Immunonutrition

Question 1

incidence of infection and training r’ship

Answer 1

Most at risk if intense training

Bad if intensified training period

Question 2

URTI symptoms: is it just man flu?

Answer 2

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

Question 3

how and why do you get ill post exercise?

Answer 3

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

Question 4

training continuum

Answer 4

Cannot ethically overtrain people – usually overreaching

Question 5

immune system and intensified training

Answer 5

Fall in function from normal to intensified training

Immune cells don’t function as well following week intensified training

Increase again with recovery training

Question 6

SIgA: influence of training

Answer 6

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

Question 7

SiGA falls when ill - warning sign?

Answer 7

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

Question 8

American college footballers: IGA and URTI

Answer 8

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

Question 9

intensified training protocol

Answer 9

Fed them their diet – high and normal protein amount

Sub max exercise – time trial – 1h rest

Intensified – 19h of training

Question 10

lymphocyte subdivisions

Answer 10

–>

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

Question 11

CD8 t-lymphocytes

Answer 11

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

Question 12

the badass t-lymphocytes

Answer 12

Fall in amount released into blood during higher intensity exercise

Reduction in amount given to tissues that need them -leave tissues susceptible to infection

Question 13

the weak and feeble t-lymphocytes

Answer 13

Not as good at getting it into the tissues

More at risk of infection after ex

Question 14

nutrient deficiencies and immune function

Answer 14

Nutrient deficiency

• Protein energy
• Vit A
• Vit D
• Iron
• Zinc
• Copper
• Selenium

Avoid deficiency in total energy intake

Question 15

nutritional strategies

Answer 15

1. avoid deficiencies of energy
2. take CHO during exercise
3. avoid deficiencies of micronutrients/some maybe supplement (polyphenols)
4. take a daily lactobacillus probiotic
5. ensure sufficient protein (maybe more)

Question 16

what can I do if i need to train intensely?

Answer 16

CHO during ex – reduces cortisol response

Prevents rise in cortisol and adrenaline

Maintains blood glucose concs – prevent associated decline in immune function

Question 17

CHO and intense training: DALDA

Answer 17

Scores lower with high carb – feeling better with carb

Question 18

IFN-Y production by t-lymphocytes: CHO is good

Answer 18

Carb prevents fall in IFN interfering with gamma

more stimulation of CD8+/IFN-y with carbohydrate

Question 19

what else can I take: Quercetin

Answer 19

Quercetin gave slight improvement to lymphocyte function – not major

more proliferation with Quercetin

Question 20

non-alcoholic beer

Answer 20

Reduction in risk of infections 2 weeks after marathon with beer

1st bar control

2nd bar beer

Question 21

probiotics and infection risk

Answer 21

Daily probiotic drink/placebo for 16 weeks during winter training in endurance athletes

Randomised double-blind study

Lower incidence of infections

Question 22

intensified training and DALDA: protein influence

Answer 22

Higher protein – no significant difference – prevents increase in URTI symptoms

Question 23

WBC response to training and protein

Answer 23

Normal to high protein = no significant change in leukocyte or granulocyte concentrations

Question 24

CB8 lymphocytes: intense training and protein

Answer 24

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

Question 25

cytotoxic: intense training and protein

Answer 25

Need cells to have ability to fight infection

Question 26

evidence of other suggested supplements

Answer 26

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)