Japanese people are known for their long life expectancy, but a new study from Karolinska Institutet and collaborators released on Mar. 23 suggests that Japanese and Swedish older adults have a similar number of healthy life years if 'healthy' is defined as living at home without the need for formal elder care. The research also found that mortality among individuals receiving elder care is lower in Japan than in Sweden.
The topic matters because it challenges common assumptions about longevity and health, showing that longer lives do not always mean more years spent in good health. The findings highlight differences in how elder care systems may affect both lifespan and quality of life for aging populations.
"Perhaps Japan's long life expectancy is not primarily due to the population being healthier? Our findings paint a more nuanced picture and instead suggest that the differences mainly arise among those who require care," said Karin Modig, senior lecturer and associate professor at the Institute of Environmental Medicine, Karolinska Institutet.
The study compared remaining life expectancy at age 75 for women and men in Sweden and Japan using register data from over 850,000 individuals in Sweden and more than 330,000 from nine municipalities in Japan. Participants were divided into three groups: those with no formal elder care, those receiving home care, or those living in residential care. Results published in BMC Medicine showed Japanese older adults generally had lower mortality rates than Swedes—mainly among people receiving some form of elder care. For example, a 75-year-old Japanese woman could expect an average of 10.4 'healthy' years (without formal care) compared to 9.9 years for her Swedish counterpart; she would also spend more time with elder care—5.1 years versus 3.8 years for Swedish women.
"This means that Japanese women can expect to spend more years in elder care, but we need to understand what drives these differences. It is important to identify which aspects of elder care influence longevity, especially as more people live to very old ages," said Shunsuke Murata, researcher at Karolinska Institutet and Kobe University.
For men aged 75, the difference was small: an average of 9.8 healthy life years without formal care for Japanese men versus 9.6 for Swedish men; both groups spent just over two years with some form of elder care.
Researchers suggested several possible reasons behind these trends—including when individuals begin receiving formal support, how each country organizes its system of support services for elders, differences such as greater medical treatment near end-of-life stages in Japan or heavier reliance on family-based caregiving there.
"These are the first results from a collaborative project examining health among older adults in Sweden and Japan. We have already begun the next study, which will compare health across different stages of care," concluded Modig.
