While sugar warnings have seen sales of some of the UK’s biggest milk chocolate brands fall, more of us have turned to the dark side – as sales of some "quality" dark chocolate brands, perceived to be a healthier indulgence, grew 14% in 2017.
Small wonder that mainstream brands want a taste of the action. Galaxy recently launched a "Darker Milk" variety – a blend of milk and dark chocolate, following Cadbury, which introduced its Darkmilk’ version of Dairy Milk last autumn. Many studies suggest a link between dark chocolate and improved health.
Earlier this year, Portuguese researchers reported in the journal Nutrition that eating a few squares of 90% cocoa dark chocolate every day could lower blood pressure.
The benefits are thought to be down to compounds called flavanols in cocoa, particularly one called epicatechin that helps keep blood vessel walls elastic.
Some of the first evidence that chocolate may be good for the heart came from Panama’s Kuna Indians.
When researchers in the Nineties compared data from these remote islanders, who consumed lots of a bitter cocoa drink, with people living in Panama City who didn’t, the cocoa drinkers were found to have better blood pressure and lower rates of diabetes, cancer and stroke.
However, the flavanol content of cocoa beans is reduced dramatically by the processing needed to turn it into chocolate we find palatable – and can vary significantly between products.
"We know fresh, unprocessed cocoa beans contain 10% flavanols, but processing the beans into chocolate can reduce this to between 0.5% and even as low as 0.001%," explains Dr Karin Ried, an associate professor at the National Institute of Integrative Medicine in Melbourne, who has produced a review of the evidence on chocolate and blood pressure for the respected Cochrane Collaboration.
While you might assume the darker the chocolate, the higher the flavanol content, this isn’t necessarily so.
"Research that compared the flavanol content of 41 different commercial brands of dark and milk chocolate has shown no correlation between the percentage of cocoa and the flavanol content," says Dr Ried. "When it comes to health, we need to look at not just cocoa and flavanols, but what else is in there."
This includes the amount of sugar.
"In general, a higher cocoa content is healthier," says Dr Ried. "And with a darker chocolate – I’d recommend 75% cocoa solids and up – you also have a higher amount of nutrients such as magnesium (for healthy muscles and nerves), zinc (for a healthy immune system), and iron (to make red blood cells), as well as a little fibre.
"Darker chocolate also tends to be more satisfying, and you’ll get more caffeine and theobromine, which are mood-enhancing. A couple of squares a day is not a bad thing."