Advertisement

What are the risk factors for Alzheimer's disease?

Dr. David B. Reuben, MD
Geriatric Medicine Specialist

These are several risk factors for Alzheimer’s disease, a common form of dementia. First is age; the older you are, the more likely you are to develop dementia. Family history can be important, particularly if someone developed early-onset Alzheimer’s in his or her 50s or 60s. In these cases, it’s much more likely to be hereditary. There is a genetic profile called ApoE4, and if you have this gene, you’re more likely to develop Alzheimer’s disease.

Older age is a risk factor for Alzheimer's disease -- the usual onset is over 65 years. The older the person, the higher the risk. Having a family member with Alzheimer's, especially if he was diagnosed at an age under 60, is also a factor. Alzheimer's is inheritable, and the genetic basis is best understood in the early-onset forms. This follows an autosomal dominant pattern. People with Down syndrome are at a high risk also, and they tend to develop Alzheimer's disease at an earlier age than the general population.

Risk factors for Alzheimer's disease include:
  • Age. Risk usually rises after age 65 and doubles every five years thereafter.
  • Genetics. Heredity is a major factor in only a small number of families, usually those in which the disease begins before age 60. Mutations in three genes are known to cause this type of Alzheimer's: amyloid precursor protein gene, presenilin 1, and presenilin 2. All three genetic mutations increase the production of beta-amyloid, which is deposited in the plaques found in Alzheimer's disease.
  • APOE4, one allele (version) of the gene for apolipoprotein E, a protein that plays a role in several biologic processes, has been found in about 40% of patients with late-onset Alzheimer's disease. An estimated 25% to 30% of the population carries APOE4.
  • Cardiovascular risk factors. Many studies show physiological conditions that harm the heart and blood vessels also increase the risk of Alzheimer's disease. These include high blood pressure, high cholesterol, obesity, and smoking. All of these factors also increase the risk of stroke, a direct cause of dementia.
  • Diabetes. People with diabetes have a greater risk of Alzheimer's disease. Research indicates that this increase in risk may reflect a shared mechanism: a deficiency or dysfunction of insulin, the hormone that enables cells in the body to use glucose.
  • Head injury. The microscopic changes in the brains of boxers with dementia resemble those in Alzheimer's disease. The observation has led researchers to wonder if brain injury might be a factor in the disease.

Many studies show that physiological conditions that harm the heart and blood vessels increase the risk of Alzheimer's disease and vascular dementia. These include high blood pressure, high cholesterol, obesity, and smoking, which all increase the risk of stroke, a direct cause of dementia. But such risk factors may also indirectly lead to Alzheimer's disease by other means. Many of these risk factors are also common in people with diabetes -- yet another condition linked to Alzheimer's disease. Most of these factors can be controlled by lifestyle changes, either alone or with medications.

Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

Age and family history are only two of the factors that play into your risk of getting Alzheimer's disease. Learn what factors into your chances of getting Alzheimer's disease as Dr. Oz and researcher Dr. Murali Doraiswamy discuss the risks in this video.

Dr. Randolph P. Martin, MD
Cardiologist (Heart Specialist)

Age, genetic, and serious head injuries are all risk factors for Alzheimer's disease. Every 5 years after 65 years of age your risk for Alzheimer's disease doubles.  Watch this video to learn more from Dr. Randy P. Martin about Alzheimer's disease.

Apparent risk factors for Alzheimer's disease include age, genetic inheritance and gender.

Those older than age 65 are much more likely to get Alzheimer's disease. Genetics also seem to play a role, especially if an immediate blood relative had Alzheimer's, and women tend to get Alzheimer's more frequently because they live longer than men.

The risk factors for Alzheimer's disease are frequently classified into genetic risks and environmental risks. True genetic Alzheimer's disease is really very rare, but there are some risk genes that can increase a person's risk of developing Alzheimer's disease. Doctors do not test for those genes, because having the gene does not guarantee developing the disease, and not having those genes does not guarantee that the disease will not occur.

The environmental factors that could increase the risk of developing Alzheimer's disease include risk factors for cardiovascular disease, such as high blood pressure, diabetes, high cholesterol. More and more data show that people who are not physically active might be at increased risk for Alzheimer's disease, or at least the physical activity might decrease the risk or slow down the disease progression.

Some data show that certain types of diets might be protective over Alzheimer's disease, such as a Mediterranean diet with a significant amount of fruits, vegetables, fish and healthier oils.

Trinity Health is a Catholic health care organization that acts in accordance with the Catholic tradition and does not condone or support all practices covered in this site. In case of emergency call 911. This site is educational and not a substitute for professional medical advice, always seek the advice of a qualified health care provider.

Although age, family history and heredity are all risk factors for Alzheimer’s disease and can’t be changed, research increasingly links the risk of Alzheimer’s with overall health. These studies find that having high cholesterol or high blood pressure levels, being overweight, getting little exercise and following an unhealthy diet can increase your risk for getting the disease.

The majority of people with Alzheimer's disease are diagnosed after age 65. They have the “sporadic” form of the disease. In this form, genes may influence your risk for developing the disease, but environmental factors may also play a role.

Continue Learning about Alzheimer's Disease Causes

Type 3 Diabetes: The Alzheimer’s-Glucose Connection
Type 3 Diabetes: The Alzheimer’s-Glucose Connection
Alzheimer’s disease is common and mysterious, well-documented and hidden. Though it affects an estimated 5.4 million Americans (5.3 million are 65 or ...
Read More
What are the risk factors for Alzheimer's disease?
Peter Gliebus, MDPeter Gliebus, MD
The risk factors for Alzheimer's disease are frequently classified into genetic risks and environmen...
More Answers
Can smoking cause Alzheimer's disease?
John H. Growdon, MDJohn H. Growdon, MD
Smoking is a risk factor for cardiovascular disease, so it makes sense that it would also make y...
More Answers
How Was the Connection Between Down's Syndrome and Alzehimer's Disease Made?
How Was the Connection Between Down's Syndrome and Alzehimer's Disease Made?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.