Dementia Risk Factors

What are risk factors?

A risk factor is something known to increase a person’s chance of developing a disease.  These factors can be both uncontrolled, such as age or gender, and controlled, such as diet or smoking. Having some of these risk factors is not a guarantee that a person will develop dementia in the future, but knowing what the risk factors are is important because it could help you to control the ones you can. When someone receives a diagnosis of dementia, it is not possible to say which particular risk factor was the cause as many factors often contribute to the diagnosis, including those that might have been avoidable and those that were not. 

The following are risk factors that you cannot control:


Your age is the greatest risk factor for developing dementia. As we age the risk of developing dementia increases. In Canada, the occurrence of dementia more than doubles every 5 years for Canadians age 65 and older, from less than 1% for those age 65 to 69 to about 25% for those 85 and older. (Data from: 


Dementia is more likely to occur in females than in males, and this gap increases with age, even when taking into account that females typically live longer than males. In Canada, from age 80 the prevalence of dementia is about 1.3 times higher for women than for men (20.8% versus 15.6%). (Data from:


Evidence shows that people from certain ethnic backgrounds are at a higher risk of developing dementia than others.  In the U.S., among people ages 65 and older, African Americans have the highest prevalence of Alzheimer’s disease and related dementias (13.8 percent), followed by Hispanics (12.2 percent), and non-Hispanic whites (10.3 percent), American Indian and Alaska Natives (9.1 percent), and Asian and Pacific Islanders (8.4 percent). (Data from: Limited available evidence suggests that rates of dementia in Canada have been increasing more rapidly among Indigenous people compared to the general population, and that dementia onset may be earlier in Indigenous people (Data from: 


The genes that you inherit from your parents can influence your chance of developing dementia.  There are genes that can affect a person’s risk of developing dementia, but having these genes does not directly cause it, and there are genes that directly cause dementia, however, these are very rare.  Having a family history of dementia also increases your risk of developing it sometime in your lifetime, but does not mean that dementia will be inevitable. 

The following are risk factors that you can control:

Cardiovascular risk factors

These are the most important risk factors for dementia that we can control. Anything that can damage the heart, arteries or blood circulation can also affect the brain and possibly lead to dementia. This includes high blood pressure (hypertension), high cholesterol, build up of fats in your artery walls (atherosclerosis), diabetes and obesity. Cardiovascular risk factors can be controlled by talking with your health care professional who can suggest medication and lifestyle changes.


Being physically inactive is one of the biggest lifestyle risk factors for developing dementia. It is linked to an increased risk for the cardiovascular diseases mentioned above and has direct effects on the structure and function of the brain. Regular physical exercise is one of the best things you can do to reduce your risk of developing dementia. 


Although there is no known diet which can reduce the risk of dementia, it is known that people who eat unhealthy diets are at an increased risk of acquiring dementia. A diet high in saturated fats, raises cholesterol and contributes to the narrowing of arteries.  A diet high in salt contributes to high blood pressure. An unhealthy diet may also lead to vitamin and nutritional deficiencies which have also been linked to dementia risk. A diet high in sugar contributes to the development of diabetes. Eating a diet that is comprised mainly of fruits and vegetables, whole grains, nuts and seeds may help to reduce your risk of dementia. 


Smoking has negative effects on the blood vessels in both your heart and your brain; it increases the chances of developing diabetes, atherosclerosis, stroke and heart disease.  Smokers are at a 45% higher risk of developing dementia versus non-smokers or even ex-smokers. (Data from: Smokers who quit can reduce their risk of developing dementia. 

Excessive alcohol 

Drinking more than 14 drinks per week for women and more than 21 drinks per week for men is considered excessive alcohol consumption. Heavy drinking is known to be linked to brain changes, cognitive impairment and dementia. (Data from: However, some studies have shown that moderate amounts of alcohol may reduce the risk of dementia. 


People who experience bouts of depression may be at an increased risk for dementia. There is evidence that depression in middle age can lead to an increased incidence of dementia. Depression in later life, however, may be an early symptom of dementia more so than a risk for it. It is important to talk to your heath care provider about your depression so that they can help you manage it, thereby reducing your dementia risk. 

Social isolation

Being socially isolated is associated with higher rates of depression and is linked to a 60% increase in the risk of dementia.  (Data from: Keeping a social circle of friends and family will help to reduce the risk of dementia and can also help to slow down disease progression.  

Less education

People who have less education (such as not finishing high school) have a higher risk of developing dementia. This is because learning new things and challenging yourself through hobbies and higher education helps to build your cognitive reserves.  Having more of these reserves protects your brain against the damage caused by dementia. 

Hearing loss

Mild hearing loss in later life can contribute to a two-fold increase in your risk of developing dementia. (Data from: Hearing loss can contribute to social isolation and loss of independence. It is one of the top potentially modifiable risk factors for dementia as it can be modified by resorting auditory input with the use of hearing aids. You can also prevent hearing loss by avoiding exposure to loud sounds. It is important to get your hearing tested so that any hearing loss can be identified and treated as early as possible.

Head injuries

A person who experiences even one head injury during their lifetime may increase the risk of developing dementia in their future by 25%, and this risk increases with each subsequent head injury. (Data from: This risk factor is important for those that play sports in which head injuries are common. Wearing helmets can help to avoid head injuries when doing activities such as skating, skiing, and cycling. Falls are also common causes of head injuries so it is important to be cautious of icy walkways in the winter and to remove tripping hazards from your home. 

Air pollution

Although air pollution has yet to be directly linked to dementia, the evidence shows that particulate pollutants are associated with poor health. Individuals living close to high traffic areas (within 50 meters) face a higher risk (7% greater) of developing dementia than those who live further away. (Data from: Other sources of air pollutants are power plants and indoor wood burning fires.