10.10.2: Dementia and Alzheimer’s Disease
Dementia is a rather broad category of any type of cognitive decline with age that begins to affect a person’s memory, their capacity to function in daily life, and eventually their ability to take care of themselves (CDC, 2024a). Probably the most significant and familiar type of dementia is Alzheimer’s disease, which is characterized by troubles with memory, language, and thinking. It is thought to be caused by the buildup and changes of specific proteins in the brain, which cause damage to neurons. This damage results in chronic inflammation and potentially even shrinkage of brain tissue. Alzheimer’s disease is progressive and eventually deadly, killing more people than breast cancer and prostate cancer combined (Alzheimer’s Association, 2024b).
It is estimated that almost 7 million Americans currently live with Alzheimer’s disease, and by 2050 that number could be as high as 13 million (Alzheimer’s Association, 2024b). Age is the most common risk factor: it affects approximately 10.9% of people over the age of 65, and 33.4% of those over 85. Specific genes have been identified in the process of developing Alzheimer’s disease - one of them being the APOE-e4 gene that helps create a protein for transporting cholesterol in the blood. Protective factors include maintaining cardiovascular health with nutrition and exercise, as well as fostering social connections and intellectual stimulation. Education may also be protective by helping develop a “cognitive reserve” in mid-life, thus delaying symptoms, or it may also be associated with other healthy behaviors (such as not smoking and exercise) or a corelary with socioeconomic status and other social determinants of health (Alzheimer’s Association, 2024a). Physical activity and exercise in a variety of forms has been shown to have a very powerful protective effect on the brain. It can both prevent and delay symptoms of Alzheimer’s or dementia of any type (Foreman, 2020).