Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.
Skip to main content
Uk and japan cohort dementia study

Can cultural differences also affect the risk of developing dementia? If so, there could be important policy implications. Dr Dorina Cadar is part of an international team of researchers doing cross-country comparative with UK and Japanese cohorts.

Culture – the ideas, customs, and social behaviour of any particular group of people can have significant effects. The difference in regional habits, food traditions, festivals is what makes travel interesting. Holidays in other countries give a real escape from day-to-day norms, opening windows into other cultures. But can these cultural differences also affect the risk of developing dementia? If so, there could be important policy implications.

Cross-country comparative research is common in policymaking – policymakers, eg, in education, learn best practices from other countries that have better outcomes in the population. But long before the policy changes comes population research. It starts with being able to compare data from different groups and different countries. As countries with completely different cultural bases and histories, it’s particularly interesting to compare Japan and the UK populations. Year after year, Japan has topped the international league tables for life expectancy. This could be the result of various health policies from childhood vaccination programmes and the introduction of universal health insurance, to campaigns to reduce salt consumption, and the use of medication to reduce blood pressure.

The findings from this study will help policymakers and practitioners develop policies and interventions that can help improve the health of older individuals and reduce dementia risk, especially in the most vulnerable groups. - Dr Dorina Cadar

Some research has found that living with a sense of meaning and purpose may also help Japanese people live longer. The elderly are more involved in the local community in Japan compared to the UK and spend more time around younger family members. Other contributing factors might be the lifestyle that Japan’s older population tends to enjoy. Some of the Japanese secrets for healthy life are portion control (they only eat until 80% full), the power of miso soup-served with most meals, a growing appreciation towards the importance of eating local. Retirees in Japan stay active, and many older people continue working by choice rather than economic needs. However, the number of people affected with dementia is rising sharply, and we need to understand why. Perhaps there are changes in their working culture and other individual trends. Compared to the UK, Japan is known to have a culture of presentism at the office; the dedication of many Japanese to their company for life is also recognised more commonly there. The UK like the US is also known to value individualism generally and many more women assume more traditional female roles in Japan compared to the UK. Could such cultural differences also affect risk of dementia? The data is pointing to some interesting divergent trends between Japan and the UK, offering new opportunities for  cohort researchers to investigate.

In my research with largescale population data, I’ve been delving to some interesting figures: in the UK, even though dementia risk is rising (due to higher numbers of people surviving into older ages), recent evidence suggests that the UK is experiencing a decline in dementia incidence. By contrast, Japan has witnessed a different trend, with an increased number of cases of dementia. Social and cultural factors are known to have an influence on mental health and dementia risk.

How could this be? I’m working with a team of international collaborators and we are are interested in exploring these differences and their emerging roots. Could these differences be related to dementia diagnostic practice within each country or to aspects of the culture and lifestyle behaviours that are fundamentally different between the two countries and could, in turn, affect the risk of disease? In either case, there are opportunities to learn and inform governments, charities, health professional and individuals with the knowledge acquired and construct tailored advice that could reduce dementia risk.

On 6 November 2019, several of my colleagues from ELSA team lead by PI Professor Andrew Steptoe, the director of DPUK Professor John Gallacher, and world-recognised leaders in dementia research Carol Brayne, Gill, Livingston,will be meeting with Japanese researchers from Osaka University to exchange views and findings from each country on dementia prevalence and country-specific investigation of risk factors.  They will be presenting significant updates on their work with each cohort and then looking at how these cohorts can be considered together in the two-day data harmonization workshop which is open to all interested researchers. The comparisons will shine a light on the social and biological mechanisms associated with dementia. Charities like Alzheimer Society, ARUK, Mind AgeUK, and DPUK already provide advice to older people about the activities they can do, which reduce dementia risk. My team’s research, which is part of the UK Japan Dementia Research Network, will add further weight to this understanding. The findings could contribute to the knowledge base underpinning country-specific health policies targeting older people's health, reducing the existing socio-economic inequalities, and introducing new effective interventions to reduce dementia risk.

The research meeting takes place in London at Friends House on 6 November. It is open to all researchers. Researchers from the English Longitudinal Study of Ageing (ELSA) and different Japanse cohorts such as the Japan Collaborative Cohort Study (JACC) and Japan Gerontological Evaluation Study of Aging (JAGES) will showcase their work on this area. This will provide opportunities for cross-country and cross-cohort investigation with other studies via the Dementia Platform UK Data Portal to further explore the biological and psychosocial factors that are underlying the different dementia risk in the UK and Japan. If you plan to attend please register here.