Basics of Antioxidants
March 12, 2009
1
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
1. INTRODUCTION
3
Definitions
• Oxidation=
Losing electrons
• Reduction=
Gaining electrons
4
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.
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.
Foster, 2007; EUFIC, 2009; IFIC, 2009
5
Free Radicals 2
•
Free radicals attack stable molecules and steal an electron- creating a new
radical→ chain reaction.
Fatty acids
Lipid
peroxidation
→ CVD
DNA
Mutations→
Cancer
Proteins
Enzyme inhibition
Denaturation &
degradation
Halliwell, 1997; Foster, 2007
*CVD: cardiovascular disease
6
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.
Image from www.welchs.com
•
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
Halliwell, 1997; Foster, 2007
7
Oxidative stress and disease
FR
AOx
Oxidative Stress
Chronic Injury
Cancer, atherosclerosis, CVD, cataracts, immune
dysfunction, Alzheimer´s disease, age-related macular
degeneration, rheumatoid arthritis, aging, etc.
8
2. TYPES OF ANTIOXIDANTS
9
Types of Antioxidants
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 prooxidative enzymes
Different types of AOx →different measurement methods
ORAC
Pokorný, 2007
FRAP
TRAP
10
ORAC*
ORAC of Selected Foods- USDA database 2007
* all values presented are Total ORAC= H-ORAC and L-ORAC
Spices/
herbs
Cocoa
Nuts
Wine
Fruits
Tea
Description
Mean
Spices, cinnamon,
ground
Sorghum, bran, hitannin
Spices, Oregano, dried
Sorghum, bran, black
Cocoa, dry powder,
unsweetened
Spices, basil, dried
Sage, fresh
Marjoram, fresh
Rice bran, crude
Nuts, pecans
Ginger root, raw
Elderberries, raw
Peppermint, fresh
Nuts, walnuts, english
Nuts, hazelnuts
Alchoholic beverage,
wine, table, red,
Cabernet Savignon
Raspberries, raw
Strawberries, raw
Pears, raw
Tea, green, brewed
Tea, brewed, prepared
with tap water
Lettuce, raw
*ORAC= Oxygen Radical Absorbance Capacity
Cucumber, raw
Unit
2675.4
µmol TE/1g
2400.0
2001.3
1008.0
µmol TE/1g
µmol TE/1g
µmol TE/1g
809.3
675.5
320.0
273.0
242.9
179.4
148.4
147.0
139.8
135.4
96.5
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
50.3
48.8
35.8
29.4
12.5
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
µmol TE/1g
11.2 µmol TE/1g
µmol TE/1g
2.73
µmol TE/1g
1
11
ORAC
ORAC method set up internally to measure AOx
capacity of fruits, chocolates, flours, etc.
New High
Antioxidant
Chocolate: Ox-Anti
Ox-Anti (Belcolade)
Acticoa (Callebaut)
Berries
Topfil Blueberry
Topfil Berrissimo
Rye flour
Wheat flour
12
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
Different types of AOx →different AOx Mechanisms, one defense system
Enzymes
Dietary AOx
SOD
(Superoxide
Dismutase)
Vitamin E, Vitamin C,
β-Carotene,
Flavonoids
Vitamins
A
Geissler & Powers, 2005
ILSI Europe, 1996
E
Other Low
molecular
weight AOx
Uric Acid
Glutathione
Polyphenols
C
Flavonoids
Non- Flavonoids
Flavonols→ Quercetin
Flavones
Flavanols→ Catechin
Flavanones
Iso-Flavonoids
Anthocyanidins
Stilbenes → Resveratrol
Phenolic alcohols
Hydroxybenzoic acids
Hydroxycinnamic acids
Lignans
13
Dietary Antioxidants
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
Pokorný, 2007
Geissler & Powers, 2005
Foster, 2007
14
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
Pokorný, 2007
Geissler & Powers, 2005
Foster, 2007
15
Flavonoids
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
•
•
•
•
•
•
Flavonols
Flavanols
Flavonones
Anthocyanins
Isoflavones
Flavones
D´Archivio, 2007
16
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
3. HEALTH EFFECTS
18
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
Hypothesis: F&V contain compounds responsible for the health effects
ILSI Europe, 1996
19
Vitamin E
Health Effects- Vitamin 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
*ATBC= Alpha Tocopherol, Beta-Carotene Cancer Prevention Trial.
*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.
*MONICA= Monitoring trends and determinants In Cardiovascular disease
*CHD is Coronary heart disease refers to the failure of coronary circulation to supply adequate circulation to cardiac muscle and surrounding tissue.
20
Vitamin A (βCarotene)
Health Effects- Vitamin A
• 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!
Possibility: Cancer process was
accelerated by β-Carotene in smokers
*ATBC= Alpha Tocopherol, Beta-Carotene Cancer Prevention Trial. * CARET=Beta Carotene and Retinol Efficacy Trial
21
Vitamin C (Ascorbic
acid)
Health Effects- Vitamin C
• 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.
Li and Schellhorn, 2007
EPIC= European Prospective Investigation of Cancer
22
Flavonoids
Health Effects- Flavonoids
• Coronary Heart Disease
• Zutphen Elderly Study; Finnish Mobile Clinic Health Survey; Ding et al 2006 (metaanalysis).
• 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
23
Antioxidants and health effects
Antioxidants
CVD
-Vitamin E indications of
Cholesterol
reduced risk of Ischemic
- Flavonoids inhibit/retard
Heart disease and
LDL Oxidation
Angina pectoris
-Flavonoids modulate
inflammation markers
Blood Pressure
- Flavonoids inhibit
platelet aggregation
24
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:
IFIC, 2006
Willet, 20001
Toner, 2004
– What causes the health effects? The food matrix as a
whole or the individual components ?
25
– F& V or supplements?
The Innova Database
4. THE AOX TREND:
PRODUCTS AND CLAIMS
26
Market for AOx
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
27
Antioxidant Trend for 2009 (Mellentin,J.)
In 2008, AOx were listed as a
“Key Trend” for the year.
In 2009, AOx are predicted to
become a “Micro Trend”
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
28
Mellentin, 2008- 10 Key Trends in Food, Nutrition and Health.
Bakery & Cereals and Confectionery categories
Bakery and Cereals category
5 year Data from 02/2004 – 02/ 2009
Confectionery category
29
Confectionery
“Natural source
of flavanol
antioxidants.
measured by an
ORAC (Oxygen
Radical
Absorbance
Capacity)
USA
“ With Grape pulp
extract, naturally-rich
in Antioxidants”
“With Cacao
Flavanols for
good blood
circulation”
Germany
Netherlands
“Natural
source of
Flavanol
Antioxidants
”
“ With Chilli, naturalsource of Antioxidants”
“ Extra
Antioxidants from
ACTICOA®”
USA
“Natural source
of Antioxidant
Flavonoids”
30
Brazil
UK
Bakery and Cereals
“Fiber plus
Antioxidants”
“Natural
Antioxidants and
slow energy”
Hungary
“Purpur wheat, contains 10 times
more Anthocyanins than other
kinds of wheat. Anthocyanins have
an antioxidant effect”.
USA
“A soft, sliced bread
with sunflower seeds.
Contains vitamins and
minerals, antioxidants,
and fiber”
“With two
sources of
antioxidants:
green tea extract
and vitamin E”
Sweden
Sweden
“A better protection
against oxidant stress,
thanks to addition of
natural antioxidants.”
“with precious
antioxidants in order to
protect your body from
aging”
31
India
France
Other products
“Contains
Antioxidants”
Cranberry and
Wine sauce
“Coffee Arabica
enriched with
Antioxidants”
“Naturally rich in
Catechins”
Portugal
UK
France
« Contains
natural
antioxidants ».
“With fibers,
Antioxidants,
Vitamins and
Minerals (from
berries)”
Russia
“Source of
Antioxidants”
« natural
antioxidants »
32
India
NL
5. SUMMARY
33
Summary
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
34
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
35
Puratos wants to contribute
to the balanced diet of
consumers
36