A SCIENCEBASED PLATFORM FOR DESIGN AND USE OF FUNCTIONAL FOODS: why and how - PowerPoint PPT Presentation

Loading...

PPT – A SCIENCEBASED PLATFORM FOR DESIGN AND USE OF FUNCTIONAL FOODS: why and how PowerPoint presentation | free to view - id: 100b8d-MWEwZ



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

A SCIENCEBASED PLATFORM FOR DESIGN AND USE OF FUNCTIONAL FOODS: why and how

Description:

Lack of overall control or standardized procedures to safeguard the truth of ... Benzie & Strain, Methods In Enzymology, 1999;299:15-27. Red and white wines ... – PowerPoint PPT presentation

Number of Views:44
Avg rating:3.0/5.0
Slides: 34
Provided by: thi120
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: A SCIENCEBASED PLATFORM FOR DESIGN AND USE OF FUNCTIONAL FOODS: why and how


1
A SCIENCE-BASED PLATFORM FOR DESIGN AND USE OF
FUNCTIONAL FOODS why and how
  • Iris FF Benzie
  • The Hong Kong Polytechnic University

2
What is a functional food?
  • No internationally agreed definition
  • Generally, are foods that claim (explicitly or
    implicitly) to improve health or well-being, or
    to help prevent specific disease
  • Regulatory frameworks for claims vary in
    different countries
  • Lack of overall control or standardized
    procedures to safeguard the truth of
    health-related claims and guide promotion of
    functional foods

3
Functional foods include
  • Whole natural foods/beverages/herbs, e.g., red
    wine, green tea, honey, soy products, milk, oily
    fish
  • Foods which contain added vitamins, minerals or
    other nutrients, e.g. folate-enriched cereals,
    pre-biotic foods
  • Food enriched with pro-biotic bacteria
  • Non-foods, e.g. sugar alcohols in chewing gum
    to prevent dental caries, plant sterols to block
    fat absorption
  • Global sales of functional foods US50 billion
    in 2001

4
Claims for functional foods are often a mixture
of fact, equivocation and implication
  • About the content or characteristic of the food
  • Rich in calcium
  • Rich in vitamin C
  • Contains plant sterols
  • High antioxidant capacity
  • About the effect of the food
  • Promotes bone health
  • Strengthens the immune system
  • Lowers cholesterol
  • Lowers blood pressure

About disease prevention Prevents
osteoporosis Prevents SARS Prevents
cancer Prevents heart disease
5
Key Issues Safety, Quality, Characterization
Efficacy
  • What is it (source/characterization/quality)?
  • How is it taken (preparation/dose/frequency)?
  • What does it do (various types and sources of
    solid science-based evidence for health-related
    effects)?
  • Who will benefit (the old? the already sick?
    children? pregnant women? hypertensive or
    diabetic subjects)?
  • How does it compare with other similar products
    (contents, effects)?

6
How do we know?
  • Source/manufacturing must be regulated to ensure
    quality and consistency of composition
  • Scientific evidence is needed to validate
    health-related claims of functional foods and aid
    responsible and successful promotion/marketing/use
    of these

7
Investigate, using an objective, scientific
approach, the reported/reputed properties in
relation to content and effect
  • antioxidant-rich.increases antioxidant
    status.lowers oxidative stress.slows
    ageing..prevents age-related disease
  • lowers cholesterol.prevents heart disease
  • boosts immune system..prevents SARS/prevents
    cancer
  • improves insulin sensitivitylowers blood
    glucoseprevents diabetes
  • high in calcium.promotes bone healthprevents
    osteoporosis
  • anti-inflammatory.prevents RA and CVD
  • lowers blood pressureprevents stroke
  • contains pre- and pro- bioticsprevents colon
    cancer
  • carotenoid-rich.prevents macular degeneration
  • rich in lycopene.prevents prostate cancer
  • contains omega 3 fatty acidsprevents heart
    diseaseslows cognitive declineprevents dementia

Antioxidant-rich foods
8
Alzheimers Parkinsons
Cataract Macular Degeneration
Cardiovascular Disease
Oxidative damage to protein, lipid DNA
(oxidative stress) is implicated in ageing and
ALL age-related diseases
Cirrhosis
Diabetic complications
Cancer
Autoimmune disease
Arthritis
9
Conceptually
  • If oxidative damage to key biomolecules increases
    risk of disease
  • then
  • Preventing or delaying damage by increasing
    antioxidant defences will decrease risk and help
    maintain health
  • Therefore,
  • Antioxidant-rich foods are suggested to slow
    ageing and prevent/delay age-related disease

10
Strong Inverse Relationship between Vitamin C in
the blood plasma mortality in next 8 years men
(n8,860) women (n10,636) (from Khaw et al,
Lancet 2001357657-663)
Mortality Rate
Ascorbic acid quintile Mean (M/F) plasma ascorbic
acid ?M
21/29 38/49 48/60 58/69 74/86
11
Key Questions in Antioxidant Research
  • Which foods have the highest antioxidant content?
  • Are antioxidant(s) in these foods absorbed and
    systemically distributed (are they
    bioavailable)? Which ones?
  • Do these antioxidants protect key biological
    sites?
  • Does increased dietary intake increase
    antioxidant status?
  • Is there evidence such an increased status is
    associated with beneficial effects that may lower
    risk of disease/delayed mortality (biomarker and
    physiological changes)
  • Does increased dietary intake lead to improved
    health/lowered mortality (long-term
    supplementation studies and epidemiological
    studies)?

same questions relate to all reputed active
components of functional foods
12
Different foods and beverages have different
antioxidant capacity (FRAP) values Benzie
Strain, Methods In Enzymology, 199929915-27
Red and white wines
Black, oolong and green teas
13
Antioxidant Content of Fresh Fruits and Vegetables
1 Strawberry 2 Orange 3 Kiwi 4 Apple 5
Grape 6 Banana 7 Pineapple 8 Choy Sum 9
Mange-tout 10 Broccoli 11 Tomato 12 Carrot 13
Potato
um/Kg fresh wet weight
Szeto, Tomlinson, Benzie, Br J Nutr 20028755-59.
14
Diet and Cancer Risk WCRF estimates that up to
40 of all cancers are preventable by improved
diet
15
Are antioxidants absorbed/bioavailable?
  • Bioavailability The degree and rate at a which
    a substanceis absorbed into a living system or
    is made available at the site of physiological
    activity
  • Merriam-Websters Dictionary

16
Bioavailability requires
  • Absorption
  • Distribution to site(s) of utilisation (via blood
    plasma)
  • Active form to be present in viable amounts at
    these sites

17
In Vivo Study to Assess Bioavailability of
Antioxidants in Green Tea, and Ganoderma lucidum
(Lingzhi)
?
Photo courtesy of NAMMEX
Agent ingested
  • Acute post ingestion (up to 3h
    placebo-controlled)

1.1g, n10
3.3 g, n7
Blood collected
400 ml strong green tea
Urine collected
18
Antioxidant bioavailability studies increase in
total antioxidant power of plasma after ingestion
of green tea or water mean SEM, n10
n7 for water
Szeto, Benzie, Strain, Tomlinson, Nutr Cancer
1999 34 83-87
19
Bioavailability of Lingzhi (Ganoderma lucidum)
Antioxidants
Wachtel-Galor, Tomlinson, Benzie. Int J Food Sci
Nutr 2004175-83
significantly (Plt0.05) different from
time-matched level after placebo significantly
(Plt0.05) different from pre-ingestion value
20
Fasting plasma ascorbic acid concentration of
healthy subjects before and after 4 weeks
supplementation with 1g/day vitamin C or placebo

Plt0.001
21
Marked increase (averaging 250) in fasting
plasma zeaxanthin after 28 days Kei Tze
(15g/day n14) supplementation (placebo
controlled study (n13) of parallel design)
Cheng, Chung, Szeto, Benzie. Br J Nutr 2005 (in
press)
Fasting plasma zeaxanthin umol/l

significantly greater (Plt0.01) than
pre-supplementation level and post-placebo
response
22
Do antioxidants protect key sites (e.g.,
membranes, DNA?)
Protection of red cell membranes from oxidant
challenge
?
?
?
Chung WY, Yow CMN, Benzie IFF. Redox Report 2003
85-8.
23
Quercetinprotects DNA in vitro
Plt0.05 Plt0.01
Szeto YT, Collins AR, Benzie IFF. Free Rad Res
2002 36113-118
24
The biomarker approach generally needed to
assess in vivo effects on health status and
risk of disease
Measurement of biological or biochemical
components or characteristics of cells or
biological fluids, such biomarkers being affected
by extrinsic (dietary/lifestyle/ environmental)
and intrinsic (biological/genetic) effects on
integrity and function of organelles, cells,
tissues, organs and homeostatic systems and which
reflect health status or risk/onset of
disease. Use of a wide range of biomarkers is
advisable
25
28 days Lingzhi supplementation
  • No evidence of liver or renal toxicity seen
  • No significant change in biomarkers of
    antioxidant status, oxidative stress or markers
    of CHD risk in healthy subjects
  • Some indication of lowered lipid and improved
    antioxidant status (Wachtel-Galor, Tomlinson,
    Benzie, Br J Nutr 200491263-269).

26
Possible immunomodulatory effects of Lingzhi
preliminary findings in human subjects
After 4 weeks supplementation with Lingzhi,
preliminary data (n9) indicate some evidence of
immunomodulatory effect
27
A SCIENCE-BASED PLATFORM FOR DESIGN AND USE OF
FUNCTIONAL FOODS why and how
  • Food for Thought

28
Functional foods include fruits, vegetables,
teas, wines, herbs, chocolate, honey, milk,
yoghurt, berries, fungi, spices .
29
Health-related claims of functional foods
  • Many varied and drive high volume global market
  • Many claims have not been scientifically
    validated
  • Issues of reputation vs. evidence, real benefit
    vs. short-term market demand must be addressed to
    turn the promise of functional foods into a
    reality that benefits BOTH human health and
    commercial interests of producers
  • However, there is no incentive to underpin vague
    claims with solid scientific evidence when
    functional food products can be marketed on the
    basis of allusions of benefit

30
The future of functional foods
  • If governments do not set clear and strict
    standards for efficacy and safety of functional
    foods, then the field has no long-term future
  • Katan MB, de Roos NM. Science 2003299206-207

31
Regulation is required to prohibit vague
claims and allow hard claims for disease
reduction if evidence is solid
  • Regulation will create incentive for food
    companies to fund research to
  • underpin/ substantiate claims
  • validate their products
  • develop new products
  • create a sustainable market for functional foods

32
Functional Foods To play a sustained and valued
role in the Future of Asian Health, there must be
  • Independent
  • scientific research
  • Collaborative
  • development
  • Evidence-based
  • promotion

British Journal of Nutrition Current Topics
in Nutraceutical Science
Graphic courtesy of S Wachtel-Galor
33
With Thanks To
Brian TomlinsonJohn BuswellSean Strain Timothy
KwokAndrew Collins Vincent YeungPauline Cho
Szeto Yim-tong Chung Wai-Yuen Sissi
Wachtel-Galor Choi Siu-wai John Yuen Wai-man Rema
Vazhappilly Camus Choy Kar-man
WCRF International
The Hong Kong Polytechnic University
Vitagreen Hong Kong Ltd Rich Nature Ltd
About PowerShow.com