Alzheimer’s disease is a neurological disease characterized by changes in the brain.
These changes include brain atrophy or atrophy, and the accumulation of amyloid and tau in the brain. The accumulated amyloid forms abnormal clumps in the brain called amyloid plaques. In contrast, excess tau protein can form tangled fibers in your brain cells called neurofibrillary tangles.
These tangles and plaques can damage brain cells called neurons, especially the part of the brain that controls memory. This prevents neurons from sending information to each other, interfering with functions such as thinking, memory, learning, and planning, and ultimately leading to dementia.
These changes in the brain sometimes begin 10 years before any symptoms of Alzheimer’s disease appear. Over time, this condition can spread to other parts of the brain, leading to the loss of neurons and causing the brain to shrink.
These neurological changes are caused by age-related degeneration and other genetic, physical, and lifestyle factors. The role of these factors in the risk of Alzheimer’s disease varies from person to person. However, the exact reason for this situation is not fully understood.
Brain and body risk factors
Aging is the main risk factor for Alzheimer’s disease because it causes changes in the brain. Other health conditions and head trauma can also increase the risk of Alzheimer’s disease.
Aging may be the most important risk factor for Alzheimer’s disease. After 65, the number of people with Alzheimer’s disease doubles every five years.
Although aging does not cause Alzheimer’s disease, and many people live to 90 years of age and beyond without suffering from any form of dementia, about one-third of people over the age of 85 may have This disease.
These are some of the age-related changes that may occur in the brain: atrophy, inflammation, blood vessel damage, and increased production of unstable molecules called free radicals.
These changes can affect neurons in the brain and lead to the progression of Alzheimer’s disease. However, Alzheimer’s disease is not a normal part of aging. As the disease progresses, the brain shrinks significantly.
The following health conditions can also increase your risk of Alzheimer’s disease:
- heart disease
- High cholesterol
These conditions reduce the speed at which the brain removes excess amyloid, leading to the accumulation of protein in the brain. These conditions pose a greater risk to people 50 years and older.
Mild cognitive impairment
Mild cognitive impairment (MCI) is a disease marked by cognitive decline that affects functions such as thinking, memory, and language. This decline is usually greater than the normal level of the person’s age, but not as severe as the decline associated with dementia. People with MCI can still play a role in a work or social environment.
MCI can sometimes be an early sign of Alzheimer’s disease and dementia. If people with MCI mainly suffer from memory loss, then the risk of being diagnosed with Alzheimer’s disease is high.
Everyone with MCI does not necessarily suffer from Alzheimer’s disease or dementia. However, being diagnosed with MCI can encourage healthier lifestyle choices, help you develop strategies for dealing with memory loss that accompany these diseases, and ensure that you visit your healthcare provider regularly to monitor your symptoms.
Head injury causes trauma to the brain and increases the risk of Alzheimer’s disease. Severe injuries, multiple injuries, or injuries after the age of 50 can further increase the chance of Alzheimer’s disease.
Family history and genetics
The role of genes in Alzheimer’s disease is complex and is still being studied.
If your parents or siblings have Alzheimer’s disease, the risk of Alzheimer’s disease is higher; however, having a family history of the disease does not guarantee that you will also get the disease. If several people in your family have Alzheimer’s disease, especially at a young age, you should consider genetic counseling to assess your chances of developing Alzheimer’s disease.
There are two types of Alzheimer’s disease; both types have genetic risk factors associated with them:
- Early-onset Alzheimer’s disease: This is a rare condition. Symptoms may appear any time after the age of 30. Inheritance of a genetic mutation in one of the three genes can lead to early-onset Alzheimer’s disease.
- Late-onset Alzheimer’s disease: This is a more common condition, with symptoms first appearing in the mid-1960s. People with a gene variant called APOE ɛ4 on chromosome 19 may be more likely to develop late-onset Alzheimer’s disease. However, having a variation does not mean that you will definitely get Alzheimer’s, and some people with Alzheimer’s do not have APOE ɛ4.
Having Down syndrome (an inherited chromosomal disease) also increases the risk of Alzheimer’s disease. This is because people with Down syndrome have an extra copy of chromosome 21, so they have an extra gene that can produce the protein that causes beta-amyloid.
People with Down syndrome usually show symptoms of Alzheimer’s disease 10 to 20 years earlier than others.
Lifestyle risk factors
Other lifestyle, developmental and environmental factors can also affect your brain and increase your risk of Alzheimer’s disease. These include:
There are some steps you can take to keep your brain and body healthy to prevent cognitive decline and reduce the chance of Alzheimer’s disease and dementia: