AM I AT RISK OF GETTING ALZHEIMER'S DISEASE?
Although Alzheimer's disease is not contagious, there are several factors that increase or decrease the risk of the late-onset form - the most common form of the disease that typically appears after age 65:
- Age: Age is the number one risk factor for Alzheimer's disease with the risk of contracting the disease doubling every five years beyond age 65, which is why the burden of Alzheimer's disease has increased exponentially among societies with increasing overall life expectancy.
- Genetic Influence:The presence of Alzheimer's disease in a family member increases an individual's risk, and this risk goes up even further when multiple family members are affected. The reasons for this have been linked to our genes. The early-onset form of Alzheimer's disease, which occurs between the ages of 30-50 years, is associated with three known genes that may be inherited from a person's parents. These genes can be tested for using genetic testing in advanced Alzheimer's Disease centers. However, genetic testing is not recommended for those at risk of the more common late-onset form, such as the one afflicting Dr Gabi Williams. Note that there are two types of genes that influence whether a person gets Alzheimer's disease: risk genes and deterministic genes. Risk genes increase the chance that a person will get the disease but do not guarantee that they will get it, and there are many people with risk genes who never get the disease. Deterministic genes, on the other hand, are causative, virtually guaranteeing that the affected individual will get the disease. Unlike risk genes, which exceed 30 in number and are typically associated with the late-onset form, deterministic genes are few in number and are usually found in the early onset form of the disease. Given the lack of specificity and variable sensitivity of risk genes and the unavailability of preventative measures, genetic testing for the late-onset form is generally not recommended. Despite an increasing number of genes linked to the late-onset form, one gene worth mentioning: this is the apolipoprotein E (the APOE4 allele) gene whose presence is linked to an increased risk of Alzheimer's disease. Of note, however, is the finding that this gene may be a less frequent contributor to the disease in Africans compared to Europeans.
- Cardiovascular Disease: the rising presence of diabetes, high cholesterol, high blood pressure, obesity, smoking, heart disease in Sub Saharan Africa along with high rates of illiteracy, increases the risk for Alzheimer's disease. These conditions are the most treatable risk factors for Alzheimer's disease.