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This month at Traverse, we are writing about life stages and the distinctiveness of particular moments in a Japanese persons’ life. I decided to write, not about old age, but about age longevity in Japan, as I’m particularly fascinated by the fact that people there live for a long time. In fact, according to data based on the latest United Nations Population Division estimates, as of 2021 Japan has the second-highest life expectancy in the world at 85.03 years.
With this in mind, it will come as no surprise that Japan is one of the countries in the world with a blue zone. Blue zones are regions in the world where people are thought to live much longer than the average. But how have blue zones come about and why does Japan have a much higher life expectancy than other countries?
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The History of Blue Zones
The term “Blue Zone” originates from work carried out by Gianni Pes and Michel Poulain, published by the journal Experimental Gerontology in 2004. In it, they identify Sardinia's Nuoro province as the region with the highest concentration of male centenarians (those who live to the age of 100).
In fact, a village called Seulo, located in the Barbagia of Seulo, holds the record of 20 centenarians from 1996 to 2016. This makes it "the place where people live the longest in the world". As Pes and Poulain zeroed in on the cluster of villages with the highest longevity, during their work, they began referring to the area as the "Blue Zone". This became one of four blue zones in the world. The others are: the islands of Okinawa in Japan, Nicoya Peninsula in Costa Rica, and Icaria in Greece.
Criticism
It must be said that the term “blue zone”, as well as the selection of its regions, has been the subject of scrutiny since its inception. As Harriet Hall writes, controlled studies into the Blue Zones are lacking and the Blue Zones diet is based on speculation, not solid science. Furthermore, recent data has shown that life expectancy in Okinawa is no longer exceptional when compared to the rest of Japan: "male longevity is now ranked 26th among the 47 prefectures of Japan."
Whether it is right or not to designate certain regions of the world as “blue zones”, it does in no way refute the fact that Japan has the second-highest life expectancy in the world. But why? As you would expect, this is not an easy question to answer.
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Diet
One piece of the puzzle in the journey to longevity is undoubtedly diet. According to Dr Martin Juneau, the higher life expectancy of Japanese people is mainly due to fewer deaths from ischemic heart disease and cancers, particularly breast and prostate cancer.
He goes on to write that the low mortality from these diseases is mainly attributable to a low rate of obesity, low consumption of red meat, and high consumption of fish and plant foods such as soybeans and tea. This diet is similar to what is often referred to as the “Mediterranean diet” which is potentially why there are also a high number of centenarians in places like Italy and Greece.
Public Healthcare
Japan’s public health service also plays a role in the country's life expectancy. The first form of public healthcare in Japan began in 1927 with an employee health plan. By 1961, it had evolved into a system of universal coverage available to locals, foreigners, and expats.
The system puts a high priority on preventative care instead of reactive care. It even offers free screening tests for certain illnesses and has superb prenatal programs. It presents us with another ingredient for why Japanese people suffer from “fewer deaths from ischemic heart disease and cancers, particularly breast and prostate cancer”, as stated earlier in this article.
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Lifestyle versus Genealogy
Some studies throw a final curve ball into understanding the reasons why some people live longer. Scientists in 2015 discovered that there are certain genes in humans that are responsible for a longer or shorter life. Lead researcher, Michael Ristow, went on to say one gene in particular, the bcat-1 gene, appeared to be incredibly influential in determining how long an animal would live. "When we blocked the effect of this gene, it significantly extended the mean lifespan of the nematode by up to 25 percent," said Ristow. The same gene also exists in humans and some people have higher levels of the gene than others. This suggests that people with lower levels of bcat-1 gene are more likely to live longer.
A different study in 1975 looked into the significance of Japanese immigration to the United States (especially California and Hawaii) and South America (Brazil, Peru). After a few generations, the descendants of Japanese migrants adopted the way of life of the host countries. While Japan has one of the lowest incidences of cardiovascular disease in the world, this incidence of cardiovascular disease doubled among the Japanese who migrated to Hawaii and quadrupled among those who chose to live in California. What is surprising is that this increase has been observed regardless of blood pressure or cholesterol levels, and seems rather directly related to the abandonment of the traditional Japanese way of life by migrants. In complete contrast to my previous paragraph, this study suggests that lifestyle has a dramatic effect on whether you are likely to live longer.
Consistent exercise is one part of lifestyle that leads to a longer life. Unsurprisingly, it plays a major role in many Japanese lives, well into older years. Rajio Taiso is a good example of this: “Rajio taiso”, or radio calisthenics, is a short exercise routine broadcast daily on Japan’s national radio, streamed on YouTube, followed in parks and schools every day – sometimes several times a day – by all generations of Japanese people.
In Summary
Although there seems to be no easy answer for explaining why people in Japan live longer, there are definitely elements in one’s life that you can get right. If long life were a recipe, you would want a slice of good dieting, a tablespoon of public healthcare, a pinch of good genes and a large dollop of a peaceful lifestyle, most probably with some exercise thrown in for good measure.