Lifestyle Change and the Prevention of Cognitive Decline
Lifestyle Change and the Prevention of Cognitive Decline
Purpose of review: Effective pharmaceutical treatment of dementia is currently unavailable. Epidemiological work has, however, identified modifiable lifestyle factors, such as poor diet and physical and cognitive inactivity, that are associated with the risk of dementia. These factors may be useful targets for the prevention of cognitive impairment and dementia. Much recent research has, therefore, adopted an interventional focus. We review this work, highlight some methodological limitations, and provide recommendations for future research.
Recent findings: Change from a sedentary lifestyle to moderate physical activity has beneficial effects on cognitive functioning, and preliminary evidence suggests that such change may reduce the incidence of dementia. The evidence on cognitive benefits of lifestyle changes towards more intellectual engagement is insufficient. Nutritional supplements to treat deficiency may improve cognitive performance, but supplements on top of a healthy diet cannot be recommended.
Summary: Introduction of physical activity can reduce the risk of cognitive impairment in old age. Future research on nutritional supplements must consider the principle of an inverted U-shaped association between nutritional level and cognitive function. Work on the effects of cognitive training must use transfer tasks as primary outcome measures, and investigate whether effects of cognitive training generalize beyond the trained cognitive tasks.
The prevalence and incidence of dementia and cognitive impairment increase exponentially with advancing age. The increase of the older population will, therefore, dramatically increase the prevalence of dementia. In 2010, the global number of individuals with dementia was estimated at 35.6 million. This number will increase to 115.4 million by 2050, unless effective reductions of the incidence of dementia can be implemented. Identifying means to delay the onset of dementia is, thus, of great importance for alleviating the rising pressures of this disease on health-care systems and societies.
No effective pharmaceutical treatment of dementia is currently available. Epidemiological work has, however, identified a number of modifiable factors that are associated with increased risk of dementia. Vascular risk factors, such as hypertension, hypercholesterolemia, high BMI, and physical inactivity, have all been associated with incidence of dementia in several population-based longitudinal studies. Healthy diet, with low intake of saturated fat and higher intake of polyunsaturated and fish-related fat, vitamins B6 and B12 and folic acid, and antioxidant nutrients (e.g., C and E vitamins), have also been related to reduced risk of dementia. Finally, psychosocial factors, including education, higher work complexity, social participation, and intellectual activities, have been linked to dementia onset and cognitive decline. In total, up to half of all dementia cases may be attributable to inactivity and vascular factors. Importantly, these factors are modifiable and could, therefore, be useful targets for the prevention of cognitive decline and dementia. During recent years, we have witnessed an increase in randomized controlled trials (RCT) evaluating the effects of physical, cognitive, and nutritional interventions on cognitive performance and the incidence of dementia in old age. Here we review the developments in this field during 2012, highlight methodological limitations, and provide recommendations for future research.
Abstract and Introduction
Abstract
Purpose of review: Effective pharmaceutical treatment of dementia is currently unavailable. Epidemiological work has, however, identified modifiable lifestyle factors, such as poor diet and physical and cognitive inactivity, that are associated with the risk of dementia. These factors may be useful targets for the prevention of cognitive impairment and dementia. Much recent research has, therefore, adopted an interventional focus. We review this work, highlight some methodological limitations, and provide recommendations for future research.
Recent findings: Change from a sedentary lifestyle to moderate physical activity has beneficial effects on cognitive functioning, and preliminary evidence suggests that such change may reduce the incidence of dementia. The evidence on cognitive benefits of lifestyle changes towards more intellectual engagement is insufficient. Nutritional supplements to treat deficiency may improve cognitive performance, but supplements on top of a healthy diet cannot be recommended.
Summary: Introduction of physical activity can reduce the risk of cognitive impairment in old age. Future research on nutritional supplements must consider the principle of an inverted U-shaped association between nutritional level and cognitive function. Work on the effects of cognitive training must use transfer tasks as primary outcome measures, and investigate whether effects of cognitive training generalize beyond the trained cognitive tasks.
Introduction
The prevalence and incidence of dementia and cognitive impairment increase exponentially with advancing age. The increase of the older population will, therefore, dramatically increase the prevalence of dementia. In 2010, the global number of individuals with dementia was estimated at 35.6 million. This number will increase to 115.4 million by 2050, unless effective reductions of the incidence of dementia can be implemented. Identifying means to delay the onset of dementia is, thus, of great importance for alleviating the rising pressures of this disease on health-care systems and societies.
No effective pharmaceutical treatment of dementia is currently available. Epidemiological work has, however, identified a number of modifiable factors that are associated with increased risk of dementia. Vascular risk factors, such as hypertension, hypercholesterolemia, high BMI, and physical inactivity, have all been associated with incidence of dementia in several population-based longitudinal studies. Healthy diet, with low intake of saturated fat and higher intake of polyunsaturated and fish-related fat, vitamins B6 and B12 and folic acid, and antioxidant nutrients (e.g., C and E vitamins), have also been related to reduced risk of dementia. Finally, psychosocial factors, including education, higher work complexity, social participation, and intellectual activities, have been linked to dementia onset and cognitive decline. In total, up to half of all dementia cases may be attributable to inactivity and vascular factors. Importantly, these factors are modifiable and could, therefore, be useful targets for the prevention of cognitive decline and dementia. During recent years, we have witnessed an increase in randomized controlled trials (RCT) evaluating the effects of physical, cognitive, and nutritional interventions on cognitive performance and the incidence of dementia in old age. Here we review the developments in this field during 2012, highlight methodological limitations, and provide recommendations for future research.
