As if you didn't have enough reasons to eat it already, chocolate could also help maintain your brain's processing power from the effects of age and fatigue.
A team of Italian researchers from the University of L’Aquila and the University of Rome has news which I'm sure will delight everyone. They recently performed a meta-analysis (a study of pre-existing studies) of the effects chronic and acute cocoa doses have on the inner workings of the brain. Esentially, they wanted to see what we know up to now of what happens in the brain a few hours after you eat chocolate, and how it behaves when you keep chocolate in your diet for longer periods of time.
The work was prompted by a class of natural chemical compounds that cocoa is rich in, flavonols. These are known to have good neuroprotective properties, meaning they help maintain neuron's health and function. Since chocolate is one of the best sources of flavanols, the team wanted to see if these neuroprotective properties would still hold in the finished product.
While randomized controlled trials looking into the effects of acute flavonol doses were sparse, the team reports that the majority point to a beneficial effect on cognitive performance. Participants usually showed a greater performance in working memory, an improved ability to process visual information, and other similar 'upgrades' in cognitive abilities after consuming cocoa flavanols in the form of chocolate. Women, in particular, seemed to benefit from the mental pick-me-up: the team writes that eating chocolate could counter the cognitive effects of a full night's sleep-depravation for them, opening an interesting (and tasty) new avenue of research for those suffering from chronic sleep deprivation or those who work shifts.
The effect, they detail, comes down to flavanols, not "other functional ingredients, such as the methylxanthine caffeine and theobromine, with the potential to influence neurocognitive function," which, relative to total flavonols content, are found in concentrations "lower than those required to exert significant pharmacological actions."
Still, there is a caveat. The team reports that acute doses of flavanols' observed effects directly depend on the length and mental load of the tests used in each study -- in other words, they might not make a difference for short, easily solvable tasks. For young adults, a highly demanding cognitive test was needed to spot the subtle effects acute doses of flavonols had the participants' behavior.
On the other hand, the effects of long-term consumption of flavanols (from 5 days up to 3 months) have largely been investigated in elderly individuals. These studies report that a daily intake of flavonols led to an improvement in cognitive performance, citing improvements particularly in areas such as attention, processing speed, working memory and verbal fluency. The greatest effects, however, were seen in older adults who were already experiencing mild memory or cognitive decline.
"This result suggests the potential of cocoa flavanols to protect cognition in vulnerable populations over time by improving cognitive performance," the authors write. "If you look at the underlying mechanism, the cocoa flavanols have beneficial effects for cardiovascular health and can increase cerebral blood volume in the dentate gyrus of the hippocampus. This structure is particularly affected by aging and therefore the potential source of age-related memory decline in humans."
So why don't we just chow on chocolate all day long if it's good for our brains? Well, the team points out that there are potential side-effects to eating chocolate, "generally linked to the caloric value of chocolate, some inherent chemical compounds of the cocoa plant such as caffeine and theobromine, and a variety of additives we add to chocolate such as sugar or milk."
The best middle ground, the authors say, is to go for dark chocolate -- a little bit every day should be enough.
The full paper "Enhancing Human Cognition with Cocoa Flavonoids" has been published in the journal Frontiers in Nutrition.