Like all types of dementia, Alzheimer's is caused by brain cell death. It is a neurodegenerative disease, which means there is progressive brain cell death that happens over a course of time. The total brain size shrinks with Alzheimer's - the tissue has progressively fewer nerve cells and connections.
<span>factors such as radiation can </span>cause DNA<span> damage, </span>resulting<span> in as many as 1 million ... Many of </span>these<span>lesions </span>cause<span> structural damage to the </span>DNA<span> molecule and</span>normal metabolic activities and environmental
