When the Australian broadcaster and physician Dr Norman Swan set out to investigate the science of ageing brains, he expected a story about loss. Instead, what he found was something far more uplifting: a roadmap for pushing back what he calls the “brain cliff” — that dreaded point where cognitive function takes a steep dive.
In his new book, The Brain Cliff, Swan distils years of research and interviews with extraordinary individuals he calls “cognitive super-agers” into a practical manifesto for keeping the mind sharp well into later life. The good news, he says, is that genetics plays a smaller role than most of us assume. How we live — what we eat, how we move, whether we ruminate or recover — matters enormously.
“I’ve no intention of retiring,” Swan, who is well known in Australia as the host of the ABC’s Health Report, tells The Update Desk. “Retirement is bad for your brain. So the ABC will have to sack me.”
Change, not decline
One of the most damaging myths about midlife, Swan argues, is the assumption that the brain is in a state of deterioration. It is not. It is in a state of change.
Our fluid intelligence — the speed and quick problem-solving of youth — does peak in our 20s. But for most of us, that matters far less than crystallised intelligence: the accumulated wisdom and knowledge that can actually grow stronger with age. Comparing a 55-year-old brain to a 25-year-old brain is simply not a valid benchmark, he says, and dwelling on the perceived gap only makes matters worse.
The real story is what neuroscientists call scaffolding. As the years pass, the brain builds out networks of supporting nerve cells, much like the metal frame around a skyscraper under construction. These networks wrap around our existing cognitive abilities, protecting them and, in some cases, enhancing them. The stronger the scaffolding, the further away the cliff edge.
“The more successfully we scaffold, the further away we push the brain cliff,” Swan explains.
Scaffolding initially spreads across broader brain regions before concentrating in the prefrontal cortex — the area responsible for judgment, emotional regulation and decision-making. This is where rumination, depression and alcohol all do their worst damage. Anything that interferes with the prefrontal cortex brings the cliff closer.
What super-agers have in common
To understand what scaffolding looks like in practice, Swan interviewed seven people he considers cognitive super-agers. They include a 95-year-old illiterate shoemaker, a 94-year-old woman still working at McDonald’s in Kyushu, Japan, and a woman who once taught Mick Jagger statistics.
They are wildly different on the surface. Underneath, though, they share striking similarities.
“They get over it. They problem-solve. They don’t ruminate,” Swan says. Where most of us get stuck circling the same anxious thoughts, super-agers move on — and that matters because rumination occupies the very brain space we need for higher cognitive function.
Genes, Swan emphasises, account for far less of the variation than people imagine. Lifestyle, environment and daily habits are the real determinants.
One surprising case was a 100-year-old neuropsychiatrist from New Jersey whose family history might have suggested an inevitable decline. Instead, he had taken up pencil drawing, attended classes and built a fresh social circle — actively rewiring his brain through novelty and connection.
Exercise, diet and the wandering mind
The practical prescriptions in The Brain Cliff will be familiar to anyone who follows health news, but Swan argues the evidence is now strong enough to act on with confidence.
Regular moderate-to-vigorous exercise enhances brain plasticity, which in turn encourages scaffolding. An anti-inflammatory diet — leafy greens, berries, yoghurt and fermented foods, with red meat kept to a minimum — supports the gut microbiome and the direct absorption of bioactive compounds that help build neural infrastructure.
One of the more unexpected recommendations is to let the mind drift. When the brain enters its “default mode network” — that daydreaming state during which disparate regions begin chatting to one another — scaffolding appears to strengthen. Mental time travel, whether reliving old memories, savouring the present or imagining the future, seems to be particularly potent in midlife, when the balance between past and future is at its most useful.
“Mental time travel and mind wandering seem to encourage our scaffolding,” Swan notes.
The case against retirement
Swan is unequivocal on the subject of stopping work. The evidence, he says, is robust: cognitive decline accelerates after retirement. But he is careful to define what he means. Trading a career for volunteering, learning complex new skills or deep engagement with hobbies is not retirement — it is simply different work.
What damages the brain is the couch-and-Netflix version of later life, where stimulation dries up and social circles shrink. Swan himself has overhauled his own habits in the course of writing the book. He has become more vigilant about catching himself in rumination, has cut back on alcohol, watches his cholesterol and blood pressure closely, and treats vigorous exercise as non-negotiable.
For those struggling with rumination or chronic stress, he recommends seeking help. Variations on cognitive behavioural therapy, delivered by a well-trained clinical psychologist, can be transformative.
Why it Matters
The looming fear of cognitive decline has become one of the defining anxieties of midlife, and dementia rates continue to climb across ageing populations worldwide. Swan’s central message — that we have far more agency than we assume — challenges the fatalism that often surrounds brain health. With midlife now understood as a critical window for building the neural scaffolding that will support decades of thinking ahead, the choices made in one’s 40s and 50s carry consequences that ripple into the 80s and beyond. For employers, healthcare systems and policymakers, the implication is profound: keeping people engaged, connected and mentally active may matter just as much as any pill yet developed.