Welcome to Running: A FEVER, which is a show about fitness, diet, and medicine. The goal is a long, healthy, happy, active life right up to the very end.
And we also talk about longevity quite a bit, especially people who live longer than 100 years, known as centenarians, and even those who live longer than 110 years, known as supercentenarians.
If you look at the top ten list of the longest-lived people of all time, you’ll notice that three of them are from Japan, more than any other country represented. The second oldest woman of all time was Japanese, Kane Tanaka, over 119 years old when she died. The top ten overall are all women, of course, but if you look at the top 10 oldest men, you’ll also see Japan on there multiple times. Two of them are Japanese, including the oldest man ever, Jiroemon Kimura, at 116. The United States is well-represented on the men’s list, with three of the top 10, but other than that, no other country besides Japan has more than one on either list.
Worldwide, Japan has more centenarians by far than any other country. The numbers are somewhat in dispute, though. According to World Population Review, as of 2025, Japan has over 123,000 citizens over the age of 100, almost twice that of the country in second place, the United States.
A 2021 article on the World Economic Forum website credits the United States with 97,000, and the highest centenarian population in the world, though it does say Japan has the highest per-capita number, with .06% of its population. The article has a nice picture of Kane Tanaka, aged 117 at the time, who was then the oldest living woman.
Wikipedia has a list of countries, not dated, but from the context I think it was 2024. It credits Japan with the most at 99,000, and the U.S. second with 98,000. Seems to be a little friendly competition going on here.
An article on Nippon.com said that almost one in five of the world’s centenarians live in Japan, 87% of them women.
The problem, as stated in the same Wikipedia article, is that, and they credit a Nobel Prize-winning study for this, the numbers are inflated by welfare and pension fraud and poor record-keeping, neither of which is uniform across jurisdictions. So we may never know the real numbers, at least not until they start chipping us all at birth.
Even though the article is about all centenarians, it has a special section for Japan. Apparently, Japan’s high life expectancy is attributed to the typical Japanese diet, which is particularly low in refined simple carbohydrates, and to hygienic practices. And within the country, Shimane Prefecture (I think a prefecture is like a state) has the highest per capita population of centenarians, 114% higher than the national average.
The ratio was 92% higher in Okinawa Prefecture. You may remember some talk about Okinawa in my Blue Zones episodes. In addition to diet, I remember mention of the custom of women developing three-member groups early in life, who maintained the friendships for life. Okinawa is technically part of Japan, but it has a unique culture. I remember going there en route from my ship, which was returning from a deployment, to our home base of Yokosuka. I was at Kadena Air Force Base, which was the largest base I’ve ever seen. Miles and miles of it. Anyway, that’s one of the things that makes Okinawa unique: the influence of the U.S. Military. Let’s get back on track. Okinawans not only live longer than the rest of the world, but they also live longer than most Japanese as well.
There have been several studies of longevity in Okinawa. They have found these factors that contribute to the large number of centenarians there:
1. A diet that is heavy on grains, fish, and vegetables and light on meat, eggs, and dairy products.
2. Low-stress lifestyles, which are proven significantly less stressful than those of mainland Japanese inhabitants.
3. A caring community, where older adults are not isolated and are taken better care of.
4. High levels of activity, where locals work until an older age than the average age in other countries, and more emphasis on activities like walking and gardening to keep active.
5. Spirituality, where a sense of purpose comes from involvement in spiritual matters and prayer eases the mind of stress and problems.
Let’s talk about the diet in detail. The Japanese eat less than half as much meat as Americans, and about five times as much seafood. This means a reduced intake of saturated fatty acids, associated with a reduced risk of ischemic heart disease. Also, the omega-3 fatty acids found in seafood contribute to the same reduction. This effect on cardiovascular disease is significant, as CVD is the number one cause of death worldwide. The reduction in saturated fat also reduces the risk of stroke, which is the second leading cause of death worldwide, responsible for about 11% of global deaths.
Japan is aging in its population proportions, due to longevity and sub-replacement fertility rates. It is expected that by 2060, 40% of the population will be over 65. In the 1950s, after the baby boom, it was 5%. This contributes to the likelihood that people will work until they reach an older-than-average retirement age. Factors such as improved nutrition, advanced medical and pharmacological technologies, and improved living conditions have all contributed to the longer-than-average life expectancy.
According to an article in The Economist, Japan’s population is aging faster than any other country on the planet. But overall life expectancy is higher. For women in Japan, it is 88; for men, 82. Women and men live five years longer than in the U.S.
In addition to the traditional healthy diet, Japan has a culture of walking and cycling that keeps its population fit. There is also a unique concept called hara hachi bu, a cultural practice of stopping eating when about 80% full, which encourages moderation and calorie control.
The habits that lead to longevity are built early. Children learn healthy eating habits from a young age through nutritionally balanced school lunches that emphasize fruits and vegetables. Also, many children walk or cycle to school, establishing an active routine early on.
Unlike healthcare in other cultures, the Japanese healthcare system emphasizes preventive care and regular health screenings. The government provides low-cost health insurance, which means broad access to medical services. And policies like Shokuiku (culinary education) and initiatives to prevent non-communicable diseases have supported long-term public health.
Japan also has a low mortality rate from ischemic heart disease and cancers, particularly breast and prostate cancer. This is attributed to a low rate of obesity (4.8% for men and 3.7% for women, compared with over 40% combined in the U.S.), and the aforementioned diet, which likely contributes to the low obesity rate.
In short, the Japanese diet keeps the most deadly diseases at bay. A culture of activity keeps the people fit, and working later in life gives them purpose. All of these contribute to longer life.
We should consider adopting some of these practices. I like seafood, but I rarely eat it. I need to find some vegetables that I like besides tomatoes, but perhaps I can add some rice and tea into the mix. Worth a try, I think. I’ll keep you apprised. In the meantime, are you going to try a Japanese diet? What about more walking or cycling? Leave a comment; I’ll be sure to read it.
Thanks for listening and watching! I hope you’ve learned as much as I have from this episode. I have a ton of references that I got info from this time, so check out the blog at http://RunningAFEVER.com/451. Until next time, if you’ve got the fever, keep it burning, and if you don’t, catch the fever, and I will see you again on Running: A FEVER.
References:
https://worldpopulationreview.com/country-rankings/centenarians-by-country
https://en.wikipedia.org/wiki/Jiroemon_Kimura
https://en.wikipedia.org/wiki/Oldest_people
https://tinyurl.com/raf-wef
https://en.wikipedia.org/wiki/Centenarian
https://en.wikipedia.org/wiki/Aging_of_Japan
https://www.economist.com/banyan/2014/03/25/the-incredible-shrinking-country
https://en.wikipedia.org/wiki/Elderly_people_in_Japan
https://www.nippon.com/en/features/h00110/
https://observatoireprevention.org/en/2021/03/09/why-do-the-japanese-have-the-highest-life-expectancy-in-the-world/