In May 2016 researchers from Portugal published the results of their study to assess the relationship between chocolate consumption and cognitive decline. 531 individuals with no history of cognitive decline were included in the study and followed up for approximately 4 years. Dietary habits were collected at the start of the study and cognitive function assessed periodically. Results showed that chocolate intake was associated with a reduced risk of cognitive decline. However, this protective effect was observed only in those individuals who had an average daily consumption of caffeine lower than 75 mg.
Moreira A et al. Chocolate Consumption is Associated with a Lower Risk of Cognitive Decline. J Alzheimers Dis. 2016 May 6;53(1):85-93