Cocoa Polyphenols Heli Roy, PhD Shanna Lundy, BS Beth Kalicki, BS

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Cocoa PolyphenolsHeli Roy, PhD Shanna
Lundy, BSBeth Kalicki, BS
Publication 2

• Pennington Biomedical Research Center
• Division of EducationPhillip Brantley, PhD,
  DirectorPennington Biomedical Research
  CenterSteven Heymsfield, MD, Executive Director

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Overview

• 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

• 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 20091191433-1441
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Chocolate Consumption

• 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

• 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

• 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

• 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

• 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

• 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
Source Flavanol Content, mg/kg or mg/L
Chocolate 460610
Beans 350550
Green tea 100800
Apricots 100250
Red wine 80300
Black tea 60500
Cherries 50220
Peaches 50140
Blackberries 130
Apples 20120
Cider 40
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.2009 119 1433-1441
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• Antioxidant Capacity

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Atherogenesis

• Phenolic antioxidants have been shown to inhibit
  the oxidation of low-density 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

• 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
Corti R et al. Circulation 20091191433-1441
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Endothelium-dependent effect of cocoa polyphenols
Corti R et al. Circulation 20091191433-1441
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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

• 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

• 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.

Eat more fruit
PM Grapes
AM Berries
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More studies

• 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

• 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

• Although flavanol-rich cocoa and chocolate have
  the potential to improve an individuals
  antioxidant defense system, there are other
  cellular mechanisms through which these
  flavanol-rich foods can affect cardiovascular
  health
• InflammationPlatelet aggregationNitric 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 ways- through
  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
  anti-inflammatory prostacylin and
  pro-inflammatory leukotriene concentrations.

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Conclusions

• 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 black-eyed
  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
  20091191433-1441.
• 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. 811 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. 2090005
  436S-439S. Available at http//www.jacn.org/cgi/c
  ontent/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. 745 596-602. http//pubs.acs.org
  /hotartcl/tcaw/99/jul/chocolate.html
• http//sciweb.nybg.org/science2/pdfs/mb/chocolate.
  pdfsearch'alternative20therapies20sept/oct20c
  hocolate

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