Dementia is a term generally referencing a decline in memory, problem-solving, and other cognitive abilities. Dementia isn’t in and of itself a single disease. It’s instead a term covering a wide range of conditions, including Alzheimer’s disease, which is the most common cause of dementia. Dementia disorders are caused by abnormal changes in the brain.
These changes can lead to declines in thinking skills which are cognitive abilities. The declines can be severe enough to impact the ability to function independently, and they can impair daily life. The symptoms and declines also affect feelings, behaviors, and relationships.
Alzheimer’s accounts for around 60 to 80% of cases. The second most common cause of dementia is vascular dementia. Vascular dementia occurs as the result of blood vessel blockages in the brain and microscopic bleeding.
People with brain changes characteristic of multiple types of dementia at the same time may be diagnosed with mixed dementia. There are also a lot of conditions that are reversible but can cause symptoms similar to dementia, such as vitamin deficiencies and thyroid problems.
Signs of dementia can vary a lot between individuals, but examples include trouble with short-term memory, problems remembering appointments, traveling out of the neighborhood, or having a hard time keeping up with things like a wallet or purse.
Below, we discuss some of the potential risk factors for developing dementia.
1. Head Trauma
If someone is involved in an accident or sustains a traumatic brain injury, they are at a greater risk of developing Alzheimer’s disease. Large studies have found in people who are 50 and older with a traumatic brain injury, the risk of dementia and Alzheimer’s goes up. The risks increase for people whose brain injuries are more severe and for people who experience multiple TBIs.
Some studies show the risks may be the most significant within the first six months up to two years after someone has a traumatic brain injury.
Having a history of a brain injury doesn’t mean that you automatically develop dementia, of course. It’s just one of many potential risk factors.
2. Age
There are some dementia risk factors that you have at least a level of control over, and others you don’t. One that you don’t is age. The biggest risk factor for dementia is aging. As you get older, your risk goes up.
The risk doubles about every five years. By the time people are older than 90, around 33 in every 100 people will have dementia.
Aging is a risk factor because dementia takes a long time to develop. It’s caused by diseases that damage the brain, and it often takes a very long time for the brain damage to become significant to the point it causes dementia symptoms. The longer someone lives, the more time there is for dementia to develop.
3. Genetics
There are some genes that people may inherit from a parent that can increase the likelihood of dementia.
Familial genes will cause dementia definitively if they’re passed down from a parent to a child.
Familial genes are rare for most types of dementia, with the exception of a less common form called frontotemporal.
Risk genes are much more common than familial genes, and they don’t always cause someone to develop dementia. There are more than 20 genes that have been identified so far, and most only slightly raise the risk of developing dementia.
4. Cognitive Reserve
The term cognitive reserve refers to someone’s ability to deal with the disease in their brain. You build up cognitive reserve by keeping your brain active throughout your lifetime.
The more cognitive reserve you have, the longer it takes brain diseases to cause problems in everyday tasks.
People with larger cognitive reserves may have delayed symptoms of dementia for longer periods of time.
There are three factors that lead to a smaller cognitive reserve. One is leaving education early, the second is having a less complex job that doesn’t require a lot of mental skills, and the third is social isolation.
5. Lifestyle Factors
There is an abundance of evidence showing that lifestyle factors and choices can influence the likelihood of developing dementia. The dementia risk is lowest in people who have several healthy behaviors such as regular mental, social and physical activity, not smoking, and drinking alcohol only in moderation.
A healthy diet can also be important in reducing the risk of developing dementia.
If you’re physically not very active, it can contribute to many of the risk factors for dementia, including high blood pressure and also type 2 diabetes. When you don’t eat a healthy diet, it can increase your blood pressure, and that can increase the risk. Too much alcohol regularly exposes your brain to high amounts of toxic substances that can, over time, cause damage to nerve cells.
6. Diabetes
Briefly mentioned above is the fact that diabetes can put someone at a greater risk of eventually developing dementia.
There are multiple reasons for this connection.
One reason is that diabetes affects the heart, and heart and brain health are linked to one another. Another issue is hypoglycemia, which is associated with memory loss and damage. Low blood sugar, which can occur in diabetes, can damage the hippocampus. The hippocampus is the brain’s memory center.
There seem to be other links as well. For example, insulin plays a role in forming amyloid plaques. It’s possible that insulin resistance in the body can cause type 2 diabetes, and in the brain, it can lead to the plaques of Alzheimer’s.
7. Sex and Gender
Finally, there are more women than men with dementia. This is primarily because women tend to live longer, but women are still at slightly higher risk regardless.
There are theories as to why. One is that women may have had fewer educational or career opportunities in their lives compared to men, lowering their cognitive reserve.
There could also be links between sex hormones around menopause and the risk of dementia.
