Could coffee reverse dementia?

There's one phrase that always depresses me when I read a piece of research—"in mice." Or rats, or whatever unfortunate laboratory animal is involved. It's not just about the ethics of animal testing, rather that it's a long way from results in animals to the same results in humans.

So when I read that giving mice caffeine seems to reverse the effects of dementia, I was suspicious. Surely if coffee worked to treat dementia, we'd already have found that out?

The research was actually quite persuasive, showing that mice that had been bred to develop dementia did much better on a test of memory and thinking (negotiating a maze) after being given caffeinated water for four weeks.

Not only that, but when researchers dissected the mice after the experiment, their brains had fewer of the amyloid plaques that are associated with the damage in dementia, compared to similar mice that had not had caffeine. Now, that's not the sort of experiment you can do in humans.

So could caffeine have a similar effect in humans? Some previous research suggests that coffee drinkers are less likely to get dementia than people who don't drink coffee, although that could be a reflection of other factors.

Researchers are now planning a clinical trial where seniors with mild memory problems are given caffeine to see if it helps. If it does, we could be looking at an exciting development. In the mouse study, the amount of caffeine given was the equivalent of about five cups of coffee a day, which is likely to be safe for most people.

But we still need to be cautious before jumping to conclusions. Until we see the research in humans, the research only applies to genetically-modified mice.

What you need to know. Studies in mice show that caffeine has promise as a treatment for dementia. But we need good-quality studies in humans before we know whether it would work for us. Pregnant women and people with high blood pressure are advised to avoid excessive caffeine.

—Anna Sayburn, patient editor, BMJ Group

ConsumerReportsHealth.org has partnered with The BMJ Group (British Medical Journal) to monitor the latest medical research and assess the evidence to help you decide which news you should use.

Read about how drinking coffee might protect your brain and your heart, find out if you're at risk for dementia, and for more on drugs that treat dementia, see our Treatment Ratings(subscribers only) and our free Best Buy Drugs report.