The smell of chocolate increases theta brain waves, which triggers relaxation.
Theta brain waves occur mostly when we dream and also in deep meditation. It’s a state which we normally experience as we wake or drift off to sleep.
There are 4 types of brain waves; beta, theta, alpha and delta and each one is activated according to your level of activity. For example, if you are in conversation you would be in beta mode. In deep sleep you would be in delta mode.
Have you ever driven down a motorway and fallen into a daydream – you still maintain your task but it’s like being in overdrive - that’s theta mode and probably it’s time to pull over.
We’re in theta mode when we start to fall off to sleep. Our brain waves will go from beta to alpha to theta and finally to delta when we're asleep. That must be why a cup of hot chocolate is a great way to get us off to sleep at night.
So in times of stress, it makes perfect sense to Keep Calm and Eat Chocolate x
Knowledge base taken from https://www.scientificamerican.com/