ALZHEIMER'S RISK FACTORS
This section discusses both Mild Cognitive Impairment (MCI) and early Alzheimer’s disease. Learn more about the symptoms of both.
Are there Risk Factors for MCI and how is Alzheimer’s diagnosed?
There are a number of risk factors that lead to cognitive decline. The main factors are:
- Age - With increasing age, there is a greater incidence of cognitive decline.
- Family history - If someone’s first-degree relative (mother, father, or sibling) has Alzheimer’s, the chances are up to seven times greater that they may develop the disease.
- Genetic Predisposition - A person with two APOe-4 genes is at a higher risk of developing Alzheimer’s disease in later life.
- Head injury
- Cardiovascular disease
The good news is that many risk factors can be controlled effectively by adopting correct lifestyle choices to prevent Alzheimer's. The three most important ways in which lifestyle modifications can impact our brain health are:
Alzheimer’s and Genetics
Perhaps the most investigated field of the new millennium is genetics. Diseases such as cystic fibrosis, muscular dystrophy, and Huntington’s disease are single-gene disorders. If a person inherits the gene that causes one of these disorders, he or she will usually develop the disease. Alzheimer’s disease, on the other hand, is not caused by a single gene.
The two basic types of Alzheimer’s are Familial and Sporadic:
- Familial - Familial Alzheimer’s disease (FAD) is a rare form of early-onset Alzheimer’s, affecting less than 10 percent of Alzheimer’s patients. This form is inherited within families from generation to generation.
- Sporadic - The majority of Alzheimer’s cases are sporadic, late-onset, usually developing after age 65.
Sporadic, late-onset Alzheimer’s disease has no known cause and shows no obvious inheritance pattern. However, in some families, clusters of cases are seen. Although a specific gene has not been identified as the cause of late-onset Alzheimer’s, genetic factors do appear to play a role in the development of this form.
Two risk factor genes have been linked to Alzheimer’s diseases so far. Researchers have identified an increased risk of developing late-onset Alzheimer’s related to the apolipoprotein E (APOE) gene found on chromosome 19. The APOE gene comes in several different forms, but three occur most frequently: APOE e2, APOE e3, and APOE e4. People inherit one APOE from each parent. Having the e4 form is a risk factor for Alzheimer’s disease, but it does not mean that Alzheimer’s disease will necessarily develop. The e3 form is the most common form found in the general population and may play a neutral role in AD. The rarer e2 form appears to be associated with a lower risk of AD.
The second gene that has just been discovered and appears to be associated with a higher risk for Alzheimer’s is the mutated TREM2 gene. Research is underway to establish how this gene plays a role in the development of the disease.
The exact degree of risk of Alzheimer’s for any given person cannot necessarily be determined based on APOE status.
Reducing Your Risk Factors
It is possible to evaluate your predisposition to develop Alzheimer’s disease and make lifestyle choices that reduce your risk factors. More and more evidence is emerging that proves environmental factors play a significant role in determining if the disease will develop and progress.
- Use the Internet to do research on genetic conditions. Some useful sites are:
- Learn as much as you can about your family health history, especially about your siblings, parents, and grandparents.
- Share information with your physician. He or she needs to be aware of your family history in order to help you make medical decisions.
- Consult a genetic counselor. Genetic counselors provide information and support to families who may be at risk for a variety of inherited conditions. They identify families at risk, analyze inheritance patterns and risks of recurrence and discuss options with the family. Locate a counselor at the National Society of Genetic Counselors.
- Have a memory screening done on a regular basis, as part of your annual physical. Many memory difficulties are due to correctable conditions, such as vitamin deficiencies or stress.
- Consult a doctor if you are concerned about a head injury and Alzheimer’s.
- Make healthy lifestyle choices. By using programs like the ARPF’s 4 Pillars of Alzheimer’s Prevention it is possible to minimize the risk factors and prevent memory loss.