TOKYO -- Japan's average life expectancy reached 85.2 years in 2021, 5.8 years longer than about three decades before, but the period spent with health issues and prefectural disparities also grew, a research team has reported.

In a study published March 20 online in The Lancet Public Health, a sister journal of Britain's The Lancet, the team, including Keio University researchers, analyzed data from the Vital Statistics, National Health and Nutrition Survey and prior studies on disease prevalence, independently calculating average life expectancy and related figures for each prefecture. Based on the results, they suggested a new social approach to achieve a healthy society with long lifespans.

The research showed average life expectancy rising from 79.4 years in 1990 to 85.2 years in 2021, while healthy life expectancy increased from 69.4 years to 73.8 years. The period spent living with health issues grew by 1.4 years to 11.3 years.

All figures were rounded to one decimal place. Healthy life expectancy, unlike national indicators, reflected the degree and impact level of disease prevalence.

By prefecture, Okinawa had the longest average lifespan at 80.6 years in 1990, while Osaka recorded the shortest at 78.2 years, a difference of 2.3 years. By 2021, all prefectures saw growth in life expectancy, but the gap widened to 2.9 years, with Shiga at 86.3 years and Aomori at 83.4 years as the longest and shortest respectively.

Mortality rates, excluding major aging diseases like stroke, ischemic heart disease and stomach cancer, decreased by an average of 2% annually from 1990 to 2005, slowing to 1.1% annually from 2015 to 2021.

The team noted that while medicine has advanced significantly, a multifaceted approach including enhanced social care is needed alongside medical care. Regarding prefectural disparities, Shuhei Nomura, a specially appointed professor at Keio University specializing in global health studies, stated, "By following the example of regions achieving longevity through proper allocation of medical resources and lifestyle modifications, the gaps could be expected to be reduced."

(Japanese original by Ryo Watanabe, Lifestyle, Science & Environment News Department)