Chocolate's benefits can be attributed to cocoa bean, which is its main ingredient and a rich source of flavanols - a class of natural compounds that has neuroprotective effects, the study said.
The findings demonstrated that older adults who had a daily intake of cocoa flavanols showed improvements in general cognition, attention, processing speed and working memory.
"This study suggests the potential of cocoa flavanols to protect cognition in vulnerable populations over time by improving cognitive performance," Valentina Socci from the University of L'Aquila in Italy.
"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 ageing and therefore the potential source of age-related memory decline in humans," Socci added.
Further, cocoa also showed promising results for people, especially women, suffering from chronic sleep deprivation or work shifts, who face less accuracy in performing tasks.
The effect of cocoa was relatively seen for a long-time, ranging from five days up to three months, the researchers said, in the paper published in the journal Frontiers in Nutrition.
"Regular intake of cocoa and chocolate could indeed provide beneficial effects on cognitive functioning over time," however, "there are potential side effects," said Michele Ferrara from the University of L'Aquila in Italy.
"Those are 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," Ferrara added.