Experts do not fully understand what causes Alzheimer’s disease in most people. The causes may include a combination of age-related changes in the brain, along with genetic, environmental and lifestyle factors. The importance of any of these factors in increasing or decreasing the risk of Alzheimer’s disease may differ from person to person.
Alzheimer disease is a progressive brain disease. It is characterized by changes in the brain — including amyloid plaques and neurofibrillary, or tau, tangles — that result in loss of neurons and their connections. These and other changes affect a person’s ability to remember and think and, eventually, to live independently.
Here are the factors that the researchers identified — and why they are associated with a higher risk.
Alzheimer disease is the most common form of dementia. About a third of people 85 and older show signs of illness. The genes you get from your parents play a role at this age, but so do things like your diet, exercise, social life, and other illnesses. Dementia is not a normal part of aging.
Evidence shows that keeping our brain active can also fight dementia. Activities like word puzzles stimulate your brain and can strengthen the connectivity between brain cells. This connectivity breaks down in dementia.
This latest study shows that we need to continue to keep our brains active, even in our older age. Other studies agree that challenging our brains does indeed reduce our chances of developing dementia.
Lower education levels are associated with an increased risk of Alzheimer’s disease. Previous evidence has shown that the longer you spend in education, the lower your risk of developing dementia. Research looking at the brains of people from different educational backgrounds has also shown that people who are more educated have heavier brains. While you have lost a third of your brain weight to dementia, a heavier brain can make you more resilient.
The study found diabetes was linked to a higher incidence of Alzheimer’s. Because diabetes makes your bodies unable to properly regulate insulin, it alters the way your brain cells communicate and your memory functions — both of which are impaired in Alzheimer’s disease.
Insulin is very important, because it regulates the metabolism of carbohydrates, fats and proteins by helping blood glucose to absorb into the liver, fat and muscles. Alzheimer’s disease seems to interfere with the brain’s ability to react to insulin.
Past head trauma is a risk factor — and there is clear evidence that head trauma, such as a concussion, can contribute to the development of dementia. These links were first observed in 1928.
However, it is uncertain whether single or repeated head trauma is a causative factor. It is clear that the brain damage from head trauma is similar to that of dementia. This makes the person more susceptible to further deterioration later from dementia.
Those living with Alzheimer’s also frequently suffer from depression, although it is uncertain whether depression causes Alzheimer’s or is just a symptom of the disease. However, there is plenty of evidence to support that depression is indeed a risk factor, as this new study found. Research has even shown an association between the number of depressive episodes — particularly ten years before the onset of dementia — and a higher risk.
Depression raises levels of harmful chemicals in our brains. Imbalances in these chemicals can cause the loss of brain cells. This, coupled with the loss of brain cells in dementia, increases the chances of Alzheimer’s.
High blood pressure
Even if you don’t have other health problems, having high blood pressure makes you more likely to get vascular dementia and Alzheimer’s. That’s probably because high blood pressure damages blood vessels in your brain. It can also lead to other conditions that cause dementia, such as a stroke. Managing your blood pressure with diet and exercise — and drugs, if needed — can slow or prevent this from happening.