Caffeine and the risk of dementia
Learn about research into the link between drinks containing caffeine, such as tea and coffee, and the risk of developing dementia.
Can caffeine increase the risk of dementia?
There is no strong evidence to say that caffeine increases a person’s risk of developing dementia.
The effects of caffeine on the risk of developing dementia have been studied many times. These studies can attract quite a bit of media attention, but this can often overstate the impact of the research.
Some studies have shown that caffeine in coffee and tea may reduce dementia risk by a small amount, while other studies show no effect or a slightly increased risk.
How to reduce the risk of dementia
A lifelong approach to good health is the best way to lower your risk of dementia.
There are some lifestyle behaviours with enough evidence to show that changing them will reduce your risk of dementia.
Studies into caffeine and dementia risk work in one of two ways:
- Whether people who drink caffeinated drinks are more likely to develop dementia than those who don’t
- Studying coffee and tea drinking in people with memory and thinking problems or dementia
One report that collected findings from many studies suggested that caffeine reduces dementia risk, but only in women. There was also a study that looked at caffeine intake and dementia in groups of people in the UK and USA, which found opposite effects between the two groups.
These types of studies cannot be relied on for a definitive answer as they cannot show the cause and effect. It is difficult to determine if the caffeine levels affected dementia, or if it is the other way around. For example, sleeping problems brought on by dementia might cause someone to give up caffeine. These studies often require self-reporting of caffeine intake, which can be unreliable.
The best way to find out if caffeine is linked to changes in dementia progression is a randomised controlled trial. This is where people are randomly split into two groups and given caffeine or a placebo and then monitored over time. Only one study into the effects of caffeine is active at the moment and is due to end in 2024.
Research looks at how caffeine acts on the brain to help understand if there really is a connection between caffeine and dementia risk.
These studies are not normally done in humans as they need to look at the brain and brain cells in more detailed ways. Instead, animals - often mice - are sometimes used. These can be bred with genetic mutations to simulate Alzheimer’s disease.
Some of these studies showed that caffeine can reduce memory and thinking decline. Research in mice also showed that caffeine decreases the build-up of amyloid and reduces inflammation and cell death in the brain.
While this research suggests how caffeine may reduce dementia risk, it has only been shown in mice and not humans. The connection in humans is still not certain. Therefore, more research needs to establish if caffeine is beneficial for reducing dementia risk.
Further reading
Alzheimer's Society dementia support line
Call 0333 150 3456.
If you are affected by dementia, worried about a diagnosis or a carer, trained staff are ready to give you the support you need. Opening hours (excluding bank holidays): Mon to Weds: 9am – 8pm, Thurs and Fri: 9am – 5pm, Sat and Sun: 10am – 4pm.
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