Near a beach in northern Okinawa, a group of 161 islands that stretch between Japan and Taiwan, is a large stone on which the following proverb is carved: "At 70 you are but a child, at 80 you are merely a youth, and at 90 if the ancestors invite you into heaven, ask them to wait until you are 100... and then you might consider it."
The archipelago, known as the Galapagos of the East because of its tropical rainforest and abundance of unique fauna and flora, has long been rumoured to be home to the longest-living people in the world. Now, after a 25-year scientific study, the rumour has been proved to be fact. Its population of 1.3 million includes more than 400 centenarians (85.7 per cent of whom are female) – nearly four times the rate in Western countries, and more per head of population than anywhere in the world. The average age at death is 81.2 years – around five years older than that of Westerners.
But what, perhaps, is more striking is the extraordinarily rude health that the elderly islanders enjoy. The study, which was funded by the Japanese Ministry of Health, revealed that Okinawans had among the lowest mortality rates in the world from many chronic diseases of ageing. As a group, coronary heart disease, strokes and cancer – the three leading killers in the West – are least likely to afflict people living in Okinawa than anywhere else in the world. As a result, they enjoy not only the world's longest life expectancy, but the world's longest health expectancy.
Dr Bradley Willcox, a fellow in geriatric medicine at Harvard Medical School and co-investigator of the study, said: "Ninety-seven per cent of their life expectancy is disability-free. While you do see ill centenarians, their illness has generally occurred a few months before they die."
The Okinawa Centenarian Study, which began in 1976, concentrated on genetics and lifestyle. Over 600 centenarians and elders in their seventies, eighties and nineties were examined.
The study showed that while genetics had a part to play in Okinawans' longevity, most of the "successful ageing" was, in fact, due to lifestyle. Okinawans who grow up in other countries and lead a different lifestyle have an increased mortality rate.
Elderly Okinawans were found to have "young, clean" arteries, low cholesterol and low homocysteine levels (an amino acid which causes damage to arterial walls) when compared to Westerners. This helps reduce their risk of coronary heart disease by up to 80 per cent and keeps stroke levels low.
The scientists concluded that their healthy arteries were largely due to their lifestyle: diet, regular exercise, moderate alcohol intake, avoidance of smoking, blood pressure control and a stress-minimising psycho-spiritual outlook.
They were also found to be at an extremely low risk of hormone-dependent cancers. They suffer less than a quarter of the level of breast, ovarian and prostate cancer as Westerners, and half the rate of colon cancer. This is believed to be due to low calorific intake, a diet high in fruit, vegetables, "healthy" fats and fibre, low body fat, high levels of physical activity and and high intake of protective antioxidants such as flavonoids (oestrogenic compounds from plant foods).
Okinawans also manage to stay lean in old age by eating a low-calorie, unrefined complex carbohydrate diet, and practising a cultural habit called "hara hachi bu", which involves ceasing to eat when they are 80 per cent full. They also keep physically active "the natural way" by dancing, soft martial arts, walking and gardening.
The women have fewer complications such as hot flushes, hip fractures and coronary heart disease during menopause, which occurs nearly 10 years later than it does in Western women.
The Okinawans' rate of dementia is low, and they appear to enjoy good mental health generally. "They're a very happy, carefree people," commented Dr Willcox.
Elderly female Okinawans were found to have the lowest suicide rate in East Asia, an area notorious for suicide among elderly women. The study discovered links between their traditional spiritual beliefs and their sense of life satisfaction. Women are the religious leaders of society, and the eldest female in the family is responsible for keeping a spiritual connection with ancestors. This encourages a feeling of usefulness and self-worth. Okinawans also have a strong social network, with large extended families – up to 1,000 people routinely attend weddings or funerals. They often take part in "Moai" – support groups where mutual problems can be worked out.
Dr Willcox and his fellow investigators, who have written about their findings in a new book, The Okinawa Way, believe that Westerners can increase the length of their their lives by up to 10 years by adopting the major principals of the Okinawan lifestyle.
"On a population level, it could add five to 10 years of healthy life expectancy for most people," claimed Dr Willcox. "A lot of middle-aged men will die of a heart attack aged 55 or 60. For those people, it could help add another 30 years to their life expectancy."
The programme they suggest in the book looks at diet, exercise, psycho-social coping techniques and spirituality. "We have more hard evidence for the diet and exercise than we do for the other two, but we still think that they are important," he said.
The two principal factors of the diet are that it is low in calories and it incorporates plenty of vegetables. Okinawans eat more food in weight than North Americans, but because they eat less fat, and so take in fewer calories, they manage to keep lean. Fifty per cent or more of one's total calories should come from complex carbohydrates.
"The diet that the Okinawans eat is about three-quarters plant food, and one quarter animal food," said Dr Willcox. Crucially, they stop eating when they are 80 per cent full. "You should stop at the first feeling of fullness you get. Most of us start to feel full and carry on eating. When you start to feel full your stomach really has become full, but physiologically there's about a 20-minute delay before the stomach tells the brain."
As regards fitness, an exercise programme should target cardio-vascular fitness, as well as strength and flexibility. "Okinawans do things they enjoy. That's important," said Dr Willcox. "They do a mix of activities, mainly martial arts, walking and gardening, which they do in abundance. But you don't have to do that. I, myself run, I do weights and I stretch, and I'm getting all three components."
When it comes to stress, Okinawans have developed what seem to be stress resistant personalities, said Dr Willcox.
"A lot of the elderly have very strong personalities, a can-do attitude, yet they do not suffer from time-urgency. They are not trying to do more and more things in less and less time. They are working on their own schedules, which are more in time with their biological clocks. And you can't say that this is a stress-free society. A third of the population was killed in the Second World War, they've been invaded by foreign powers since 1609, and they have the lowest socio-economic status in Japan. There are stresses, but people cope with them."
Okinawans incorporate quiet time into their day, and regularly pray at a shrine in their homes. "For us, in more practical terms, something we could do is meditation to really slow down. You don't have to be a religious person to be spiritual. You can listen to music that's soothing, have some plants around you and pictures of loved ones, and try to slow down for 20 minutes a day.
"Westerners are going from six or seven in the morning, fired up on caffeine all day and taking sleeping pills at night. When we don't have some quiet time, we cannot react well to stress. And stress can accelerate the ageing process."
Another factor in the islanders' well-being is their high rate of social support. As well as family support, they have strong friendship networks. "If they don't show up and open up the fish store at the age of 100, as they've been doing every day for years, someone will knock on their door." Those of us who do not have enough friendships could join a social group, become a volunteer or take up a new sport.
"There's no magic pill," concluded Dr Willcox. "We're not coming out with some weird and wonderful theory. It's calories in and calories out, maintaining your fitness levels and getting in touch with your spiritual side and healthy ways of coping with stress."
'The Okinawa Way: How to Improve Your Health and Longevity Dramatically', by Bradley Willcox, Craig Willcox and Makoto Suzuki is published by PenguinReuse content