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

Age

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: https://www.cihi.ca/en/dementia-in-canada/dementia-in-canada-summary). 

Gender

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: https://www.cihi.ca/en/dementia-in-canada).

Ethnicity

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: https://www.cdc.gov/media/releases/2018/p0920-alzheimers-burden-double-2060.html). 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: https://www.nccih.ca/docs/emerging/RPT-Alzheimer-Dementia-MacDonald-Ward-Halseth-EN.pdf). 

Genetics

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.

Inactivity

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. 

Diet

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

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: https://alzheimer.ca). 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: https://www.thelancet.com/article/S0140-6736(20)30367-6/fulltext). However, some studies have shown that moderate amounts of alcohol may reduce the risk of dementia. 

Depression

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: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(00)02113-9/fulltext). 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: https://www.thelancet.com/article/S0140-6736(20)30367-6/fulltext). 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: https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.12315). 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: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)32399-6/fulltext). Other sources of air pollutants are power plants and indoor wood burning fires. 

Is your loved one living with the early signs of dementia?

As we age, the lapses in memory that we ourselves may experience or observe in our loved ones, become more concerning.  They make us question if this is part of the normal, healthy aging process or if it is an early sign of dementia.  So how can we tell when it might be time to talk to a health care professional about memory loss?  The following are some early signs of cognitive decline that you can look for in your aging loved one. It is important to know these signs, because early detection is advantageous for prompt diagnosis and slowing disease progression. Note that seeing one of these signs does not necessarily mean a diagnosis of dementia. However if you see several, it may mean your loved one needs to talk with their health care professional.

1. Memory loss – This is the most common early sign of dementia.  Your loved one may forget faces, information they just learned, or important events that have happened.  They may be consistently losing their car keys and you may find that they are increasingly relying on post-it notes and reminders to remember and complete tasks. 

2. Vision problems – One of the earliest signs of dementia is changes in vision.  Your loved one may have trouble reading, or correctly identifying the colour of items.  They may have trouble judging distances such as when navigating between a table and chair or when putting items onto a shelf. These difficulties might also contribute to a decrease in their ability to drive.
3. Problems managing money – Another common early sign of dementia is being unable to manage money.  This task comprises many skills such as reasoning, calculating, and planning.  Your loved one may no longer be able to keep track of the money they have spent.  They may purchase an item multiple times because they do not remember previously buying it.  They may end up with many overdue bills because they have forgotten to pay them.   
4. Speaking or writing problems – You may find that your loved one begins to have trouble following conversations.  They may stop in the middle of a sentence and not know how to proceed and have trouble finding the right words when they do. They may begin to repeat sentences during a conversation or even ask the same question multiple times within a conversation. Their handwriting may become less legible and there may be increased spelling, grammar and punctuation errors. 
5. Social withdrawal – Your loved one may stop attending work or other social activities because they are feeling uneasy not knowing how to act around others. They may feel embarrassed during conversations if they realize they are making mistakes. Being in a group with many people and increased noise may increase this unease, as they are unable to follow the conversations going on around them.  These problems may contribute to them not wanting to spend time with family and friends. 
6. Changes in mood and personality – You may see that your loved one has a sudden change in their personality.  Someone who is shy may become very outgoing. They may also experience mood swings or become irritable, depressed or anxious.  
7. Poor judgement – Your loved one may no longer understand what is typically appropriate and blurt out whatever comes to mind. They may ask strangers for odd items, or tell them personal information. They may also pay less attention to keeping themselves clean; leave the house in their pyjamas instead of getting dressed.  They may no longer understand how to dress appropriately according to the weather.     
8. The past, present and future are blurred – Your loved one may only be able to focus and understand what is going on in the immediate present.  They may forget what or if they ate that day or who has been to visit them. They may be able to remember an event that occurred in their childhood but forget where they parked the car.  You may find your loved one tending to their garden but not realizing that it is winter.
9. Getting lost – Your loved one may no longer remember common routes to stores or relatives’ houses. This can lead to minor traffic accidents and unsafe driving such as running stop signs. Familiar landmarks may become unrecognizable to them. They may have a poor sense of direction and their spatial orientation may deteriorate. 
10. Inability to focus – Your loved one may start a task and then not be able to finish it. The dishwasher may be half-empty or they could forget to change the clothes from the washer into the dryer for many days.  They may not be able to follow a recipe or get lost with the plot of a movie. They may put their car keys in an odd spot, such as a flowerpot and then lose them. They may become increasingly confused as their ability to focus deteriorates.