Life-affirming ways to stave off dementia

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As part of our 30-day Health Kick month, leading science journalist Helen Thomson reveals some scientifically proven ways to boost brain power.

By the time we’re 40, many of us will notice that we can’t remember new names. But it’s not that our brains are overloaded, as we might try to tell ourselves — in fact, our memory capacity is almost unlimited.

Rather, gradual changes in brain structures, such as a reduction in connections between nerve cells, make the creation and retrieval of memories less efficient.

As well as slowing down, certain other memory skills shift to a lower gear with age. Multi-tasking, for instance, becomes more difficult. 

But it’s never too early to start the good habits that will help us in our golden years … 

Keep friendships- and learn the violin 

One option that appears to be beneficial to brain health is being socially active.

Some evidence suggests that being married is strongly associated with a reduced risk of cognitive decline and dementia — in theory because of the regular conversation and mental effort involved in maintaining a good relationship.

But no one type of social contact is better than another, so work on your friendships whenever possible.

Something else you may want to try is learning a language or musical instrument. People who are bilingual develop dementia later than monolinguals, and musical training seems to protect some areas of the brain from decline. 

Your toothbrush is an anti-ageing tool 

Exercising your heart, muscles and lungs can boost brain chemicals that help ward off dementia, while a good diet can add years of healthy cognitive function. Meanwhile, a good night’s sleep can help clear out potentially damaging brain gunk each night.

But perhaps one of the most novel ideas to come from recent studies is that good gum health may be vital to the prevention of cognitive decline.

A 2017 study followed the lives of 8,000 people in China for 13 years, recording their cognitive function and tooth count, and found a strong correlation between tooth loss and a drop in cognitive function, even after accounting for the natural changes that occur in both with age.

Fast-forward to 2019 and a landmark paper offered compelling evidence that Alzheimer’s may be caused by a bacterium involved in gum disease.

For decades, the accumulation of two types of proteins in the brain — amyloid and tau — has been the focus of researchers studying the disease.

The proteins form sticky plaques and tangles that destroy neurons (or nerve cells, the basic working units of the brain). But it has become obvious that trying to clear these proteins isn’t working; Alzheimer’s drug development has had a 99 per cent failure rate.

The landmark paper, published in the journal Science Advances, shone a spotlight on the main bacterium involved in gum disease, Porphyromonas gingivalis.

Previous studies had shown that this bacterium invades and inflames brain regions affected by Alzheimer’s; that gum infections can worsen symptoms in mice with Alzheimer’s; and this can cause Alzheimer’s-like brain inflammation, neural damage and amyloid plaques in healthy mice.

In 2019, scientists reported finding the two enzymes that P. gingivalis uses to feed on tissue in almost all the 54 human Alzheimer’s brain samples they examined. These protein-degrading enzymes are called gingipains, and were found in higher levels in brain tissue that had more tau fragments and more cognitive decline.

If that wasn’t enough, when the researchers looked for signs of P. gingivalis in the brains of healthy people, although they found some, these were at low levels. This supports the theory that P. gingivalis doesn’t get into the brain as a result of Alzheimer’s — but may be the cause.

It is not necessarily the only cause, of course, but for now it might be wise to take care to prevent gum disease just in case. 

Become a memory champion… 

It sounds implausible, but study after study shows it to be true: superior powers of recall are due to well-practised strategies and memory tricks, not any innate talent for remembering.

The brains of ‘mnemonists’, or memory champions, look like everyone else’s — and it is easier to become one than you think.

What you need to practise is the ‘method of loci’. This involves imagining a route you know well, such as your commute to work, and associating the information to be learned with landmarks along that route.

You can retrieve the information later by making the same journey in your mind and visualising the objects connected to each landmark. It really works — scientists have proved it time and again with volunteers who previously had no special powers of recall.

The secret of this trick is that the brain prefers storing images to words and numbers — particularly if you place those images in an orderly location. The more bizarre you can make this imagery, the more easily it will be recalled.

Get on your bike three times a week  

There is one miracle cure that’s guaranteed to slow the ageing processes in your body, including your brain — and that’s exercise.

It can fend off cancer, obesity, diabetes, depression and heart attacks. It prevents more premature deaths than any known medical drug, and when done correctly it has zero side-effects.

It’s only relatively recently that research has begun to highlight the profound effects exercise can have on your mental faculties and wellbeing. But if you were to peer inside the heads of people who like to keep active, you’d see that different exercises strengthen and sculpt the brain just as they do the body, boosting creativity, helping you focus, minimising your stress levels and even curbing your cravings.

This was first suggested in the 1990s, when researchers discovered that exercise cultivated the growth of new neurons in mice. As a result of working out, mice showed improvements in memory that allowed them to navigate mazes better.

Similar indications soon came from humans, too. Older adults who did aerobic exercise (such as running or cycling) three times a week for a year grew larger hippocampi (the hippocampus is a brain area intimately involved in memory), and performed better in tests of memory, according to a 2011 study in the journal Proceedings of the National Academy of Sciences.

Several studies suggest that people with a better grip strength also score higher on tests of attention and reaction time, as well as on assessments of verbal and spatial abilities (though exactly why is unclear).

Combining exercise types might be particularly powerful because strength-training triggers the release of a molecule called insulin-like growth factor-1, a hormone known to affect communication between brain cells, which is the basis of how we learn, and promotes the growth of new neurons. Meanwhile, aerobic exercise boosts a protein called brain-derived neurotrophic factor, which also triggers the growth of neurons and helps them resist age-related decline.

There’s something in it for the kids, too. If you want them to focus for an hour on a maths test, say, the best bet is to let them have a quick runaround first. 

Studies show a 20-minute walk, sprint or skip has immediate effects on children’s attention, executive function and achievement in maths and reading tests. 

Time to put on a wetsuit? 

As an adult, you may want to consider adding any exercise that challenges your sense of proprioception (the position and orientation of your body). Something involving navigation, calculation or locomotion — where you need to balance and think at the same time — is particularly beneficial.

A good example is surfing, where you have to focus attention on staying on the board at the same time as judging the best position to catch a wave and determining whether another surfer might be in your way.

These kinds of exercises have a dramatic effect on our working memory. This is the ability to hold on to information and manipulate it at the same time, allowing us to process what we need and ignore the irrelevant. 

Prioritise your sleep 

A lack of sleep is associated with problems with our immune system, with obesity — and with a raised risk of Alzheimer’s.

Trials suggest fixing sleep problems can slow the rate of cognitive decline and delay the onset of Alzheimer’s by up to ten years.

There are scientifically sound things you can do to help improve your ability to slumber.

First, make sure you feel safe and comfortable where you sleep. Next, keep cool. There is a sweet spot of around 18.5 c at which most people can sleep optimally. And keep it dim: get yourself a blackout curtain or eye mask.

Phones truly make the worst bedfellow, as using them late at night will stimulate the brain and make it harder to sleep.

And stay away from alcohol. Drinking disrupts deep sleep and causes more wakefulness in the second half of the night.

Extracted from This Book Could Fix Your Life by New Scientist and Helen Thomson (John Murray, £14.99). © 2021 Helen Thomson. To order a copy for £13.19 go to mailshop.co.uk/books or call 020 3308 9193. Free UK delivery on orders over £15. Promotional price valid until January 15.