One well-known gene that influences Alzheimer's risk is the apolipoprotein E (APOE) gene. The APOE gene is involved in making a protein that helps carry cholesterol and other types of fat in the bloodstream. Problems in this process are thought to contribute to the development of Alzheimer's.
In general, the greater the number of relatives who have had dementia – particularly FTD or ALS – the greater the chances of developing 'familial' FTD. Of the different types of FTD, the behavioural form is the one that is inherited most often.
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.
Genetic causes of dementia
If a parent has a mutated gene that causes FAD, each child has a 50% chance of inheriting it. The presence of the gene means that the person will eventually develop Alzheimer's disease, usually in their 40s or 50s.
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.
Family history by the numbers
In absolute numbers, a 2% annual risk means that two out of 100 65-year-olds will develop dementia every year. Family history raises the 2% annual risk by about 30%, to 2.6% per year. That means going from 20 cases in a group of 1,000 to 26 in 1,000, or six additional cases in 1,000.
There may be specific instances when an individual living with Alzheimer's should discuss genetic testing with their physician, as the results could impact a treatment decision. In addition, a physician may utilize genetic testing as part of the diagnostic process for more rare types of dementia.
There's no certain way to prevent all types of dementia, as researchers are still investigating how the condition develops. However, there's good evidence that a healthy lifestyle can help reduce your risk of developing dementia when you're older.
Yes. Women have a greater risk of developing dementia during their lifetime. In fact, around twice as many women have Alzheimer's disease – the most common type of dementia – compared to men.
Dementia is caused by many different diseases or injuries that directly and indirectly damage the brain. Alzheimer disease is the most common form and may contribute to 60–70% of cases.
In addition, highly intelligent people have been found, on average, to show clinical signs of Alzheimer's later than the general population. Once they do, they decline much faster. Thought to reflect their greater mental reserves, this different pattern may call for a different approach to diagnosis.
Dementia is more prevalent at older ages.
About 3% of adults ages 70 to 74 had dementia in 2019, compared with 22% of adults ages 85 to 89 and 33% of adults ages 90 and older.
Introduction: The five-word test (5WT) is a serial verbal memory test with semantic cuing. It is proposed to rapidly evaluate memory of aging people and has previously shown its sensitivity and its specificity in identifying patients with AD.
This includes purchasing and selling property, managing bank accounts, paying bills, et cetera. In most cases, a conservator of a person with dementia will assume both of these responsibilities. Most often, it is a family member who takes on the responsibility of being a loved one's conservator.
A condition is considered Y-linked if the altered gene that causes the disorder is located on the Y chromosome, one of the two sex chromosomes in each of a male's cells. Because only males have a Y chromosome, in Y-linked inheritance, a variant can only be passed from father to son.
The Mini-Cog test.
A third test, known as the Mini-Cog, takes 2 to 4 minutes to administer and involves asking patients to recall three words after drawing a picture of a clock. If a patient shows no difficulties recalling the words, it is inferred that he or she does not have dementia.
The Montreal Cognitive Assessment (MoCA) is a tool that helps healthcare professionals detect mild cognitive impairment and Alzheimer's disease in people. A 2021 study found that it is a better measure of cognitive function than the MMSE. It consists of 30 questions that take 10–12 minutes to accomplish.
MRI scans. MRI scans can help confirm the type of disease causing a person's dementia. It can do this by: showing if blood vessels are damaged, which happens in vascular dementia.
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.
Alzheimer's disease accounts for 60-80% of cases. Vascular dementia, which occurs because of microscopic bleeding and blood vessel blockage in the brain, is the second most common cause of dementia. Those who experience the brain changes of multiple types of dementia simultaneously have mixed dementia.
Other foods that may reduce dementia risk
The MIND diet encourages people to eat green leafy vegetables, berries, nuts, whole grains, fish, poultry, beans, unsaturated fats like olive oil, eggs, and low amounts of red meat.