We know there are genetic risk factors that differ across the human population. Some people get the disease and some people don't.
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.
Researchers have suggested that people who have more education or do more mentally stimulating activities throughout life build up a higher cognitive reserve, allowing their brain to resist damage caused by disease like Alzheimer's for longer.
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.
Some people have two APOE e4 genes, one from each parent. Having two genes increases the risk of getting Alzheimer's disease even more, about eight- to twelvefold. But not everyone who has one or even two APOE e4 genes gets Alzheimer's disease. And many people who don't have an APOE e4 gene get the disease.
Those who have a parent, brother or sister with Alzheimer's are more likely to develop the disease.
According to the Alzheimer's Association, 10% of all people over the age of 65 have Alzheimer's disease, and as many as 50% of people over 85 have it. The number of people with the disease doubles every 5 years beyond age 65.
Is Alzheimer's passed on by mother or father? Alzheimer's is not passed on by the mother more than the father, or vice versa. A mother or father may pass on an “Alzheimer's gene” or mutation that increases your risk. Even if both your parents pass on a risk gene, your Alzheimer's risk is higher, but not certain.
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.
The causes probably include a combination of age-related changes in the brain, along with genetic, environmental, and lifestyle factors. The importance of any one of these factors in increasing or decreasing the risk of Alzheimer's disease may differ from person to person.
Age is the single most significant factor. The likelihood of developing Alzheimer's disease doubles every 5 years after you reach 65. But it's not just older people who are at risk of developing Alzheimer's disease. Around 1 in 20 people with the condition are under 65.
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.
GENETIC DIFFERENCES
Women are more vulnerable to the APOE4 variant, which increases risk for Alzheimer's disease. Due to an extra X chromosome, women have more robust immune responses than men, which may lead to neuroinflammation.
They think forgetfulness is the first sign of Alzheimer's disease. But not all people with memory problems have Alzheimer's. Other causes for memory problems can include aging, medical conditions, emotional problems, mild cognitive impairment, or another type of dementia.
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.
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%.
In some cases, if a person has symptoms at an early age with a strong family history of Alzheimer's, a neurologist or other medical specialist may order a genetic test for APP, PSEN1, and PSEN2. Although APOE testing is also available, the results cannot fully predict who will or won't develop Alzheimer's.
In fact, around twice as many women have Alzheimer's disease – the most common type of dementia – compared to men. The main reason for this greater risk is because women live longer than men and old age is the biggest risk factor for this disease.
$99. This at home test identifies your APOE gene status with an easy mouth swab instead of a blood test. If you have a variant (APOE4) of the APOE gene, you could be at greater risk of developing late-onset Alzheimer's disease and dementia.
In the vast majority of cases (more than 99 in 100), Alzheimer's disease is not inherited. The most important risk factor for Alzheimer's disease is age.
“Improvements in lifestyle in adults in developed countries and other places — including increasing access to education and greater attention to heart health issues — have reduced incidence in recent years, but total numbers with dementia are still going up because of the aging of the population,” said Maria C.