Why might chocolate be good for us? How reliable is the evidence? Does it matter what kind of chocolate we eat? Can we become addicted?

Chocolate (along with cocoa) is made from cacao beans – a rich source of flavanols and other antioxidants, as well as essential minerals and vitamins. So, in principle, there could be potential health benefits. Researchers found that an Indian people in Panama who consumed large amounts of cocoa had a low risk of heart disease. Whereas when they moved to other parts of the country and stopped drinking ‘natural’ cocoa their levels of heart disease increased. Having said this, the research was funded by a chocolate company and has more recently been questioned.

A number of studies since then, though, have also suggested health benefits. For example a 2017 review of 35 short term studies of dark chocolate and cocoa prodicts concluded there was moderate quality evidence of a small but statistically significant lowering of blood pressure.

How reliable is the evidence?

Unfortunately we can’t always rely on the evidence presented in favour of chocolate. For instance: 

• Much of the research has been undertaken with cocoa drinks, which may contain more concentrated cacoa than chocolate. 
  
• When chocolate is made, fat and sugar are usually added (which isn’t exactly healthy) and sometimes alkali is used to reduce the bitterness. These all dilute the effect of the cocao.
• The nutritional content of cocoa beans varies between regions and depends how they are processed, meaning the nutritional content of the chocolate produced from the beans is also likely to vary.
  
• Some of the research has been funded by chocolate manufacturers, like Mars. For example seven of the 35 studies reviewed in 2017 were funded by chocolate companies. This doesn’t necessarily mean the results are unreliable but does raise a possible question mark.

Having said this, research has suggested a number of possible health benefits i.e that chocolate:

• Reduces the risk of cardiovascular disease (angina, heart attack and stroke) for people already at increased risk. This is based on an Australian study of 2013 people. The study estimated that daily consumption of dark chocolate could reduce cardiovascular events by 85 per 10,000 people treated over 10 years.
• Helps ‘flow mediated dilation’ (important for blood flow and believed to reduce the risk of angina, heart attack and stroke)
• May improve vascular function.
• Might help improve cognitive function in elderly people with mild cognitive impairment.

However, the research relating to cognitive function involved the regular consumption of cocoa flavanols rather than chocolate, it was a small scale study (of 90 people) and it was funded by Mars (who had a potential commercial interest in the outcome).

A 2012 systematic review of randomised controlled trials of flavonoid-rich food products concluded that there does not seem to be a dose-response association. It seems the effect of flavonoid rich food, such as some types of chocolate, may have different effects on the body depending on the biological make up of the person eating it

What kind of chocolate is best?

Dark chocolate is assumed to have a higher flavanol (antioxidant) content and usually less sugar than white chocolate. So it is usually seen as healthier. However, due to their bitter taste flavanols are sometimes removed even from bitter/dark chocolate, without this being indicated on food labels.

So it is probably more rational and beneficial to consciously increase consumption of healthy foods such as apples, raspberries, vegetables and green tea which naturally contain flavanols and a range of other essential nutrients.

Victoria Taylor, senior heart heath dietician at the British Heart Foundation, comments, “Evidence does suggest chocolate might have some heart health benefits but we need to find out why that might be…If you want to reduce your heart health risk, there are much better places to start than at the bottom of a box of chocolates.”

Is chocolate addictive?

Experiments have suggested the sugar content is addictive for rats. A small scale study in humans suggested that multiple characteristics of chocolate, including sugar, cocoa and the drug–like effects experienced, play a role in the desire to consume it. 

However, another source suggests that generally researchers believe chocolate “addiction” is not a true addiction. Chocolate may contain potentially mood-altering substances. However, these are all found in higher concentrations in other less appealing foods such as broccoli. Chocolate cravings can perhaps be explained by a combination of cultural factors (being seen as ‘naughty but nice’), sensory characteristics — sweetness, texture and aroma — nutrients and chemicals, together with hormonal and mood swings.

Conclusions

• Chocolate is made from cacao beans – a natural source of healthy nutrients.
• However this healthy nutrient content is significantly reduced during the manufacturing process.
• And some organisations funding the research have a commercial self interest in the findings.
• However, the evidence suggests that chocolate (dark chocolate that hasn't been too processed in particular) is likely to modestly reduce the risk of type 2 diabetes, angina, stroke and heart attack.
• At the same time the healthy ingredients in chocolate can be found in fruit, vegetables and green tea – without sugar and fat having been added.
• Chocolate can give rise to cravings but is probably not a true ‘addiction.’ 

Updated and reviewed by Hannah Kurian, February 2019. Next review due January 2023.