nutrition & the immune system

7/26/2019 Nutrition & the Immune System

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Minidian Fasitasari

Department of Nutrition

Medical Faculty of Unissula Semarang

November 12, 2007

Malnutrition & immunity

Influence of micronutrients on immunefunction

The role of probiotics

Food intolerance & food allergy

Lactose intolerance

Poor nutrition compromises immune function

Generalized PEM in developing countries

Undernourished in developed countries hospitalized px,

alcoholics, elderly, food faddist.

Studies of nutrition-immunity in PEM & hospitalizedpx

multiple deficiencies of nutrients difficult to interpret

Infection (+) hosts immune response & nutritional status

Def. of single nutrient-immunity in experimental animals

Intake energy & macronutrient


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Def vit A

The 2nd most serious deficiency worldwide Associated with increased morbidity in children

(RTI & measles)

Studies: a marked declined in measles-related

deaths in vit A def children supplemented with vitA

Adverse effect restored to normal aftersupplemenetation

A water-soluble antioxidant

Affect most aspects of the immune system

Affecting the bacterial killing efficiency of WBC

Common cold symptoms reduction ~ 2-3g/d

when started at the onset

Scurvy: extreme vit C def.

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Rickets(bone weakening)

Interfere NK cell function increased infection

Hormonal form: 1,25-(OH)2D3 regulation of immune fx ingeneral

Inhibits Ly proliferation & Igproduction, interfere with T-helper cell

Little info: effects on thedeveloping human immune

system

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A major lipid-soluble antioxidant

Maintains cell membrane integrity by limiting lipidperoxidation by free oxygen radicals

Deficiency: Reduced antibody production & T-cell proliferation following

mitogen stimulation Rare, except in premature infants & elderly

Supplement 60 800 mg/d 30 days: Improvements in cytokine production (IL-2)

Delayed hypersensitive response

Enhanced Hep B vaccination antibodies

> 1600 mg/d inhibition of neutrophil function

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Common among children & pregnant women

Incidence of infection is increased in the presence of

deficiency or during iron supplementation??

Some bacteria need iron for multiplication ironsupplementation worsen the clinical situation

Fe def. T-ly numbers & function; bactericidal

activity of neutrophils restored by Fe suppl.


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Rare in humans

In premature infants & px with parenteral nutrition A complete absence of copper-carrying protein

caeruloplasmin in the blood & subsequent severecoppper deficiency:

Impaired T-cell immunity

Increased bacterial infections

Diarrhea

Excess may impair immune function

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An essential trace element & concentrate in

lymph nodes, liver, spleen.

In china: endemic heart & bone disease

In px long-term parenteral nutrition

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Increase atopic disease ~ a lack of counterbalancing

microbial exposure at an early stage

Infants immature intestinal immune system develops

as it is exposed to dietary & microbial antigens in the

gut

Probiotics: live bacteria, beneficial to the host by

affecting microbial balance

Prebiotics: non-digestible food additives, often fructo-

oligosaccharides (FOS), beneficially affect the host by

selectively stimulating the growth &/or activity of

limited number of bacteria in the colon

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Probiotics in early live >< atopic dermatitisin high-risk children

Treatment of cows milk allergy-related

diarrhea

Optimal dose? Adverse effect?


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Adverse reaction to ingested food (+) symptoms,

syndromes, & disease sensitivity, allergy, intolerance

Not based on an immunological mechanism: Enzyme deficiency

Lactase deficiency

Pharmacological effect

Caffeine

Non-immunological direct histamine containing or releasingeffects

Certain shellfish & cheeses

Direct irritation

Trough gastric acid in esophagitis & spices

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Food intolerance & food sensitivity:

A general sense for all reproducible, unpleasant reactionsto a specific food or food ingredients that are not

psychologically based Food allergy:

Reproducible food intolerance, evidence of an abnormalimmunological reaction to the food & plausible mechanismimplicating immunological processes (see table)

Psychologically based food reactions (food aversions)

Psychological avoidance & psychological intolerance

Caused not directly by the food but by emotions associatedwith the food

Does not occur when the food is given in unrecognizableform

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In children

Eczema, wheeze, urticaria, mood changes, angio-edema, epilepsy, failure to thrive, diarrhea, vomiting &GI blood loss

In adults

Incidence lower than in childhood

Asthma, urticaria, & anaphylaxis

Have history of food adverse reactions in childhood

Migraine, arthritis, psychiatric symptoms, GI (nausea,vomiting, abdominal pain, constipation, & diarrhea)

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Lactose:

A disacharride, only in milk & milk products

Hydrolyzed in small intestine by lactase

glucose & galactose

Develop 1-3h ingests lactose in food

nausea, vomiting, abdominal pain, & diarrhea

Closely related to dose, wide variation in the

dose-response phenomenon.


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Clinical syndromes:

Abdominal pain in children

Diarrhea after gastric surgery

Multiple pathology

Treatment:

A diet with low oral, tolerated, lactose content

Most px tolerate 10g fermented milk product

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Any component of the immune system may be absent or

abnormal; the effect may range from trivi al to fatal

Dysfunction of immune system may be genetically determined oracquired from disease, drug treatment or radiotherapy

Immune deficiency may result in underactivity of the system &

susceptibility to infection, or abnormal regulation as in allergy or

autoimmunity

Poor nutrition compromises immune function not only in the

malnourished of developing countries, but also in the

undernourished of industrialized nations, such as those in

hospital with infection, surgery, trauma, or cancer, alcohol users,

the elderly & food faddist

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Protein energy malnutrition (PEM) in children causes atrophy of

the lymph organs (thymus, tonsils, spleen, lymph nodes, Peyers

patches), which affects the overall immune status of individual

Deficiency vitamins A, E, B6, pantothenic acid & folate all

decrease cell & humoral immunocompetence, with an increased

suspectibility to infections

Vitamin C enhances bacterial phagocytosis

Def. Fe, Zn, Ca, Mg, Mn, Cu, Se, Cd, Cr, I, depresses

immunocompetence as do toxic levels of the heavy metals Pb,

Hg, Cd.

Iron supplements should be given wi th caution to malnourished

patients with infections as iron may stimulate bacterial

multiplication

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Def. Zn in fetal & early neonatal stages delays the development

of the immune system

Food intolerance & food sensitivity are terms often used for all

reproducible adverse reactions to specific foods or ingredients

Lactose intolerance can be managed with a low lactose diet.

Fermented milk (yoghurt) & lactose-reduced milk products may

be used to supplement small amounts of milk

The main food i ncriminated in causing food allergic reactions:

milk, egg, soy, wheat, peanut, tree nuts, fish, shellfish

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nutrition & the immune system

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