Alzheimer’s disease

Alzheimer’s disease is the leading cause of dementia in people over the age of 65, affecting over 4 million North Americans. The disease is characterized by abnormal deposits of a protein called beta-amyloid (plaque) in the brain as well as by twisted fibers caused by changes in a protein called “tau” (tangles). Before arriving at a diagnosis, tests are needed to rule out a stroke, a brain tumor, and other possible causes of dementia.

Blood tests can uncover genetic markers for the disease. The cause of Alzheimer’s disease remains unknown, but researchers theorize that chromosomal and genetic factors are responsible for some cases. The increased incidence of Alzheimer’s disease among those with Down’s syndrome, which is caused by a chromosomal abnormality, seems to support this theory. Researchers have discovered a genetic marker, apolipoprotein E, which can be detected by blood tests, that identifies those likely to develop the disease. About 40 percent of the sufferers have the gene that produces this protein.

In addition, hormonal factors are under study too, especially in case of woman. Studies indicate that estrogen replacement can prove protective in the development of this disease in woman. Thyroid disorders are also linked to the disease, while the long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) have been linked with a reduced Alzheimer’s risk. It has been shown that these drugs may reduce inflammation in the brain linked with the disease. However, still there is insufficient evidence for physicians to recommend taking anti-inflammatory drugs to ward off Alzheimer’s.