A risk factor is something that increases your likelihood of getting a disease or condition.
It is possible to develop Alzheimers disease with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing Alzheimers disease.
There are still many questions regarding the exact cause of Alzheimers disease, so risk factors are still being identified. Currently, risk factors for Alzheimers disease include:
Age
Age is the most important known risk factor for developing Alzheimers disease. The number of people with Alzheimers disease doubles every five years beyond age 65 until age 85, when almost 50% of all people have the disease.
Gender
Alzheimers disease affects both men and women, but women may have a slightly higher risk of developing the disease than men. Some experts believe that this is due to the fact that women live longer than men, but others dispute this claim.
Genetic Factors
Individuals with a first-degree relative of someone with Alzheimers disease (a parent or sibling) have a two- to three-times risk of developing the disease when compared to the rest of the population. In addition, there has been a clear genetic link established for an early-onset form of Alzheimers disease (occurs in people during their 30s, 40s, and early 50s), and a genetic link is suspected for late-onset Alzheimers disease. However, a specific gene has not yet been identified. One gene that has been implicated as being a major risk factor for late-onset Alzheimers disease is the ApoE4 gene. Scientists continue to study the role of genetic factors in the development of this disease.
Medical Conditions
Head InjuriesThere 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 Alzheimers disease.
Down SyndromeNearly all people with Down syndrome who live to be age 40 or older develop Alzheimers disease. Women who give birth before age 35 to a child with Down syndrome are also at higher risk of developing Alzheimers disease.
High Cholesterol and Hypertension Recent research suggests that people who have high cholesterol and high blood pressure may be at increased risk of developing Alzheimers disease.
B Vitamin DeficiencyLow levels of the vitamin B12 and folate have been linked to a development of Alzheimers disease.
Mental Activity and Education
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 Alzheimers disease. However, some experts suggest that this finding may actually be due to the fact that those with higher education levels tend to do better on the psychological tests used to diagnose Alzheimers.
Environment
Some theories suggest that Alzheimers disease may be linked to exposure to certain environmental factors, such as toxins, certain viruses and bacteria, certain metals, or electromagnetic fields, but there is currently no conclusive evidence to support these theories.
References:
Alzheimers Association website. Available at: http://www.alz.org/.
Last reviewed April 2007 by Roshni N. Patel, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
