Risk factors are characteristics of the person, their lifestyle and environment that contribute to the likelihood of getting the disease. They can include family background, work history or exposure to a substance or product.
Some risk factors can be modified (for example, lowering blood pressure). Other risk factors cannot be modified (for example, one’s age or family history).
Risk Factors that Cannot be Modified
The most important risk factors for dementia is age. The older you become, the greater the risk of developing Alzheimer’s disease or another dementia. In Canada, 1 in 20 people over the age of 65 is affected by Alzheimer’s disease. For people over 85 years, the likelihood of having dementia increases to approximately 1 in 4 people.
Women rather than men are more likely to get the disease. This is mainly in part because women have a longer life expectancy than men. Sixty-four per cent of Manitobans with Alzheimer`s disease are women.
The majority of cases of Alzheimer’s disease in people over the age of 65 have the sporadic, or “late onset” form of the disease, which suggests that there is no family link.
The “Familial” or “early onset” Alzheimer’s is a rare form of the disease that runs in families and is responsible for about seven per cent of all cases.
With Familial AD, at some point in the family’s history, certain genes become “mutated” from having normal to abnormal characteristics. If one parent has a mutated gene, each child has a 50 per cent chance of inheriting the disease gene and it is possible that those children will go on to develop Alzheimer’s disease in adulthood.
The causes of Alzheimer’s disease are not fully understood, however, many studies have identified a gene called apolipoprotein E (APOE). This is not an abnormal gene and everyone inherits a copy of some form of APOE from each parent. A variation or form of this gene (an allele), is the APOE e4. Dozens of studies suggest that the APOE e4 allele increases the risk of developing Alzheimer’s disease.
Genetic risk factors alone are not enough to cause Alzheimer’s disease, so researchers are actively exploring other factors which may play a role in the development of this disease. Further research is still needed.
Risk Factors that Can be Modified
Below are some risk factors that you can influence and change.
Research shows that people with adult onset diabetes (sometimes called Type-2 Diabetes) are twice as likely to develop Alzheimer’s disease. There are many health complications that go along with diabetes and the risk of developing Alzheimer’s disease should be one risk that prompts people to manage their illness.
The connection between the two disease is not yet clear. Obesity and high blood pressure, which are problems associated with diabetes, are also risk factors in Alzheimer’s disease and vascular dementia.
Cardiovascular Risk Factors
Keeping a healthy heart is beneficial for keeping a healthy brain. High blood pressure, high cholesterol and obesity are things that can increase your risk of developing Alzheimer’s disease.
Your brain is nourished through a rich network of blood vessels. Each heartbeat pumps about 20 to 25 per cent of your blood to your head, where brain cells use at least 20 per cent of the food and oxygen that your blood carries.
The risk of developing Alzheimer’s disease or vascular dementia appears to be increased by many conditions that damage the heart or blood vessels.
Another risk factor for the development of Alzheimer’s disease is brain injuries. This is especially true if there are repeated concussions. Protecting your head by wearing a helmet during activities such as biking or skiing is recognized as one way to reduce your risk of Alzheimer’s disease.
It is important to remember that exposure to any or even to all of the known risk factors does not mean that a person will develop Alzheimer’s disease. Similarly, having little or no exposure to known risk factors does not necessarily protect a person from developing Alzheimer’s disease. Further research is the key to helping us deepen our understanding of the role of risk factors in developing Alzheimer’s disease.
You can alter your lifestyle and reduce some of the risks that can be modified. Here are some suggestions:
- Eating a well-balanced and healthy diet
- Avoiding smoking and excess alcohol
- Maintaining your weight
- Keeping your cholesterol and blood pressure levels in check
- Exercising regularly
- Getting regular sleep
- Maintaining a social network
- Stimulating your brain by doing the crossword, taking dance lessons, or learning a new language
- Protecting your brain by wearing a helmet when you bike
- Learn more about brain health…
Read more about risk factors.