Healthy volunteers are required by researchers who want to see how compounds in dark chocolate might help protect against heart disease.
Cardiovascular disease (CVD) - diseases of the heart and circulatory system - is the main cause of death in the UK, causing more than one in three deaths.
Now scientists want to see how compounds called flavonoids – found naturally in various foods, particularly cocoa – might help fend off these diseases because of what they do to our blood.
Dr Baukje de Roos, Principal Investigator from the University of Aberdeen Rowett Institute of Nutrition and Health, said: "A main characteristic of cardiovascular disease is impaired blood flow and the formation of blood clots.
"Platelets play a key role in our blood preventing bleeding if we have suffered a cut or a wound. But in disease conditions platelets can go into overdrive and stick together forming blood clots and blocking blood vessels.
"We already know that flavonoids can stop platelets from sticking together but we don't know how they do this.
"Our study will help us understand how these flavonoids may benefit blood platelets and, in turn, help protect against cardiovascular diseases such as heart disease and stroke."
Forty volunteers aged between 18 and 70 will be asked to eat three small bars of either a cocoa rich dark chocolate - specially made for the study; standard chocolate, or white chocolate.
Urine and blood samples will then be taken to assess the impact the compounds in cocoa have on blood function.
Luisa Ostertag, a fellow study researcher from the University, added: "The standard and white chocolate bars are being used as a control in the study as they will have no benefit on platelets because it is the compounds in cocoa that hold the key.
"But eating a lot of dark chocolate bars is not the answer to protecting against cardiovascular disease because they are high in saturated fat and sugar.
"But perhaps studies like ours could ultimately lead to these special compounds being included in healthier foods or in health supplements."
Anyone interested in taking part in the study, who has no health problems, should contact Luisa Ostertag on 01224 716693 or email href="mailto:email@example.com" title="mailto:firstname.lastname@example.org">email@example.com</a></p>