Coffee, Tea Consumption Linked to Dementia Risk, Study Examines Amount You Drink

Moderate caffeine intake in midlife may be linked to a lower risk of dementia in later life, according to a perspective published in npj Dementia.

The article reviewed evidence from prospective studies, meta-analyses and experimental research, suggesting that moderate coffee and tea consumption may offer more benefits than very low or high intake. However, researchers stressed that the evidence does not prove caffeine prevents dementia.

One prospective cohort study found an 18% lower dementia risk with 2-3 cups of caffeinated coffee and a 14% lower risk with 1-2 cups of tea. Among people aged 75 or younger, the association was stronger. Another study suggested that genetic differences in caffeine metabolism may influence the relationship. People with a slower-metabolising CYP1A2 variant showed lower dementia risk with higher coffee consumption, while fast metabolisers did not show the same benefit and could have increased risk at high doses.

UK Biobank data from 8,715 adults aged 60-85 linked moderate coffee and tea consumption with slower declines in cognitive abilities, including fluid intelligence. However, higher coffee intake was associated with more visual memory errors.

Researchers proposed several possible mechanisms. Caffeine blocks adenosine receptors, increasing neural activity and potentially supporting complex brain-network function. Coffee and tea compounds may reduce oxidative stress and neuroinflammation. Some research, however, has linked caffeine or coffee consumption with reduced brain grey matter, although the significance of this remains still uncertain today.

The authors highlighted that genetics, age, beverage preparation and ingredients such as milk and sugar could influence caffeine’s effects. They noted that South Asian populations require further study because tea is commonly consumed with milk and sugar.

Importantly, most evidence remains observational, with possible confounding, measurement errors and reverse causality. Randomised trials testing whether caffeine can prevent dementia are still lacking.

REFERENCE: Balakrishnan, R., Subbarayan, R., & Shrestha, R. (2026). Midlife window: Moderate caffeine consumption and reduced dementia risk. Npj Dementia, 2(1), 79. DOI: 10.1038/s44400-026-00134-3, https://www.nature.com/articles/s44400-026-00134-3