Japanese people are more likely to reach 100 years old than anyone else in the world, a fact that some researchers attribute to their diet. So, are they right – and is eating tofu and squid the place to start?
Last week, the oldest man ever on record, Jiroemon Kimura, from Kyotango near Kyoto, passed away at the age of 116. His death, and the fact that the new record holder, 115-year-old Misao Okawa, is from Osaka, reminded us that the Japanese know a trick or two when it comes to living beyond 100. According to the UN they have the greatest proportion of centenarians in the world – and a great deal of that knowhow concerns diet.
Ogimi, little more than a dirt street lined with small houses, home to more than a dozen centenarians. Old folk tended vegetable patches or sat on porches watching a funeral procession go by. They dined on rice and tofu, bamboo shoots, seaweed, pickles, small cubes of braised pork belly and a little cake at the local “longevity cafe” beneath flowering dragon fruit plants.
Dr Craig Willcox, who has spent many years investigating Okinawan longevity and co-wrote a book, The Okinawa Program, outlining his findings (recommending that we “Eat as low down the food chain as possible” long before Michael Pollan’s similarly veg-centric entreaty).
Willcox summarised the benefits of the local diet: “The Okinawans have a low risk of arteriosclerosis and stomach cancer, a very low risk of hormone-dependent cancers, such as breast and prostate cancer. They eat three servings of fish a week, on average … plenty of whole grains, vegetables and soy products too, more tofu and more konbu seaweed than anyone else in the world, as well as squid and octopus, which are rich in taurine – that could lower cholesterol and blood pressure.”
Okinawa’s indigenous vegetables were particularly interesting: their purple sweet potatoes are rich in flavonoids, carotenoids, vitamin E and lycopene, and the local bitter cucumbers, or “goya”, have been shown to lower blood sugar in diabetics.
Of course, your destiny as a potential centenarian will also be determined by your DNA, upbringing and temperament, as well as how physically active and sociable you are; the climate where you live; the standard of healthcare available; how relaxed you are about timekeeping; whether you take naps and are religious; wars, and so forth. Being born a girl helps: 85% of the world’s centenarians are female. But it is generally accepted that diet determines around 30% of how long we live. Some argue it can add as much as a decade to your life. So, the question then becomes, should we all switch to a diet of tofu, sweet potatoes and squid?
According to Professor John Mather, a director of the Institute for Ageing and Health at Newcastle University, it probably wouldn’t do any harm but the prevailing scientific evidence weighs more heavily in favour of the Mediterranean diet. “There is not enough research on people who adopt the Japanese diet in non-Japanese settings.”
“It is true Japan holds the [longevity] record at the moment, but if you go back a little it was Sweden or New Zealand.” (The Chinese have referred to Okinawa as the Land of the Immortals for centuries, but this probably does not constitute strong epidemiological evidence.)
Mather, who has worked in nutrition for 40 years, adds that the Nordic diet has made a late surge, with recent research pointing to the benefits of its fish- and, more controversially, dairy-rich diet (the latter is an anomaly in longevity diets: the Japanese eat little dairy, and in the Mediterranean diet it is mostly limited to cheese and yoghurt). But he still prefers to point to the well-documented longevity of the people of the Nuoro province of Sardinia or the Greek island of Ikaria, the latest destination on the fountain-of-youth trail.