A recent projection by a health ministry team in Japan indicates that the number of individuals aged 65 or older with dementia is estimated to reach 5.84 million by the year 2040, accounting for approximately 15% of that age group. This forecast signifies a notable decrease from a previous projection made in 2015, which suggested that over 8 million people would be affected by dementia by 2040. The revised estimate is linked to a shift in societal behavior towards better health practices, enabling individuals to address health issues such as high blood pressure, diabetes, and hyperlipidemia more effectively.

The decline in the projected number of dementia cases is also credited to an improvement in lifestyle choices and a reduction in smoking rates across the population. The health ministry noted that as individuals have become more health-conscious, they are making positive changes to their lifestyles that contribute to overall better health outcomes, potentially lowering the risk of conditions like dementia. Despite this positive trend, the projection still indicates a continuous growth in dementia cases within the elderly demographic in Japan, as the country's population ages rapidly. This suggests that by 2040, around 1 in every 6.7 elderly individuals could be living with dementia.