Cocoa makes you alert
A 40-g piece of dark chocolate activates the brain, makes you feel more awake, more alert and less sleepy, according to an article by psychologists at Northern Arizona University in NeuroRegulation. Yet another reason why adding a couple of tablespoons of cocoa to your pre-workout shake, as some athletes do, isn't such a bad idea at all.
Cocoa is a stimulant
Cocoa contains a cocktail of interesting bioactive substances, such as theobromine and caffeine. It also contains phenols that are capable of boosting the concentration of natural pep-hormones such as adrenalin and noradrenalin.
So it wasn't a huge surprise when British researchers announced ten years ago that cocoa had a stimulatory effect on people with chronic fatigue. But until recently no studies had been done in which researchers measured the electrical activity in the brain as a result of ingesting cocoa. And that's exactly what the researchers at Northern Arizona University have now done.
The researchers did experiments with 122 students, aged between 18 and 25. They divided their subjects into six groups and gave the subjects in three of these a 40-g piece of chocolate. The chocolate they used was manufactured by The Hershey Company, the sponsor of the study.
One group was given higher-cacao chocolate, which consisted of 60 percent cacao. The students ingested 24 g cacao (which corresponds to 5 tablespoons of cocoa powder).
Another group was given 40 g low-cacao chocolate. This was white chocolate that contained no cacao, but more sugar and fat.
The third group was given higher-cacao chocolate to which the manufacturer had added the amino acid L-theanine.
The exact composition of the three different types of chocolate is shown in the table below.
Two control groups drank water that contained sugar. The high-sugar group ingested the same amount of sugar as the low-cacao chocolate group had ingested in the form of chocolate; the low-sugar group ingested the same amount of sugar as the higher-cacao chocolate group had been given. A third control group was given water with no additives.
The researchers attached electrodes to the students' head to measure the electrical activity of the brain, and took measurements just before the students were given their chocolate or water and 90 minutes later. The figures below show the differences between the two sets of measurements.
In the students that had been given higher-cacao chocolate the theta waves had decreased. The brain produces more theta waves the sleepier you are.
In the higher-cacao chocolate group – and also in the high-sugar group – the researchers observed a significant increase in beta waves. Your brain produces more beta waves the more alert you are, and the more you aware of your surroundings.
"Chocolate is indeed a stimulant and it activates the brain in a really special way", researcher Larry Stevens announced in a press release. [news.nau.edu May 7, 2015] "It can increase brain characteristics of attention."
NeuroRegulation, 2(1), 3–28. doi.org/10.15540/nr.2.1.3.