Though tremendous advances have been made in understanding Alzheimer's disease and its process, researchers have yet to uncover the causes of this debilitating brain disorder. That said, researchers have identified some factors that increase the risk of developing Alzheimer's disease. The most known risk for the disease is aging, and other evidence suggests that family history, genetics, diet and nutrition and environment also could be among the risk factors for the disease.
In his latest publication, Dr. Peter Rabins writes a comprehensive guide to Alzheimer's and memory loss. In this guide, Rabins names seven common risk factors for developing the disease, which include aging, being female, genetics, cardiovascular disorders, Down syndrome, head trauma and depression.
Aging is the strongest risk factor as the chance of developing Alzheimer's doubles every five years beginning at age 65. After 85, the risk reaches 50 percent. Women are more at risk of developing the disease than men, even though their life spans are longer. Researchers do not understand why women are more at risk but hypothesize the decreased levels of estrogen after menopause and rising rates of cardiovascular disease contribute to the risk factors.
Genetics always has been a risk factor; however, only a few people with Alzheimer's (less than 2-3 percent) have the disease as a result of one of three identifiable defective gene mutations because the prevalence of these gene mutations is typically low. Having a genetic predisposition to Alzheimer's is different from carrying a genetic mutation. A predisposition means that even though the disease could "run in the family," it is not associated with gene mutation or defect. Many family members will develop the disease while others do not. The predisposition might suggest that other risk factors interact with the individual's genetic makeup that increases the chance of developing Alzheimer's or to cause it to develop it later in life.
When looking at cardiovascular disease as a risk factor, that includes not only elevated LDL cholesterol levels and low HDL levels and high blood pressure, but also other contributors such as smoking, excess body weight, consumption of unhealthy fats, lack of exercise and type 2 diabetes.
It is not well known that the risk of Alzheimer's disease is three to five times higher among individuals with Down syndrome than in the general population. The genetic abnormality responsible for this syndrome is located on chromosome 21, which contains the amyloid precursor gene. The amyloid protein is the primary component of amyloid plaques found in the brains of individuals with Alzheimer's disease.
Much has been in the news recently concerning the rising incidences of chronic traumatic encephalopathy, which is a degenerative brain disease found in athletes, military veterans and others with a history of repetitive brain trauma. In a recent released study by Dr. Ann McKee, of Boson University, CTE was found in 99 percent of the studied brains of deceased football players.
There is a strong link between serious head injury and the risk of developing Alzheimer's disease. For instance, someone who has sustained a moderate head injury (defined as a loss of consciousness for more than 30 minutes) has twice the risk of developing the disease, while some with a severe head injury (loss of consciousness for more than 24 hours) is associated with a 4.5 times greater risk.
Finally, individuals who experience depression stand at a greater risk and susceptibility for developing Alzheimer's disease. Researchers have found that a history of depression can double the risk and that cognitive decline seemed more rapid in those individuals. It was not clear if treating the depression would reduce the overall risk of developing the disease.
Questions about Alzheimer's disease or a related disorder can be sent to Dana Territo, the Memory Whisperer, director of services at Alzheimer's Services of the Capital Area at firstname.lastname@example.org or visit the organization at 3772 North Blvd., Baton Rouge.