Scientific
S
i tifi requirements
i
t for
f substantiation
b t ti ti
of claims on the immune function
Henk van Loveren
Panel Member
EFSA Scientific
S i tifi Panel
P l on Dietetic
Di t ti Products,
P d t Nutrition
N t iti & Allergies
All i
EFSA Scientific Meeting on Health Claims related to Gut and Immune Function
2 December 2010, Amsterdam
The immune system
An effectively functioning immune system is crucial
for maintaining physiological integrity and thus
for health
The immune system provides defence against tumours
and infections caused by pathogenic microorganisms
2
Allergies
Allergic manifestations, such as asthma, urticaria,
and eczema, are caused by undesired immune
responses to environmental allergens
3
Immunological parameters, e.g.
• lymphoid subpopulations
• production
d ti off cytokines
t ki
• phagocytic activity
• lytic activity of natural killer cells
• Langerhans cells
•
•
•
•
proliferative responses of lymphocytes
lytic
y activityy of cytotoxic
y
T cells
immunoglobulin levels
delayed-type hypersensitivity responses
4
Stimulation of immune parameters is not
necessarilyy beneficial
5
Claims related to the immune system
Non-defined, e.g.
•
•
•
•
Immune system
Immune health
Natural defence
Strengthening the immune system
Defined e.g.
Defined,
eg
• Maintaining the normal skin immune function after UVexposure
p
• Defence against pathogens by stimulating immunologic
responses
• Reducing
R d i risk
i k factors
f t off e.g. allergic
ll i rhinitis
hi iti
6
Outcome measures
• Claims related to immune defence against pathogens
– Incidence/duration/severity/relative risk of upper
respiratory tract infection, gastrointestinal tract, infection,
urinary tract infection
– Reduction of numbers of pathogens
– The incidence of infection or reduction of numbers of
pathogens may not necessarily represent an effect on the
i
immune
system,
t
for
f claims
l i involving
i l i the
th immune
i
system,
t
evidence of a relevant change in immunological parameters
needs to be provided
7
Outcome measures, e.g.
• lymphoid subpopulations
• production of cytokines
• phagocytic activity
• lytic activity of natural killer cells
• Langerhans cells
•
•
•
•
proliferative
lif ti responses off lymphocytes
l
h t
lytic activity of cytotoxic T cells
g
levels
immunoglobulin
delayed-type hypersensitivity responses
preferentially in same studies
8
Restoring immunological parameters –
evidence alone might be sufficient
• N
Naturally
ll outside
id normall range (e.g.
(
elderly)
ld l )
• Outside normal range associated with life
styles/events
t l /
t (e.g
( diet,
di t stress)
t
)
• Outside normal range due to an experimental
challenge model of life style/event (e.g.
challenge-model
(e g stress,
stress sleep
deprivation)
• Outside the normal range by other factors (e.g.
(e g UV)
9
A measure that might be enough
Stimulation of pprotective antibody
y response
p
to
vaccination
Protective
P
t ti antibody
tib d titres
tit
Number of protected individuals
Impact goes beyond the purpose of vaccination
Claim: Defence against pathogens by stimulating
immunologic responses
10
Allergy
• Claims
Cl i related
l d to response to allergens
ll
– Incidence of allergic manifestations
– Self reported allergies are usually unreliable
– Need to include physician diagnosed allergies
– Immunologic nature needs to be corroborated with
appropriate measures
11
Inflammation
• Chronic inflammation is associated with a number
of diseases
12
Inflammatory markers, e.g.
•
•
•
•
•
•
•
Cytokines
C
ki
(TNFα,
(TNF IL-1α,
IL 1 IL-6,
IL 6 etc))
Components of arachidonic acid pathway
sCRP
Components of complement cascade
Neutrophils
Lymphocytes
etc
13
Inflammation
• Inflammation is a non
non-specific
specific physiologic response
to tissue damage that is mediated by the immune
system.
• Adequate inflammatory responses are of primary
importance for the defence against injury of any
origin.
• Changes in markers of inflammation such as various
i
interleukins
l ki andd others
h per se do
d not indicate
i di
a
beneficial physiological effect.
14
Inflammation
• Suggestions received:
– in study populations with life events (e.g. injury, high
saturated fat diet)
– in study populations where the response is out of normal
range
– elderly population
• Consequence or cause?
• Reducing
R d i inflammatory
i fl
t
markers
k without
ith t reduction
d ti off
the cause of inflammation may not imply a beneficial
effect
15
THANK YOU
16