Alzheimer's disease is the main cause of dementia in the elderly population. This disorder affects their behavior, judgment, language and memory. Although scientists have known for some time that people with this disease have deposits of the beta-amyloid and tau proteins, it now appears that they also have a high level of the homocysteine amino acid in their bloodstreams.
Alzheimer's Disease
More than 65 percent of the elderly population with dementia have it as a result of Alzheimer's disease, according to Alexander Auchus, M.D., Professor of Neurology at the University of Tennessee Health Science Center in "The Merck Manual for Healthcare Professionals." Approximately four percent of people 65 to 74 years old have Alzheimer's, while an estimated 30 percent of people over 85 years old have this disease. Those with Alzheimer's have deposits of a beta-amyloid protein in their brain, along with accumulations and tangles of a tau protein and lost nerve cells.
Symptoms of Alzheimer's Disease
People with this disease may have memory problems at first, as explained by Dr. Auchus in "The Merck Manual for Healthcare Professionals." They may have problems remembering new information and finding the right words to express their thoughts. They can then develop problems with the normal activities of life, with remembering where they placed personal possessions, finding their homes, or even finding the bathroom or bedroom. Their symptoms can cause them to become agitated and irritable.
Homocysteine
Methionine is an essential amino acid, meaning people have to get this amino acid from their diets. The cells then make homocysteine from methionine, explains Gerhard Meisenberg, Ph.D. of the Department of Biochemistry at Ross University School of Medicine in "Principles of Medical Biochemistry." Once the cells have homocysteine, they can break down this amino acid to form a different one called cysteine and even change it back to methionine. To change homocysteine back to methionine, the cells must have enough vitamin B12 and folic acid.
Homocysteine and Alzheimer's Disease
Scientists have determined that people with Alzheimer's disease have a higher level of homocysteine in their bloodstreams than people of the same age who do not have Alzheimers, according to John Engstrom, M.D., Professor of Neurology at the University of California in "Harrison's Principles of Internal Medicine." Dr. Engstrom writes about one study that demonstrates this, involving approximately 1,000 people who were monitored for eight years. Thus, a high blood homocysteine level is considered to be a risk factor for this disease, but more research needs to be done. Folic acid lowers the blood homocysteine levels.
References
- "Harrison's Principles of Internal Medicine"; Anthony Fauci, M.D., Dennis Kasper, M.D., Dan Longo, M.D. et al.; 2008
- The Merck Manual for Healthcare Professionals: Dementia
- "Principles of Medical Biochemistry"; Gerhard Meisenberg, Ph.D., William Simmons, Ph.D.; 1998
