Coffee, tea, or caffeine consumption may be protective against cognitive impairment and dementia. We estimated the association between change or constant habits in coffee consumption and the incidence of mild cognitive impairment (MCI). We evaluated 1,445 individuals recruited from 5,632 subjects, aged 65-84 year old, from the Italian Longitudinal Study on Aging, a population-based sample from eight Italian municipalities with a 3.5-year median follow-up. Cognitively normal older individuals who habitually consumed moderate amount of coffee (from 1 to 2 cups of coffee/day) had a lower rate of the incidence of MCI than those who never or rarely consumed coffee [1 cup/day: hazard ratio (HR): 0.47, 95% confidence interval (CI): 0.211 to 1.02 or 1-2 cups/day: HR: 0.31 95% CI: 0.13 to 0.75]. For cognitively normal older subjects who changed their coffee consumption habits, those increasing coffee consumption (>1 cup of coffee/day) had higher rate of the incidence of MCI compared to those with constant habits (up to ±1 cup of coffee/day) (HR: 1.80, 95% CI: 1.11 to 2.92) or those with reduced consumption (<1 cup of coffee/day) (HR: 2.17, 95% CI: 1.16 to 4.08). Finally, there was no significant association between subjects with higher levels of coffee consumption (>2 cups of coffee/day) and the incidence of MCI in comparison with those who never or rarely consumed coffee (HR: 0.26, 95% CI: 0.03 to 2.11). In conclusion, cognitively normal older individuals who increased their coffee consumption had a higher rate of developing MCI, while a constant in time moderate coffee consumption was associated to a reduced rate of the incidence of MCI.
Keywords: Alzheimer’s disease; caffeine use; coffee consumption; dementia; mild cognitive impairment.