Is Alzheimer’s Hereditary?

If you have a family member who has been diagnosed with Alzheimer’s disease, you may be wondering:

Is Alzheimer’s hereditary?

While your genes do have an impact on your chances of developing Alzheimer’s, they don’t tell the whole story about the hereditary risk of the disease. Here’s what we do know about Alzheimer’s and heredity, as well as some steps you can take to reduce the chances of developing - or delaying the onset of - this disease.

Genetics and Risk Genes

Genes can play a role in the development of Alzheimer’s disease. In most cases, however, having a family member with Alzheimer’s doesn’t necessarily mean you’ll inherit the disease. Similarly, having no relatives with the disease does not guarantee you won’t develop it.

Scientists have identified several genes that may contribute to a person’s risk of developing Alzheimer’s. Apolipoprotein E-e4, or APOE-e4, the gene with the strongest influence on the risk of developing Alzheimer’s, may be a factor in 40 to 65 percent of Alzheimer’s cases, according to the Alzheimer’s Association.

Someone who inherits this gene from one or both parents has an increased risk of Alzheimer’s. These genes may be detected with a blood test, but they cannot predict who will or will not develop Alzheimer’s disease.

Deterministic Genes

In addition to risk genes, scientists have discovered deterministic genes which directly cause Alzheimer’s disease. Although extremely rare, these genes cause a familial early-onset form of Alzheimer’s disease.

The Alzheimer’s Association reports that deterministic genes are responsible for less than one percent of Alzheimer’s cases overall, and worldwide, have been found in only a few hundred extended families. These genes, too, can be identified through blood tests.

Family History

Your chances of developing Alzheimer’s are higher if you have an immediate family member with the disease. The risk grows according to the number of family members with Alzheimer’s.

In other words, the higher the number, the greater the risk. The Alzheimer’s Association points out that while a high family incidence may be caused by genetics, environmental factors or a combination of both can also be to blame.

Other Factors That Affect Your Alzheimer’s Risk

As with family history, there may be more than genetics at work in cases of Alzheimer’s that develop after age 65. According to the National Institute on Aging (NIA), later-onset Alzheimer’s is likely caused by a combination of genetic, environmental, and lifestyle factors.

Even as more research is completed, scientists don’t expect they’ll ever answer the question, “Is Alzheimer’s hereditary?” with a simple yes or no. Many other factors may play a role.

How to Reduce Your Risk for Alzheimer’s

There are certain risk factors contributing to the development of Alzheimer’s that are beyond your control. Age, considered the most significant, is a good example: The risk of Alzheimer’s disease grows dramatically the older we get.
There are, however, several risk factors you can control that may reduce your odds of developing or help to postpone the onset of Alzheimer’s:

Mind the heart-head connection: There is a significant amount of research that shows a connection between heart disease, high blood pressure, and other vascular diseases with an increased risk of developing Alzheimer’s disease.

Additional research needs to be done to fully understand the connection between the two, and whether controlling cardiovascular diseases will lower the risk of developing Alzheimer’s. In the meantime, the Alzheimer’s Association suggests that keeping your heart healthy may also keep your brain healthy.
Guard against head trauma: Growing evidence points to a strong link between serious head injury and future risk of Alzheimer’s. This is especially true with mild head injuries that occur repeatedly or more severe head trauma that involves loss of consciousness.

Follow measures that will help protect your brain: buckle your seatbelt, wear a helmet when participating in sports, and make sure your home is “fall-proof.”
Maintain an active mind: Staying socially connected with family and friends and keeping your brain engaged through intellectually stimulating activities are also associated with a lower risk of Alzheimer’s.

Some researchers believe that, at a minimum, these activities help establish a “cognitive reserve” that allows older people with dementia to function more effectively for a longer period of time, even after some brain function is lost.
Practice Healthy Habits: Exercise regularly, maintain a healthy weight, eat a diet rich in fruits and vegetables, and avoid tobacco and excess alcohol. Any steps you can take toward healthy aging will keep both your body healthier and may protect your brain from Alzheimer’s disease as well as other forms of dementia.

Early Detection of Alzheimer’s

Finally, remember the importance of early detection. If you notice signs of possible memory loss in yourself or in a loved one, consult a physician.

Scientists are working on developing strategies for earlier diagnosis, such as simple blood tests, that are designed to more quickly identify Alzheimer’s disease, dementia, and mild cognitive impairment. The earlier these conditions are diagnosed, the more options you may have for treatment that can help prolong your independence and cognitive health.

More Resources on Dementia and Alzheimer’s

If you’re caring for someone with Alzheimer’s or another form of dementia, we have the resources to help answer your questions. Read more about related topics like how to find the right memory care community, essential questions caregivers should be asking doctors, and tips for defusing aggressive behavior in people with dementia or Alzheimer’s.

Is Alzheimer’s Hereditary?