Immunonutrition Flashcards
incidence of infection and training r’ship
Most at risk if intense training
Bad if intensified training period
URTI symptoms: is it just man flu?
Looked at infections over 5 months
J-shaped curve in both situations - unidentified cause and identified URTI
lowest number of infections with recreational
highest number of infections with elite
how and why do you get ill post exercise?
Prolonged (>90 mins) hard bouts ex depress immune function
Decrease blood glucose and muscle glycogen
Increase in interleukin-6, stress hormones and free radicals
Leads to depressed immune function, increased risk of infection
With single and repeated bouts of ex
training continuum
Cannot ethically overtrain people – usually overreaching
immune system and intensified training
Fall in function from normal to intensified training
Immune cells don’t function as well following week intensified training
Increase again with recovery training
SIgA: influence of training
Measure of immune function from saliva
Study with sailors
R = -0.41
N = 50
P < 0.005
as combined sailing and training load increased, SIgA decreased - negative correlation
SiGA falls when ill - warning sign?
See fall before infection - warning sign to risk of infection
Most then did get an infection
40% fall+ = 1 in 2 chance of getting infection
American college footballers: IGA and URTI
Easy to collect saliva than blood
More training in autumn and spring
Fall in SIGA in high training – more at risk of infection
Coincided with increase in URTIs
intensified training protocol
Fed them their diet – high and normal protein amount
Sub max exercise – time trial – 1h rest
Intensified – 19h of training
lymphocyte subdivisions
–>
CD8 t-lymphocytes
–>
Naïve CD8+ t-lymphocytes – weaker – less effective at fighting pathogens
central memory CD8+ t lymphocytes
effector memory CD8+ t lymphocytes
Effector memory RA + CD8+ t lymphocytes - most potent – most cytotoxic – most effective at killing pathogens
CD8 t-lymphocytes
Less CD8 released with max ex
Less cells taken out of blood and into cells after ex
Lower egress – take up into tissues – may be a bad thing
the badass t-lymphocytes
Fall in amount released into blood during higher intensity exercise
Reduction in amount given to tissues that need them -leave tissues susceptible to infection
the weak and feeble t-lymphocytes
Not as good at getting it into the tissues
More at risk of infection after ex
nutrient deficiencies and immune function
Nutrient deficiency
- Protein energy
- Vit A
- Vit D
- Iron
- Zinc
- Copper
- Selenium
Avoid deficiency in total energy intake
nutritional strategies
- avoid deficiencies of energy
- take CHO during exercise
- avoid deficiencies of micronutrients/some maybe supplement (polyphenols)
- take a daily lactobacillus probiotic
- ensure sufficient protein (maybe more)
what can I do if i need to train intensely?
CHO during ex – reduces cortisol response
Prevents rise in cortisol and adrenaline
Maintains blood glucose concs – prevent associated decline in immune function
CHO and intense training: DALDA
Scores lower with high carb – feeling better with carb
IFN-Y production by t-lymphocytes: CHO is good
Carb prevents fall in IFN interfering with gamma
more stimulation of CD8+/IFN-y with carbohydrate
what else can I take: Quercetin
Quercetin gave slight improvement to lymphocyte function – not major
more proliferation with Quercetin
non-alcoholic beer
Reduction in risk of infections 2 weeks after marathon with beer
1st bar control
2nd bar beer
probiotics and infection risk
Daily probiotic drink/placebo for 16 weeks during winter training in endurance athletes
Randomised double-blind study
Lower incidence of infections
intensified training and DALDA: protein influence
Higher protein – no significant difference – prevents increase in URTI symptoms
WBC response to training and protein
Normal to high protein = no significant change in leukocyte or granulocyte concentrations
CB8 lymphocytes: intense training and protein
Tendency for decrease in normal diet
Non sig change in high protein – amount of cells released into blood
Taken from blood into tissues = sig decline
Non sig on high protein
Protein maintains release of immune cells into blood and removal from immune cells into tissues where needed
cytotoxic: intense training and protein
Need cells to have ability to fight infection
evidence of other suggested supplements
Herbals (e.g. echinacea, Kaloba) – no strong support in human studies for reduced infection incidence but may shorten duration of symptoms when coming down with a cold
Zinc – may reduce cold symptom duration (Singh and Das, 2011)
Bovine Colostrum – mixed results for saliva IgA levels in athletes; some evidence of decreased URTI episodes though mechanism not clear (Crooks et al., 2006/10)
Glutamine – not responsible for ex-induced immunodepression (Hiscock and Pedersen, 2002)
Beta-Glucan – evidence of effectiveness in reducing ex-stress associated viral infection in mice (Davis et al., 2004) but not in humans (Nieman et al., 2008)
