Causes of Alzheimer's disease

Until now, the exact causes of Alzheimer's disease are not known; neither is it known how to completely halt the progression of this disease. So what do we know about Alzheimer's disease? Researchers have concluded that:

• Alzheimer's is not a part of normal aging
• Alzheimer's affects both men and women.
• Alzheimer's becomes more common with age - most people with the disease are over 65
• Alzheimer's is not caused by hardening of the arteries
• Alzheimer's isn't caused by a virus

Scientists do not yet fully understand what causes Alzheimer's disease. Most likely there isn't one single cause, but several factors that affect each person differently. Age is certainly the most important known risk factor for Alzheimer's. The number of people with the disease doubles every 5 years beyond age 65.

Family history is another risk factor. Scientists believe that genetics may play a role in many Alzheimer's cases. For example, early-onset familial Alzheimer's disease, a rare form of Alzheimer's that usually occurs between the ages of 30 and 60, is inherited. The most common form of Alzheimer's is late-onset Alzheimer's, which occurs later in life, with no clear family history shown by patients.

However, several risk factor genes may interact with each other, and with non-genetic factors, to cause the disease. The only risk factor gene identified so far for late-onset Alzheimer's is a protein called apolipoprotein E (ApoE). Although everyone has Apo3, only about 15 percent of people have a form that increases the risk of Alzheimer's. It is likely that other genes may cause Alzheimer's, whilst some help prevent its onset, but they remain undiscovered.

Alzheimer's disease causes a general decrease in function for certain areas of the brain that control thinking, communication, and behavior. Some of the deterioration may be related to a loss of chemical messengers (neurotransmitters) in the brain - acetylcholine, in particular - that allow nerve cells in the brain to work properly.

Some studies have recommended that zinc or aluminum could help in the treatment of Alzheimer's disease symptoms, although more research is needed. Experts agree both zinc and aluminum play crucial roles in our diet, in improving memory and brain function.