Can daily coffee or tea intake slow cognitive decline in older adults?

Drinking coffee or tea daily appears to be associated with slower cognitive decline, particularly fluid intelligence, in older adults, according to a recent study presented at AAIC 2024.

“Several observational and epidemiological studies have shown consistent evidence that coffee and tea intake have beneficial effects on stroke, heart failure, cancers, diabetes, and Parkinson's disease,” said study author Dr Kelsey Sewell from Murdoch University in Perth, Australia.

Fluid intelligence is defined as reasoning ability, and the ability to generate, transform, and manipulate different types of novel information in real time. [https://doi.org/10.1016/B978-0-12-417148-0.00008-X] Fluid intelligence declines with advancing age, starting in early adulthood. [Wellcome Open Res 2018;3:38]

Using data from the UK Biobank, the researchers analysed 8,451 cognitively unimpaired older adults (mean age 67.8 years, 60 percent female) with self-reported daily intake of coffee and tea at baseline. Coffee and tea consumption was categorized as never, moderate (1–3 cups/day), and high (≥4 cups/day). Cognitive function assessments were performed using pair matching, reaction time, numeric memory tests, and fluid intelligence. [Sewell K, et al, AAIC 2024]

Compared with those who consumed ≥4 cups/day of coffee, a slower decline in fluid intelligence was observed among those who consumed 1–3 cups/day of coffee (β=0.07; p<0.001) as well as those who never drank coffee (β=0.06; p=0.005).

“These results show an upper limit to coffee intake with a maximum of 3 cups per day being consumed for beneficial effects, and no coffee intake being more beneficial than ≥4 cups per day,” said the researchers.

In terms of tea consumption, with a different pattern of results, those who had never consumed tea had a greater decline in fluid intelligence than those who consumed moderate or high amounts of tea (β=0.06 for both; p=0.009 and p=0.003, respectively).

“Conversely, high tea consumption provided positive effects on cognition in addition to moderate consumption, with high tea consumption being more beneficial than no tea consumption,” the researchers noted.

Taken together, based on the observed dose-response effect, drinking a maximum of three cups of coffee per day or more than one cup of tea per day was associated with benefits, according to Sewell.

“Overall, our results further support the hypothesis that both coffee and tea intake may be a protective factor against cognitive decline, particularly for maintaining fluid intelligence,” said Sewell.