moderation, if at all
e.
Select foods low in fat and salt
f.
Prepare and store foods safely
g.
Avoid tobacco