Why do people live longer in Japan?
People in Japan usually live longer than in other countries. Do they just have good genes? Is it good healthcare? Or is it something else, like their diet, lifestyle and society? What makes the difference - and is this relevant to those of us living in other countries?
Genes help – Studies have suggested two genes in particular (DNA 5178 and the ND2-237Met genotype) help the Japanese live longer longer, by protecting them against some adult onset diseases. However, this doesn’t seem to apply equally across the population. Some families in Okinawa for instance, have inherited more good genes than others. And even here other factors, including personality (especially conscientiousness, openness and being extroverted) also seem to be important.
Universal healthcare – This has been in place in Japan since 1961. It was seen as a significant factor in a 2011 study by the Lancet. Interestingly this universal healthcare has been provided for just 8.5% of Japan’s GDP (Gross Domestic Product). That's around half the proportion the USA spends on private and public healthcare. Does this mean that Japan is more effective at providing healthcare – or that people in Japan are healthier so need less healthcare – or some combination of the two?
Diet – The high levels of vegetables and pulses has been seen as one reason for Okinawa previously having unusual longevity. Following an increase in Western diets and lifestyles in Okinawa the number of people living longer is falling. A high consumption of taurine (in fish) and of fucoidans (in seaweed) have also been suggested as helping Japanese people live longer.
However, the Lancet suggests the dietary picture is more mixed. The introduction of a more Western diet appears to have brought some health benefits, like a reduced salt intake. A straightforward correlation between diet and illness hasn’t always emerged. And some aspects of the Japanese diet (like a preference for highly refined rice and bread as staples) could be responsible for increasing rates of diabetes (through a low dietary fibre intake and a high glycaemic index).
Lifestyle – The National Geographic cites a number of differences it perceives between Japanese and Western Lifestyles: The Japanese tend to eat less than their Western counterparts; to walk or cycle more frequently; to undertake tai chi, reiki and yoga; and even (due to the small size of many homes) to go out more to socialise. This is an attractive hypothesis. However, it would be helpful to see more evidence to support it, particularly because some aspects of Japanese lifestyle (like relatively high salt consumption) would normally be perceived as unhealthy.
Health Conscious – "First, Japanese people give attention to hygiene in all aspects of their daily life. This attitude might partly be attributable to a complex interaction of culture, education, climate [eg humidity, temperature], environment [eg having plenty of water and being a rice-eating nation] and the old Shinto tradition of purifying the body and mind before meeting others.” That’s the view of Professor Kenji Shibuya, of the department of global health policy at the University of Tokyo, and his colleagues, quoted in The Guardian - "Second, they are health conscious. In Japan, regular check-ups are the norm. Mass screening is provided for everyone at school and work or in the community by local government authorities.”
Social Equality and Cohesion - Shiro Horiuchi, in the Japanese Journal of Population Studies considers a range of possible factors contributing to people in Japan living longer and identifies social cohesion as providing a particular advantage when it comes to longevity.
He accepts there are growing inequalities in Japan but provides evidence that Japanese people feel close to each other and strongly group-oriented. He contrasts this, for example, with the caste system in India. He argues, ‘The strong group orientation seems conducive to the psychological well-being of Japanese people with low socio-economic status. It gives them deep feelings of belongingness to organizations and communities, keeping them from feeling alienated in the society…. The feeling gives them relatively high self-esteem (in spite of their low ranks and salaries), and helps them to have positive perceptions, emotions and attitudes about their lives….Persons with constructive attitudes toward their lives tend to be concerned about their health, adopt healthy life styles, and make effective use of medical services.’
But not the way children look after their parents? This has been suggested as another possible factor helping older people live longer. However, the tradition of care for parents appears to have begun to erode from around 1986 and a 2011 paper concludes, ‘ Widespread optimistic and simplistic assumptions concerning care of older people in Japan need to be challenged. The limits of family care have a longer pedigree and more serious consequences than is generally recognised. ‘
Will they continue to live longer? Some researchers believe that Japanese longevity is under threat from relatively high levels of smoking, alcohol consumption, suicide and changes in diet that have raised BMI (Body Mass Index). Will the Japanese health system cope with the effects of these health changes as well as the growing number of elderly Japanese – and will social cohesion survive? Only time will tell.
However The Lancet, which raised such questions, sees signs of hope in the commitment and expertise of younger Japanese. It notes, ‘Central to the sustainability of a health-care system is the quality and commitment of its youngest members. One less publicised legacy of the Great East Japan Earthquake was that it was young people, skilled in social media, who coordinated assistance for 180,000 stranded commuters in Tokyo during the hours after the earthquake, and who—months later—continue to provide free medical services in the areas hardest hit by the tsunami.’
What lessons can we learn from the Japanese?
- Eat plenty of fish, pulses and vegetables. Walk and cycle when you can. Try Tai Chi, yoga and other healthy activities. Keep and build up your social networks. Find organisations you can contribute to and from which you can gain the benefits of social cohesion (eg as a volunteer or team member or member of a faith group). These all seem to help the Japanese live longer - and could help you too.
- Avoid smoking, salty food, eating too much, and drinking too much alcohol – as these seem to have an adverse effect on longevity in Japan.
Amended Version Published 24/09/13, Updated , Review date May 2014