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How long you live can now clearly be linked to what you eat, not just your genetic make-up. For a shot at living to 100, read on.
There is no foolproof recipe for making it to 100 years old and beyond but there are strong clues from longevity hot spots such as the Mediterranean regions of France and Italy, parts of Spain, Nicoya, in Costa Rica, and Okinawa, in Japan. These are all places with high numbers of long-lived people, according to Dr Preston Estep, director of gerontology at the Harvard Personal Genome Project
They do not always eat the same food but their diets have much in common – a lot of plant food, moderate amounts of fish but not so much meat and added sugar, says Estep, whose book, The Mindspan Diet, looks at the eating habits of people who not only live longer but also have lower rates of dementia. Their fat intake varies, but where diets are high in fat it is usually mono-unsaturated fat – the kind found in olive oil, for example. And when they raise a glass, it is usually with meals and in moderation.
But what about our genes?
"Except for some rare genetic conditions, it's not our genes that matter so much as what we do with them," says Merlin Thomas, professor of medicine at Monash University, whose research specialises in how disease develops in the human body.
We used to think genes largely determined our health and longevity but we are now learning that environmental factors, including diet and other lifestyle habits, can turn genes on or off or up and down, he explains.
"There's almost always some wiggle room, meaning that even with bad genes good outcomes can still occur – equally with good genes, bad things can occur. But either way, there's a lot we can do to influence our health ourselves," says Thomas, who has written The Longevity List, a new book that explains how the right choices – including what we eat – can boost our odds of living longer.
Food and lifestyle can have a lot to do with the numbers we get on a blood pressure test, for instance – and keeping blood pressure healthy is probably the simplest and cheapest way to make sure we're on track for 100 birthdays, Thomas says.
"It's been estimated that if we all reduced our blood pressure it would reduce heart attack and strokes globally and add nearly 10 years to the average life span. What's not to like?
"Looking at people around the world and comparing their blood pressure numbers with their lifestyle habits tells us that people who eat diets rich in vegetables and fruit but with less salt, and those exposed to less stress and who don't gain too much weight tend to have lower blood pressure.
"Lifelong vegetarians also have lower blood-pressure levels – although exactly what part of fruit and vegetables it is that lowers blood pressure is unclear."
So what if the weight has already piled on?
Getting it off can really help – losing 10 kilograms can lower our blood pressure as much as is achieved with many blood-pressure-lowering drugs, Thomas says. And while we are on the subject of waistlines, keeping them under control gets another thumbs up for longevity.
"The main thing that stops us living longer is putting on too much weight around the middle," he says, explaining that surplus midline fat becomes deadly when it spills over into the bloodstream and into organs where it is not meant to be.
It is when fat overfills the pancreas that the body struggles to control blood glucose, for instance – and that puts us on the road to type 2 diabetes.
"This is the reason we all should aim to keep our waistline under control – in the long term it will generally mean a longer and healthier life," he says.
This is also where the F word – fibre – comes in. It is not the sexiest word in the food lexicon, but a real star when it comes to delivering health benefits, including waist control. Diets that are naturally rich in fibre because they include lots of wholegrains, legumes and nuts are very filling and help us to eat less, Thomas says.
There is also evidence that these diets are linked to a reduced risk of developing type 2 diabetes, which should make us think twice about stripping wholegrain bread, legumes and starchy vegetables out of our diet.
"We may be removing some of the things that keep diabetes at bay, including fibre and other nutrients," he points out.
These benefits may explain why high-fibre diets have been linked to a greater chance of reaching old age in good health. When researchers from the Westmead Institute for Medical Research looked at health data from more than 1800 older people living in the Blue Mountains last year, they found that those with the highest fibre intake had an almost 80 per cent greater likelihood of living a long and healthy life.
Photo: William Meppem
The longevity (shopping) list
Merlin Thomas, professor of medicine at Monash University, and contributor to the excellent Slow Ageing blog, has compiled a list of foods that can help boost the chances of a longer, healthier life.
They are rich in antioxidants and a good source of fibre, but also, importantly, they provide concentrated flavour to add to other foods like yoghurt without the need for sugar. Oats and berries for breakfast?
"My kids can't imagine what beef mince looks like without [cooked] brown lentils mixed into it – they add flavour and make a dish so filling that you can halve the amount of meat you'd normally use," Thomas says. It's the same story with his chicken curry, which is half chicken and half chickpeas. In fact, he eats legumes – which some studies have linked to longevity – in some form or other almost every day, and suggests we all do the same. A dollop of hummus on roast veg or with bread, a few falafels, or spicy little brown lentils (canned are fine) drained and added to salads are simple ways to ease them into your diet – and provide food for friendly gut microbes. "They're not a cure-all but they're a healthier alternative to overcooked meat," he says.
Just don't convert to a daily legume habit overnight. Instead, introduce them gradually into your diet – this gives your system time to adjust and avoid the bloating that can occur when happy gut microbes binge on all that fibre, producing gas.
The allium family
Onions, shallots, garlic and leeks. These are natural flavour makers with benefits – high in fibre, a source of antioxidants as well as a fat-soluble form of vitamin B1, which our bodies can use more readily than the water-soluble B1, Thomas says. Some research has also found that garlic contains compounds that may have an anti-ageing effect by counteracting a process called glycation, which ages the body's tissues and is thought to increase the risk of type 2 diabetes.
Not just broccoli, kale, cauliflower, cabbage and brussels sprouts but also bok choy and spinach. "They're rich in fibre and high in a range of sulphur compounds thought to boost the body's antioxidant defences, and they're also linked to less heart disease. Like the compounds in garlic, these sulphur compounds are also the subject of research into their anti-ageing properties," Thomas says.
Nuts and seeds
These tiny foods punch above their weight. "They're a source of plant protein, fibre, antioxidants and healthy fats. Research into the Mediterranean diet has found that people who regularly eat a lot of nuts have less heart disease and longer survival," Thomas says.
Low-fat probiotic yoghurt
Research now suggests that full-fat dairy food is not such a bad guy after all, at least as far as the heart is concerned. Although it contains saturated fat, it is thought that other protective elements of yoghurt and cheese may offset any harm from saturated fat. That said, Merlin Thomas still argues for low-fat yoghurt because it delivers the benefits of yoghurt, such as calcium, protein and probiotics, but with fewer kilojoules – and eating fewer kilojoules rather than more is linked to longevity.
It is high in fibre (unlike fruit that's turned into juice) and antioxidants and it tastes good. "Regularly eating fresh, flavoursome foods – including fruit – makes added sugar superfluous," Thomas points out. "Sugar then need only be added for special occasions, when it can be enjoyed without guilt."
Dark chocolate (just a bit)
Combined with a high-fibre, wholefood diet, dark chocolate can indirectly help preserve your waistline by delivering a reward that can curb cravings and prevent overeating.
Cold al dente pasta contains higher levels of resistant starch. Photo: Marina Oliphant
Culinary tricks for healthier eating
The case for twice-cooked pasta
One type of fibre with special health benefits is resistant starch. It nourishes gut microbes, which return the favour by producing a substance called butyrate that helps keep the gut wall healthy – and may protect its cells from cancerous changes. You will find resistant starch in lentils, peas, beans, some wholegrains, green bananas and cooked and cooled pasta and potatoes. To maximise the resistant starch in your pasta, Thomas suggests undercooking the pasta and then leaving it to cool and reheating it later. Providing you keep the heat to less than 120 degrees Celsius for the second cooking, you'll retain more resistant starch. You will also lower the GI of the pasta, meaning you will digest it more slowly and feel fuller for longer.
"You get the same effect if you eat al dente pasta cold – and the same principle applies to reheating (or just eating cold) potatoes, as well as other starchy vegetables and grains like rice.
Turn up the moisture and turn down the heat
One theory about why a traditional Mediterranean diet is so healthy is that it favours slower, more moist cooking methods as opposed to the high-heat cooking that helps create substances that age the body's tissues faster in a process called glycation. Known as Advanced Glycation End Products or AGEs, some of these substances are formed naturally in the body, but others are produced by browning and cooking foods high in fat at high temperatures. Their crunchy textures and taste have a lot of appeal – think pork crackling or chips – but the crunch comes with a cost: many studies have linked AGEs in the diet with a number of age-related diseases, including type 2 diabetes, kidney disease and high blood pressure.
"Glycation also stiffens blood vessels and is a major contributor to hardening of the arteries as we get older," Thomas says.
His tips for reducing AGEs in food? Eat fresh, unprocessed foods, choose lean cuts of meat, remove skin from poultry and cook food slowly at lower temperatures, using moister cooking methods such as poaching, stewing, steaming or using a slow cooker.
Alcohol – busting a few myths
Red wine might be the tipple with the healthiest reputation, yet over all the health outcomes of moderate drinkers are much the same whether they are drinking merlot, beer, gin or scotch – it is moderation, not the drink itself, that really counts, Thomas says.
"Alcohol is a test of self-control and self-awareness. For those who pass the test, alcohol can be one of life's shared pleasures. It can help us feel happy, relaxed and social. But it's a delicate balance. A little glass can easily become more, especially if the bottle is open. Sometimes it's easier for us not to drink at all and to give up the booze than go down this slippery slope."
A few words about beetroot
Thomas is not one to bang on about individual superfoods – good health, after all, depends on eating a broad range of whole foods. But beetroot's effect on arteries deserves a special mention. Beetroot is rich in chemicals that help the body produce nitric oxide – which happens to relax our blood vessels, helping them to dilate and improve blood flow.
"This improvement in blood flow is thought to be why beetroot is able to improve performance in sport and is why many athletes now have beetroot before an event," he says
The Longevity List by Professor Merlin Thomas is published by Exisle, $34.99