nutrtion and immune health Flashcards
(25 cards)
importance of nutrition and immune health
affect all aspects of immune system
macronutrients - immune cell metabolism and protein synthesis
micronutrients - immune cell replication and antioxidant defences
impact of nutrient deficiencies
impair immune function
depressed cell mediated immunity
t-lymphocyte proliferation
complement formation
phagocyte function
humoral and secretory antibody production
altered cytokine production
direct negative effects of inadequate nutrition on immune function
altered availability of nutrients/coenzymes/cofactors involved in immune cell energy metabolism and protein synthesis
direct negative effects of inadequate nutrition on immune function
immunotegulatory effects of stress hormones
altered hormone response to stress
increase in:
adrenaline
acth
cortisol
glucagon
insulin
testosterone
decrease in immune function
decrease in
cell mediated immunity
cell proliferation
complement formation
phagocyte function
antibody production/affinity
increase in URTI
how does cho effect immune function
glucose acts as fuel substrate for immune cells - post exercise hypoglycaemia could endanger immune cell function
catecholmaines (adrenaline and noradrenaline) and cortisol, potent modulatory effects on immune function, increasing cho may more likely act indirectly by reducing stress hormone responses, limiting exercise induced impairments
evidence for CHO supplementation
lack of evidence that cho modifies infection risk in athletes
is evidence for stress hormone response and in vitro immune responses, acute supplement during exercise
shown to enhance aspects of recovery and performance
prescription of CHO
30-60g per hour during sustained intensive exercise
consume 1-1.2g/kg 0-2 hours post exercise
absolute amount adjusted on intensity and duration
attenuate rise in stress hormone, limit degree of exercise induced immune impairment
train low strategies, periodise training to reduce immune impairment and ability to perform
what’s class as vitamin d deficiency
<30nmol/l
maintenance dose for vitamin d
1000-2000iu/day
reverse vitamin d deficiency
4000 iu/day
what vitamin should you supplement with
vitamin d3
what should you take into account when supplementing vitamin d
latitude, skin type, train indoors, religious clothing
should you supplement if you have enough vitamin d
no avoid excess intake
what was seen in people who were vitamin d deficient
67% deficient reported urti
27% who had optimal levels reported URTI but illness severity was less
He and colleagues 2013
where do we get vitamin d from
sun exposure 90%
how much vitamin d do we need
5-15 ug/day
evidence for vitamin d supplementation
moderate to strong
deficiency associated with increased risk of URTI
how does vitamin d effect immunity
anti inflammatory, influences several aspects of immunity
both innate and acquired arm through modulation of gene expressions
up-regulates gene expression and antimicrobial peptides and downregulates expression of inflammatory cytokines
immunomodulatory effect of t and b lymphocytes in acquired immunity
how should you supplement probiotics
14 days prior to overseas travel or comp to ensure colonisation
multi strain probiotics, genus lactobacillus and bifdobacterium
more than 1x10 to the 9 - 1billion cfu to ensure greatest survival in gut and immune modulation
side effects of probiotics
transient increase activity in the gut during consolation period
rumbles, flatulence
athletes should be informed of possible mild side effects
what are probiotics useful for
reducing the risk of common respiratory and gut issues by improving immune and gut barrier function
during prolonged and intensive exercise mucosal surfaces can be disturbed, increasing risk of common gut problems
how do probiotics work
increase secretion of mucins and iga
enhance gut wall integrity
inhibit the overgrowth of pathogenic bacteria
competing with pathogenic bacteria for binding sites on mucins and/or epithelial cells
evidence for probiotic use
moderate to strong evidence in athletes with a daily dose
50% decrease in URI incidence and 2 days shortening of URI length
more evidence required for supporting probiotic efficacy to reduce gastrointestinal distress and infection
some benefit with little evidence of harm
