Am I at Risk for Alzheimer’s Disease?

Here is the last of a three-part series on Alzheimer’s disease, the most common cause of memory loss and dementia. Part 1 discussed its pathology and stages. Part 2 discussed how Alzheimer’s disease can be diagnosed during life.

Family history of Alzheimer’s disease increases the chances of developing it between twofold and fourfold

Because Alzheimer’s is the most common disorder affecting thinking and memory in old age, we are all at risk for developing the disease, approaching 40 to 50% by age 85. If one has a family history of memory problems that sound like Alzheimer’s disease in a parent or a sibling, the risk of Alzheimer’s disease does rise, such that it becomes two to four times more likely that the cause of the memory problems is due to Alzheimer’s rather than something else. For example, if the overall risk of developing Alzheimer’s disease between ages 65 and 70 is about 2.5%, the risk without a family history is about 1.5%, whereas the risk with a family history is between 3 and 6%. But there is certainly a large proportion of people with a family history of Alzheimer’s who never develop the disease themselves.

Genes can cause too much beta amyloid to accumulate

We know that some people have genetic differences that cause either too much amyloid to be formed or not enough to be cleared. The most common genetic variation that can lead to Alzheimer’s disease is the APOE-e4 gene, which appears to be related to reduced clearance of beta amyloid. This gene is a major reason that individuals with a family history of Alzheimer’s are more likely to develop the disease themselves. But we do not recommend testing for it, as it cannot determine whether Alzheimer’s disease is present or not, nor whether it will develop in the future.

Alzheimer’s disease is more common in women

Of the 5.1 million people in the United States with Alzheimer’s disease age 65 and older, approximately 3.2 million are women. Part of the answer is that Alzheimer’s is more common as people age, and women live longer than men. Other explanations are being actively investigated.

Alzheimer’s disease is not part of normal aging

Given how common Alzheimer’s disease is in individuals in their 70s and 80s, it is reasonable to wonder if Alzheimer’s is just part of normal aging. However, there are many people who live into their 90s or even 100s without developing Alzheimer’s disease either clinically or pathologically (when their brains are looked at after death under a microscope). In fact, it is estimated that roughly half of individuals age 85 and older do not have Alzheimer’s or any other type of dementia. So, although Alzheimer’s disease is more common with aging, it is not a normal part of it.

Reduce your risk of Alzheimer’s disease by aerobic exercise, eating healthy, and being socially active

Want to reduce your risk of developing Alzheimer’s disease? There is increasing evidence that several lifestyle choices including engaging in regular aerobic exercise, eating a Mediterranean-style diet, staying socially active, and can help to keep your thinking and memory as strong as possible.

Key Questions:

Q: Your friend told you that there is nothing you can do about Alzheimer’s disease because if we live long enough everyone will get it. Is that true?

A: No. Alzheimer’s disease is more common in aging but many people live to age 90 or 100 without the disease. Aerobic exercise, social activities, and healthy eating can all help reduce one’s chances of developing Alzheimer’s disease.

Q: No one in my family history had Alzheimer’s disease. That means I won’t get it, right?

A: No. Although the risk is less without a family history, everyone is at risk for Alzheimer’s disease as they get older.

© Andrew E. Budson, MD, 2019, all rights reserved.