Promising new medicines are on their way to treat dementia. A recent trial of the drug donanemab has shown it slows progression of Alzheimer’s – the most common form of dementia – by up to 35%. The drug clears away the brain amyloid plaques believed to play a role in the disease. Other therapies that work in a similar way have now been approved in the US by the Food and Drug Administration. These aren’t cures however, and won’t improve a patient’s cognitive abilities, only delay decline when Alzheimer’s is caught in the early stages.
“It is good news that we’re developing drugs, but they do have side effects and they won’t be for everyone,” says Joanne Ryan, head of the dementia research unit at Monash University’s School of Public Health and Preventive Medicine in Melbourne.
Ryan’s focus is on keeping the brain healthy as we age. “It’s not just about dementia prevention, but about remaining as cognitively active and engaged as we can so we can continue to do the things we love and be independent for as long as possible,” she says.
Her latest research has involved drilling down into data from a longitudinal healthy-ageing study, the ASPREE trial, to find out which kinds of activities have the greatest brain benefits.
Involving more than 10,000 older Australians, it shows a clear win for active mental pursuits such as playing cards or chess and doing puzzles. These were associated with an 11% lower risk of dementia, as were adult literacy activities such as writing a journal, using a computer or taking education classes.
With all those pursuits, you have to use multiple areas of the brain and process new information. “They require memory, critical thinking, strategy, problem-solving,” says Ryan. “What seems most beneficial for the brain is to be constantly learning new things and challenging yourself.”
Creative activities such as painting or drawing and passive mental activities such as reading books or listening to music are also associated with reduced dementia risk, but to a lesser extent. The thinking is some creative pursuits, once you do them a number of times, may become routine and don’t require high-level thinking.
“We found men benefited more from creative activities than women and we think it’s because those activities are different – men were more likely to engage in things like woodwork.”
Interestingly, being socially connected and going on lots of outings does not show up as a protective factor against dementia as other studies have suggested. Ryan suspects the results were skewed by the fact most participants in the ASPREE trial had moderate to large social networks.
Another recent clinical trial, by the Lawson Health Research Institute in Canada, suggests combining mentally challenging activities with physical exercise may be the way to go. Working with participants aged 65-84 who had mild cognitive impairment, the researchers found that 30 minutes of computerised brain exercises followed by 60 minutes of aerobic and resistance training significantly improved cognition.
Episodic memory, attention and orientation all benefited and the effects were still seen a year on. Balancing and toning exercises weren’t effective though.
Getting enough rest is also important for healthy brains. There is new science to show that sleeping for fewer than six hours a night leads to faster cognitive decline for those in their fifties and sixties even if they are active.
And mental health is also involved, although it isn’t yet clear exactly how.
“There’s definitely a link between depression and dementia,” says Ryan. “But it’s quite challenging to tease apart. Depression can be misdiagnosed as dementia because sometimes when a person is depressed they’re not functioning cognitively as well as they should be. We also think they may have a common genetic basis and risk factors.”
In 2022, 55 million people worldwide were living with dementia. According to the World Health Organisation, 10 million new cases are emerging a year.
Prevention is the first line of defence. Evidence abounds of the benefits of physical activity and a Mediterranean-style diet rich in fruits and vegetables. Now, there is more showing regular mental workouts are likely to have a positive pay-off too. “I encourage people to learn new things and take part in activities that challenge the mind,” says Ryan. “But find something you enjoy– don’t learn chess if you hate it.”
