A risk factor is something that increases your likelihood of getting a disease or condition. There are still many questions regarding the exact cause of Alzheimer disease, so risk factors are still being identified.

It is possible to develop Alzheimer disease with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing Alzheimer disease. Currently, risk factors for Alzheimer disease include:

Age is the most important known risk factor for developing Alzheimer disease. The number of people with Alzheimer disease doubles every 5 years beyond age 65 until age 85. By age 85, almost 50% of all people have the disease.

Alzheimer disease affects both men and women. Women may have a slightly higher risk of developing the disease than men. Some experts believe that this is because women live longer than men.

Individuals with a parent or sibling with Alzheimer disease have a 2-3 times risk of developing the disease compared to the rest of the population. In addition, there has been a clear genetic link established for an early-onset form of Alzheimer disease. This form of the disease occurs in people during their 30s, 40s, and early 50s. However, a specific gene has not yet been identified. One gene that has been implicated as being a major risk factor for late-onset Alzheimer disease is the ApoE4 gene. Additional genes likely play a role in the increased risk of Alzheimer disease. Scientists continue to study the role of genetic factors in the development of this disease.

  • Head injury—there are some studies that suggest that people who suffered a serious, traumatic head injury at some time in their lives may be at higher risk of developing Alzheimer disease. Chronic traumatic brain injury is associated with increased risk of dementia.
  • Vascular risk factors. These may be associated with an increased risk of Alzheimer disease
  • Down syndrome—nearly all people with Down syndrome who live to be age 40 or older develop Alzheimer disease
  • High cholesterol and high blood pressure
  • Vitamin B12 deficiency—low levels of the vitamin B12 and folate have been linked to a development of Alzheimer disease
  • Depression and anxiety
  • Overweight or obese
  • Diabetes
  • Atherosclerosis

Some research has suggested that people who have higher education levels and continue to be mentally active and engaged in their later years are less likely to develop Alzheimer disease. However, some experts suggest that this finding may be related to the fact that those with higher education levels tend to do better on the psychological tests used to diagnose Alzheimer.

Some theories suggest that Alzheimer disease may be linked to exposure to certain environmental factors, such as toxins, certain viruses and bacteria, certain metals, or electromagnetic fields. Currently, there is no conclusive evidence to support these theories.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 09/2017 -
  • Update Date: 09/17/2014 -