What keeps your memory sharp in later life?

Not everything in memory declines with age. Processing speed, working memory and attention show the steepest drops, but language, general knowledge and visual perception remain largely intact. The difficulty older adults have with remembering usually lies in retrieving information, not in storing it. What is more, older adults recall positive and personally meaningful things remarkably well. If you want to learn something new, make it relevant to yourself.

Sleep is one of the most concrete levers available. During deep sleep, memories are consolidated. As we age, that deep sleep gradually diminishes, and this is associated with poorer memory consolidation, particularly for skill-based tasks. Sleep disorders also increase the risk of dementia. Getting good sleep is therefore not a luxury, but an active memory tool.

Diet has a modest but measurable effect. People who follow the MIND diet, a combination of the Mediterranean diet and the DASH diet, focused on vegetables, berries, nuts, fish and little red meat, showed a lower risk of dementia and better overall cognition in several large population studies. However, the effect on decline over time is less clear: only a minority of long-running studies found a benefit. The evidence also comes almost entirely from observational research in North America, so certainty about cause and effect is lacking.

Targeted cognitive training can also help. Adults aged 60 to 85 who trained with a specially designed multitask video game subsequently outperformed untrained twenty-year-olds on tasks measuring cognitive control, working memory and attention. That gain lasted six months. This is not evidence that every brain game works, but it does show that targeted, adaptive training can measurably improve the brain in later life.

Finally, research into so-called 'superagers', people in their eighties with the memory of a fifty-year-old, shows that memory decline at an advanced age is not inevitable. Their brains are structurally younger, with greater volume and fewer signs of Alzheimer's-related damage. Which factors provide that protection has not yet been established. Alongside this, there is preliminary evidence that chronic exposure to UV radiation may suppress the formation of new brain cells via stress hormones. This has been little studied in humans and should not be treated as settled fact at this point.