In the second part of our special series on the health benefits of cocoa polyphenols, NutraIngredients looks at the science behind the claims, and asks how much is too much
The health benefits of polyphenols from cocoa have been gathering increasing column inches in the national media. To date studies have reported potential benefits for cardiovascular health, skin health, and even brain health.
But before exploring the science it is important to make some distinctions: “Chocolate and cocoa are two different terms and are not interchangeable,” explains a recent review in the British Journal of Nutrition.
Reviewers led by Gary Williamson from the Nestlé Research Center note: “Cocoa is the non-fat component of cocoa liquor (finely ground cocoa beans) which is used in chocolate making or as cocoa powder (commonly 12 per cent fat) for cooking and drinks.
“Cocoa liquor contains approximately 55 per cent cocoa butter and together this comprises cocoa solids, often referred to on chocolate packaging. Chocolate refers to the combination of cocoa, cocoa butter, sugar, etc. into a solid food product,” added the reviewers.
Mary Wagner, chief technology officer for Mars Botanical, a scientific division of Mars Inc, says that the benefits of the bean revolve around the flavanols (also known as flavan-3-ols or catechins), and particularly the monomeric flavanol (-)epicatechin.
“Cocoa polyphenols can benefit any health condition that is impacted by circulation,” says Wagner.
Mars’ interest in the active compounds started about 20 years ago when its scientists sought to understand the flavour components of chocolate. The bitter and astringent compounds were isolated, and further study and clinical work showed the health benefits of the monomers and the tannins, particularly (-) epicatechin, she said.
“In the last 10 years there have been about 30 human studies looking at potential heart health benefits of cocoa or chocolate, and many have shown a measurable improvement in at least one cardiovascular parameter, such as blood pressure, or blood antioxidant status,” explains Nestlé’s Hilary Green, PhD, head of R&D communications.
A meta-analysis by researchers from the University Hospital of Cologne found that consumption of cocoa had significant positive effects on blood pressure.
"The magnitude of the hypotensive effects of cocoa is clinically noteworthy; it is in the range that is usually achieved with monotherapy of beta-blockers or antiotensin-converting enzyme inhibitors," wrote the authors in the Archives of Internal Medicine.
A recent study using Natraceutical’s CocoanOX powder, and funded by the company, found that rodents fed 300 milligrams of cocoa powder per kilogram of body weight experienced a reduction in blood pressure similar to a 50 mg/kg dose of Captopril, a well-known pharmaceutical anti-hypertensive (Journal of Agricultural and Food Chemistry, Vol. 57, pp. 6156-6162).
Recently, work with Barry Callebaut’s Acticoa ingredient reported that eating flavanol-rich chocolate may help protect the skin from the damaging effects of UV light (Journal of Cosmetic Dermatology, Vol. 8, pp. 169-173).
In 2006, German researchers led by Wilhelm Stahl from the Heinrich-Heine University in Dusseldorf reported that a daily flavanol-rich chocolate drink, providing 326 milligrams of flavanols per day, may could thicken skin and reduce reddening by 25 per cent (Journal of Nutrition, Vol 136, pp 1565-1569).
The first reported benefits for flavanol-rich chocolate for benefiting brain health, and reducing the risk of dementia and stroke was reported by Boston-based researchers in 2006 in the journal Neuropsychiatric Disease and Treatment (Vol. 4, pp. 433-440).
The research, supported by Mars, found that two weeks of consuming flavanol-rich chocolate, providing 900 mg of cocoa flavanols daily, produced significant improvements in the blood flow in the brain, particularly in the middle cerebral artery.
A year later n 2007, cocoa researcher Ian Macdonald from the University of Nottingham in the UK told attendees at the annual meeting for the American Association for the Advancement of Science that the consumption of a flavanol-rich cocoa beverage (supplied by Mars) resulted in regional changes in blood flow in study participants.
“Our study showed that acute consumption of this particular flavanol-rich cocoa beverage was associated with increased blood flow to grey matter for 2 to 3 hours,” said Macdonald in 2007.
How much is too much?
“Chocolate is predominantly a food for pleasure, and many people incorporate it into part of a healthy, varied and balanced diet,” writes Dr Williamson and his co-reviewers. “However, there is controversy over whether it should be recommended for its health benefits.”
Herwig Bernaert, innovation manager for Barry Callebaut, explained standard dark chocolate contains only about 20 per cent of the initial flavanol levels, but consumption would have to be large in order to achieve a physiologically active dose of flavanols. “But this also means you get a large amount of fat and sugar, and this would negate the benefits of the flavanols,” he said.
According to Nestlé’s Dr Williamson and his co-reviewers: “The polyphenol content is of more importance and it is essential that, in future, all published trials give a full characterisation of the chocolate or cocoa used and the calculated dose. This characterisation should include a breakdown of the types of polyphenols, especially monomer content.”
To access yesterday’s article about the global functional chocolate market click here.