Highlighting JAPAN

For Longevity, Good Things Come in Threes

An Interview with Dr. Yukio Yamori, Director of the Institute for World Health Development at Mukogawa Women’s University

With over fifty thousand of its citizens over a century old, Japan’s life expectancy ranks high in the world. While Japanese cuisine is generally nutritious, how much do other factors such as location and lifestyle influence longevity? To find out, we spoke with Dr. Yukio Yamori, a global preventive nutritionist and longevity expert who is the director of the Institute for World Health Development at Mukogawa Women’s University. We asked him about the role of the Japanese diet in longevity, his research on diet in 61 communities from 25 countries, and additional factors that are vital to health and longevity.

What is the relationship between the Japanese diet and longevity?
Japanese women have the world’s longest life expectancy, living to an average age of eighty-seven, while Japanese men are in the top ten. The Japanese diet is a crucial factor. Japan’s climate and topography have helped contribute to a healthy diet, and because it is an island country, fish are easy to obtain here and can be consumed fresh in the form of sashimi. Fish is high in beneficial omega-3 fatty acids, while seafood in general supplies crucial magnesium and taurine. Japan’s climate is also suitable for producing rice and soy, which are both very low in cholesterol. For all of these reasons, Japan has the world’s lowest rate of coronary heart disease.

The disadvantage with Japanese cuisine, however, is that it can be high in sodium and low in calcium. This is because the soy sauce and miso paste frequently used in Japanese cuisine are high in salt, while consumption of calcium-rich dairy products never really became common. Across Japan, our research has found differences in health and longevity in areas with high salt and preserved foods, such as in northern Aomori Prefecture, when compared to areas that use less salt, like Okinawa. High salt intake results in higher mortality rates of stroke and stomach cancer, and consequently a lower average life expectancy.

What have you learned about diet in regard to health and longevity from your research in other countries?
First of all, our life is not fixed entirely by our genomes—our longevity can be improved through better eating habits and lifestyle. Okinawans once had the highest life expectancy in Japan, so we studied what happened to Okinawans that moved abroad. Brazil in particular has a large community of people of Okinawan Japanese descent, and meat is very inexpensive there. Since they ate more meat than before while their soy and fish intake decreased, their incidences of diabetes increased dramatically.

The indigenous peoples of Australia traditionally lived in nature and ate a diet consisting of nuts, berries, vegetables and lean meat. Our research found that the indigenous peoples who now live in Australia’s cities and have diets high in wheat, salt, sugar, meat and fat are suffering from obesity and a greatly reduced life span. Contrastingly, the indigenous peoples in more rural areas near the sea who are consuming fish are consequently much slimmer and live longer, healthier lives.

This brings us to the “three S” concept of “salt (reduced salt intake), seafood and soy” when thinking about the nutrition required for longevity. The idea is to limit salt, which causes high blood pressure and stomach cancer. Instead, we should eat more seafood for its omega-3 fatty acids, which help prevent coronary heart disease. Finally, we need to consume more soy, because it is high in isoflavones, which rejuvenate cells in the skin and organ tissue by improving blood circulation and protect against cancer.

What other factors are important for longevity?
Longevity involves a combination of several factors, as we observed in Hong Kong, which follows Japan as the number two area with the world’s greatest overall life expectancy. Similarly to Japan, the diet in Hong Kong—and the neighboring Canton Province, for that matter—involves the consumption of fresh fish and vegetables. Hong Kong’s limited space also means that people get physical exercise walking up and down stairs and hills. And finally, even though extended family members cannot all live in one urban high-rise dwelling due to space constraints, they often live close by on floors above or below, and get together for family meals. This is an opportunity to show respect and appreciation for elderly family members, and supports their family bond.

Thus we can say that there are three overall components to longevity. Nutrition is undoubtedly a crucial element for dietary health, but physical exercise and a healthy spirit are just as vital for physical and spiritual wellbeing.