A nutritionist explains the health benefits of dark chocolate, which nutrients it contains, what a healthy portion size looks like and how to buy the best.
It might sound too good to be true, but dark chocolate (enjoyed as part of a balanced diet) can have some health benefits. We asked nutritionist Nicola Shubrook to explain its nutritional profile, plus how to buy the best dark chocolate.
What is dark chocolate?
Dark chocolate is a rich, bitter chocolate that is typically made of cocoa solids, sugar and cocoa butter (and doesn't contain any milk). The percentage of cocoa affects the flavour and bitterness.
There isn't a minimum amount of cocoa that needs to be present for the chocolate to be labelled 'dark', so you typically find dark chocolate containing anything from around 50% cocoa all the way up to 100%. Most brands contain 70%, 85% or 90% cocoa.
Nutritional profile of dark chocolate
The exact nutritional values will vary from brand to brand, as they depend on the different levels of cocoa butter and sugar added. Let's take a 70% cocoa dark chocolate, for example. This is a high-fat food, and a 20g serving (around six small squares) contains just over 8g of fat, of which 5g is saturated fat. It's high in sugar, with around 6g per 20g serving, but is also a good source of fibre and protein, with approximately 2g of each per 20g serving.
To compare, an 85% dark chocolate is higher in fat with almost 10g per 20g, of which 6g is saturated fat, but it is lower in sugar with just 3g per 20g. The protein and fibre content is also a little higher, at around 2.5g of each per 20g serving.
There is very little salt in dark chocolate, if any – unless you're buying one with added sea salt, of course!
Dark chocolate does have some impressive health benefits as it is naturally high in iron, magnesium, copper and manganese.
Iron is important for making red blood cells, which carry oxygen around the body, while copper triggers the release of iron to form haemoglobin, the substance that carries the oxygen around the body. Magnesium ensures that our parathyroid glands can work normally to produce hormones that are important in bone health. Manganese helps to make and activate certain enzymes in the body, including those which break down food.
What are the health benefits of dark chocolate?
One of the benefits of dark chocolate is that it is high in antioxidants and flavanols. A study in 2011 compared dark chocolate and cocoa powder to 'super fruits' because of their concentrated source of these phytonutrients, which were found to be higher than those in blueberries and pomegranates.
Studies show that diets high in flavanols improve vascular endothelium function (the cells that line the insides of our blood vessels) and reduce the risk of cardiovascular disease. Enjoyed as part of a balanced and varied diet, dark chocolate can make a valuable contribution of flavanols.
Studies also demonstrate that flavanols also offer some neuro-protective benefits and may offer some protection again conditions such as Parkinson’s and Alzheimer’s, as well as offering a potential anti-inflammatory effect in digestive issues such as inflammatory bowel disease.
What is a healthy portion size?
Enjoyed as an occasional treat, around 20g of dark chocolate is a good portion size – this is around six small pieces or two large squares, depending on the bar. However, as dark chocolate is high in saturated fat and sugar, it's important that it is enjoyed as part of a balanced diet.
How to buy the healthiest dark chocolate
The darker the better! Generally speaking, the higher the cocoa percentage, the better the health benefits (e.g. 20g of 90% cocoa chocolate is going to offer more health benefits than 20g of 75% cocoa chocolate).
Flavoured dark chocolates, such as orange, caramel or sea salt, are likely to contain more sugar and salt, so stick to plain dark chocolate to maximise the health benefits.
How is dark chocolate made?
Making dark chocolate is quite a lengthy process. Cacao beans are picked from the cacao tree when ripe, then cleaned and left to ferment for around two to nine days, using the naturally present yeasts or with a yeast-based starter, depending on the manufacturer. The beans are then covered by banana leaves or put in wooden sweating boxes to develop their flavour. The temperature, humidity and aeration will all add to the flavour.
After fermentation, the beans are dried and roasted, much like coffee, allowing them to darken in colour to a rich, dark brown and develop additional flavour and aroma.
The roasted beans are then winnowed, which is a process that removes the bean’s outer shell, or hull, and leaves behind the inner bean, or nibs. These nibs are then ground or milled at high pressure to produce cocoa mass – also known as chocolate liquor – and cocoa butter.
The cocoa mass and cocoa butter are then mixed together with sugar to produce a paste that then goes through a process known as conching. This is a careful process of rolling, kneading, heating and aerating the mixture under heat until it becomes smooth and creamy. The longer the mixture conched, the smoother the chocolate will be – some high-quality brands may do this for several days.
A stabiliser such as soy lecithin is added, along with any other additional flavours, such as sea salt or vanilla, before the chocolate is tempered. Tempering is the process whereby chocolate is slowly bought to a specific temperature, then poured into a mould to cool and become its stable, solid, edible chocolate form.
This article was published on 15 February 2019.
Nicola Shubrook is a nutritional therapist and works with both private clients and the corporate sector. She is an accredited member of the British Association for Nutrition and Lifestyle Medicine (BANT) and the Complementary & Natural Healthcare Council (CNHC). Find out more at urbanwellness.co.uk.
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