Health and wellbeing:Chocolate can certainly make you feel good but now scientists have found that there may be health benefits from certain types of chocolate, including helping you to live longer.
"Jeanne Louise Calment lived to 122 and she claimed to drink a glass of wine a day and to eat 1kg of chocolate a week until she was 119," Prof Roger Corder told the festival in York yesterday. "Her account has led scientists like myself to be fascinated by the contribution chocolate may have made to her long life."
Prof Corder, from the William Harvey Research Institute at Queen Mary University in London, focuses his work on the importance of improving health and wellbeing through diet.
"The choice of chocolate is important to gain maximum benefit while preventing over-consumption of what is otherwise a calorie-rich and potentially fattening food. It is important to see if cocoa is beneficial and how it works," he said.
A number of studies in different parts of the world have shown that regular consumption of cocoa products has a role in counteracting age-associated increases in blood pressure and reduction in the numbers of deaths from heart disease.
"With age, our blood vessels change from being clean and clear to becoming blocked by the slow build-up of fatty deposits. This increases the likelihood of blood clots forming that could cause a heart attack or stroke," said Prof Corder.
"In addition, the single layer of cells, or endothelium, that lines our blood vessels produces factors to keep our blood vessels functioning. Dysfunction of the endothelium with age can lead to constriction of the vessels and higher blood pressure." Work by Prof Corder and others has shown that constituents of cocoa beans, called polyphenols or flavonoids, cause the beneficial actions associated with the cocoa products. Polyphenols act on the function of the blood vessel endothelium.
"These natural plant molecules [ polyphenols] reduce constriction and increase dilation of the blood vessels, and also reduce the potential for blood clots to form by boosting anti-thrombotic mechanisms, a profile of actions not seen with any prescription medicine," he said.
Polyphenols levels vary considerably in different cocoa products. Although levels are high in cocoa beans themselves, during the production process large amounts are lost.
"Further work is required to fully establish the health potential of dark chocolate and define the optimal daily amount. The benefit may be derived only from dark chocolate containing high amounts of flavonoid polyphenols," said Prof Corder.
"Interestingly, it is the same polyphenols in red wine that are most important for the protective effects of red wine. So there is a close parallel between research on chocolate and red wine."
Polyphenols may explain the action of cocoa products on blood pressure. However, according to Prof Peter Rogers from University of Bristol, addiction is not so easy to explain.
"What is special about chocolate is our attitudes towards it, not its physical and biological properties," he said.
"Attitudes towards chocolate [naughty but nice] explain 'chocoholism' and why chocolate is craved and described as 'moreish'. Taste is important, but potential psychoactive constituents play little or no role in the special appeal of chocolate."