DR MICHAEL MOSLEY: Cheer up… this is how faking a smile could help you live to be 100 years old!

A friend’s father recently died at the fine old age of 98. He hadn’t had a particularly healthy lifestyle — he smoked and drank quite a bit in his youth, and fought in tanks in World War II. He attributed his longevity to the support of his wife and an exceptionally positive outlook on life.

So was he right? In fact, there’s a wealth of evidence that feeling positive about your life, and about growing older, has a striking impact on longevity.

And now a study just published in the Journal of Happiness Studies has identified six other aspects of personality linked to an exceptional old age. The study was based on data from Spanish centenarians, ranging in age from 100 to 107: as well as positivity — feeling grateful for life and celebrating the good things that happen — the centenarians all exuded vitality, loved learning new things, were conscientious, sociable, intellectually curious, self-reliant and resilient.

I am a bit of an Eeyore, with a tendency to expect the worst and look on the dark side of life, so I’ve long been interested in research on the impact of personality on life expectancy.

A decade ago I made a documentary on the science behind such claims and came across a social experiment with truly fascinating implications for longevity.

In a study that began in the 1970s in the small town of Oxford, Ohio, in the American Midwest, all the residents aged over 50 were asked to fill in questionnaires covering their jobs, health, family and attitudes towards growing older.

Decades later, researchers from Yale University went back to those people and found that being an optimist was a strong predictor of how long they were likely to live. Death records showed that those who had felt most optimistic about their lives and getting old then lived on average about seven-and-a-half years longer than those who didn’t.

To put these results in context, if we could cure cancer tomorrow it would add, on average, half as much as that — three to four years — to life expectancy.

Why ‘being positive’ leads to a longer life is not clear, but it could be that optimistic people seek out and get more social support from others, and are less likely to suffer from chronic stress, which we know can affect your immune system and shorten your life. Further evidence for the role of the immune system in linking personality type and longevity came in a study published in the journal Brain, Behaviour, and Immunity, in 2021.

Researchers from the University of Limerick compared the results of personality tests against blood samples from more than 900 older adults over a 14-year period — amazingly, just as with the Spanish study, those who scored higher for being conscientious lived an average 35 per cent longer. Additionally, they had significantly lower levels of interleukin-6, a measure of chronic inflammation that, in turn, is linked to a lower risk of heart disease, cancer, depression and dementia.

As for the other personality characteristics linked to longevity, the researchers think being sociable and intellectually curious means you’re more likely to look after your health; and being resilient means you have a greater sense of purpose — in other words, a reason to get out of bed in the morning.

If, like me, you’re not a naturally positive, conscientious, happy soul, here are a few things that I’ve found helpful:

• Set yourself small, simple goals, and pat yourself on the back when you have achieved them. This is the basis of my podcast series, Just One Thing, as there’s plenty of evidence that as well as the benefits you get from doing the ‘thing’, you also benefit from the sense of achievement of having taken a small, positive step.

• Practise gratitude meditations. My brother-in-law, who teaches at the Oxford Mindfulness Centre, suggested I put aside a few minutes each day for writing down or just reflecting on everyday things I can be grateful about. I find doing this really does help me to focus more on the positive.

• Keep your friends and family close, and extend your social network. Easier said than done, I know, but there’s abundant evidence that having close friends is one of the most important forms of protection against stress and premature ageing. One of the best things I’ve done on this front was joining a book club more than 20 years ago, as it’s provided me with a really diverse social network.

• Striking up conversations with strangers on planes and trains, even queuing to buy a coffee, is also meant to be good, but I can’t quite bring myself to do it.

• Try to reframe situations: when I catch myself having catastrophising thoughts about the future, I aim to remember that these thoughts are not real and that things will probably turn out fine. Which they usually do.

• And smile. I’ve noticed that when people take photos of me, off guard, I am rarely smiling. Yet a study of nearly 4,000 people, published in Nature Human Behaviour last year found that even faking a smile does have an effect on reducing stress and boosting happiness, albeit a small one.

Whether such attempts to tweak my underlying Eeyore personality will help me live to 100, only time will tell. But at least I’m more fun to have around.

Save YOUR marriage from a sleep divorce

I was struck by the recent article in the Mail where Susannah Constantine described her ‘sleep divorce’ from her husband — moving into a separate bedroom because of the terrible impact her loud snoring was having on their sleep.

‘Sleep divorce’ is very common. A survey last year suggested that five million UK couples sleep in separate beds to improve their sleep, and more than half of us currently sharing a bed are thinking about sleeping elsewhere.

Not surprisingly, the most common reason is a partner’s snoring. I’ve thought about moving into another room — not because my wife Clare snores, but because she’s prone to sleepwalking and talking; she often gets out of bed in the middle of the night, turns on the lights, and starts looking in the cupboards for hamsters, patients, or something else she’s convinced has gone missing.

All while completely sound asleep. After a few minutes she gets back into bed, with no memory of any of this the following morning.

But I value the closeness (and warmth) too much to ask for a sleep divorce. However, if you’re on the brink of your own sleep divorce, there are steps to avoid it.

If snoring is the issue, tackle it by losing weight, avoiding alcohol late at night and (after speaking to your dentist) investing in a mandibular advancement device (a mouthguard that stops your tongue blocking your airways).

And if it’s a partner’s twitching, or duvet hogging, try a bigger bed — and a second duvet.

If all else fails, every night before you move off to your separate bedroom, make time for a chat and a snuggle. Staying intimate is one of the best ways to help keep ‘real’ divorce off the cards.

What do Jeremy Clarkson and I have in common? Apart from being ageing males occasionally on television, it turns out we both suffer from hearing loss; in his case, bad enough to get a hearing aid.

This could more than halve his risk of developing dementia, as we know from research. And now, thanks to a team from the University of California San Diego, we also know why poor hearing is linked to dementia: it seems the extra effort involved with trying to hear causes changes in the brain that, in turn, lead to the increased risk of dementia.

Perhaps next time we meet, Jeremy and I will be comparing the latest ear trumpets.

Who doesn’t secretly yearn for a pill that offers the benefits of exercise without the tedious huffing and puffing. 

Well, researchers at the University of Florida have now had some success with this (in mice studies, at least), with a drug called SLU-PP-332. 

This targets proteins that, in turn, make energy-hungry tissues such as muscles, more active. 

An ‘exercise mimetic’, the drug doesn’t replace exercise, but boosts its impact, leading to weight loss and greater fitness. The researchers think it could help maintain muscle mass as you get older, when the impact of exercise tends to be reduced.