The greatest known risk factor for Alzheimer's and other dementias is increasing age, but these disorders are not a normal part of aging. While age increases risk, it is not a direct cause of Alzheimer's. Most individuals with the disease are 65 and older. After age 65, the risk of Alzheimer's doubles every five years.
Older age does not cause Alzheimer's, but it is the most important known risk factor for the disease. The number of people with Alzheimer's disease doubles about every 5 years beyond age 65. About one-third of all people age 85 and older may have Alzheimer's disease.
Scientists believe that for most people, Alzheimer's disease is caused by a combination of genetic, lifestyle and environmental factors that affect the brain over time. In less than 1% of cases, Alzheimer's is caused by specific genetic changes that almost guarantee a person will develop the disease.
Who is affected? Alzheimer's disease is most common in people over the age of 65. The risk of Alzheimer's disease and other types of dementia increases with age, affecting an estimated 1 in 14 people over the age of 65 and 1 in every 6 people over the age of 80.
Studies show that dementia risk is lowest in people who have several healthy behaviours in mid-life (aged 40–65). These behaviours include: ∎regular mental, physical and social activity ∎not smoking ∎drinking alcohol only in moderation ∎keeping a healthy diet.
Alzheimer's disease is thought to be caused by the abnormal build-up of proteins in and around brain cells. One of the proteins involved is called amyloid, deposits of which form plaques around brain cells. The other protein is called tau, deposits of which form tangles within brain cells.
Although scientists have conducted many studies, and more are ongoing, so far nothing has been proven to prevent or delay dementia caused by Alzheimer's disease. But researchers have identified promising strategies and are learning more about what might—and might not—work.
We all inherit a copy of some form of APOE from each parent. Those who inherit one copy of APOE-e4 from their mother or father have an increased risk of developing Alzheimer's. Those who inherit two copies from their mother and father have an even higher risk, but not a certainty.
For most people with Alzheimer's — those who have the late-onset variety — symptoms first appear in their mid-60s or later. When the disease develops before age 65, it's considered early-onset Alzheimer's, which can begin as early as a person's 30s, although this is rare.
Change in routine
This means that a sudden disruption in routine may cause dementia symptoms to get worse. This is especially true if a person experiences stress. Some changes that might trigger worsening symptoms include: moving to an assisted living facility or a nursing home.
At first, Alzheimer's disease typically destroys neurons and their connections in parts of the brain involved in memory, including the entorhinal cortex and hippocampus. It later affects areas in the cerebral cortex responsible for language, reasoning, and social behavior.
According to the Alzheimer's Research and Prevention Foundation, regular physical exercise can reduce your risk of developing Alzheimer's disease by up to 50 percent. What's more, exercise can also slow further deterioration in those who have already started to develop cognitive problems.
Treatment for mild to moderate Alzheimer's disease
Galantamine, rivastigmine, and donepezil are cholinesterase inhibitors that are prescribed for mild to moderate Alzheimer's symptoms. These drugs may help reduce or control some cognitive and behavioral symptoms.
The Self-Administered Gerocognitive Exam, known as SAGE, is a brief, pen-and-paper cognitive assessment tool designed to detect the early signs of cognitive, memory, or thinking impairments. The test evaluates your thinking abilities.
Physicians use diagnostic tools combined with medical history and other information, including neurological exams, cognitive and functional assessments, brain imaging (MRI, CT, PET) and cerebrospinal fluid or blood tests to make an accurate diagnosis.
Studies of family history say that if you have a close relative who has been diagnosed with Alzheimer's disease—the most common form of dementia in older adults—your risk increases by about 30%. This is a relative risk increase, meaning a 30% hike in your existing risk.
Familial Alzheimer's disease, or FAD—the most common type of early-onset Alzheimer's—is inherited. If a parent has a gene for FAD, there is a 50/50 chance that a child will inherit the gene. If the gene is passed down, the child will usually—but not always—have FAD.
There is no test yet to predict if someone will get late-onset Alzheimer's, in which symptoms become apparent in a person's mid-60s. If someone is worried about changes in his or her memory or other problems with thinking, he or she should talk with a doctor.