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Infection & Immunity Block > Nutrition and Immunity > Flashcards

Flashcards in Nutrition and Immunity Deck (38):
1

Adipokines

Energy balance
Ideal BMI: 19-24
25-35kcal/kg

Obese adipose tissue secretes adipokines that contribute to low-level systemic inflammation
Mediate inflammation and insulin resistance

Cytokines increase T-lymphocyte production, which may contribute to risk of autoimmunity and cancer risk in morbidly obese

2

Obesity and Immune Effects

Immune system cells do not function normally with overweight or elevated cholesterol/triglyceride levels

Positive associations between overweight and cancers of the breast, endometrium, kidney, colon, prostate, and others

Overweight increases risk of cancer recurrence and decreases survival

3

Protein and Immune Function

Need enough protein for adequate number of amino acids to help immune system increase its numbers
AA make Ab and other components

4

Protein Energy Malnutrition (PEM)

Marasmas and cachexia- prolonged starvation with decreased calorie/protein intake
Muscle wasting
Emaciated

Kwashiorkor- inadequate consumption of protein; higher intake of carbohydrates
Edema
Hypoalbuminemia

Marasmic Kwashiorkor
Wasting, edema, stunted growth

5

PEM Effects

Lymphoid and thymus atrophy
Depressed cutaneous response, even with moderate deficiencies
Reduction in mature T lymphocytes
Reduced antibody-producing cells and reduced immunoglobulin (while serum antibody response is preserved, antibody affinity is reduced)
Reduced phagocytosis
Increase in number of bacteria adhering to respiratory cells – risk of respiratory infection

6

Arginine and Glutamine

Arginine and Glutamine: non-essential amino acids
conditionally essential

Consuming adequate amounts of daily protein consistent with individual needs will assure production of adequate amounts of arginine and glutamine

Synthesized in body under normal conditions, and are essential in critically ill because the body uses them so much and need more intake in order to obtain the optimal levels
In a healthy state, most people can obtain these levels through diet alone, but when critically ill these aren’t always available to the level they need

7

Arginine

Mechanism in critically ill patients
Increases T cell number and release
T lymphocyte proliferation
Considered appropriate for surgical patients
“Immuno-specialized” enteral formulas is controversial for some patients
In trauma and sepsis, arginine is used to release NO, which contributes to inflammation.
Ammonia controversy: how body detoxifies it and excretes it

8

Glutamine

Mechanism
Lymphocytes, macrophages, and neutrophils use glutamine
Glutamine appears to enhance antimicrobial activity in neutrophils
Cell proliferation
Antigen presentation
Cytokine production
Helps to prevent atrophy of the gastrointestinal tract smooth muscle for a patient on enteral feeding, cancer, or not consuming a lot of calories

9

Antioxidants

Vitamin A (Beta carotene)
Vitamin C (Ascorbic acid)
Vitamin E
Selenium

What do they do?
Disarm free radicals: Free Radical Scavengers
Ensure lymphocytes can divide and reproduce
Ensure neutrophils and macrophages can engulf and kill bacteria

10

Free Radical Scavengers

Free radical scavengers: donate electrons when and then become oxidized and aren’t harmful to body; it is a matter of balance because if over oxidation then can be a problem
Too many free radicals: contribute to inflammation and course to chronic disease; antioxidants through diet can be supportive

11

Free Radical Cycle

A chemically reactive O2 free radical attacks fatty acid, DNA protein, or cholesterol molecules, which form other free radicals

This initiates a rapid, destructive chain reaction

The result is disabling injury to lipids of cell membranes and cellular proteins, damage to DNA, or oxidation of cholesterol. These changes may initiate steps leading to diseases such as heart disease, cancer, macular degeneration, and others

Antioxidants, such as vitamin E, stop the chain reaction by changing the nature of the free radical

12

Dietary Reference Intake Recommendations

Vitamin A: 700-900 mcg/day

Vitamin C: 75-90 mg/day; add another 35 mg if a smoker

Vitamin E 15 mg/day

Selenium 55 mcg/day

13

Vitamin A Mechanism

Beta carotene: known antioxidant
High blood levels of carotenoids reduce risk of several chronic diseases
cell growth regulation
induction of enzymes

Visual pigment

Cell differentiation

Gene regulation

Used in innate immune system for NKC, macrophages, and neutrophils to function properly
Adaptive: plays a role in development of T helper cells and B cells
Someone who has celiac or Chrohn’s disease (GI not completely intact) need increased vitamin A and E because not absorbed as well (fat soluble)

14

Vitamin A Deficiency

Impairs regeneration of mucosal barriers
Epithelial function (differentiation and production)

Decreases function of neutrophils, macrophages, and NK cells

Diminishes antibody-mediated responses

Increases susceptibility to bacterial, viral, and parasitic infections

15

Vitamin A Sources, Functions, Deficiency, and Toxicity

Fortified milk, carrots, sweet potatoes, spinach, beef liver, bok choy, and apricots

Chief Functions; vision, maintainence of cornea, epithelial cells, mucous membranes, skin, bone, and tooth growth, regulation of gene expression, reproduction, and immunity

Deficiency: night blindness, impaired bone growth and decayed teeth, keratin lumps on the skin, impaired immunity

Toxicity: increased activity of bone dismantling cells causing reduced bone density and pain, liver abnormalities, birth defects

16

Ascorbic Acid: Mechanism

Vitamin C
Stimulates WBC production
Synthesis of collagen, norepinephrine, carnitine; promotes resistance to infection by increasing antibodies
Enhances phagocyte oxidative burst activity
Enhances T cell and B cell function

17

Vitamin C Deficiency

Easily destroyed by oxidation and heat

Scurvy

Impaired wound healing; edema; hemorrhages; and weakness in bone, cartilage, teeth, and connective tissues

18

Vitamin C Sources, Functions, Deficiency, and Toxicity

Sweet red peppers, Brussel sprouts, grapefruit, sweet potato, orange juice, green peppers, broccoili, strawberries, bok choy

Chief Functions: collagen synthesis, antioxidant, restores vitamin E to active form, supports immune system, and boosts iron absorption

Deficiency: scurvy, pinpoint hemorrhages, fatigue, bleeding gums, bruises, bone fragility, joint pain, poor wound healing, frequent infections

Toxicity: nausea, abdominal cramps, diarrhea, rashes, interference with medical interventions/therapies, aggravation of gout or kidney stones

19

Vitamin E: Mechanism

Primary role = lipid soluble antioxidant
Protects cell membranes from oxidation-first line of defense
Also protects Vitamin A and carotenes from oxidation (work in synergy with each other)
Thought to prevent LDL oxidation and reduce risk of heart disease, but supplemental Vit E hasn’t been found effective
Tocopherols (plants); tocotrienols (whole grains)

20

Vitamin E Deficiency

Can take years to develop

Effects the neuromuscular, vascular and reproductive systems

21

Vitamin E Sources, Functions, Deficiencies, and Toxicity

Safflower oil, wheat germ, mayonnaise, canola oil, and sunflower seeds

Chief Functions: antioxidant, protects cell membranes, regulates oxidation reactions, protects polyunsaturated fatty acids

Deficiency: RBC and nerve damage

Toxicity: neuromuscular, vascular, and reproductive systems

22

Selenium Mechanism

Part of enzyme systems

Antioxidant that works with Vit E

Kills invading pathogens, fungi

Virus removal

Healing

23

Selenium Deficiency

Uncommon

Deficiency favors formation of pro-inflammatory compounds

Less effective neutrophils

24

Selenium Food Sources

Brazil nuts
Seafood
Meats
Whole grains
Vegetables grown in Se rich soil

25

Zinc Mechanism

Functions in association with more than 100 enzymes

Thymulin: T-cell differentiation and T and NK cell functions

T lymphocyte development

26

Zinc Deficiency

Decreased taste acuity, white spots on nails
Growth retardation (protein synthesis, DNA, cell division)
Impaired lymphocyte response and reduced cutaneous reactions (decreased wound healing, skin lesions)
Promotes apoptosis in B and T lymphocytes, hinders function of macrophage, alters the productions and potency of cytokines
Poor thymic development in infants

27

Zinc Sources, Chief Functions, Deficiencies, and Toxicity

Seafood, enriched cereals, yogurt, pork, beef

Chief Functions: activates many enzymes, associated with hormones, synthesis of genetic material and proteins, transport of vitamin A, taste perception, wound healing, and reproduction

Deficiency: growth retardation, delayed sexual maturation, impaired immune function, hair loss, eye and skin lesions, loss of appetite

Toxicity: loss of appetite, impaired immunity, reduced copper and iron absorption, low HDL cholesterol (risk factor for heart disease)

28

Vitamin D Mechanism

Mechanism
Liver converts vitamin D to CALCIDIOL
Kidneys convert stored Vit D into CALCITRIOL which is a powerful steroidal hormone
Calcitriol targets more than 2,000 genes and may well be responsible for boosting immune response as well as fighting cancer
Vit D deficiency link to autoimmune disorders

29

Vitamin D Functions

Down regulates PAMP receptors
Down regulates cancer cell growth and increases apoptosis
Down regulates inflammatory cytokines
Innate immunity: up-regulate antimicrobial peptides in epithelium
Adaptive immunity: stimulate macrophages to produce defensive proteins
Cell growth, differentiation, proliferation activity
Premyeloid WBC and stem cells into macrophages and monocytes

30

Vitamin D Sources, Functions, Deficiency, Toxicity

Fortified milk, shrimp, sunlight, salmon

Chief Functions: mineralization of bones and teeth via increase absorption from GI tract, withdrawing Ca2+ from bones, and stimulating retention by kidneys

Deficiency: abnormal bone growth resulting in rickets in children, osteomalacia in adults, malformed teeth, and muscle spasms

Toxicity: elevated blood Ca2+, calcification of soft tissues, excessive thrist, headache, nausea, weakness

31

Fats

Unsaturated vs. Saturated fats
Om-3 FA vs. Om-6 FA
1:1 – 1:4 ratio ideal
EPA/DHA
Important because Om 6 is proinflammatory FA, but once get beyond 1:4, then induces proinflammation

32

Types of FA: ALA, EPA, DHA

ALA – alpha linoleic acid – Omega 3
Flaxseed

EPA – Eicosapentaenoic acid – Omega 3
Fish Oil

DHA – Docosahexaenoic acid – Omega 3
Fish oil and algea

33

Types of FA: GLA, OA, and Coconut Oil

GLA – Gamma linoleic acid – Omega 6
borage oil, evening primrose oil, hemp oil, black current seed oil

OA – Oleic acid – Omega 9
Olive Oil

Coconut Oil – Saturated fat –
Medium chain triglyceride-lauric acid
Plant source of saturated fat

34

Fat Mechanism

High fat diets decrease T lymphocyte function

Trans fat contributes to chronic low grade inflammation

Omega 3 FA (EPA & DHA) increase anti-inflammatory pathways & prostaglandins

Reduction in total fat = increase number of monocytes and T and B lymphocytes

35

Phytochemicals

Bioactive Food Components:
molecules that influence biological responses, including gene expression

Occur naturally in plants

Mechanism of action not entirely known
antioxidant
apoptosis
cell-cell communication
environmental toxin exposure defense

36

Prebiotics and Probiotics

Prebiotics: non-digestible plant components that are used by the flora for nourishment.
Fructooligosaccharides: onion, asparagus, artichoke, chicory, banana; inulin supplement

Probiotic: “live microbial food ingredient that is beneficial to health”
Examples: Lactobacillus acidophilus LA5, Bifidobacterium lactis Bb12
Bifidobacterium lactis Bb12 enhances intestinal antibody response in formula-fed infants

37

Prebiotics and Probiotics Functions

Promotes non-immunologic gut barrier (stabilizes gut microflora)

Modulates host response to microbial pathogens

Mediates balance of pro- and anti- inflammatory cytokines in the GI; anti-TNF-a effects

May stimulate immune cell production system wide

Different strains used for different purposes
Lactobacillus rhamnosus GG
70% reduced risk of developing antibiotic-associated diarrhea in children

38

Prebiotics and Probiotics Sources

Rich sources include: fermented dairy products (kefir, yogurt, buttermilk), miso, tempeh, bean pastes, soy beverages, soy sauce and fermented vegetables like sauerkraut and kimchi, kombucha

Advise clients to look for live active cultures (National Yogurt Association)

Encourage the incorporation of fermented dairy products into overall diet (smoothies, salad dressings, yogurt)
Plain vs. flavored (to avoid added sugar)