Causes and Risk Factors of Alzheimer’s Disease

Table of ContentsView AllTable of ContentsBrain & Body Risk FactorsFamily History & GeneticsLifestyle Risk FactorsNext in Alzheimer’s Disease GuideHow Alzheimer’s Disease Is Treated

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Brain & Body Risk Factors

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Lifestyle Risk Factors

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These changes includebrain atrophy, or shrinkage, and a build-up of amyloid and tau proteins in the brain. The accumulated amyloid protein can form abnormal clumps in the brain, known as amyloid plaques. In contrast, excess tau protein forms tangled fibers in your brain cells, known as neurofibrillary tangles.

These tangles and plaques can damage brain cells, known asneurons, particularly in the part of the brain that controls memory. This can prevent neurons from sending messages to each other, interfering with functions such as thinking, remembering, learning, and planning, and eventually leading todementia.

These changes in the brain can sometimes begin 10 years before anysymptoms of Alzheimer’s diseaseappear. Over time, the condition spreads to other parts of the brain, resulting in a loss of neurons, causing the brain to atrophy.

Can Alzheimer’s Disease Be Prevented?

Aging is a major risk factor for Alzheimer’s disease as it causes changes in thebrain. Other health conditions and head trauma can also raise your risk of developing Alzheimer’s.

Aging

Aging is perhaps the most significant risk factor of Alzheimer’s disease. After the age of 65, the number of people with Alzheimer’s disease doubles every five years.

While aging does not cause Alzheimer’s, and many people live till 90 and beyond without developing any form of dementia, roughly one-third of all people over the age of 85 may have this condition.

Some of the age-related changes that may occur in the brain are atrophy, inflammation, vascular damage, and increased production of unstable molecules known as free radicals.

These changes affect neurons in the brain and contribute to the progression of Alzheimer’s disease. Alzheimer’s is not a normal part of aging, however. The brain shrinks considerably as the condition progresses.

Health Conditions

The following health conditions can also raise your risk of Alzheimer’s disease:

These conditions can reduce the rate at which the brain can clear out excess amyloid protein, leading to a build-up of protein in the brain. These conditions pose a greater risk to those who are 50 and older.

Mild Cognitive Impairment

MCI can sometimes be an early sign of Alzheimer’s disease and dementia. If a person with MCI is primarily experiencing memory loss, there is a significant risk of eventually beingdiagnosed with Alzheimer’s disease.

Everyone who has MCI doesn’t necessarily develop Alzheimer’s disease or dementia. However, being diagnosed with MCI can encourage healthier lifestyle choices, help you develop strategies to cope with the memory loss that accompanies these conditions, and ensure that you see your healthcare provider regularly to monitor your symptoms.

Head Trauma

Having a head injury that caused trauma to the brain can raise the risk of developing Alzheimer’s disease.Severe injury, multiple injuries, or getting injured after the age of 50 can further increase the chances of developing Alzheimer’s.

Phineas Gage: His Accident and Impact on Psychology

The role of genes in Alzheimer’s disease is complex and still being investigated.

The risk of developing Alzheimer’s disease is higher if your parents or siblings have had it; however, having a family history of the condition doesn’t guarantee that you’ll have it, too. If several people in your family have had Alzheimer’s, particularly at a younger age, you should consider genetic counseling to evaluate your chances of developing it.

There are two types of Alzheimer’s disease; both types have genetic risk factors associated with them:

Having Down syndrome, agenetic chromosome disorder, can also raise your risk of developing Alzheimer’s disease. This is because people with Down syndrome have an extra copy of chromosome 21, so they have an additional gene producing the protein that leads to the production of beta-amyloid.

People with Down syndrome exhibit symptoms of Alzheimer’s 10 to 20 years before other people usually do.

Other lifestyle, developmental, and environmental factors can also affect your brain and raise your risk of Alzheimer’s disease. These include:

There are steps you can take to keep your brain and body healthy in order to prevent cognitive decline and lower your chances of developing Alzheimer’s disease and dementia:

What Are the Early Signs of Dementia?

4 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute on Aging.What causes Alzheimer’s disease?Alzheimer’s Association.Alzheimer’s disease facts and figures.Ramos-Cejudo J, Wisniewski T, Marmar C, et al.Traumatic brain injury and Alzheimer’s disease: The cerebrovascular link.EBioMedicine. 2018;28:21-30. doi:10.1016/j.ebiom.2018.01.021National Down Syndrome Society.Alzheimer’s disease and Down syndrome.

4 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute on Aging.What causes Alzheimer’s disease?Alzheimer’s Association.Alzheimer’s disease facts and figures.Ramos-Cejudo J, Wisniewski T, Marmar C, et al.Traumatic brain injury and Alzheimer’s disease: The cerebrovascular link.EBioMedicine. 2018;28:21-30. doi:10.1016/j.ebiom.2018.01.021National Down Syndrome Society.Alzheimer’s disease and Down syndrome.

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

National Institute on Aging.What causes Alzheimer’s disease?Alzheimer’s Association.Alzheimer’s disease facts and figures.Ramos-Cejudo J, Wisniewski T, Marmar C, et al.Traumatic brain injury and Alzheimer’s disease: The cerebrovascular link.EBioMedicine. 2018;28:21-30. doi:10.1016/j.ebiom.2018.01.021National Down Syndrome Society.Alzheimer’s disease and Down syndrome.

National Institute on Aging.What causes Alzheimer’s disease?

Alzheimer’s Association.Alzheimer’s disease facts and figures.

Ramos-Cejudo J, Wisniewski T, Marmar C, et al.Traumatic brain injury and Alzheimer’s disease: The cerebrovascular link.EBioMedicine. 2018;28:21-30. doi:10.1016/j.ebiom.2018.01.021

National Down Syndrome Society.Alzheimer’s disease and Down syndrome.

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