Today Alzheimer’s disease is considered to be one of the most common causes of dementia and is estimated to be impacting around 5.3 million Americans. It is an irreversible, progressive brain disease that destroys brain nerve cells and disrupts the memory and thinking skills of the patient. Although scientists still do not know what causes it, they believe that a combination of various genetic and environmental factors lead to Alzheimer’s.
The changes and deterioration in certain areas of the brain, with Alzheimer’s, affect thinking, communication, and behavior. Less than 5 percent of the time, the disease is caused by specific genetic changes that virtually guarantee a person will develop the disease. Some of the deterioration can be due to the loss of chemical messengers (neurotransmitters) in the brain called acetylcholine.
These messengers allow the nerve cells to communicate properly. Although it is not very clear why these changes occur, they are a major focus of Alzheimer’s research. Although most people who have the disease do not have a family history of the condition, those who do have a family member with Alzheimer’s do have increased risk of getting it.
Dr. Alois Alzheimer from Germany was the first to identify Alzheimer’s disease in 1906. During those days, it was considered a rare disorder as compared to today when it is recognized as the most common cause of dementia. Brains affected by Alzheimer’s often show the presence of fiber tangles within the nerve cells and clusters of degenerating nerve endings. Since the identification of the disease, scientists have been trying to find out the causes that lead to its inception. Some of the major factors that contribute to the disease are:
Age – Advancing age is the number one risk factor for developing Alzheimer’s disease. It is estimated that among the people over 65 years of age, one out of eight is likely to have Alzheimer’s and the probability of being diagnosed with the disease nearly doubles every five years after age 65.
Family History – Researchers agree that if you have one or more parent or close family member with Alzheimer’s disease, then you can be at a greater risk to develop the disease. A genetically inherited gene ApoE4 increases your likelihood of getting Alzheimer’s disease. The second kind of gene called a deterministic gene is a rare gene and is found only in a few hundred extended families around the world. If this deterministic gene is inherited, the person will undoubtedly develop Alzheimer’s and also will probably do so at a much earlier age in life.
Lifestyle factors – Some of the lifestyles that we follow can be very unfriendly to the brain and can increase the risk of Alzheimer’s disease. People who have sustained concussions or head injury through sports, work, or accidents have a greater risk of getting Alzheimer’s. Positive lifestyle habits, including exercise, a healthy diet rich in antioxidants, socialization, lifelong learning, and avoidance of tobacco use, may prevent or delay the onset. The Alzheimer’s Association does suspect links between heart health and brain health. They argue that what is good for the heart is good for the head.
High blood pressure and high cholesterol – Ongoing research on Alzheimer’s shows that cardiovascular disease, specifically related to high cholesterol and high blood pressure, can also be a risk factor for the disease.
Diabetes – High blood sugar is also considered a risk factor for eventually developing Alzheimer’s. Lot of studies are being done to understand the connection and some diabetes drugs do appear to slow down the cognitive decline of Alzheimer’s patients. It is expected that controlling the blood sugar levels with diet and medication may help.
Plaques and Tangles – Research is going on to find out the causes behind the buildup of plaques and tangles in the brain. Plaques consist of the protein beta amyloid that accumulates in the spaces between the nerve cells while tangles are fibers that accumulate inside the nerve cells. These proteins can block the ability of the cells to communicate eventually leading to cellular death. This can ravage the brain and cause the progressive symptoms of Alzheimer’s disease.
Aluminum– has become one of the most controversial risk factors for the onset of the disease. Researchers have found traces of the metal in autopsies of patients. Aluminum does turn up in higher amounts than normal in some patients but not in all of them. However, other studies have found that people who are actually more exposed to higher levels of aluminum did not show any signs of increased risks. Therefore, it is still uncertain if the exposure to aluminum has any decisive role in Alzheimer’s disease.
Education level – Research suggests that a person with more years of formal education is less likely to develop Alzheimer’s. This is because longer education may help produce a denser network of synapses, the nerve fiber connections that enable neurons to communicate with one another. The synapses create a neural reserve to enable people to compensate longer for the early brain changes associated with Alzheimer’s.
Race and Ethnicity – Studies have shown that older African-Americans and Hispanics are twice as likely to develop Alzheimer’s as compared to their white American counterparts. However, the reason for this could be a higher incidence of high blood pressure and diabetes among African-Americans and Hispanics.
Researchers seem to be hopeful that steps are being laid out and strategies will be developed soon to delay the onset of Alzheimer’s or prevent it altogether.