Polyphenol-Rich Cocoa Consumption As Part of Balanced Diet

By Edward Amporful

Recently I received an enquiry from a Ghanaian student studying abroad. I gathered there was a discussion in class and knowing that Ghana was noted for cocoa production wanted to know the amount of cocoa one should consume per day as part of a balanced diet. I checked this one out and found out that this enquiry had been a subject handled by the European Food Safety Authority (EFSA) in 2012.

An entity had sought the opinion of the EFSA on the matter in 2012. The ensuing captures what the EFSA went through in coming out with a position on the matter.

The Panel on Dietetic Products, Nutrition and Allergies (NDA) of the EFSA was asked to deliver an opinion on the scientific substantiation of the health claim related to cocoa flavanols and maintenance of normal endothelium-dependent vasodilation.

The food constituent that was the subject of the health claim was cocoa flavanols. Flavanols are flavonoids and belong to a larger group of polyphenols. The flavanols in cocoa (Theobroma cacao L.) consist of monomeric catechins (mainly epicatechin) and oligomeric flavanols (procyanidins) ranging from dimers to decamers. The Panel considered that cocoa flavanols are sufficiently characterised.

The variety and country of origin, as well as the fermentation and roasting processes applied to cocoa beans, affected the flavanol content in cocoa. This fact underlied, for example, why Ghana's cocoa is reputed to be of premium quality- because of the processes applied to cocoa beans. The EFSA noted that flavanols are measurable in foods by established methods. In cocoa beans fermented for several days, the amount of monomeric flavanols accounted for 34-37 % of total flavanol content (Wollgast and Anklam, 2000). This work identified three groups ofpolyphenols in cocoa beans: catechins,which constitute about 37% of the polyphenol contentin the beans, anthocyanidins (about 4%), and proanthocyanidins(about 58%).

The claimed effect was that cocoa flavanolshelp maintain endothelium-dependent vasodilation which contributed to healthy blood flow. The target population proposed by the applicant was the general healthy adult population.

The capacity of blood vessels to respond to an increase in blood flow by dilating is designated as flow-mediated dilation (FMD). Endothelium-dependent vasodilation contributes to the maintenance of an adequate blood flow to body cells and tissues. The Panel considered that a sustained increase of endothelium-dependent vasodilation in fasting conditions in response to an intervention (e.g. regular consumption of a food/constituent) was a beneficial physiological effect. The Panel considered that maintenance of normal endothelium-dependent vasodilation was a beneficial physiological effect

Theentity seeking the opinion of EFSA provided three human intervention studies as supportive evidence for the scientific substantiation of the claim. The evidence investigated the effects of cocoa flavanols on endothelium dependent flow-mediated dilation (ED-FMD) in fasting conditions during repeated consumption of the food constituent (for 30 days to 6 weeks) in subjects with coronary artery disease (CAD) under pharmacological treatment for this condition. Two out of the three studies showed an effect of cocoa flavanols consumed for 30 days on fasting ED-FMD in subjects with CAD who were under pharmacological treatment. The effect occurred after seven days of consumption of cocoa flavanols.

A number of human intervention studies had been conducted in different population subgroups (e.g. smokers, older adults, obese subjects, subjects with type 2 diabetes and CAD). These addressed the acute effects of cocoa flavanols when consumed on a single occasion on ED-FMD. The information was provided by the entity as supportive evidence for the scientific substantiation of the claim. One of the studies also assessed the acute effects of cocoa flavanols on ED-FMD during repeated consumption (for seven days) of the food/constituent. Consumption of cocoa flavanols on a single occasion induced an acute, dose-dependent increase in ED-FMD which was maximal two hours after consumption of the food constituent. This paralleled blood concentrations of the flavanol metabolites. This returned to baseline six hours after ingestion, and is sustained with repeated consumption of cocoa flavanols.

A study found the highest plasma peak concentrationsof flavanols were obtained 2 to 3 hours after ingestionin a dose-dependent manner and still measurable after8 hours(Serafiniet al.Plasma antioxidants from chocolate. Nature. 2003; 424:1013.21).

In weighing the evidence, the Panel took into account that cocoa flavanols consumed for 12 weeks had been shown to increase fasting ED-FMD significantly in the target population in one human intervention study. In another human intervention study the effect was dose-dependent and occurred after one week of consumption under the conditions of use proposed by the entity. The effect was supported by two additional intervention studies, and that it was also observed in two out of three studies in patients under pharmacological treatment for CAD.

The Panel also took into account that consumption of cocoa flavanols on a single occasion induced an acute and dose-dependent increase in ED-FMD which is sustained with regular consumption of the food/constituent. The acute effect was mediated by the enhancement of NO production in the endothelium each time cocoa flavanolswere consumed.

The Panel concluded that a cause and effect relationship had been established between the consumption of cocoa flavanols and maintenance of normal endothelium-dependent vasodilation. The Panel considered that the following wording reflected the scientific evidence-that Cocoa flavanols helped to maintain endothelium-dependent vasodilation, which contributed to normal blood flow.

In order to obtain the claimed effect, 200 mg of cocoa flavanols should be consumed daily. This amount could be provided by 2.5 g of high-flavanol cocoa powder or 10 g of high-flavanol dark chocolate. These amounts of cocoa powder or dark chocolate could be consumed in the context of a balanced diet. The target population is the general population.

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