In 2018, we're living longer than ever. Life expectancy for humans, on average, has more than doubled since 1900. In 1841 a 5-year old could expect to live 55 years. Today, a 5-year old should live to 82.
Although we're living longer, we're not necessarily enjoying great health for all of those years. Diseases, as most of us will be aware, can rob us of quality of life, to the point where we may be living longer, but not living well.
Experts are now focusing more on health expectancy. How can we give ourselves the best chance of living long, staying healthy for as long as possible, living life to the full then popping off peacefully in our sleep?
This is what Professor David Katz, founder of the True Health Initiative — a global movement dedicated to sharing "the fundamental truths about healthy, sustainable living and eating" — calls having "more life in our years, as well as more years in our lives".
The initiative promotes six core principles aimed at doing this.
"To me the operative word is not live, but well," says initiative council member and sports medicine expert Dr Geoffrey Moore.
"Health care has done humanity a disservice by focusing on longevity, when vitality and quality-of-life are what people really want most.
"Sadly, few discover that until they're burdened with a chronic condition, when they realize what they want is to live well, hopefully for a long time.
"In my view, medicine has gotten the priorities of longevity and vitality in the wrong order."
Cindy Geyer, Medical Director of famous American wellness retreat Canyon Ranch, says its founder, Mel Zuckerman, "used the phrase 'living younger longer', which captures this idea well".
What do the experts recommend for vitality? What can we do to live younger longer?
I asked global experts for their top tips and got some surprising answers — as well as some we might expect.
Move your body
Probably one of the more predictable tips, exercise is key to keeping our bodies young. All the experts I talked to included this in their list.
As we age, we lose muscle mass and our joints and bones can start to degrade. Exercise helps prevent this. Keeping joints moving prevents pain, and conserving muscle mass protects joints and bones, as well as helping us retain a healthy weight.
Although intense exercise in the gym is great, and it's never too late to start, experts emphasise that moving any way we can is the main thing. "ChefMD" Dr John La Puma is a fan of moving naturally, doing activities such as gardening and working outside.
Dan Buettner, author of the Blue Zones books, which focus on what we can learn from the world's longest-living communities, notes these groups tend not to participate in organised exercise, but they all include incidental movement in their days. "[They] don't pump iron, run marathons or join gyms," he says.
"Instead, they live in environments that constantly nudge them into moving without thinking about it. They grow gardens and don't have mechanical conveniences for house and yard work."
Former US Surgeon General Richard Karmona has simple advice: "Keep moving every day."
Deal with stress
There's more recognition that stress can play a huge part in how well we age, as well as affecting our risk of many chronic diseases. Finding ways to deal with stress, and eliminating as much as possible, is key to living well for longer. Buettner calls it "down shifting" — having daily routines to eliminate stress. As practised in the Blue Zones, it can be anything from a nap to a prayer — the Sardinians have happy hour.
Geyer has these suggestions: "Turn off your phone, go outside, engage your senses and experience the awe of Mother Nature.
"Do something kind for someone else. Share a hug with someone you love. And don't take yourself too seriously.
"Sometimes laughter truly is the best medicine."
Have purpose and connection
Many of the things experts recommend for longevity are less about food or exercise, and more about psychology and behaviour. An important theme is a sense of purpose and strong connections with community, family and friends.
"A life well-lived is a life with purpose," says Moore.
"Something that moves one to wake up in the morning and think: 'Today, I'm going to do …' and then bring all of one's heart and soul to bear on the challenge and be filled with the zest of life and appreciation of one's small bit of time on this blue orb."
Buettner agrees. "Be able to articulate your purpose and apply it daily at work or through volunteering."
Power up on plants
There's no disagreement on this point: eating more plants is good for us. And for optimal ageing, more plants and less meat is probably ideal. The Blue Zones communities have different diets — from fish and rice in Okinawa to beans and sweet potatoes in Nicoya — but they follow similar plant-based patterns.
We don't have to eat only plants, although vegetarians do have a lower risk for some diseases.
But treating meat as a garnish or occasional celebration food is a healthy practice. Buettner suggests we "eliminate or reduce animal products, especially processed meats, to fewer than five times a month".
Don't be too fat — but don't be too thin, either
Maintaining a healthy weight is important. Obesity is a contributor to the diseases that tend to claim us as we age, such as heart disease and some cancers.
But there's also evidence we can be too thin for our own good, too, especially as we get into our 70s and 80s.
Recent studies have found there's a greater risk of mortality for older people with BMIs lower than 23 (a healthy range is 18.5-24.9) — similar to those in the obese category.
Being slightly overweight is associated with better outcomes, perhaps because we're less at risk of becoming dangerously thin when we get sick if we have a little extra meat on our bones.
Experts now suggest that healthy weight ranges be set a little higher for older people.
Other small things that might make a big difference
Have a little faith
People who live a long and healthy life tend to have some sort of religious faith, according to Dan Buettner, author of the Blue Zone books. "All but five of the 263 centenarians we interviewed belonged to some faith-based community.
"Denomination doesn't seem to matter. Research shows that attending faith-based services four times a month will add 4-14 years of life expectancy," he says.
It's early days for the research on fasting, whether intermittent or otherwise. But it is getting a lot of attention from scientists, because there is emerging evidence fasting may alter the activity of mitochondrial networks inside our cells, which could help us stay healthier for longer.
If fasting's too much for you, try applying the Japanese hara hachi bu theory: always eat until you are only 80 per cent full.
Have a wine (but just the one)
Although there's much evidence of the harms of alcohol, including its causal relationship to cancer, there is also evidence very moderate drinking may be beneficial.
Most people in the Blue Zones drink moderately and regularly, according to Buettner — just one or two glasses of wine a day "preferably Sardinian Cannonau wine", he says, with friends and with food. Note: it doesn't work if you "save up" and have 14 drinks on Saturday night.
Live somewhere healthy
The environment we live in can significantly impact how well we age. It is not always easy or possible, but setting ourselves up in physical environments that support healthy practices can really pay off.
"Health is more a product of the right environment than sustained, conscious behaviour optimisation," says Buettner.
"So, move to a socially-connected, healthier place — walkable, bikeable — with easy access to affordable fruits and vegetables."
Pump up the protein
We need more protein as we get older, and our needs increase significantly after 70. Getting enough, and spreading it out throughout the day, is important, so include protein sources in every meal and snack if you can: that's meat, fish, chicken, eggs, dairy, soy, nuts and pulses.
What's your body's Real Age?
If you want to know how old your body's biological age (as opposed to your birthday age) try the Real Age test. It's an algorithm developed by Dr Michael Roizen. Visit https://you.sharecare.com/you/real-age-test to take the test. And if you're inspired to make some changes, take the test again in a year to see how far you've come.
• Niki Bezzant is a writer, speaker and editor-at-large for Healthy Food Guide.