Daily Coffee Habit Linked to 35% Lower Dementia Risk, Study Finds

A growing body of research suggests that a simple daily habit—drinking coffee or tea—could play a meaningful role in protecting brain health. A massive long-term study now adds weight to this idea, linking moderate caffeine intake to a significantly lower risk of dementia, particularly before the age of 75. But the findings also come with an important caveat: more is not always better.

The study tracked over 131,000 participants for up to 43 years and found that those who consumed moderate amounts of caffeinated coffee or tea were less likely to develop dementia. The most striking benefit was seen in people aged 75 and younger, where consuming around 250mg–300mg of caffeine daily—roughly two to three cups of coffee—was associated with a 35% lower risk.

Scientists believe caffeine may help maintain brain function by keeping key neurotransmitters active while reducing harmful processes linked to cognitive decline. It blocks adenosine, a chemical that slows brain activity, thereby supporting dopamine and acetylcholine—both crucial for memory and cognition. At the same time, caffeine may reduce inflammation and limit the buildup of amyloid plaques, which are strongly associated with Alzheimer’s disease.

Beyond caffeine, coffee and tea contain antioxidants and compounds that support blood vessel health, further contributing to brain protection over time.

Why does the benefit stop after moderate intake?

While moderate caffeine intake appears beneficial, the study found that increasing consumption beyond two to three cups of coffee per day did not provide additional protection. In fact, excessive intake may even counteract the benefits.

One explanation lies in how the body processes caffeine at higher doses. Too much caffeine can disrupt sleep and increase anxiety—both of which are known to negatively impact brain health. This aligns with the Yerkes-Dodson law, a long-standing psychological principle suggesting that performance improves with stimulation only up to a certain point, after which it declines.

The findings reinforce the idea that balance is key. Even though caffeine can enhance alertness and cognitive performance in small amounts, overstimulation may lead to diminishing returns.

What other factors did the study uncover?

The research also highlighted some surprising patterns. Participants who drank more caffeinated coffee were often younger but also more likely to smoke, consume alcohol, and have higher calorie intake—all factors linked to increased dementia risk. Despite this, moderate caffeine consumption still showed protective effects.

An unexpected trend was observed among those who consumed decaffeinated coffee. These individuals experienced faster memory decline, though researchers suggest this may not be due to decaf itself. Instead, it could reflect underlying health issues, as people often switch to decaf due to sleep problems, high blood pressure, or heart conditions—factors already associated with cognitive decline.

The study also found that tea drinkers benefited, with one to two cups per day offering strong protection. Across 38 additional studies analysed, caffeine consumers had a 6% to 16% lower dementia risk overall, reinforcing the broader pattern.

(With inputs from ANI)