The importance of dementia as a public health concern is rising in the context of population aging (World Health Organization, 2017). Its significant social and economic impact, mainly due to a lack of curative treatment, requires public health to focus on what’s currently possible. First and foremost that is: reducing modifiable risk factors for cognitive decline and dementia (World Health Organization, 2019). A life-course model of dementia prevention highlights 12 modifiable risk factors, which are estimated to account for at least 40% of dementias worldwide: low education in early life, hearing loss, traumatic brain injury, hypertension, obesity, alcohol consumption above 21 units a week in midlife, diabetes mellitus, depression, physical inactivity, smoking, social isolation, and exposure to air pollution in later life (Livingston etal., Reference Livingston2020). The occurrence of these risk factors varies across and within countries and cultures, but they cluster around inequalities – with individuals who are most deprived being typically most exposed. Therefore, Hofbauer and Rodriguez’s study, which presents the validation of a social deprivation index in association with cognitive function and cognitive decline in older adults (Hofbauer and Rodriguez, Reference Hofbauer and Rodriguez2021b), addresses an important, but still under-recognized aspect in the field of dementia risk reduction and brain health promotion.
Hofbauer and Rodriguez replicated and extended the findings of their previous study, in which they constructed a social deprivation index (including education, income, wealth, health insurance status, job stability, and neighborhood safety) based on the US Health and Retirement Study (HRS). In the nationally representative sample of over 11,000 study participants at least 50 years old, they found that social deprivation predicted cognitive function and cognitive decline (Hofbauer and Rodriguez, Reference Hofbauer and Rodriguez2021a). The authors were able to replicate the findings in a European sample drawing on data of the Survey of Health, Ageing, and Retirement in Europe (SHARE). SHARE, a sister study of HRS and thus similar in study design, provided information on 51,630 individuals aged at least 50 years old. Comparable to the results of the US sample, a higher score in the social deprivation index in the European sample indicated lower cognitive function and faster cognitive decline. Moreover, Hofbauer and Rodriguez made use of the further social deprivation items available in SHARE, and tested whether a more comprehensive index would increase the explanatory power with regards to cognition. Indeed, adding items that mostly captured various aspects of an individual’s ability to afford certain life expenses (e.g. groceries, replace worn-out clothing and shoes, a holiday, and unexpected expenses) showed a stronger association with cognitive function and cognitive decline. Notably, regardless of which index, social deprivation was stronger associated with the level of cognitive function than cognitive decline.
More than three decades have passed since the publication of Peter Townshend’s paper “Deprivation” which was a milestone towards its conceptualization. According to Townshend, people are deprived if they “lack the material standards of diet, clothing, housing, household facilities, working, environmental and locational conditions and facilities which are ordinarily available in their society, and do not participate in or have access to the forms of employment, occupation, education, recreation and family and social activities and relationships which are commonly experienced or accepted” (Townsend, Reference Townsend1987). Since then, many works have built on and extended on the original publication, developing manifold indices for deprivation (e.g. Świgost, Reference Świgost2017; Alkire etal., Reference Alkire, Roche, Ballon, Foster, Santos and Seth2015; Allik etal., Reference Allik, Leyland, Travassos Ichihara and Dundas2020). The multitude of approaches to define, operationalize, and measure deprivation reflects the complexity of the concept. It is applied to individuals, small areas such as neighbourhoods, or whole countries. Most deprivation measures include items regarding income, employment, housing and household assets, education, ownership of goods, and social class (Allik etal., Reference Allik, Leyland, Travassos Ichihara and Dundas2020) – typically covering material aspects and often social aspects. Despite the heterogeneity in defining, operationalizing, and measuring social deprivation, there is robust evidence for poorer health outcomes in socially deprived individuals (Marmot etal., Reference Marmot, Friel, Bell, Houweling and Taylor2008).
The results of Hofbauer and Rodriguez’s study particularly point the finger to the importance of social determinants of brain health, with implications for risk reduction of cognitive decline and dementia. Especially structural determinants (e.g. education and income, access to health care, health care insurance) shape the conditions of daily life which result in brain health inequities – contributing significantly to who is more likely to develop a dementia syndrome and at what age. Emerging studies on the relationship of social determinants and lifestyle factors for brain health help us to develop best practice approaches for dementia risk reduction and prevention. Strategies of upstream prevention involve intervening on social determinants of brain health with the goal to create healthy environments and conditions that allow individuals to practice healthy brain lifestyles – this approach benefits societies at large, but particularly socially deprived groups. From a public health perspective, socially deprived individuals may have the largest room for the improvement of brain health. For example, Deckers etal. showed that socioeconomic differences in dementia risk were partly explained by differences in modifiable health conditions and lifestyle factors. In fact, 52% of the risk difference between the highest and lowest wealth group was explained by differences in lifestyle (Deckers etal., Reference Deckers, Cadar, van Boxtel, Verhey, Steptoe and Köhler2019). In a sample of cognitively healthy individuals in midlife and early late life, 12% to 23% of the differences in cognitive function between individuals with high socioeconomic status and low socioeconomic status could be attributed to modifiable health and lifestyle factors (Roehr etal., Reference Roehr2020). Basically, this is not a new idea: an empirical analysis of the contributions of structural and behavioral factors on health inequalities from the late 90s concluded that both groups of factors played a substantial role; however, the total (direct and indirect) contribution of structural factors was larger than that of behavioral factors (Stronks etal., Reference Stronks, van de Mheen, Looman and Mackenbach1996). Current recommendations – a prominent example is the World Health Organization’s guideline on risk reduction of cognitive decline and dementia (World Health Organization, 2019) – tend to focus on lifestyle behaviors and managing health risk factors. Notably, there is an evidence that multidomain lifestyle-based interventions targeting lifestyle and cardiovascular risk factors can preserve cognitive functioning and reduce the risk of cognitive decline among older adults at risk for dementia (Rosenberg etal., Reference Rosenberg, Mangialasche, Ngandu, Solomon and Kivipelto2020). In line with the above-outlined evidence, it seems reasonable to conclude that socially deprived individuals may particularly benefit from lifestyle interventions. At the same time, however, people from socially disadvantaged groups tend to be heavily under-represented in public health research – regardless of type of study (Bonevski etal., Reference Bonevski2014). This requires bringing environments and the conditions they provide into the equation. The social–ecological approach, for example, argues for creating environments and policies that make it convenient, attractive, and economical to make healthy lifestyle choices (Golden & Earp 2012). From this perspective, we have to acknowledge that there may be limits to what lifestyle interventions can achieve for the individual if contextual factors are not considered. Thus, the potential for dementia risk reduction could likely be maximized if the social determinants of brain health were addressed as well: equal opportunities for people to receive a good education, good jobs with decent income, and health care access (and other factors) allow for better living conditions, which in turn enable lifestyles that promote brain health. Hofbauer and Rodriguez’s study provides a validated social deprivation index, that could be easily implemented in future studies, which are needed to establish more evidence on the relationship between social deprivation, lifestyle factors, and brain health outcomes, particularly from low income regions and countries. The scientific evidence is pivotal to inform policy and call politicians to action: their decisions will have significant weight in reducing the scale and impact of dementia.
You have
Access
The importance of dementia as a public health concern is rising in the context of population aging (World Health Organization, 2017). Its significant social and economic impact, mainly due to a lack of curative treatment, requires public health to focus on what’s currently possible. First and foremost that is: reducing modifiable risk factors for cognitive decline and dementia (World Health Organization, 2019). A life-course model of dementia prevention highlights 12 modifiable risk factors, which are estimated to account for at least 40% of dementias worldwide: low education in early life, hearing loss, traumatic brain injury, hypertension, obesity, alcohol consumption above 21 units a week in midlife, diabetes mellitus, depression, physical inactivity, smoking, social isolation, and exposure to air pollution in later life (Livingston etal., Reference Livingston2020). The occurrence of these risk factors varies across and within countries and cultures, but they cluster around inequalities – with individuals who are most deprived being typically most exposed. Therefore, Hofbauer and Rodriguez’s study, which presents the validation of a social deprivation index in association with cognitive function and cognitive decline in older adults (Hofbauer and Rodriguez, Reference Hofbauer and Rodriguez2021b), addresses an important, but still under-recognized aspect in the field of dementia risk reduction and brain health promotion.
Hofbauer and Rodriguez replicated and extended the findings of their previous study, in which they constructed a social deprivation index (including education, income, wealth, health insurance status, job stability, and neighborhood safety) based on the US Health and Retirement Study (HRS). In the nationally representative sample of over 11,000 study participants at least 50 years old, they found that social deprivation predicted cognitive function and cognitive decline (Hofbauer and Rodriguez, Reference Hofbauer and Rodriguez2021a). The authors were able to replicate the findings in a European sample drawing on data of the Survey of Health, Ageing, and Retirement in Europe (SHARE). SHARE, a sister study of HRS and thus similar in study design, provided information on 51,630 individuals aged at least 50 years old. Comparable to the results of the US sample, a higher score in the social deprivation index in the European sample indicated lower cognitive function and faster cognitive decline. Moreover, Hofbauer and Rodriguez made use of the further social deprivation items available in SHARE, and tested whether a more comprehensive index would increase the explanatory power with regards to cognition. Indeed, adding items that mostly captured various aspects of an individual’s ability to afford certain life expenses (e.g. groceries, replace worn-out clothing and shoes, a holiday, and unexpected expenses) showed a stronger association with cognitive function and cognitive decline. Notably, regardless of which index, social deprivation was stronger associated with the level of cognitive function than cognitive decline.
More than three decades have passed since the publication of Peter Townshend’s paper “Deprivation” which was a milestone towards its conceptualization. According to Townshend, people are deprived if they “lack the material standards of diet, clothing, housing, household facilities, working, environmental and locational conditions and facilities which are ordinarily available in their society, and do not participate in or have access to the forms of employment, occupation, education, recreation and family and social activities and relationships which are commonly experienced or accepted” (Townsend, Reference Townsend1987). Since then, many works have built on and extended on the original publication, developing manifold indices for deprivation (e.g. Świgost, Reference Świgost2017; Alkire etal., Reference Alkire, Roche, Ballon, Foster, Santos and Seth2015; Allik etal., Reference Allik, Leyland, Travassos Ichihara and Dundas2020). The multitude of approaches to define, operationalize, and measure deprivation reflects the complexity of the concept. It is applied to individuals, small areas such as neighbourhoods, or whole countries. Most deprivation measures include items regarding income, employment, housing and household assets, education, ownership of goods, and social class (Allik etal., Reference Allik, Leyland, Travassos Ichihara and Dundas2020) – typically covering material aspects and often social aspects. Despite the heterogeneity in defining, operationalizing, and measuring social deprivation, there is robust evidence for poorer health outcomes in socially deprived individuals (Marmot etal., Reference Marmot, Friel, Bell, Houweling and Taylor2008).
The results of Hofbauer and Rodriguez’s study particularly point the finger to the importance of social determinants of brain health, with implications for risk reduction of cognitive decline and dementia. Especially structural determinants (e.g. education and income, access to health care, health care insurance) shape the conditions of daily life which result in brain health inequities – contributing significantly to who is more likely to develop a dementia syndrome and at what age. Emerging studies on the relationship of social determinants and lifestyle factors for brain health help us to develop best practice approaches for dementia risk reduction and prevention. Strategies of upstream prevention involve intervening on social determinants of brain health with the goal to create healthy environments and conditions that allow individuals to practice healthy brain lifestyles – this approach benefits societies at large, but particularly socially deprived groups. From a public health perspective, socially deprived individuals may have the largest room for the improvement of brain health. For example, Deckers etal. showed that socioeconomic differences in dementia risk were partly explained by differences in modifiable health conditions and lifestyle factors. In fact, 52% of the risk difference between the highest and lowest wealth group was explained by differences in lifestyle (Deckers etal., Reference Deckers, Cadar, van Boxtel, Verhey, Steptoe and Köhler2019). In a sample of cognitively healthy individuals in midlife and early late life, 12% to 23% of the differences in cognitive function between individuals with high socioeconomic status and low socioeconomic status could be attributed to modifiable health and lifestyle factors (Roehr etal., Reference Roehr2020). Basically, this is not a new idea: an empirical analysis of the contributions of structural and behavioral factors on health inequalities from the late 90s concluded that both groups of factors played a substantial role; however, the total (direct and indirect) contribution of structural factors was larger than that of behavioral factors (Stronks etal., Reference Stronks, van de Mheen, Looman and Mackenbach1996). Current recommendations – a prominent example is the World Health Organization’s guideline on risk reduction of cognitive decline and dementia (World Health Organization, 2019) – tend to focus on lifestyle behaviors and managing health risk factors. Notably, there is an evidence that multidomain lifestyle-based interventions targeting lifestyle and cardiovascular risk factors can preserve cognitive functioning and reduce the risk of cognitive decline among older adults at risk for dementia (Rosenberg etal., Reference Rosenberg, Mangialasche, Ngandu, Solomon and Kivipelto2020). In line with the above-outlined evidence, it seems reasonable to conclude that socially deprived individuals may particularly benefit from lifestyle interventions. At the same time, however, people from socially disadvantaged groups tend to be heavily under-represented in public health research – regardless of type of study (Bonevski etal., Reference Bonevski2014). This requires bringing environments and the conditions they provide into the equation. The social–ecological approach, for example, argues for creating environments and policies that make it convenient, attractive, and economical to make healthy lifestyle choices (Golden & Earp 2012). From this perspective, we have to acknowledge that there may be limits to what lifestyle interventions can achieve for the individual if contextual factors are not considered. Thus, the potential for dementia risk reduction could likely be maximized if the social determinants of brain health were addressed as well: equal opportunities for people to receive a good education, good jobs with decent income, and health care access (and other factors) allow for better living conditions, which in turn enable lifestyles that promote brain health. Hofbauer and Rodriguez’s study provides a validated social deprivation index, that could be easily implemented in future studies, which are needed to establish more evidence on the relationship between social deprivation, lifestyle factors, and brain health outcomes, particularly from low income regions and countries. The scientific evidence is pivotal to inform policy and call politicians to action: their decisions will have significant weight in reducing the scale and impact of dementia.