Can your morning coffee really prevent dementia?

Your morning coffee might be helping to ward off the onset of Alzheimer’s disease, a new study from Italy has found.

The latest research by the University of Verona shows that compounds found in a rich, dark shot of espresso coffee can inhibit the development of rogue tau proteins, which are linked to the development of Alzheimer’s, Parkinson’s and dementia.

This is encouraging to those of us worried about the possibility of living with Alzheimer’s and Parkinson’s in the future – and follows the good news last year of successful clinical trials of donanemab, a drug that slows mental decline.

The science

Coffee has "remarkable" powers

Previous studies have also found a link between drinking coffee and lower risk of dementia. This study showed that coffee works to control tau proteins, which can clump together in the brain to form longer ‘fibrils’ or tangles and affect healthy neurons. This protein ‘clumping’ can lead to slower thinking and poor memory skills, but the experiment showed that drinking the ingredients in an espresso can stop the aggressive and damaging process.

The study looked at the effects of coffee extract (made from espresso), and also looked separately at the effects of caffeine and genistein, a type of antioxidant found in coffee (and some vegetables such as broad beans and soya beans).

All three substances showed improvements, but the coffee extract had the strongest effect. It’s important to understand that this research was carried out on cells in a test tube, not on humans. This study also can’t tell us how much coffee you would need to drink to experience any positive effects. The new report, published in the Journal of Agricultural Food and Chemistry, described the effect of coffee on cells as “remarkable”.

“Even in the presence of low quantities of the mixture, the formation of long fibrils was compromised and only a few short fibrils were visible. The coffee extract at high concentrations strongly interfered with fibril formation,” it reports.

Coffee and your health

There are lots of benefits but more research is needed

Coffee used to have a question mark over its healthy properties, but research in the last ten years has shown that drinking it moderately is linked to a lower chance of type 2 diabetes, heart disease and depression.

Last year, a study by UK Biobank showed that over-50s who drank light to moderate amounts of coffee (up to three cups a day) had a lower risk of heart disease and stroke. GP Dr Thuva Amuthan is cautiously optimistic about today’s developments. “Anyone who’s come into contact with Alzheimer’s and dementia would welcome this news,” says Amuthan.

“Many studies have shown the positive effects of coffee on Alzheimer’s and dementia, but we’re yet to have a randomised study (in humans) that shows a direct link. It would be difficult to do that because it would take a very long time, but this latest research adds to that body of evidence of a positive link. It’s important to carry on looking into the causes of dementia because it’s becoming more of a care need as we live longer.”

Similarly, the Alzheimer’s Society has this to say about studies looking at coffee and dementia risk: “The gold standard for this type of research is a randomised controlled trial, where people are randomly split into two groups – one with caffeine and one without – and they are monitored over time. However, there have been no studies of this kind to confirm the link.”

How to drink coffee wisely

Just don't go overboard

You might be tempted to increase your cappuccino habit in the light of the latest news, but Amuthan is keen to stress the importance of balancing the benefits with the risks of too much caffeine.

“Everything in moderation is good, and for a lot of people that warm cup of coffee is your morning pick-me-up. It lifts your mood, which is a positive impact we all know about,” he says.

“The downside is that if you have too much coffee, your body gets used to it and so you lose the effect. Remember that coffee is a diuretic too, so if you drink too much you’ll find yourself needing to pee more.” And although your morning coffee can give you a much-needed energy boost, it’s sensible to only drink it in the day so you don’t find yourself wide awake when you need to wind down at bedtime.

“I’d personally go with no more than two cups of coffee a day and I try not to drink it past 6pm if I want to be in bed and asleep by 10pm,” says Amuthan. “If you have irritable bladder or urinary problems, you need to be even more cautious because it could make them worse.

And if you’ve got a fast-beating heart then you need to steer clear of caffeine altogether, but you could try decaf as a substitute if you still want to drink coffee.”