Transcript Cacao Polyphenols - Pennington Biomedical Research Center

Publication # 2
Pennington Biomedical Research Center
Division of Education
Phillip Brantley, PhD, Director
Pennington Biomedical Research Center
Steven Heymsfield, MD, Executive Director
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Overview…
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 An increasing body of epidemiologic evidence supports the
concept that diets rich in fruits and vegetables promote health
and attenuate, or delay, the onset of various diseases, including
cardiovascular disease, cancer, and certain neurodegenerative
disorders.
 Epidemiologic data has linked these health benefits, at least in
part, to the presence of certain flavonoids in fruits and
vegetables.
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Flavonoids…
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 Flavonoids are a group of polyphenolic compounds that occur
widely in fruits, vegetables, tea, red wine, and chocolate.
 Cocoa and chocolate products have the highest concentration of
flavonoids among commonly consumed foods.
 Over 10 percent of the weight of cocoa powder is flavonoids.
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 Cocoa and chocolate products have been delicacies for
hundreds of years.
 Cocoa and chocolate have only recently have they been
recognized as significant sources of phytochemicals, with
healthful effects.
 Cocoa and chocolate are among the most concentrated sources
of the procyanidin flavonoids, catechin, and epicatechin.
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The fruit of the Theobroma cacao tree
Corti R et al. Circulation 2009;119:1433-1441
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Chocolate Consumption
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 Americans eat a lot of chocolate in the form of candy
(about 5.5 kg/year per person or 12 pounds), but not as
much as people in some northern European countries.
 In Germany, the country with the highest chocolate
consumption, it is estimated at 11.4 kg/year (25
pounds) for each person.
 Each candy bar contains about 210 calories, 13 g fat (7
of which is saturated), 23 g of carbohydrate, and 3 g of
protein.
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Flavonoids in Chocolate
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 The flavonoids in cocoa/chocolate, principally
catechin and epicatechin, exist in long molecules.
 In most foods, catechins are fairly short
molecules, maybe two, three linked together, but
in chocolate and cocoa they are much longer.
 These structural characteristics of catechin and
epicatechin represent the molecular basis for
both their hydrogen-donating (radical-scavenging)
properties and their metal-chelating antioxidant
properties.
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Flavonoids in Chocolate
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 Processing of cocoa results in 60% loss of total flavonoids.
 Among flavanols, epicatechin has the largest decline (67%).
 In terms of flavonols, quercetin declines the most (86%).
 Most cocoas undergo fermentation steps which subject
flavonoids in the cocoa to heat and acidic conditions.
 High processing temperatures, alkali treatment and longer
processing time all reduce the amount of cocoa polyphenols.
C.L. Hii et al. As. J. Food Ag-Ind. 2009, 2(04), 702-722
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Flavonoid Content: Variable
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 The actual recipe for the finished food or beverage product
determines the amount of a given cocoa (and flavonoid) added.
 Other ingredients can influence the final product such as the
type of fat used, type of milk and milk products used and the
addition of sugar and salt.
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Flavonoid Content
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 Different types of chocolate contain varying antioxidant content.
 In finished products, the amount of cocoa ranges from
7% to 35% in milk chocolate and 30% to 80% in dark chocolate.
 Consequently, there is a lot of variability and is generally
twice as high in dark than in milk chocolate.
 Also interesting is the fact that white chocolate does not contain
polyphenols.
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Recent Studies
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 Several studies have looked at the total polyphenols in
foods and beverages in the American diet, and chocolate
and cocoa have one of the highest levels of antioxidants
consistently.
 Cocoa and chocolate have higher levels of polyphenols
than in many fruits. It is 20 times higher than in tomatoes,
2 times higher than in garlic, and over 3 times higher
than in grapes.
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Catechin/Epicathecin
concentrations in foods
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Source
Chocolate
Beans
Green tea
Apricots
Red wine
Black tea
Cherries
Peaches
Blackberries
Apples
Cider
Flavanol Content, mg/kg or
mg/L
460–610
350–550
100–800
100–250
80–300
60–500
50–220
50–140
130
20–120
40
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Circulation March 17, 2009 vol. 119 no. 101433-1441
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Numerous dietary intervention studies in humans and animals
indicate that flavanol-rich foods and beverages might exert
cardioprotective effects with respect to vascular function and
platelet reactivity. There is an improvement in blood vessel wall
function, reduction in platelets, and improvement in blood
pressure, insulin resistance and blood lipids.
Circulation
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.
2009; 119: 1433-1441
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Antioxidant Capacity
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Atherogenesis…
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 Phenolic antioxidants have been
shown to inhibit the oxidation of lowdensity lipoprotein (LDL) cholesterol,
and mounting evidence suggests
that it is the oxidized form of LDL
that leads to the buildup of fatty
plaques in arteries.
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Atherogenesis…
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 Extracts of cocoa powder have also shown to
significantly inhibit LDL oxidation.
 Studies have found that cocoa preserves the lipids in
the lipid droplets in the circulatory system and it is
concentration-dependent. Higher amount of cocoa
polyphenols preserves greater amount of lipid droplets.
 Cocoa phenols has shown to inhibit LDL oxidation by
75%, whereas red wines only inhibit LDL oxidation by
37-65%.
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Health-relevant effect of epicatechins
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Corti R et al. Circulation 2009;119:1433-1441
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Endothelium-dependent effect of cocoa polyphenols
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Corti R et al. Circulation 2009;119:1433-1441
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 Interestingly, cocoa powder and cocoa extracts have been
shown to exhibit greater antioxidant capacity than many other
flavanol-rich foods and food extracts, such as green and black
tea, red wine, blueberry, garlic, and strawberries.
 However, no long-term studies have evaluated the effects of
cocoa polyphenol compounds on the oxidative modification of
LDL in humans.
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Short-term human studies…
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 The levels of epicatechin and catechin were measured
in humans at zero, one, two, and six hours following
consumption of a single meal of chocolate.
 The concentration in plasma levels peaked at about
one hour; however, by six hours the concentrations had
almost disappeared from the plasma.
 Indicated that cocoa flavonoids are absorbed and
cleared from circulation relatively quickly.
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Short-term human studies…
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 Support the recommendations to
consume several servings of fruit and
vegetables per day as seen in a
number of clinical trials with chocolate
and other flavonoid-rich foods.
 Spacing intake of flavonoid-rich foods
throughout the day could help to
provide a continuous supply.
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AM:
Berries
More studies…
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 Because there is six to seven times more
epicatechin than catechin in cocoa/chocolate, most
attention has focused on epicatechin in scientific
studies.
 Consistent with early studies, human studies indicate
that small doses of epicatechin are effective.
 There is a statistically significant increase in plasma
antioxidant capacity and reduction in lipid peroxides
following cocoa/chocolate consumption.
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Benefits…
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 Epicatechin and other flavonoids not only have a
direct antioxidant effect, but they may also have a
sparing effect on other antioxidants such as
Vitamins C and E.
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Other Mechanisms…
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Although flavanol-rich cocoa and chocolate have the potential to
improve an individual’s antioxidant defense system, there are
other cellular mechanisms through which these flavanol-rich
foods can affect cardiovascular health:
Inflammation
Platelet aggregation
Nitric oxide (NO)-mediated endothelial changes
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Inflammation
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 Atherosclerosis and heart failure, as well as risk factors such
as hypertension and hypercholesterolemia, can activate
several proinflammatory enzyme systems.
 Once activated, these enzymes produce reactive oxygen
species and other radicals that can modify nitric oxide availability
and LDL and contribute to blood vessel dysfunction.
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 Flavanol-rich cocoa liquor has been shown to stimulate nitric
oxide production and to significantly reduce the activities of
enzymes involved in oxidative stress.
 In addition, cocoa flavanols and procyanidins may modulate
other mediators of inflammation.
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Platelets
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 In addition to its influence on oxidative defense mechanisms,
polyphenols seem to benefit cardiovascular health in other waysthrough regulation of platelet reactivity.
 Given the prominent role of platelets in the development and
manifestation of acute myocardial infarction, stroke, and venous
thromboembolism, antiplatelet strategies are an important
consideration.
 A modest decrease in platelet reactivity can be of value because it
reduces the probability of clotting.
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 In one study to determine whether cocoa inhibits platelet
activation and function, subjects were given either water or 300
ml of cocoa that provided a very high amount of polyphenols.
 During the six hour time period following intake of cocoa, there
was a reduction in adhesion molecules on the surface of the
platelets, making the platelets less likely to adhere to other
molecules in the bloodstream.
 This is the same response that would be seen following intake
of antiplatelet agents such as aspirin.
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Endothelium
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 There are many things that can disrupt blood vessel function
such as stress, ischemia, inflammation, and disease states such
as atherosclerosis, diabetes mellitus, and hypertension.
 Any of the above can influence the vascular tone and cause an
overall shift toward the prothrombotic state.
 According to research, it is possible that flavanols, by functioning
as antioxidants, can improve endothelial function through the
prevention and possible reduction of oxidative damage.
 About 150 mg of flavonoids is needed to modulate antiinflammatory prostacylin and pro-inflammatory leukotriene
concentrations.
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Conclusions…
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 Several large scale studies have shown that regular dietary
intake of plant-derived foods and beverages reduces the risk of
coronary heart disease and stroke and is inversely associated
with the risk of cardiovascular disease.
 Plants have many phytochemicals including flavonoids.
Consumption of flavanol-rich foods such as white, green, and
black tea, grapes, wine, apple juice, cocoa, lentils, and blackeyed peas is associated with the reduced risk for cardio vascular
disease.
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References
 Roberto Corti, Andreas J. Flammer, Norman K. Hollenberg and
Thomas F. Lüscher. Cocoa and Cardiovascular Health. Circulation
2009;119:1433-1441.
 C.L. Hii, C.L. Law, S. Suzannah, Misnawi, and M. Cloke.
Polyphenols in cocoa (Theobroma cacao L.) As. J. Food Ag-Ind.
2009, 2(04), 702-722 .
 Keen C, et al. Dietary polyphenols and health: Proceedings of the
1st international conference on polyphenols and health. Amer J Clin
Nutr. 2005. 81:1 298S-303S. Available at:
http://www.ajcn.org/cgi/content/full/81/1/298S
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References
 Keen C. Chocolate: Food as medicine/medicine as food. J
Amer Coll of Nutr. 2001. 20:90005 436S-439S. Available at:
http://www.jacn.org/cgi/content/full/20/suppl_5/436S
 Wan Y, et al. Effects of cocoa powder and dark chocolate on
LDL oxidative susceptibility and prostaglandin concentrations in
humans. Amer J Clin Nutr. 2001. 74:5 596-602.
http://pubs.acs.org/hotartcl/tcaw/99/jul/chocolate.html
 http://sciweb.nybg.org/science2/pdfs/mb/chocolate.pdf#search=
'alternative%20therapies%20sept/oct%20chocolate‘
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Pennington Biomedical Research Center

VISION
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MISSION
Our mission is to discover the triggers of chronic diseases through innovative research that improves human health across
the lifespan. We are helping people live Well Beyond the Expected.
The Pennington Center has several research areas, including:
Clinical Obesity Research
Experimental Obesity
Functional Foods
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diseases, such as heart disease, cancer, diabetes, hypertension and osteoporosis.
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findings, training programs and research areas, and coordinates educational events for the public on various health issues.
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call (225) 763-3000.
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