Читать книгу Alzheimer's Disease - Michelle Deetken - Страница 10

Dementia is not a disease in itself but rather a term used to describe a group of symptoms. These symptoms may include the decline of mental functions such as memory, reasoning, and language ability, as well as changes in personality, mood, and behavior. Dementia develops when parts of the brain are injured or diseased. There are over fifty known causes of dementia, and most of them are quite rare.

Alzheimer's disease (AD) is the most common cause of dementia. Other major causes of dementia from degenerative neurological diseases are Parkinson's disease, Huntington's disease, and some types of multiple sclerosis. Vascular dementia can be caused by multiple strokes in the brain. Traumatic head injuries caused by motor vehicle accidents, falls, or numerous hits to the brain as seen in football players and boxers can cause dementia. Dementia may also be caused by infections of the central nervous system such as meningitis and HIV. Even nutritional deficiencies, depression, the chronic use of alcohol, or drug abuse can cause dementia. Alzheimer's disease represents over half of all causes of dementia.

Alzheimer's disease is an extremely complicated and devastating disease. It is complicated in that it involves related yet separate parts of the brain that combine to manifest the disease. Understanding how these separate parts of the brain become dysfunctional enough to produce a cascading effect that corrodes the brain is very complicated indeed. This corrosion leads at first to cell dysfunction, then to a loss of areas of the brain that communicate within itself, and eventually to a loss of communication between the brain and the entire body. As many of us have witnessed, the result is a human being who has lost all of his or her dependability and proficiency.

Research has shown that the road to memory loss in our senior years may start as early as our teen years! All of us begin our lives with clear arteries, but before some of us finish our adolescence, fatty streaks (cholesterol and other lipids that have accumulated on the arterial walls) have already begun to appear. By early adulthood these fatty streaks turn into fibrous plaques that begin to calcify and become raised lesions (Berenson, G., et al., 1998). As we age, these lesions may become sites of low-grade, chronic inflammation. The lesions eventually grow larger and more numerous, restricting blood flow throughout the body. Blood restriction is the hallmark of atherosclerosis, which is the leading cause of heart disease. Research suggests that the risk factors for heart disease such as diabetes, high blood pressure, a high-fat diet, elevated homocysteine levels, cigarette smoking, and a sedentary lifestyle are also factors in the development of AD (Snowdon, D., et al., 2000 and Weir and Molloy, 2000). Thus the evidence of plaque buildup, or atherosclerosis, in the teenaged years leads many researchers to speculate that AD plaque may start its gradual corrosive process that early, as well. Nutritionally, this finding indicates that a diet that is good for the heart is also good for the brain.