Excercise/Nutrition + Immunity Flashcards
Overall benefits of exercise
- Decreased risk of chronic illness (glucose metabolism, insulin sensitivity, cardio/resp health)
- improved mental health/learning
What were the 3 principles of exercise immunology early on in history
- tranient decrease in blood immune cells in hours following vig ex
- Vig ex leads to reduction in salivary IgA lvls
- Inf risk increased after acute bout
Phases of blood lymphocytes post exercise + timeframe
phase 1- dramatic increase (one hour post) - NK, CD8
phase 2- dramatic decreases (3-72hrs)
What is the open window hypothesis
immune system is compromised 3-72hrs post vig ex (and repeated windows may add up!)
What is the J curve hypothesis
Moderate exercise reduces URTI risk but at heavy exercising the risk can go up 2-6fold
(overall moderate best (rat study))
What inflammatory cytokines are released w exercise (+ what is it important for)
active mm release cytokines like IL6 and it increases proportional w exercise severity
-IL6 is important for inducing the release of the anti inflammatory cytokine IL10
Over time with exercise what happens to cytokine release
have lower inflammatory blood cytokine levels at rest leading to reduced risk of chronic disease
How does exercise activate stress structures in the body
Adrena medulla- release epinephrine and norepenphrine
HPA- releases cortisol (has potent anti inflammatory and immune suppressing effects)
What is the current consensus on the ‘window of opportunity’
Regular exercise may reduce risk of infection and consensus is that it reduces all cause mortality
(long term benifits outweighs short term risk)
Why is there a lymphocyte redistribution in post exercise IgA lvls`
- occurs as a means of facilitating immune survelience for cancer/inf and immune regulation
- lymphocytes move into the tissues and identify and eradicate cells infected w pathogens
What is the RDA and how it relates to immune funtion
amount needed to meet requirements of 97.5% of people
may not be optimal for immune function though
What is the primary fuel source of immune cells
glucose
-low glucose associated with broad immune impairment
What is the cutoff for diabetes and what effect does it have on immune system
> 200mg/dl
- impaired phagocytosis
- Elevated pro inflammatory cytokines (TNFa, IL6)
- impaired t cell and antibody responses
difference bw soluble and insoluble fibres
Soluble- forms gel like substance in water. Slows digestion. reduces cholesterol
Insoluble fibre- adds bulk/mvmt to stool, helps with constipation
How does soluble fibre aid immunity
Redially fermented in gut into short chain fatty acids (prebiotic)
-Short chain fatty acids have antiinflammatory functions by modulating immune cell release of cytokines/chemokines, ROS
Effects of reduced pro intake on immune
- Thymic involution/atrophy of lymphoid organs
- Decreased hematopoiesis
- impaired phago
- decreased t cell/ bcell #/function
- poor wound healing (less collagen prod)
What type of fat is dietary fats
LCFA (14 or more carbons long)
Types of unsaturated FAs and differentiating factor
mono- 1 C=C (double)- omega 7,9
poly- 2 or more C=C- omega 3,6
What configuration do most FAs come in and which is associated with risk of CVD and diabetes
- most naturally occurring unsaturated FAs exist in cis
- Trans has increased risks
MUFA effect on immune
immunosuppressive/antinflamatory effects ( decreased NK, adhesion molecules etc)
effect of omega 3 PUFA on immunity
Overall: antiinflamatory
Macrophages- less inflammatory cytokines, increased IL10 , increase phase
impairment of t cell/ plasma cells (but increased treg differentiation)
what can omega 3,6 be metabolized into and what does it help w
metabolized into eicosanoids which are precursors of inflammatory lipid mediators (prostaglandins/leukotriens)
Overall role of omega 3,6
both pro and antiinflammatory roles
What effect does obesity have on the immune system
- impairments in the activity of lymphocytes
- reduced antibody and IFN y prd
- incrreased susceptibility to inf
How does overnutrition contribute to immune response
proinflammtory responses dominate, but immune dysregulation may also occur
What cytokine lvls are lower in the mediterranean diet
proinflammatory cytokine lvls lower
what is ferric iron a cofactor for
cofactor in neutrophil myeloperoxidase which is used to generate the ROS
what is iron deficiency associated w
- thymus atrophy/thymic output
- suseptibility to inf (plasmodia/mycobacteria)
- impaired antimicrobial responses/ t cell mediated immunity
Zinc is used for what cofactor and what does deficiency result in
cofactor in leukocyte enzymes that reduce oxidative damage
deficiency- Thymic atrophy, decrease hematopoiesis
What is Vit A deficiency resulting in
- profound deficiency in neutrophils, macrophages, Th1, NK
- underdeveloped mucosal tissues and loss of mucosal barrier function
What is retinoid acid associated with (3)
mucosal immune tissue development, t cell homing to the gut, IgA class switching, differentiation to T regs
What is vit b6 deficiency associated w
atrophy of immune tissues, low blood lymphocyte proliferation + antibody lvls and impaired lymphocyte proliferation
What is vit b6, b12 and folate (b9) deficiency associated w
Decreased cytotoxic cell numbers (NK cells, CD8, t cells)
what are def in vit c associated w
- impairment of phago
- impairment of t cell prolif
- impaiement of cytokine prod
- impaired monocyte adhesiion
- impaired collagen synthesis
Does taking vit c reduce respiratory inf
- did not reduce risk of getting a cold
- may slightly reduce duration of symptoms
how much does vit d supplementation reduce risk of respiratory inf and who is it most effective in
reduce risk by 12%
-stronger in those with baseline 25-hydroxyvit d lvls <25nmol/l
What is the benefit of Vit E`\
Antioxidant protecting immune cell structures from being oxidized/damaged
What are u at more risk with w vit d def
serious/freq respiratory inf
autoimmune diseases
