Cocoa contains compounds called flavanols which are a type of polyphenol. Polyphenols are naturally produced by plants and so are found in plant foods such as fruit, vegetables, tea, coffee, wine, grains and chocolate.

What research has been done on cocoa flavanols and health?

Research looking into the potential health benefits of cocoa flavanols covers a variety of different areas including effects on heart health, immunity, dental health, skin, gut bacteria and cancer. Whilst there have been some promising findings suggesting that cocoa flavanols can benefit markers of heart health (such as blood pressure and blood cholesterol), evidence relating to other health benefits is limited.

Importantly, most of the studies have given people drinks, capsules or bars of chocolate which have been specially made to contain high amounts of cocoa flavanols. The amount of flavanols present in cocoa varies due to the type and origin of the cocoa beans and losses occur due to the processes involved in chocolate making, therefore chocolate that is available to buy contains considerably fewer flavanols than the preparations used in scientific studies.

Chocolate manufacturers generally do not provide details of the flavanol content of their products on the label or on their website. A 2016 paper which analysed a variety of bars of chocolate that are commercially available in the UK found that dark chocolate contained considerably more cocoa flavanols than milk chocolate but, perhaps surprisingly, the percentage of cocoa solids was not related to flavanol content which means it’s impossible to know how much is in different chocolates.

Are there any approved health claims relating to chocolate?

In 2012, a health claim with the wording ‘Cocoa flavanols help maintain endothelium-dependent vasodilation, which contributes to normal blood flow’ was approved for use in the EU. ‘Maintaining endothelium-dependent vasodilation’ means increasing the elasticity of blood vessels, which improves circulation in the body and may be associated with improved heart health.

In order to use the claim a product must provide 200 mg of cocoa flavanols daily, which could be delivered by 2.5 g of high-flavanol cocoa powder, 10g of high-flavanol dark chocolate or less than 1g of high-flavanol cocoa extract in capsules or tablets. There are a very small number of specialist products on the market which have been made using a process which preserves the cocoa flavanols and therefore contain high amounts, however such products are expensive and are generally not available in high street shops.

So is dark chocolate healthy?

It is important to remember that most chocolate is high in calories, fat and free sugars and so should be consumed less often and in small amounts. Choosing dark chocolate over milk chocolate may help you stick to smaller portion sizes due to its stronger flavour and is likely to increase the amount of cocoa flavanols you will be consuming. While it’s difficult to be sure about the potential health effects, it’s possible that there may be some benefits to heart health from cocoa flavanols!