When we talk about healthy brain ageing we are really discussing one of two things: how to minimise ongoing damage to the hardware of the brain, mostly by keeping its blood supply as good as possible; or how to improve the operation of the brain’s software. Many ways of doing this have been suggested, but few have _______ weight behind them. There is currently no magic bullet to protect the brain, but one area that has been best researched, and about which we can say with reasonable _______ , “this will help”, is mental activity.

There is plenty of evidence that older people who stay mentally active, by learning a new language, doing crosswords or taking part in other _______ challenging activities, preserve full cognitive function for longer. They have spent more time doing cognitively demanding activities over a lifetime, and they are, to some extent, buffered (缓冲) from the _______ effects of brain ageing and degenerative (退行性的) diseases. We call this buffer “cognitive reserve” — a(n) _______ reservoir of brain function that can _______ from the consequences of brain damage, allowing us to continue to perform well. _______, people with a higher IQ, longer education or cognitively challenging employment have been found to have a(n) _______ risk of developing dementia. This is despite the fact that their brains actually show normal amounts of age-and disease-related _______.   In fact, studies have found that people with higher cognitive reserve who do get dementia exhibit less severe symptoms even when they have more brain damage than those with lower cognitive reserve.

Yet there’s still much to discover about the _______ of cognitive reserve for optimising the brain’s resilience. The more we understand about its role in protecting our brain and how to boost our reserve, the more effective we will be in designing _______ to keep the human brain healthier for longer.

The good news is that cognitive reserve isn’t _______ to those who have the IQ of a genius or who’ve devoted their life to theoretical physics. We think it can be _______ throughout life for everyone. _______, taking part in cognitively challenging activities, learning new skills and continuing to “use it or lose it” probably apply no matter how old you are. Crucially, it’s never too late to _______.