Alzheimer's disease (AD) is a slowly progressive disease of the brain that is characterized by impairment of memory and eventually by disturbances in reasoning, planning, language, and perception. Many scientists believe that Alzheimer's disease results from an increase in the production or accumulation of a specific protein (beta-amyloid protein) in the brain that leads to nerve cell death.
The likelihood of having Alzheimer's disease increases substantially after the age of 70 and may affect 38% of persons over the age of 85. Nonetheless, Alzheimer's disease is not a normal part of aging and is not something that inevitably happens in later life. For example, many people live to over 100 years of age and never develop Alzheimer's disease.
Dementia is a syndrome characterized by:
1. impairment in memory,
2. impairment in another area of thinking such as the ability to organize thoughts and reason, the ability to use language, or the ability to see accurately the visual world (not because of eye disease), and
3. these impairments are severe enough to cause a decline in the patient's usual level of functioning.
Although some kinds of memory loss are normal parts of aging, the changes due to aging are not severe enough to interfere with the level of function. Although many different diseases can cause dementia, Alzheimer's disease is the most common cause for dementia in the United States and in most countries in the world.
The cause(s) of Alzheimer's disease is (are) not known. The "amyloid cascade hypothesis" is the most widely discussed and researched hypothesis about the cause of Alzheimer's disease. The strongest data supporting the amyloid cascade hypothesis comes from the study of early-onset inherited (genetic) Alzheimer's disease.
Mutations associated with Alzheimer's disease have been found in about half of the patients with early-onset disease. In all of these patients, the mutation leads to excess production in the brain of a specific form of a small protein fragment called ABeta (Aβ). Many scientists believe that in the majority of sporadic (for example, non-inherited) cases of Alzheimer's disease (these make up the vast majority of all cases of Alzheimer's disease) there is too little removal of this Aβ protein rather than too much production. In any case, much of the research in finding ways to prevent or slow down Alzheimer's disease has focused on ways to decrease the amount of Aβ in the brain.
Age
The main risk factor for Alzheimer's disease is increased age. As a population ages, the frequency of Alzheimer's disease continues to increase. Fifteen percent of people over 65 years of age and 50% of those over 85 years of age have Alzheimer's disease. Unless new treatments are developed to decrease the likelihood of developing Alzheimer's disease, the number of individuals with Alzheimer's disease in the United States is expected to be 13.8 million by the year 2050.
Genetics
There are also genetic risk factors for Alzheimer's disease. Most people develop Alzheimer's disease after age 70. However, less than 10% of people develop the disease in the fourth or fifth decade of life (40s or 50s). At least half of these early onset patients have inherited gene mutations associated with their Alzheimer's disease. Moreover, the children of a patient with early onset Alzheimer's disease who has one of these gene mutations has a 50% risk of developing Alzheimer's disease.
Common forms of certain genes increase the risk of developing Alzheimer's disease, but do not invariably cause Alzheimer's disease. The best-studied "risk" gene is the one that encodes apolipoprotein E (apoE).
· The apoE gene has three different forms (alleles) -- apoE2, apoE3, and apoE4.
· The apoE4 form of the gene has been associated with increased risk of Alzheimer's disease in most (but not all) populations studied.
· The frequency of the apoE4 version of the gene in the general population varies, but is always less than 30% and frequently 8% to 14%.
· People with one copy of the E4 gene usually have about a two- to three-fold increased risk of developing Alzheimer's disease.
· Persons with two copies of the E4 gene (usually around 1% of the population) have about a nine-fold increase in risk.
· Nonetheless, even persons with two copies of the E4 gene don't always get Alzheimer's disease.
· At least one copy of the E4 gene is found in 40% of patients with sporadic or late-onset Alzheimer's disease.
This means that in majority of patients with Alzheimer's disease, no genetic risk factor has yet been found. Most experts do not recommend that adult children of patients with Alzheimer's disease should have genetic testing for the apoE4 gene since there is no treatment for Alzheimer's disease. When medical treatments that prevent or decrease the risk of developing Alzheimer's disease become available, genetic testing may be recommended for adult children of patients with Alzheimer's disease so that they may be treated.
Estrogen
Many, but not all, studies have found that women have a higher risk for Alzheimer's disease than men. It is certainly true that women live longer than men, but age alone does not seem to explain the increased frequency in women. The apparent increased frequency of Alzheimer's disease in women has led to considerable research about the role of estrogen in Alzheimer's disease. Recent studies suggest that estrogen should not be prescribed to post-menopausal women for the purpose of decreasing the risk of Alzheimer's disease. Nonetheless, the role of estrogen in Alzheimer's disease remains an area of research focus.
Any opinions, views and beliefs represented in this article are personal and belong solely to the author/s and do not necessarily reflect the opinion, views and beliefs of the organisation and employees of New Image™ International
Bridging The Gap In Nutrition
Children's Immunity
Colostrum – The Key To Health
Colostrum - How might it benefit my health
Bovine Colostrum
Building Strong Immunity
Colostrum and Sport
English 
Ms 
