More specifically, it is the relationship between cognitive impairment, dementia and cognitive retardation and differences in daily coffee consumption that has been studied. In total, the nine selected studies involved more than 30,000 participants aged 60 and over from Asia and Europe.
1 to 2 cups of coffee per day
The results show a less frequent occurrence of these disorders in people who consume 1 to 2 cups of coffee per day compared to people who consume less than one per day. The dose-effect relationship shows a statistically significant J curve: moderate coffee consumption has a protective effect, unlike zero consumption.
Two other studies also confirm this association: the lowest number of cases of cognitive impairment was observed in people who consumed three to five cups of coffee per day. Ethnicity, gender, study length, sample size, and coffee drinking method are found to have no clear influence on the survey results.
Coffee molecules at work
Coffee is made up of different chemical compounds, including phytochemicals, minerals, and caffeine. The latter is considered to be one of the preponderant factors of this association. It is a neurostimulant component as well as a non-selective adenosine antagonist, which may play a role in reaction time, concentration and memory.
Wu L, Sun D, He Y: Coffee intake and the incident risk of cognitive disorders: A dose-response meta-analysis of nine prospective cohort studies. Clin Nutr. doi: 10.1016/j.clnu