Japan continues its over 20-year run as the global champion of long life. The latest World Health Organization report puts Japan’s average life expectancy at birth at 83.7 years. Japanese women can expect to live to 86.8 years, longer than their menfolk, whose average life expectancy is 80.5 years. For context, the global average male life expectancy is 69.1 years, 73.8 years for women and 71.4 for both sexes combined.

In 1963, there were only 153 people aged 100 or older across Japan. By 2016, the number of centenarians had zoomed up to 65,692. The secret of long life in Japan is a matter of some debate and likely stems from a mixture of diet, policy, exercise, cultural factors and genetics, making it difficult to single out one cause. Rice, vegetables, fish and meat are staples of the Japanese diet, but given that Japan is an archipelago, residents consume more fish than the norm in most other nations. Pickled, fermented and smoked foods are also common. Fermented foods, in particular, support a healthy digestive system. Soybeans in the form are another key part of any meal. Overall, Japanese cuisine is low in calories and saturated fats, a significant factor in reducing the risk of cardiovascular disease.

A 2011 paper in the medical journal, The Lancet, credited Japan’s investment in public health in the 1950s and 1960s with creating a health and hygiene conscious culture. Childhood vaccination programmes, the introduction of universal health insurance, campaigns to reduce salt consumption, free treatment for TB and the widespread use of medication to reduce blood pressure are all alluded to. Regular medical check-ups are the norm here.

More ineffable reasons for long life include certain social and cultural traits. Ageing expert Professor Shiro Horiuchi argues in a paper in the Japanese Journal of Population Studies that social cohesion is an important, explanatory factor. According to him, the strong group orientation in Japan prevents the elderly and the economically less well-off from feeling the kind of social alienation linked to bad health. They often have a sense of rootedness and community belonging that develops positive emotions, vital to well-being. Another factor is the active lifestyle of many elderly Japanese. Retirees often continue working by choice in a voluntary or part-time capacity. Senior citizens directing traffic at parking lots, guiding schoolchildren to cross roads safely, or taking tourists around sightseeing spots are all common sights. And finally, there is some evidence that the Japanese are blessed with genetic make-up that aids longevity. Studies have suggested that two genes in particular, DNA 5178 and ND2-237Met genotype, help them live longer, by protecting them against certain adult onset diseases.

Unalloyed blessing

Longevity is, however, not an unalloyed blessing. Japan’s is one of the world’s most rapidly ageing societies. Over a quarter of the population is already 65 or older. In Tokyo alone, some 3.1 million residents will be over the age of 65 by 2025. Two decades of economic stagnation and a shrinking working age population are threatening the financial and social underpinnings of universal healthcare. Moreover, Japan’s “healthy life expectancy” is only 74.9 years which, although well ahead of the 63.1 global figure, means that on average the Japanese spend their last 8.8 years living in ill-health, often bed-ridden.

Prolonging “healthy life expectancy” and figuring out how to pay the bill for it are both tough challenges. Sushi might be nutritious enough, but the Japanese will need plenty of additional food for thought in devising ways to tackle them.