Dark Chocolate and Platelet Function in Humans

2014-08-27 03:14:45 | BioPortfolio


Cardiovascular disease is a major cause of mortality worldwide and responsible for one out of three global deaths. A main characteristic of cardiovascular disease is impaired blood flow and formation of blood clots. Platelets are clot-forming cells responsible for the prevention of bleeding. However, in disease conditions they may be overly activated, promoting blood clots and blockage of blood vessels.

Consumption of diets rich in fruits and vegetables decreases mortality from cardiovascular disease through a number of mechanisms, including the prevention of platelet clotting and aggregation. There is some evidence suggesting that platelet aggregation may be modulated through a group of compounds known as flavan-3-ols, which are found in various foods, and especially in cocoa. However, the mechanisms by which those compounds affect platelet function are not yet fully understood. We designed a human study assessing the mechanisms by which flavan-3-ols from cocoa beneficially affect platelet function and the platelet proteome.


Cardiovascular disease (CVD) is a primary cause of premature deaths worldwide, with incidence rates in the United Kingdom, particularly in Scotland, being amongst the highest worldwide. Thus identification of dietary components that most effectively prevent CVD is potentially of wide public health benefit.

Consumption of diets rich in plant-based products protects against the development of CVD. Such effects have been ascribed in part to polyphenols, which are non-nutritive but, potentially bioactive secondary metabolites ubiquitous found in fruits, vegetables, herbs, spices, teas and wines. The beneficial effects of polyphenols on CVD is believed to be mediated, at least in part, though improving platelet function. At least 10 human intervention studies found a consistent and robust beneficial effect of cocoa products on platelet function, but unfortunately all of these studies used only one or two methods to assess platelet function, therefore only getting limited insights into the complex physiological behavior of platelets. In addition, none of these studies assessed potential mechanisms by which flavan-3-ols may inhibit platelet function. Schramm et al. have shown that consumption of chocolate rich in flavan-3-ols and their oligomers (procyanidins) lead to increased production of prostacyclin, a strong platelet inhibitor. This finding has also been observed when aortic endothelial cells are treated with procyanidins in vitro. Thus the stimulation of prostacyclin production in endothelial cells may reflect one pathway by which flavan-3-ols indirectly inhibit platelet activation. Many other potential mechanisms are discussed in the literature but so far the evidence for such mechanisms is limited or non-existing.

In this study we assess effects of consumption of chocolate enriched in flavan-3-ols on platelet function by measuring not only platelet aggregation, but also in vitro coagulation and platelet activation in healthy humans. In addition, we examine the effects of consumption of flavan-3-ols on the regulation of the platelet proteome to elucidate pathways by which these bioactive cocoa compounds affect platelet function.


Acute consumption of a moderate amount of dark chocolate enriched in flavan-3-ols results in decreased platelet activation and aggregation by decreasing the levels of thromboxane A2 produced by endothelial cells.


The main objective of the proposed study is to determine whether consumption of 60 g dark chocolate enriched in flavan-3-ols results in decreased platelet activation and aggregation by decreasing levels of thromboxane A2, as well as assessing what other mechanisms could be involved.

The specific objectives of the proposed study are to determine:

1. whether acute intake of 60 g dark chocolate enriched in flavan-3-ols, as compared with standard dark chocolate low in flavan-3-ols and white chocolate containing no flavan-3-ols, affects platelet aggregation, thromboxane A2 formation upon aggregation, in vitro bleeding time, P-selectin expression, and activation of the fibrinogen receptor;

2. whether and how acute intake of 60 g dark chocolate enriched in flavan-3-ols, as compared with standard dark chocolate and white chocolate, affects the platelet proteome, and thereby potential new biomarkers of platelet function, as well as protein levels of anti-oxidant enzymes;

3. identities and concentrations of flavan-3-ols and their metabolites in plasma and/ or urine 2 and 6 h after acute intake of 60 g dark chocolate enriched in flavan-3-ols, as compared with standard dark chocolate and white chocolate.

Study Design

Allocation: Randomized, Control: Dose Comparison, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Single Blind (Investigator), Primary Purpose: Prevention


Cardiovascular Disease


Dark chocolate enriched in flavan-3-ols and procyanidins, Standard dark chocolate, White chocolate


University of Aberdeen Rowett Institute of Nutrition and Health
United Kingdom
AB21 9SB




University of Aberdeen

Results (where available)

View Results


Published on BioPortfolio: 2014-08-27T03:14:45-0400

Clinical Trials [307 Associated Clinical Trials listed on BioPortfolio]

Efficacy of Polyphenols From Milk and Dark Chocolate

Dark chocolate is one of the richest sources of polyphenols though it has been hypothesised that the bioavailability and therefore probably the bioefficacy of epicatechin from milk chocola...

Efficacy of Dark Chocolate in Achalasia Patients

Flavanols, present in dark chocolate, were shown to induce Nitric Oxide synthesis. Since Nitric Oxide facilitates smooth muscle relaxation, it might ease the relaxation of the LES (lower e...

Polyphenol Bioavailability From Chocolate

Dark chocolate is one of the richest sources of polyphenols though it has been hypothesised that the bioavailability of epicatechin from milk chocolate was reduced compared to dark. The pr...

The Effects of Dark Chocolate Implementation in Top-level Athletes

Dark chocolate (DC) is rich in epicatechin which augments nitric oxide (NO) production through endothelium-dependent influences. The increased bioavailability and activity of NO have been ...

The Effects of Dark Chocolate (70% Cacao) on EEG Brain Waves in Vigorously Active Individuals

The purpose of this graduate student study is to determine if ingestion of dark chocolate (70% cacao) will change brain frequencies between visualization at a state of rest and a state of ...

PubMed Articles [6463 Associated PubMed Articles listed on BioPortfolio]

Is Self-Interacting Dark Matter Undergoing Dark Fusion?

We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cro...

Got chocolate? Bilateral prefrontal cortex stimulation augments chocolate consumption.

Understanding the mechanisms behind exerting self-control may reveal why health behaviors are resistant to change. Activity in the right inferior frontal gyrus (rIFG) plays a role in self-control proc...

A missense mutation in TYRP1 causes the chocolate plumage color in chicken and alters melanosome structure.

The chocolate plumage color in chickens is due to a sex-linked recessive mutation, choc, which dilutes eumelanin pigmentation. Because TYRP1 is sex-linked in chickens, and TYRP1 mutations determine br...

Hazelnut-enriched chocolate improves flow-mediated artery dilatation via inhibition of oxidative stress.

Calorimetric Dark Matter Detection with Galactic Center Gas Clouds.

We demonstrate that dark matter heating of gas clouds, hundreds of parsecs from the Milky Way Galactic Center, provides a powerful new test of dark matter interactions. To illustrate, we set a new bo...

Medical and Biotech [MESH] Definitions

Sweet food products combining cane or beet sugars with other carbohydrates and chocolate, milk, eggs, and various flavorings. In the United States, candy refers to both sugar- and cocoa-based confections and is differentiated from sweetened baked goods; elsewhere the terms sugar confectionary, chocolate confectionary, and flour confectionary (meaning goods such as cakes and pastries) are used.

Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.

Food product prepared from fermenting, roasting, and grinding the seeds of the COCOA plant.

Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.

A tree of the family Sterculiaceae (or Byttneriaceae), usually Theobroma cacao, or its seeds, which after fermentation and roasting, yield cocoa and chocolate.

More From BioPortfolio on "Dark Chocolate and Platelet Function in Humans"

Quick Search


Relevant Topics

Cardiovascular disease (CVD)
Acute Coronary Syndromes (ACS) Blood Cardiovascular Dialysis Hypertension Stent Stroke Vascular Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease (angina...

Cardiology is a specialty of internal medicine.  Cardiac electrophysiology : Study of the electrical properties and conduction diseases of the heart. Echocardiography : The use of ultrasound to study the mechanical function/physics of the h...

Blood is a specialized bodily fluid that delivers necessary substances to the body's cells (in animals) – such as nutrients and oxygen – and transports waste products away from those same cells.  In vertebrates, it is composed of blo...

Searches Linking to this Trial