In a recent study researchers have created a model of the human brain and found the breakdown of myelin in midlife may be a precursor to Alzheimer's.
Myelin is a fatty insulation that has a high cholesterol content, which allows for messages to be sent through the brain. However, as the brain develops in adulthood, cholesterol levels grow and promote the production of a toxic protein that attacks the brain and may eventually lead to Alzheimer's.
Researchers say genetic factors and the brain's developmental process contribute to the degeneration of myelin. They say complex connections that take the longest to develop are among the first to deteriorate because myelin breaks down in reverse order of development. Specialists say: "The body was designed to myelinate through the natural lifespan. Medical advances, however, have expanded the lifespan well beyond the brain's natural capacity ... The process of adult brain development and becoming 'wiser' has this downside that evolution could not anticipate.
Researchers say the new brain model suggests the best time to address myelin depletion is when it begins -- middle age. They say by the time Alzheimer's begins, it may be too late to reverse the course of the disease. Close analysis of brain tissue and MRIs clearly shows that the brain's wiring develops until middle age and then begins to decline as the breakdown of myelin triggers a destructive domino effect. Now the challenge of science and medicine is to figure out how to extend the brain's peak performance.
Researchers say certain preventive therapies such as iron-lowering medications, anti-inflammatory drugs, diet and exercise programs, and possibly hormone replacement therapy designed to prevent menopause may prevent the breakdown of myelin. They also say education and other activities designed to keep the mind active may stimulate the production of myelin.