Is chocolate really good for the heart?

Chocolate is irresistible to many of us

Whenever that rarest of patients tells me they don’t like chocolate and therefore don't eat it, try as I might to not do so, I can’t help but express my surprise at this unusual revelation. “How can you not like chocolate?” I say, as I consider the truthfulness of what is being said – we sometimes tell others what we think they want to hear from us!
 
Chocolate triggers release of opiates
 
There’s a whole heap of science around why chocolate is universally enjoyed – well, by most of us, that is.  This includes chocolate’s effect of triggering the natural opiates in the brain that make us feel good and the physical properties that give it that delightfully silky surface and smooth texture, and a chemical struture that makes it melt when it hits the tongue.  We know what makes it feel good in the mouth, taste good and why it may do us some good.
 
Milk chocolate contains at least 10% of cacao (high-quality milk chocolate may contain 30-40% cacao) and at least 12% milk – the rest will be made up of sugar and vegetable fats.  Dark chocolate, which contains at least 35% cacao (it may contain as much as 90%) has less sugar than does milk chocolate and this gives it a bitterness not enjoyed by some of us.  
 
Why do people say dark chocolate is healthy?
 
The ‘goodness’ in chocolate is in the cacao beans (called cocoa beans once fermented) from which the delectably smooth mouth-candy is made.  Cacao beans, like many plants, are a source of anti-oxidants – these are compounds that help protect our heart, and other organs, from becoming damaged and diseased.  The higher the percentage of cacao solids in chocolate, the higher the concentration of its antioxidants.
 
In theory this all sounds very good. ‘Dark chocolate is heart healthy” makes an eye-catching and unlikely headline for a processed snack that is loaded with saturated fat and sugar.  Dark chocolate with 70% cacao solids can deliver a whopping 27% sugar – that’s about one teaspoon of sugar in a couple of pieces of chocolate weighing around 20g.
 
How much dark chocolate is heart healthy?
 
If dark chocolate is actually heart protective, eating around 30g three times a week is as much as needed to get this protection – eating more doesn’t seem to bring further heart health benefit.   We must of course remember that dark chocolate consumed as part of a generally unhealthy diet is not going to do much in the way of heart protection.
 
It’s important to know that organisations, such as Mars, who have a commercial interest in this area of research tend to be involved in these studies in some way.   A very small 2017 study (only 31 people), funded by The Hershey Company and the Almond Board of California, explored the impact of the combination of almonds and dark chocolate on heart disease risk factors and found that consumption of almonds alone lowered blood cholesterol – eating dark chocolate alone had no impact on blood cholesterol level.
 
Take home message ...

Chocolate tastes great (to most of us!) and there is no need to exclude it from a healthy lifestyle.  Dark chocolate has more heart-protective antioxidants than does milk chocolate, but the fat content (as high as 45%) may be higher in dark chocolate, particularly bars that have a high percentage of cacao solids.  Whichever type of chocolate you prefer, enjoy it only in moderation, because a few squares three times a week is likely to be all that’s needed to contribute to heart health.  Any more than that brings no further benefit and neither will it help with trimming the waistline.

Tony Hirving
Dietitian