Prime Highlights
- Moderate consumption of caffeinated tea or coffee is linked to a lower risk of dementia and slightly better cognitive performance over time.
- Researchers say the findings support the idea that everyday dietary habits may play a role in maintaining long-term brain health, alongside a healthy lifestyle.
Key Facts
- A US study tracking more than 130,000 people for up to 40 years found that those who drank two to three cups of caffeinated coffee or one to two cups of caffeinated tea daily had a 15–20% lower risk of dementia.
- No clear benefit was seen from decaffeinated coffee, and scientists stress that the study does not prove caffeine directly protects the brain.
Background:
Drinking a moderate amount of tea or coffee each day may be linked to a lower risk of developing dementia and a slower rate of cognitive decline, according to a large long-term study conducted in the United States.
Researchers analysing health data from more than 130,000 adults found that people who regularly consumed two to three cups of caffeinated coffee or one to two cups of caffeinated tea per day were 15–20% less likely to develop dementia compared with those who avoided these drinks altogether. The findings were published in the Journal of the American Medical Association.
However, scientists say the study does not prove caffeine protects the brain, as other health and lifestyle factors may be involved. People who avoid caffeine may already have sleep issues or health problems linked to a higher risk of cognitive decline.
According to the researchers, tea and coffee contain compounds such as caffeine and polyphenols that may support brain health by improving blood vessel function and reducing inflammation and oxidative stress. Caffeine has also been linked to a lower risk of type 2 diabetes, which is known to raise the risk of dementia.
Researchers found that the benefits were strongest with moderate consumption. Drinking more than the recommended amount did not provide extra protection. The study also found no clear link between decaffeinated coffee and a reduced risk of dementia.
Experts say more research is needed to confirm whether tea and coffee directly help slow brain ageing. While long-term clinical trials would be difficult to conduct, future studies may focus on biological markers of brain health.
Medical experts say tea and coffee should not be seen as a cure. A healthy lifestyle, including exercise, a balanced diet, good sleep and controlled blood pressure, is still key to lowering dementia risk.
