kin 146 midterm 4 Flashcards
What are the 4 antioxidants
- Vitamin A and Beta carotene (fat soluble)
- Vitamin E (fat soluble)
- Vitamin C (water soluble)
- Selenium - acts as a cofactor in enzymes tat protect from free radicals
What do enzymes require to protect against oxidative damage
Trace minerals
- Manganese
- Iron
- Zinc
- Copper
What do phytochemical do , give an example
protects against oxidative damage , such as vegetables and fruit
What is a free radical
- produced during oxidation (lose electrons)
- When an electron is released and not paired with another electron (very unstable and highly reactive)
What happens where there are too many free radicals and what should be done to prevent it
- Oxidative stress
- antioxidants donate an electron to pair up with the unstable atom/molecule , neutralizing the end chain reaction of creating free radicals
Good effects of free radicals
attack virus or bacteria in the immune system
Bad effects of free radicals
- Attack polyunsaturated fats at the double bonds
- Rupture lipid memmbranes, make lipoproteins ineffective
- Alter DNA and RNA
- Create excess and deficiency of some proteins
- Impair cell function
- Cause inflammation
- Cell damage, disease, aging
Why are antioxidants in the diet good
associated with a lower risk of
- heart disease
- cancer
- diabetes
- Immune system
- Neurological conditions
- improved microbiome dysbiosis
Vitamin A: forms found in the body , what is carried by in the blood
Retinoids (from animal based products)
- readily absorbed
Carried by Retinol Binding Protein in the blood
Carotenoids
plant based foods that can be converted to Vitamin A
- split by intestines and liver into retinol
- not as well absorbed and used by the body as retinoids
Describe the conversion of Vitamin A
Retinyl (foods) converted to Retinol (in body)
- Retinol converted to Retinal in the body (reversible)
- Retinal converted to Retinoic acid (irreversible)
Nutrient: Vitamin A ; Roles beyond antioxidant?
- Regulates genes; vision
- Protein synthesis, cell differentiation, epithelial cell integrity
- Reproduction and growth
- Remodelling of bone
Vitamin A deficiency/ excess
Deficiency:
Circulates the lymph system then Stored in liver ; dependant on vit A and protein status for RBP
hypovitaminiosis A - night blindness, infections, keratinzation
Excess:
- Pro-oxidant
- weakens bones
- birth defects
Vitamin A Diet
- Retinol Activity Equivalents (RAE)
- Liver
- Fish liver oil
- Milk, butter, eggs; fortified mik, margarine
B - carotene roles beyond antioxidant
Comes before (precursor) to retinal
B carotene Excess
Orange skin
- Supplements = pro-oxidants
B carotene diet
- orange
- dark green vegetables and fruit; better absorbed with fat in meal
Vitamin E roles beyond antioxidant
- Alpha tocopherol is most active in humans
- Powerful antioxidant
- Protects oxidation of LDL
- decrease inflammation
- decreases blood clotting
Vitamin E deficiency
Rare (fat malabsorption)
- RBC break due to oxidation of polyunsat fat in membranes aka erythrocyte hemolysis
- loss of muscle coordination, reflexes
- impaired speech and vision
Vitamin E Excess
interfere with blood clotting, hemorrhagic stroke
Vitamin E Diet
- Vegetable oils
- margarine
- wheat germ oil
- destroyed by heat
Suggestion for Beta carotene supplementation
15-30 mg daily or every other day
Vitamin C Ascorbic acid roles beyond antioxidant
Cofactor in collagen formation (protects iron as a cofactor from oxidation)
Cofactor in other reactions and making of hormone
deactivates histamine
Vitamin C Deficiency
Scurvy; increased needs with burns, temp extremes, intake of toxic heavy metals, gum bleeds, capillaries break , muscles deteriorate, wounds don’t heal, bones malformed and softened
Vitamin C Excess
- GI distress
- Diarrhea
- kidney stones
- supplements can be pro-oxidant in those with iron overload
Vitamin C Diet
Fruits
- vegetables
- affected by heat
- destroyed by oxygen
Selenium roles beyond antioxidant
- substitute for sulphur in amino acids
- enzymes that activate and deactivate thyroid hormones
Selenium Deficiency
Keshan disease (a heart disease)
Selenium Excess
- hair loss and brittleness of hair, nails
- garlic breath odour
- nervous system abnormalities
Selenium diet
Soil content varies
- grain and legume
- meat, eggs, milk
Vitamin C intake (mg/day) suggestions for men and women
Women - 75
Men - 90
What are the key nutrients involved in bone health
- Calcium
- Phosphorous
- Magnesium
- Fluoride
- Vitamins A, D, K
- Protein
Describe the composition of bone
65% inorganic mineral crystals (strength)
35% protein in the form of collagen (flexibility)
What are the two types of bone
- Cortical - very dense, outer wall of large bones, and most of tissue in small bones (exterior shell)
- Trabecular - readily release minerals due to hormone changes, lacy and less dense (fills interior)
What do osteoclasts and osteoblasts of bone do
Osteoclasts of bone degrades parts of bone
Osteoblasts have enzymes that create bone
Describe the making of strong bones
- Genetically programmed for modeling to a certain length during growth
- Remodelling is continual after growth in adulthood
(remodelling, strengthening, lose osteoblast)
What is the largest mineral content in body and where is it found
- Calcium
- 1% in blood circulation
- 99% in bones and teeth
What percent of consumed calcium is absorbed
30% (can be upregulated in pregnancy and growth)
- increased excretion with sodium and protein
Role of vitamin D in calcium absorption
makes the calcium binding protein needed for absorption
Bone nutrients: Calcium function
- Hydroxyapatite crystals on bone matrix; blood pressure, blood clotting, activation of enzymes
- stimulate hormones that break down stored fat
Bone nutrients: Calcium Deficency
- Stunting
- Osteopenia/osteoporosis
Bone nutrients: Calcium Excess
- Constipation
- Kidney stones
- Kidney dysfunction
- affects absorption of other minerals
Bone nutrients: Diet
- Milk products
- tofu made with calcium salt
- fortified beverages; almonds, sesame seeds, bread, fish bones, kale, broccoli
Bone nutrients: Phosphorous function
85% in bone crystals
Bone nutrients: Phosphorous Excess
week bones and teeth
Bone nutrients: Phosphorous diet
Protein rich foods, soft drinks
Bone nutrients: Vitamin D function
Assists in the absorption of calcium and phosphorous from intestines; promotes reabsorption of bone minerals in kidney and mobilizes from bone
- enhances or suppresses genes involved in cell growth
Bone nutrients: Vitamin D Deficiency
Impaired calcium absorption and deficiency
- rickets in children
- osteomalacia in adults ; osteoporosis
Bone nutrients: Vitamin D Excess
hypercalcemia
calcification of soft tissues
Bone nutrients: Vitamin D diet
fatty fish and egg yolks
margarine
Bone nutrients: Magnesium function
Protein making in cells
energy metabolism
enzyme systems
ATP catalyst
Protein, fat, nucleic acids synthesis
cell membrane transport
muscle contraction and blood clotting
immune system
Bone nutrients: Magnesium deficiency
exacerbate inflammation
chronic disease
proects against high blood pressure
nervous system activity
confusion
tetany
Bone nutrients: Magnesium excess
diarrhea
alkalosis
dehydration
Bone nutrients: Magnesium diet
nuts
legumes
whole grains
dark leafy vegetables
seafood
chocolate
hard water
Bone nutrients: Fluoride function
Makes bones and teeth strong
Bone nutrients: Fluoride deficiency
dental carries
Bone nutrients: Fluoride Excess
fluorosis of teeth (staining and pitting of enamal)
Bone nutrients: fluoride sources
fluoridated water
tea
fish
Bone nutrients: Vitamin K function
Metabolism of bone proteins (osteocalcin)
blood clotting
Bone nutrients: Vitamin K deficiency
hemorrhage (can’t clot blood)
Bone nutrients: Vitamin K diet
gut bacteria
leafy green vegetables
soybean oil
Osteoporosis - what is the problem?
- Silent development
- Prevalent in 1 in 3 women and 1 in 5 men will have an osteoporotic fracture
- Fractures are an end state of the condition
How to maximize bone mass
- Lay down sufficient bone mass in growth years
- Diet of calcium and vitamin D
- Resistance exercise
Why do we lose bone with age
- Decreased intake of calcium and vitamin D
- Reduced exposure to sun
- Decreased absorption of calcium
- Kidney and liver activation of vitamin D declines
- Hormones change with age , increase mineral loss from bone
How can bone loss occur for 6-8 years around menopause
- decreased estrogen with menopause
- cytokine released, causes inflammation
- Accelerate bone loss
What are some medications to support bone
- estrogen replacement therapy
- Bisphosphonates
- Denosumab
- Parathyroid hormone
What happens during supplementation of vitamin D and Calcium
- minimal benefit
- may decrease falls
Composition of blood
55% is plasma
45% is RBC
1% is platelets
Vitamin K Role
Activation of prothrombin for blood clotting
Vitamin K deficiency
Hemorrhaging
Interfere with blood anticoagulant drugs
Vitamin K diet
Gut bacteria
Liver
Leafy green vegetables
Cruciferous vegetables
milk
oils
Copper role
enzymes that consume oxygen or oxygen radicals
Key factor in hemoglobin synthesis and transport of iron
protect against oxidative damage
Energy metabolism
Copper deficiency
Anemia
Bone abnormalities
Genetic disease Menekes
Copper Toxicity
Liver damage from supplements
Genetic disease Wilson’s
Copper diet
Seafood
Nuts
Whole grains
Legumes
Zinc Role
Enzymes that synthesize genetic material and proteins , sperm, immune reactions , transport vitamin A, taste, wound healing , insulin , normal fetal development
Zinc deficiency
Impaired growth, maturation, ummune function
eye/skin lesions
poor appetite
diarrhea
poor wound healing
Zinc toxicity
poor appetite
nausea
vomitting impaired immunity
copper and iron deficiency
low HDL
Zinc sources
Protein foods
Whole grains
Fortified cereal
Legumes
Vegtables
Describe the process of blood clotting
- thromboplastin released when blood exposed to air
- which catalyzes conversion of inactive prothrombin to active thrombin
- Thrombin catalyzes conversion of fibrinogen to fibrin that forms the clot
Describe zinc absorption and metabolism
Occurs when phytates in whole grains and legumes bind
- Mucosal cells in intestine store excess zinc in metallothionein
- which releases zinc to albumin and transferrin for transport to rest of body
- pancreas uses zinc to make digestive enzymes and secretes into intestine
- when not in use zinc excreted
Describe the requirement for iron and where is it found
- Needed just in the right amount (not too much or too little)
- Found as hemoglobin in blood and myoglobin in muscle cells
- Co factor for enzymes in oxidation reduction reactions , ETC
- iron is reduced when body does not need iron
Where is Heme and Nonheme iron found
Animal flesh: provide heme and nonheme
Plant foods: non heme iron
calcium in milk, polyphenols in tea, coffee, wine bind nonheme iron
What promotes the absorption of nonheme iron
Animal flesh has MFP factor that increases absorption of nonheme iron
Vitamin C promotes absorption
Upregulated when deficient
Downgraded when in excess
Hepcidin
Produced by liver maintains iron within normal range in the blood
Hemosiderin
a long term storage, protects the body from free iron which is a free radical
What is the most common nutrient deficiency
Iron (menstruation and pregnancy)
Stage 1 of Iron deficiency
Decreased iron stores as ferritin
Stage 2 of iron deficiency
- decreased iron transport
- Increase in transferrin (to enhance iron absorption)
(more transferrin and less ferritin will indicate more severe deficiency)
Stage 3 of iron deficiency
hemoglobin production limited
- decrease in hemoglobin and hematocrit
- Increace in reythrocyte protoporphyrin that is precursor to hemoglobin
Effects of iron deficiency without anemia
Energy metabolism impaired
Neurotransmitter synthesis altered
Decreased capacity for physical work and mental capacity
Apathy
Confused with behavioural problems in children
Pica - craving for non food items
Iron deficiency anemia
- develops in stages
- small pale, red blood cells
- Can’t carry enough oxygen to the body
- Energy metabolism fails
- Symptoms: weakness, aches, fatigue
- Skin is pale, inside of eyelids, tongue
What are the stages of anemia
- Stores deplete
- Transport iron decreases
- Hemoglobin production slows
Iron overload
- Body absorbs less iron when stores full
- Disorder: Hemochromatosis
Genetic disease - Dietary iron continues to be absorbed when not needed
Alcohol abuse damages intestines
Blood transfusion (supplementation) overwhelms intestinal defence
Symptoms and Identification of iron overload
- Apathy
- Lethargy
- Fatigue
Hemoglobin will not indicate excess storage , need to assess transferrin saturation and serum ferritin
Long term effects of iron overload
- Accumulates in liver, heart, joints and other tissues
- Free radical damage
- Infections
- Cirrhosis, liver cancer
- Heart failure
- Arthritis
Iron supplementation
- Most common reason for iron poisoning in children
- Take only when prescribed
- Large doses: nausea, vomitting, diarhhea, constipation, intestinal bleeding
- Less well-absorbed than from food
How should ferrous sulphate be supplemented
take between meals or on an empty stomach to promote absorption
- Take with fluid
Iron in food recommendation
Men 8 mg (or women over 50 years of age)
Women 18 mg (18-50 years)
Vegetarians 14 mg (male), 32 mg (female)
What do phytochemicals in food provide
Flavour, Colour, Aroma
Phytochemicals
Food have benefit or function beyond essential nutrients
Phytochemical roles
antioxidants
mimic hormones
stiimulate enzymes
suppress DNA replication
Suppress inflammation
destroy bacteria
Examples of phytochemicals that can protect against DNA damage
Soy: isoflavones limites growth by blocking new blood vessels
Tomatoes: lysopeme inhibits growth, cooking increases absorption
Key phytochemicals that help with heart disease
- Flavonoids (antioxidant, reduce blood platelet stickiness, decrease oxidation of LDL , decrease inflammation)
(whole grains, legumes, soy, vegetables, tea, olive oil) - Carotenoids - lutein and beta carotein
- Plant sterols and Lignans of flaxseed (inhibits cholesterol absorption, reduced LDL cholesterol, reduce inflammation)
