basics of antioxidants - puratos.co.kr€¦ · • antioxidants (aox) are part of the defense...
TRANSCRIPT
Outline
1. Introduction
– Definitions
– Free Radicals
– Antioxidants (AOx)
– Oxidative stress
2. Types of AOx
– Different AOx: different mechanisms
– Dietary AOx
– Flavonoids
– Measuring AOx: ORAC
3. Health Effects
– Health effects for Vitamins E, A,C and Flavonoids
4. The AOx Trend: products and claims (Innova)
– Market for AOx
– AOx trend
– Products and claims for Confectionery and Bakery
5. Summary
2
Free Radicals 1
• Oxygen→ required for life but it is highly
reactive
• During metabolism or infection reactive oxygen species (ROS) are formed→ Free
radicals (FR) – H₂O ₂ = Hydrogen peroxide
– HOCl = Hypochloric acid
– OH⁻ = Hydroxyl radical
– O₂⁻ = Superoxide anion
• Free radicals = unstable and highly reactive molecules (due to unpaired electron)
• The body can initiate the creation of free radicals to defend itself against viruses or bacteria.
5 Foster, 2007; EUFIC, 2009; IFIC, 2009
Other Free radicals formed during inflammation and disease: •Reactive Nitrogen Species (RNS)
FR can be formed by exposure to UV light, cigarette smoke, radiation, pollution etc.
Free Radicals 2
• Free radicals attack stable molecules and steal an electron- creating a new radical→ chain reaction.
6
*CVD: cardiovascular disease
DNA
Mutations→
Cancer
Fatty acids
Lipid
peroxidation
→ CVD
Proteins
Enzyme inhibition
Denaturation &
degradation
Halliwell, 1997; Foster, 2007
Antioxidants
• Antioxidants (AOx) are part of the defense system of the body protecting against free radical damage.
• Most AOx donate an electron to FR without becoming FR themselves → chain reaction
stopped.
• AOx do not remove FR completely → keep them at an
optimum level.
• Dietary AOx not produced in the body→ Food
• Consumption of AOx is thought to provide protection
against oxidative stress → positive impact on health
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Image from www.welchs.com
Halliwell, 1997; Foster, 2007
Oxidative stress and disease
AOx
FR
Chronic Injury
Cancer, atherosclerosis, CVD, cataracts, immune
dysfunction, Alzheimer s disease, age-related macular
degeneration, rheumatoid arthritis, aging, etc.
8
Oxidative Stress
Types of Antioxidants
10
Different types of AOx →different AOx Mechanisms
Proper AOx: inhibitors interrupting the propagation
of the autoxidation chain reaction
Preventive AOx: inhibitors of FR oxidation reactions
Singlet Oxygen eliminators: e.g. carotenes
Reducing agents which convert hydroperoxides
into stable components in a non-radical way e.g. thiols
and sulfides.
Synergists of proper AOx: they increase the activity
of chain-breaking AOX in a mixture e.g. citric acid
Metal chelators which convert pro-oxidants
(especially iron or copper derivatives) into stable products (e.g. Quercetin,
tannins; phytates)
Inhibition of pro-oxidative enzymes
Pokorný, 2007
Different types of AOx →different measurement methods
FRAP ORAC TRAP
ORAC*
ORAC of Selected Foods- USDA database 2007
* all values presented are Total ORAC= H-ORAC and L-ORAC
Description Mean Unit
Spices, cinnamon,
ground 2675.4 µmol TE/1g
Sorghum, bran, hi-
tannin 2400.0 µmol TE/1g
Spices, Oregano, dried 2001.3 µmol TE/1g
Sorghum, bran, black 1008.0 µmol TE/1g
Cocoa, dry powder,
unsweetened 809.3 µmol TE/1g
Spices, basil, dried 675.5 µmol TE/1g
Sage, fresh 320.0 µmol TE/1g
Marjoram, fresh 273.0 µmol TE/1g
Rice bran, crude 242.9 µmol TE/1g
Nuts, pecans 179.4 µmol TE/1g
Ginger root, raw 148.4 µmol TE/1g
Elderberries, raw 147.0 µmol TE/1g
Peppermint, fresh 139.8 µmol TE/1g
Nuts, walnuts, english 135.4 µmol TE/1g
Nuts, hazelnuts 96.5 µmol TE/1g
Alchoholic beverage,
wine, table, red,
Cabernet Savignon 50.3 µmol TE/1g
Raspberries, raw 48.8 µmol TE/1g
Strawberries, raw 35.8 µmol TE/1g
Pears, raw 29.4 µmol TE/1g
Tea, green, brewed 12.5 µmol TE/1g
Tea, brewed, prepared
with tap water 11.2 µmol TE/1g
Lettuce, raw 2.73
µmol TE/1g
Cucumber, raw 1
µmol TE/1g
11
*ORAC= Oxygen Radical Absorbance Capacity
Fruits
Spices/
herbs
Cocoa
Nuts
Wine
Tea
ORAC
12
New High
Antioxidant
Chocolate: Ox-Anti
ORAC method set up internally to measure AOx
capacity of fruits, chocolates, flours, etc.
Ox-Anti (Belcolade)
Acticoa (Callebaut)
Berries
Topfil Blueberry
Topfil Berrissimo
Rye flour
Wheat flour
Values measured internally and subject to a certain standard deviation. Please refer to the
lab for more information about these ORAC values.
Types of Antioxidants 2
13
Enzymes Other Low
molecular
weight AOx
Dietary AOx
Different types of AOx →different AOx Mechanisms, one defense system
SOD (Superoxide Dismutase)
Vitamin E, Vitamin C, β-Carotene,
Flavonoids Uric Acid
Glutathione
Polyphenols
Flavonoids Non- Flavonoids
Flavonols→ Quercetin
Flavones
Flavanols→ Catechin
Flavanones
Stilbenes → Resveratrol
Iso-Flavonoids
Anthocyanidins
Vitamins
A E C
ILSI Europe, 1996
Geissler & Powers, 2005
Phenolic alcohols
Hydroxybenzoic acids
Hydroxycinnamic acids
Lignans
Dietary Antioxidants
14
Vitamin A & other Carotenoids
•Singlet oxygen quenchers; peroxyl radical scavengers
•Prevent singlet oxygen from generating FR
Vitamin E
•Proper AOx→chain breaking function
•Responsible for protecting the PUFA in cell membranes from oxidation
•Upregulates the activity of Aox enzymes
Vitamin C
• Proper AOx→chain- breaking function
• Powerful reducing agent -can directly scavenge superoxide, hydroxyl radicals, singlet oxygen and H₂O ₂
• Can re-generate Vitamin E from tocopheroxyl radical providing membrane protection
Geissler & Powers, 2005
Pokorný, 2007
Foster, 2007
Dietary Antioxidants
Zinc, Copper, Manganese & Selenium
•protect against oxidative stress indirectly serving as cofactors for AOX enzymes: SOD superoxide dismutase & GPx Glutathione peroxidase.
Polyphenols
•Effective FR scavengers; chain-breaking function
•Chelating agents : indirect AOx action
15 Geissler & Powers, 2005
Pokorný, 2007
Foster, 2007
Flavonoids
• Flavonols
• Flavanols
• Flavonones
• Anthocyanins
• Isoflavones
• Flavones
16
Flavonoids → most common group of
plant phenolics
→ +4000 identified in plants
→ Share a common structure (2 Benzene rings
and a central pyran ring) which determines their
AOx functioning
D Archivio, 2007
Flavonoids
Flavonols • Quercetin in Apples and Onions
Flavanols (Flavan-3-ols) • Epicatechin in cocoa and chocolate • Catechin in Red wine and Black tea • Epigallocatechin gallate found in Green tea
Anthocyanins • Cyanidin found in Orange juice • Malvidin found in Red wine
Isoflavones • Daidzein in Soy Milk
Flavanones • Hesperidin found in Orange Juice • Naringenin found in Grapefruit juice
17
D Archivio, 2007
Health Effects
• Epidemiologic evidence suggesting a protective effect of Fruits & Vegetables (F&V) against Cancer and Cardiovascular diseases (CVDs). – Meta-analysis by Gladys Block (2001)
– Studied relation between F& V and different types of Cancer
– 126/ 156 studies → beneficial effects
– Lung Cancer→24/25 studies showed beneficial effects.
• Conclusion: Increased consumption of F&V is protective against Cancer and CVDs
19
Hypothesis: F&V contain compounds responsible for the health effects
ILSI Europe, 1996
Health Effects- Vitamin E V
itam
in E
• Ischemic heart disease (IHD)* • MONICA (1980s) higher plasma vitamin E correlated with lower risk
of IHD • CHD* • Nurses´Health Study and Male Health Profesionals Study – high
intakes of Vitamin E correlated with lower risk of CHD • Angina Pectoris • The Edinburg study – high levels of plasma Vitamin E associated with
lowest risk of Angina Pectoris • Prostate Cancer • SELECT study no effects on prostate cancer on treatment with
Vitamin E and Selenium, but a non-significant trend found of increased incidence of prostate cancer in the treatment group.
• ATBC study –significant reduction in the incidence of prostate cancer
20 *IHDis a disease characterized by reduced blood supply to the heart muscle, usually due to coronary artery disease (atherosclerosis of the coronary arteries) Angina Pectoris: severe chest pain.
*CHD is Coronary heart disease refers to the failure of coronary circulation to supply adequate circulation to cardiac muscle and surrounding tissue. *MONICA= Monitoring trends and determinants In Cardiovascular disease
*ATBC= Alpha Tocopherol, Beta-Carotene Cancer Prevention Trial.
Health Effects- Vitamin A
21
Vitam
in A
(β
-C
aro
ten
e) • Cancer
• ATBC* study (1994)- heavy smokers • Found a statistically significant 18% higher incidence
of lung cancer in subjects supplied with β-Carotene. • CARET study(1990s)- heavy smokers • 28% increased risk for lung cancer in treatment group
and 17% increase in total mortality→trial terminated early
• Physicians Health Study • Supplementation with 50 mg β-Carotene every other day
showed no harm or benefit in smokers and non-smokers.
AOx – can potentially become
pro-oxidative!
*ATBC= Alpha Tocopherol, Beta-Carotene Cancer Prevention Trial. * CARET=Beta Carotene and Retinol Efficacy Trial
Possibility: Cancer process was
accelerated by β-Carotene in smokers
Health Effects- Vitamin C
22
Vitam
in C
(A
scorb
ic a
cid
)
• CVD • Systematic review by Asplund, K (2002)- Cohort studies showed a
reduced risk of Cardiovascular events with high consumption of vitamin / high plasma levels of vitamin C.
• Randomized Clinical Trials did not show an effect of supplementation with Vitamin C.
• Vasodilation • Vasodilation improved in patients with endothelial dysfunction→
marker for onset of atherosclerosis and CVD • Cancer • EPIC- Norfolk study, Khaw et al (2001) and Loria et al (2000)- Both
found that high plasma vitamin C correlated with lower cancer mortality.
• Moertel et al (1985) RCT- High- dose vitamin C in patients with advanced Cancer→ no effect
• Cochrane Review (2008)- No convincing evidence for all AOx – including Vitamin C- for Gastrointestinal Cancer risk.
• Yeom et al (2007) -Quality of life improvement in Cancer patients with high dose Vitamin C supplementation.
EPIC= European Prospective Investigation of Cancer
Li and Schellhorn, 2007
Health Effects- Flavonoids
23
Fla
vonoid
s
• Coronary Heart Disease • Zutphen Elderly Study; Finnish Mobile Clinic Health Survey; Ding et al 2006 (meta-analysis).
• Protective effects on non-fatal coronary heart disease • Vasodilation/ Endothelial function/ blood pressure • Duffy et al 2001; Taubert et al 2003 • Tea catechins improved short-term bloodflow and vasodilation
• Platelet function • Rein et al 2000 • Cocoa and wine flavonoids can inhibit platelet aggregation
• LDL Cholesterol • Osakabe et al 2001; Bearden et al 2000; Pearson et al 2001 • Cocoa flavonoids inhibit or retard LDL oxdiation- a marker for CVD
• Inflammation • Selmi et al 2006 • Cocoa Flavonoids modulate inflammation markers (eicosanoids)
• Cancer • Nurses´ Health Study II; Neuhouse et al 2004 • No overall association between intake of flavonols and the risk of breast cancer. • Quercetin may reduce the risk of lung cancer
Antioxidants and health effects
Antioxidants
CVD
-Vitamin E indications of reduced risk of
Ischemic Heart disease and Angina pectoris
-Flavonoids modulate inflammation markers
Cholesterol
- Flavonoids inhibit/retard LDL
Oxidation
Blood Pressure
- Flavonoids inhibit platelet aggregation
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Conclusions on Health Effects
• Good evidence for: – the role of FR in Cancer and CVD
– modulation of FR events by AOx
• Human studies suggest: – correlation between (some) AOx intakes and serum
concentration and incidence of mortality from cancer and CVD-
– But, results are not consistent!
• Optimal dosages are unknown: – the level of intake of AOx nutrients desirable for
optimal nutrition is still an open question.
– Genetics might play a role.
• Fundamental questions: – What causes the health effects? The food matrix as
a whole or the individual components ?
– F& V or supplements? 25
?
IFIC, 2006
Willet, 20001
Toner, 2004
Market for AOx
27
10% of product
launches positioned as
“Antioxidant” were
tracked in the Bakery
and Cereals category
7% of product launches
positioned as
“Antioxidant” were
tracked in the
Confectionery category
5 year Data from 02/2004 – 02/ 2009
Antioxidant Trend for 2009 (Mellentin,J.)
28
In 2008, AOx were listed as a
“Key Trend” for the year.
In 2009, AOx are predicted to
become a “Micro Trend”
Mellentin, 2008- 10 Key Trends in Food, Nutrition and Health.
The message has become a
category standard→ “all teas and
all dark chocolates contain AOx”
Regulatory problem→ what kind
of evidence needed to prove
health effects?
Industry option= add a point of
difference to the AOx message by
using specific and scientific
marketing (terms like Flavonoids
and ORAC)
Industry option= add a point of
difference to the AOx message by
combining different sources such
as Superfruits and Dark
Chocolate
Bakery & Cereals and Confectionery categories
29
Bakery and Cereals category
Confectionery category 5 year Data from 02/2004 – 02/ 2009
Confectionery
30
Brazil
“Natural source
of Antioxidant
Flavonoids”
“Natural
source of
Flavanol
Antioxidants
”
USA
“ With Grape pulp
extract, naturally-rich
in Antioxidants”
Netherlands
“ With Chilli, natural-
source of Antioxidants”
Germany
USA
“Natural source
of flavanol
antioxidants.
measured by an
ORAC (Oxygen
Radical
Absorbance
Capacity)
“ Extra
Antioxidants from
ACTICOA® ”
UK
“With Cacao
Flavanols for
good blood
circulation”
Bakery and Cereals
31
USA
“Fiber plus
Antioxidants”
Sweden
“With two
sources of
antioxidants:
green tea extract
and vitamin E”
“A better protection
against oxidant stress,
thanks to addition of
natural antioxidants.”
India
Sweden
“A soft, sliced bread
with sunflower seeds.
Contains vitamins and
minerals, antioxidants,
and fiber”
France
“with precious
antioxidants in order to
protect your body from
aging”
“Purpur wheat, contains 10 times
more Anthocyanins than other
kinds of wheat. Anthocyanins have
an antioxidant effect”.
Hungary
“Natural
Antioxidants and
slow energy”
« Contains
natural
antioxidants ». Russia
Other products
32
UK
“Contains
Antioxidants”
Cranberry and
Wine sauce
“Naturally rich in
Catechins”
Portugal
NL
« natural
antioxidants »
“Coffee Arabica
enriched with
Antioxidants”
France
India
“Source of
Antioxidants”
“With fibers,
Antioxidants,
Vitamins and
Minerals (from
berries)”
Summary
34
Free Radicals
•Needed for the defense mechanism of the body
•Unstable and reactive: an excess may damage cells
•Excess FR may damage DNA, proteins and fatty acids
Antioxidants
•Part of the defense system of our bodies
•AOX protect us from excess FR damage
•Keep FR at an optimum level to prevent oxidative stress and chronic disease
Types of Antioxidants
•Different types of AOX→different working mechanisms
• Major types: Enzymes, Dietary AOX, Other low molecular weight AOX
•Dietary AOX: Vitamins A, C, E and Polyphenols
•Flavonoids: most common group of polyphenols
Summary
Health Effects
•Good evidence for the role of AOX in modulation of FR
•Good evidence of the role of FR in the onset of some diseases (Cancer and CVD)
•No consistent results
•No optimal dosage yet
•Fundamental questions still to answer
AOX Trend
•AOX move from a key trend in 2008 to a microtrend in 2009
•AOX message has become a category standard
•Point of difference is searched by Industry
•Major category players: chocolate and tea
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