The Epidemiology of Alzheimer's Disease Modifiable Risk Factors and Prevention

Abstract

Mild Alzheimer's disease is the leading cause of dementia, accounting for 50-70% of cases. Alzheimer's disease is an irreversible neurodegenerative disease, which affects daily life activities and social functioning. As life expectancy increases and demographic ageing occurs, the global prevalence of Alzheimer's disease is expected to continue to rise especially in developing countries, leading to a costly burden of disease. Alzheimer's disease is a complex and multifactorial disorder that is determined by the interaction of genetic susceptibility and environmental factors across the life course. Epidemiological studies have identified potential modifiable risk and protective factors for Alzheimer's disease prevention. Moreover, Alzheimer's disease is considered to start decades earlier before clinical symptoms occur, thus interventions targeting several risk factors in non-demented elderly people even middle-aged population might prevent or delay Alzheimer's disease onset. Here, we provide an overview of current epidemiological advances related to Alzheimer's disease modifiable risk factors, highlighting the concept of early prevention.

Keywords: Alzheimer’s disease; epidemiology; modifiable risk factors; prevention.

Figure 1

Potential modifiable risk factors for Alzheimer's disease Risk factors mainly included pre-existing diseases, unhealthy lifestyles and environmental exposures, while some factors concerning psychosocial conditions as well as healthy lifestyles might protect against AD. In addition, some factors appeared to be risk factors as well as symptoms of AD, possibly due to the reverse causality, these factors were highlighted in bold. Abbreviation: BP = blood pressure, DASH = Dietary Approach to Stop Hypertension, MIND = Mediterranean-DASH diet Intervention for Neurodegeneration Delay, PUFA = polyunsaturated fatty acid, HDL- cholesterol = high-density lipoprotein cholesterol.

Figure 2

Implications for preventing Alzheimer's disease and slowing its progression It is imperative to increase the cognitive reserve mainly via enhancing education attainment and promoting social contact. Additionally, good conditions of body health and healthy lifestyles as well as reducing environmental exposures might be favorable to reduce the neuropathological damage for AD prevention.