Your brain on chocolate...
In the mid 1970s, psychologist Merrill Elias began tracking the cognitive abilities of more than a thousand people in the state of New York.
The goal was fairly specific: to observe the relationship between people's blood pressure and brain performance. And for decades he did just that, eventually expanding the (MSLS) study to observe other cardiovascular risk factors, including diabetes, obesity, and smoking.
There was never an inkling that his research would lead to any sort of discovery about chocolate.
And yet, 40 years later, it seems to have done just that.
Late in the study, Elias and his team had an idea. Why not ask the participants what they were eating too? It wasn't unreasonable to wonder if what someone ate might add to the discussion.
Diets, after all, had been shown to affect the risk factors Elias was already monitoring. Plus, they had this large pool of participants at their disposal, a perfect chance to learn a bit more about the decisions people were making about food.
The researchers incorporated a new questionnaire into the sixth wave of their data collection, which spanned the five years between 2001 and 2006 (there have been seven waves in all, each conducted in five year intervals). The questionnaire gathered all sorts of information about the dietary habits of the participants. And the dietary habits of the participants revealed an interesting pattern.
"We found that people who eat chocolate at least once a day tend to perform better cognitively," said Elias. "It's significant—it touches a number of cognitive domains."
Others had previously shown that eating chocolate correlated with various positive health outcomes, but few had explored the treat's effect on the brain and behavior, and even fewer had observed the effect of habitual chocolate consumption.
This, Crichton knew, was a unique opportunity.
Not only was the sample size large—a shade under 1,000 people when the new questionnaire was added—but the cognitive data were perhaps the most comprehensive of any study ever undertaken.
In the first of two analyses, Crichton, along with Elias and Ala'a Alkerwi, an epidemiologist at the Luxembourg Institute of Health, compared the mean scores on various cognitive tests of participants who reported eating chocolate less than once a week and those who reported eating it at least once a week.
They found "significant positive associations" between chocolate intake and cognitive performance, associations which held even after adjusting for various variables that might have skewed the results, including age, education, cardiovascular risk factors, and dietary habits.
In scientific terms, eating chocolate was significantly associated with superior "visual-spatial memory and [organization], working memory, scanning and tracking, abstract reasoning, and the mini-mental state examination."
Why exactly eating chocolate is associated with improved brain function Crichton can't say with absolute certainty. Nor can Elias... But they do have a few ideas.They know, for instance, that nutrients called flavanols, which are found naturally in cacao, and thus chocolate, seem to have a positive effect on people's brains.
In 2014, they concluded that eating the nutrient can "reduce measures of age-related cognitive dysfunction."
A 2011 study, meanwhile found that cacao flavanols "positively influence psychological processes."
The suspicion is that eating the nutrient increases blood flow to the brain, which in turn improves a number of its functions.
Experts have known about the wonders of eating chocolate for some time.
And a lot of previous research has shown that there are, immediate cognitive benefits from eating chocolate.
- Stuart Jones