Is it possible that about 40% of dementia cases can be prevented? Doctor explains the results of verifying possible risk reductions
Researchers at Tokai University School of Medicine investigated the extent to which 14 modifiable risk reductions are involved in dementia, based on Japanese data.
*Interviewed in January 2026.
Supervisiondoctor:
Masato Katsuki(Doctor)
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Graduated from Tohoku University in 2016/Currently works as a neurosurgeon and headache outpatient at Suwa Japan Red Cross. / Specializes in headaches, data science, and AI.
What did the research group announce?
Editorial department
Please tell us about the content presented by researchers at Tokai University School of Medicine.
Mr. Katsuki
As a result, the weighted average PAF for the 14 cases was 38.9%, indicating that approximately 4 out of 10 cases of dementia in Japan may be preventable. If we can prioritize everything and reduce it by 10%, we could prevent about 208,000 cases of dementia in the future, and if we can reduce it by 20%, we could prevent 407,000 cases of dementia in the future.It is thought that going forward, we should prioritize hearing care, physical activity, and lipid metabolism health.
What is “dementia”, the research theme?
Editorial department
Please tell us about dementia related to this research theme.
Mr. Katsuki
Dementia is a condition in which the function of nerve cells in the brain gradually changes due to various diseases, leading to a decline in functions such as memory and judgment, resulting in dementia in social life. In Japan, the number of cases is increasing as the population ages, and estimates for 2022 indicate that approximately 12% of people aged 65 and over will have dementia, and approximately 16% will have MCI (mild cognitive impairment), meaning that approximately 30% of elderly people will have symptoms related to cognitive function. Age-related symptoms tend to cause people to forget some of their experiences, while dementia is characterized by the fact that people sometimes forget their experiences, and it progresses.
What is the reception to the research content?
Editorial department
Please let me know if you accept the content presented by researchers at Tokai University School of Medicine.
Mr. Katsuki
First of all, if you find it difficult to hear conversations or the TV is too loud, get your hearing tested and, if necessary, connect with hearing aids or auditory rehabilitation so that you can maintain communication. Exercise doesn’t have to be strenuous; it’s important to create a form that you can continue to exercise, such as increasing the amount of time you spend walking.
Once dementia progresses, it is often difficult to recover from it, so it is important for younger generations to take the initiative of accumulating what they can do, rather than becoming hesitant after the symptoms appear. In order to reduce future risks as much as possible, I think it is a shortcut to continue a daily life that leads to health as a family.
Editorial department summary
A research group at Tokai University School of Medicine used data from Japan to estimate the impact of modifiable risk reduction on dementia. The results showed that about 40% of dementia cases may be caused by a preventive mindset.