When her daughter was born, Marta Zaraska was determined that nothing but the best would do. “Goji berries, chia seeds, kale: I was going crazy scouring the shops for the healthiest food,” she says. “All these things that I thought would make sure she lived to be 100.” And then it occurred to her that how we live our lives might be more important than the latest miracle food or exercise gadget. Being a science journalist with a training in law, however, she wanted proof.
She began looking through hundreds of academic papers and interviewing scores of researchers about extreme experiments with mice and monkeys, and scary biological phenomena such as zombie cells (AKA senescent cells, the bloated, not-quite dead matter that accumulates as we age, belching out toxins and turning other cells into zombies). Her research expanded beyond the scientific, taking in a Portuguese longevity bootcamp, a Polish hugging salon and a flower-pressing session for Japanese octogenarians before circling back to France, home to the world’s oldest certified centenarian.
By the time Jeanne Calment died, in a nursing home in Arles, on 4 August 1997, aged 122 years and 164 days, she had become a poster girl for longevity (although quite how long she lived has been disputed by some). She claimed to have known Van Gogh and regaled journalists with tales of her smoking and drinking. “But these were lies,” writes Zaraska. Calment only picked up smoking for two years, well after her 110th birthday. Zaraska warns of falling for longevity yarns, many of which turn out to be the product of fantasy.
Having witnessed the decline of various elderly relatives, I tell her I am pretty sure I don’t want to live to 100. But she tells me Calment’s importance isn’t simply her age, but the fact that she was in good health until weeks before her death: “Studies show that the longer you live, the higher the likelihood of staying in close to perfect shape and dying while gardening or roller-blading across the globe.” While the average person will spend almost 18% of their lives struggling with disease, for a supercentenarian that proportion falls to 5%.
Although public records show that Calment came from a line of long-lived people, Zaraska says that “how long we live is only 20% to – 25% heritable”. A gerontologist who knew Calment and researched her case argued that her love of interviews, and even her fibs (she admitted to telling journalists anything they wanted to hear), might have been key. “She was strong, rebellious, curious about the world and fiercely independent.” Crucially, she was an optimist.
So, what are your chances if you are none of those things? It is hardly news that unhappy people generally don’t live as long as happy ones. Zaraska contends, though, that one of the most damaging forms of unhappiness is loneliness. Thankfully – for those of us still in a state of semi-lockdown – this is not the same as being socially isolated. While lockdown was still in place in Zaraska’s village in northern France, the health workers were cheered every night. “You couldn’t see people, but you could hear them; you knew you were doing something together.” Loneliness is different: “You can have plenty of people around you and still feel lonely.”
It all goes back to our hunter-gatherer past and the different strategies needed to protect ourselves. The feeling of loneliness signalled the sort of isolation that put early humans in danger of animal attack. In the absence of passing lions, it now generates a constant, low-burning stress. This could lead to chronic inflammation, which is associated with everything from cancer and rheumatoid arthritis to diabetes and Alzheimer’s.
Calment may have been an outlier, but Zaraska believes that France has a message to share. “The average French person lives over four years longer than the average American – but don’t assume it’s all to do with the Mediterranean diet,” she writes. “The French do obsess about their eating – just about a very different aspect of it.” More than two-thirds of French people in their 30s and 40s eat dinner with their family, compared with 24% of Americans. “Maybe,” she says, “the life-prolonging aspect of the Mediterranean diet is not the amount of vegetables and olive oil it contains, but the way these foods are eaten: together with others.”
The statistics Zaraska has unearthed to support her thesis are startling. Sticking to the Mediterranean diet – rich in fruit and vegetables; olive oil in place of butter – may reduce your chance of premature death by 21%. Having a large network of friends, though, will cut it by 45%. Having a happy marriage will pretty much halve it.
Put them all together, she says, and you may even arrive at “the Roseto effect”. In the early 60s, the inhabitants of Roseto, Pennsylvania, were found to have very low rates of heart disease, for all that they smoked, drank and loved sausages cooked in lard (being overweight is not, statistically, a hindrance to living into old age, provided that your BMI does not stray into serious obesity).
The phenomenon was ascribed to the extreme sociability of a community of Italian immigrants who had forgotten all about the Mediterranean diet, but not about the lifestyle that went with it. Were they to abandon their neighbourly habits, a local doctor warned, their health would deteriorate. And so it came to pass. By the end of the 70s, Zaraska writes, Rosetans had succumbed to the American dream of bigger, more remote houses, reached by car rather than on foot – and had a mortality rate similar to other places in the US.
It is on the subject of personality that the book is most surprising. Extroverts tend to outlive introverts, says Zaraska, citing surveys from the US, Japan, Sweden and the Netherlands. One Dutch study claimed that each extra person in a network of regular interactions lowered the risk of dying within five years by 2%. But even if you are very introverted, there are things you can do to improve your prospects. Such as? “Don’t worry about your lack of a wide friendship group. Take good care of the few close friends you do have.”
Cheeringly, personality traits are not set in stone. They are a compound of faults and behaviours that add up over time, and can be tackled through therapy, meditation and self-discipline – although some are harder to shift than others. “If you were to pick one personality trait to work on in order to increase your chances, go for conscientiousness,” she says. As traits go, it is relatively easy to change. “Keep your office neat, organise your sock drawer, set your clothes out the night before.”
As someone who has always been a bit of a slouch in the sock drawer department, I find this alarming. How does extreme tidiness square with the idea of a harmonious family life – or of becoming a centenarian?
Conscientious people are more likely to do things that are good for them. “We invest so much money in expensive clinical trials that promise extravagant therapies to reverse ageing,” she writes. “But maybe we should just do things that are already known to work, such as volunteering, making friends and learning optimism. If we invest more in being kind, mindful and conscientious, we are more likely to improve the conditions in which we all live.”
Five easy steps to prolong your life
Offer to mow your neighbour’s lawn
Helping other people boosts your sense of wellbeing, and by extension your health, but it is most effective if it is local and involves direct personal contact. If you can combine it with a bit of exercise, bingo.
Don’t obsess about organic food and supplements
It is healthier to make time for a cup of coffee with your partner than to spend hours sourcing and concocting a perfect meal. Plus, according to some studies, the “obesity paradox” means that people with a BMI of between 30 and 35 have a better chance of surviving a range of common diseases than those who are thinner.
Work on your friendships
A happy social life will not only make you feel more optimistic, but will reduce the toxins generated by loneliness. If it has to be via social media for the time being, so be it, but beware of “phubbing” your nearest and dearest – snubbing them in favour of all those phone friends will make them feel lonely and stressed.
Attend to your ikigai
In Japan, which has one of the best longevity records, older people keep themselves busy either with work or with organised hobbies, in the interest of maintaining their ikigai – their purpose in life.
Tidy that sock drawer
Practise self-discipline in whatever way suits you, whether yoga, meditation or mindfulness. It will help you to be your best self and may even lead to you living until you are 100 – provided you don’t get too stressed about it.
Growing Young: How Friendship, Optimism, and Kindness Can Help You Live to 100 by Marta Zaraska is published by Robinson. To buy a copy for £13.04 (RRP £14.99), go to bookshop.theguardian.com. P&P charges may apply.
