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.
Everyone has a chance of developing dementia, but some people have a greater chance than others. These people are at 'higher risk'. A 'risk factor' is something that is known to increase a person's chances of developing a condition. For example, ageing is a risk factor for dementia.
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.
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.
Whites make up the majority of the over 5 million people in the United States with Alzheimer's. But, combining evidence from available studies shows that African Americans and Hispanics are at higher risk. than white Americans to have Alzheimer's and other dementias.
As scientists around the world seek solutions for Alzheimer's disease, a new study reveals that two indigenous groups in the Bolivian Amazon have among the lowest rates of dementia in the world. An international team of researchers found among older Tsimane and Moseten people, only about 1% suffer from dementia.
We know there are genetic risk factors that differ across the human population. Some people get the disease and some people don't.
Common forms of dementia
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.
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.
The current evidence indicates that while chronic stress may play a role in the development or progression of dementia, it does not necessarily cause dementia.
In rare cases, someone might inherit a gene from one of their parents that doesn't work properly. Having one of these rare mutations makes someone almost certain to develop early-onset Alzheimer's, or frontotemporal dementia, during their lifetime. However much more commonly, people can carry risk genes.
Benefits of Reading
Those who reported engaging in intellectual activities on a regular basis such as reading books, periodicals, and newspapers, as well as playing board games, had a significantly decreased risk of developing dementia.
Many people affected by dementia are concerned that they may inherit or pass on dementia. The majority of dementia is not inherited by children and grandchildren. In rarer types of dementia there may be a strong genetic link, but these are only a tiny proportion of overall cases of dementia.
Administration: The examiner reads a list of 5 words at a rate of one per second, giving the following instructions: “This is a memory test. I am going to read a list of words that you will have to remember now and later on. Listen carefully. When I am through, tell me as many words as you can remember.
exercising regularly. keeping alcohol within recommended limits. stopping smoking. keeping your blood pressure at a healthy level.
Population growth and population aging are the main reasons behind a large rise in global dementia cases. The world population is projected to reach 8.5 billion in 2030 and increase further to 9.7 billion in 2050 and 11.2 billion by 2100.
Alzheimer's disease is the most common form of dementia. Alzheimer's disease is a physical brain condition resulting in impaired memory, thinking and behaviour.
“We know that age is the biggest risk factor for dementia and we know that Australia's population is ageing.” For people aged older than 65, the risk of developing dementia doubles every five or six years. There were 401,300 Australians with dementia in 2022, the AIHW estimated, a 4% increase from 2021.
How common is dementia? In 2022, it was estimated that there were 401,300 (AIHW estimate) Australians living with dementia. Based on AIHW estimates, this is equivalent to 15 people with dementia per 1,000 Australians, which increases to 84 people with dementia per 1,000 Australians aged 65 and over.
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.
Is there a genetic test for dementia? Yes. It is possible to be tested for single-gene changes and some of the risk variants linked to dementia. However, genetic testing for dementia is not always appropriate.
Aging and Alzheimer's risk
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.