New research suggests that a higher coffee consumption is linked with better cognitive health.
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There’s arguably nothing better than starting the day with a hot brew, but the benefits of getting your daily caffeine fix may go far beyond simply energising you in the morning, as a major new study suggests that people who drink tea and coffee have a reduced risk of dementia.
Researchers from Harvard University examined data on 131,000 health workers, finding that those who drank the highest amounts of coffee on a daily basis had a significantly lower dementia risk – around 18% less than those who consumed the lowest.
Meanwhile, those who preferred to drink cups of classic ‘builder’s brew’ tea had a 16% reduction in their dementia risk.
The large-scale study, which analysed 86,000 women and 45,000 men for an average of 43 years, found that people who regularly drank tea and coffee also had better mental skills than those who didn’t.
Is coffee healthy?
There’s been some confusion in recent years about whether drinking coffee is healthy; studies have linked it to poorer sleep, an increased risk of high blood pressure and higher anxiety levels, which have triggered a swathe of TikTok videos from users on a quest to ‘detox’ and quit their caffeine habit.
In the UK, adults are advised to limit caffeine consumption to a maximum of 400mg per day, roughly equivalent to two strong cups of coffee or six cups of breakfast tea.
If you’re pregnant, the Food Standards Agency recommends slightly less: no more than 200mg.
How many cups of tea or coffee reduces your dementia risk?
Alongside finding a link between reduced dementia risk and higher caffeine intake, the researchers were also able to pinpoint the number of cups of tea and coffee each day that could offer associated benefits for brain health.
The Harvard team asked the health workers to fill out questionnaires about their diet every two to four years, including questions about how much caffeinated coffee, decaffeinated coffee and tea they drank.
Alongside this, they got the study group to perform regular cognitive tests – tasks designed to measure how well different parts of the brain are working, such as speed, working memory, attention and decision-making.
During the 43-year follow-up period, the researchers identified 11,033 cases of dementia, an umbrella term for a range of progressive, often degenerative conditions that affect the brain. There are many kinds of dementia, but the most common in the UK is Alzheimer’s disease.
From their findings, the researchers estimated that drinking around two to three cups of caffeinated coffee each day, or one to two cups of tea per day, was linked with the lowest risk of dementia compared to people who abstained entirely.
The health workers who consumed the most tea and coffee also showed a slower rate of cognitive decline compared to those who drank the least.
Figures suggest that the UK drinks about 98 million cups of coffee daily.
(wera Rodsawang via Getty Images)
Overall, the authors said that the most “pronounced association” was among people who drank a “moderate” amount of tea or coffee, with “no additional advantages” among people who consumed more.
Lead author, Yu Zhang from the TH Chan School of Public Health at Harvard University, told the Press Association: “Dementia is one of the most important and challenging public health problems worldwide, and there are still very limited effective treatments.
“So identifying modifiable lifestyle factors that may be linked to dementia risk is critical.
“Coffee and tea are widely consumed globally, so even modest associations could have meaningful population-level implications.”
However, Dr Susan Kohlhaas, executive director of research at Alzheimer’s Research UK, urged readers to approach these findings pragmatically: “This research doesn’t prove that coffee or tea protect the brain. This study shows an association, not a cause-and-effect relationship,” she said.
“People who drink coffee or tea may also differ in other ways that affect brain health, even after careful adjustment, and the study relied partly on self-reported diagnoses.
“It was also conducted in relatively similar groups of health professionals, which limits how widely the results can be applied.”
What other foods and habits may lower dementia risk?
We already know that diet is an important predictor of overall health, and that includes the health of your brain.
In recent years, researchers have been taking a closer look into certain foods that might reduce your risk of developing dementia if consumed regularly and in moderation.
For example, a large Swedish study tracking nearly 28,000 people for 25 years recently found an unexpected link between eating full-fat cheese and brain health.
Among adults who didn’t already have a genetic risk for Alzheimer’s, those who added the fridge favourite to their diet (in moderation) had a noticeably lower risk of developing the disease.
Other studies have looked at the impact of wider diet patterns, finding that sticking to a Mediterranean diet – an eating style inspired by European coastal regions that’s loaded with fruits, vegetables, wholegrains, oily fish and some dairy – could reduce dementia risk by up to 23%.
Your age, genes and exposure to air pollution can all increase your likelihood of developing dementia, but the NHS say you can generally reduce your risk by:
Maintaining a healthy weight
keeping alcohol within recommended limits
Keeping your blood pressure at a healthy level
Added to this, additional research studies have linked prioritising good oral health, including regular flossing to remove levels of harmful bacteria in your mouth, with a significantly lower risk of cognitive decline.
There’s also strong emerging evidence correlating higher risks of dementia with untreated depression, hearing loss, loneliness and sitting down for large portions of the day.