Chocolate Week – Part 2

Part 2 of Chocolate Week and it’s time to think about what chocolate does to your brain, and chocolate addiction.


The effects of chocolate on the brain

Chocolate is thought to affect the brain in a few different ways. It contains compounds which may directly stimulate the brain, and also indirectly changes the way the brain functions.

Really, does it need a caption? It's a brain.

Studies have been done to examine the areas of the brain which become active after eating chocolate, and there are specific regions of the brain which become activated after eating chocolate. These include regions which control pleasure and reward. In fact, people who crave chocolate have higher activation of the pleasure and reward centres than those who do not crave chocolate, even when just seeing chocolate. Areas which control motivation are also increased in activity after eating chocolate, as are areas which control memory storage and retrieval.

Strangely, eating chocolate also causes an increased activation of the motor cortex – the area of the brain which controls voluntary movement. This may not mean however that after eating chocolate people can move better or faster – even just reading a verb which relates to the arm, face or leg will increase activation of the motor cortex.

It is interesting to compare some areas of the brain which are activated by chocolate with those activated by an addictive substance, for example, nicotine. The pre-frontal cortex (the very front area of the brain) is associated with memory and learning, and is potentially involved in the development of addiction. Unsurprisingly nicotine causes activation of this area of the brain. However, there are similarities in the activation of this area when eating chocolate, with activation of this area occurring when eating the chocolate is thought of as being particularly good. Given the addictive nature of nicotine and the adaptations which occur in memory and learning centres of the brain during addiction, this points to a similarly addictive nature of chocolate.

The brain functions by producing chemicals called neurotransmitters which transmit messages from one part of the brain to another. Increased brain activity is due to increased levels of these neurotransmitters. Three major neurotransmitters are called dopamine, serotonin, and opioids – all are commonly affected by drugs and both have been found to be affected by chocolate.

Serotonin has many roles in the brain, including regulating sleep, appetite and mood. There has been evidence that chocolate increases serotonin levels of people who are deficient, including people with seasonal affective disorder or non-typical depression. This increase in serotonin is through an indirect mechanism using the carbohydrates in chocolate (such as sugar); however this effect is counteracted by protein and fat. There is a limit at how much protein or fat a food can contain before it stops this increase of serotonin, and, sadly, chocolate has too much of both, suggesting thatchocolate does not in fact increase serotonin at all.

When activated, opioids cause the release in the brain of endorphins, a chemical which causes a pleasurable feeling. Opioids can be released in the brain in response to sweet foods, including chocolate, and this opioid release caused by sweet foods can lead to an analgesic feeling from endorphin release.

Dopamine is involved in “reward” signalling in the brain, being increased when experiencing favourable things. This increased dopamine makes the brain remember that that was a good thing, and makes you want more; in fact dopamine is increased in anticipation of a good experience, making you want it more and more. Possibly, the sugar content in chocolate causes changes in the dopamine which make this reward signalling stronger, and a stronger reward signal may result in cravings to revisit that feeling. Also, one of the most brain-active chemicals in chocolate activates the dopamine system, further suggesting that dopamine signals may be involved in the effects of chocolate.

There have been suggestions that as chocolate contains a type of chemical called cannabinoids, that it may have a mild effect similar to marijuana. However, while chocolate does indeed contain very low levels of cannabinoids, not enough is absorbed by the body to produce any sort of effect on the brain. Similarly, other compounds which can act on the brain are present in chocolate, however do not contribute to any euphoria caused by eating chocolate, nor do they contribute to cravings as they are found in greater amounts in other foods which do not cause cravings.


Mood eating

Unsurprisingly moods do affect the amount of chocolate people eat, but the effect may be the opposite of what you think. When people were happy, they actually ate significantly more chocolate than people were unhappy, and the chocolate was reported to taste better and be more stimulating. While there is evidence that eating chocolate may temporarily improve bad feelings, there is a slump back afterwards and the improvement is very minor. This minor temporary relief can be extremely short, with some studies showing the improvement can be only while you’re actually eating, and as soon as people stopped eating they slumped back. This effect goes however for any sugary foods, not just chocolate.

In total, the evidence points to chocolate having no effect on improving mood or providing any kind of psychological benefit, and it may actually prolong a bad mood!


Chocolate cravings

The texture, aroma and fat and sugar content have been thought to be the predominant factors in causing chocolate cravings. And let’s be honest, they are pretty good. Chocolate does have a perfect combination of sweetness, creamy texture, aroma and taste. Indeed, there have been some studies which show that cravings can be ‘cured’ because of just the sensory experience. However there are other factors, such as magnesium content, and also the release of neurotransmitters, which together with the sensory pleasure of chocolate contribute to chocolate cravings.


It tastes, smells, looks and feels awesome, but its not the only reason you crave it.

Some of the areas of the brain may explain why people become addicted or crave chocolate so strongly. The areas of the brain activated include the pleasure, reward and memory centres, and non-stimulation of these areas may result in cravings as the brain seeks to return to that activated and pleasurable state. Also, the dopamine and opioid signalling increased by chocolate contributes to this effect.

Cravings have been suggested to be more a way of seeking the dopamine reward than preventing the negative consequences of not eating. The increased activation of the pleasure and reward centres of the brain in cravers supports this, that the effect on cravers is an increased reward rather than a lower level when not eating chocolate.

Finally, magnesium is found in chocolate at relatively high levels. Cravings may be a way of your body saying it is low in magnesium and it needs more, and the magnesium intake from chocolate has been suggested as being a large factor in satisfying chocolate cravings.


So while the pleasure of eating chocolate plays a role in cravings, there are sometimes actual physiological reasons for why you feel a craving for chocolate. Tomorrow – how to beat those cravings.


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