The Changing Mind: A Neuroscientist’s Guide to Ageing Well
In the fight against old age, the first battles are with misinformation, pseudoscience and outright quackery. There is a lot of it about. This is where The Changing Mind scores highly. Daniel Levitin is a distinguished American neuroscientist and this is a serious, evidence-based guide to what really works and why. It also tackles what doesn’t work — starting with sudoku and “brain training”. No good, apparently. In fact, the only thing that playing puzzles and games will do, says Levitin, is make you better at playing those same puzzles and games.
No, to counter the tendency of every ageing brain to become inflexible, we have to keep trying new things, specifically “things that require new ways of thinking”. Learning an instrument, for example. Or simply meeting people, because to our highly social brains social novelty is one of the richest challenges of all.
Levitin is sceptical about online socialising for this reason. The addictive dopamine hit you get from a social-media connection, he suspects, is a pale shadow of the rich stew of oxytocin, prolactin and endorphins provoked by “real, actual human contact”. And loneliness is a real danger. It is worse for your health
Levitin’s advice is often unsurprising, but the detail and underlying thinking can be striking. We know that exercise is good, for instance. But not, perhaps, that it is the single best treatment for pain — and not, perhaps, that it works best when performed in natural environments. A path through the woods, for example. It bristles with distractions and hazards — overhanging branches, roots, uneven slopes — all of which make the body and the brain work far harder than, say, plodding on a treadmill. Activity is not the same as exercise, Levitin says; exercise means interacting with a rich environment.
Levitin is 62, and clearly an optimist. He claims that people say they are happiest at the age of 82, and hopes his book will help “raise that number by 10 or 20 years”. His chapter on memory is surprisingly reassuring. So, yes, the hippocampus and medial temporal lobe shrink and decay as we get older, and overall brain volume declines by 5% a decade from the age of 35. Yikes!
But things are not as bad as we fear. It turns out that we have always forgotten words, keys or what we were looking for when we opened the cupboard door. When young, we blame tiredness or stress. When old, we suspect incipient dementia.
Memory tests can be misleading. Older people perform worse partly because they are conducted in unfamiliar environments or at inappropriate times. (Sundowner’s syndrome, whereby some older people become confused in the early evening, is common enough to have its own neurological nickname.) Test an older person at home, at the right time of day, and their performance might hardly differ from that of a student.
Astonishingly, 93% of the variation in tested cognitive performance between old and young could be the result of poor eyesight and hearing. Levitin recommends hearing aids. Some 90% of Americans over the age of 55 wear glasses, he notes, while only 1 in 6 Americans with hearing loss uses a hearing aid. Why rely on one prosthetic, and shun the other?
We can shore up memory by being attentive and mindful, by developing routines and externalising tasks to lists or calendars. (We should also start these habits before we decline, when they will become harder to learn.) We can also tackle sleep. A significant cause of mental decline is tiredness, caused by disruption to our circadian rhythms. Levitin offers lots of useful detail here on things such as melatonin supplements and light therapy; he also suggests the simple solution of taking a walk in the early evening.
A chapter on diet offers similarly straightforward advice. Omega-3 is good, but best eaten in oily fish, not taken as a pill. (Why? For much the same reasons that social media does not work for the brain: we need complex, rich reality, not simplified and commodified versions of it.) Prebiotics and probiotics probably do not work because the stomach acid destroys them before they can reach where they need to go. Vitamin B12 supplements, however, are useful, as are laxatives. “Constipation interferes with cognition.” As for faecal transplants, whereby healthy gut bacteria is introduced from the outside: “Don’t try it at home,” he advises.
There are gaps. Reading this book you might think older people never had sex, for instance. Levitin notes that castrated men live 14 years longer, on average. He alleges that conservative men stop having sex in their late sixties while liberals go on into their eighties. (At least according to one study. Surely dubious.) Otherwise, he has little to say.
The main argument of the book, however, is about mental attitude, not specifics. What best protects our minds against ageing, Levitin insists, is how we approach it. He has his own acronym, inevitably: Coach (curiosity, openness, associations, conscientiousness and health). Even if you are not curious, open or conscientious, Levitin insists that “personality is malleable”. Change is more difficult when you are older, but still possible. The trick is to remind yourself why you are embracing it. The alternative, as the old joke goes, is so much worse.
If there is a fault in the book, it is that Levitin himself is almost too curious and conscientious. If you were just looking for a review of the evidence, you would have to work through thickets of background science. Why your eyesight goes, how glucosamine works, whether you can test musical ability — it’s all here, along with what the Dalai Lama thinks, how Joni Mitchell keeps fit and how irritatingly productive Levitin’s elderly academic colleagues continue to be. (Retirement, apparently, is a disaster. If you can’t keep working, volunteer instead.)
And the overall message? It is this: “Try not to slow down.” I don’t know. I am sure it works, but I was rather hoping that slowing down might be one of the benefits of age.