Over the past several years a mechanistic concept has arisen that seeks to explain the pathogenesis of Alzheimer’s disease. This has been called the bioenergetic theory. Basically, it describes a situation in which the highly energy demanding cells of the brain are somehow compromised in their ability to use fuel. Make no mistake about it, brain cells require an incredible amount of energy to perform their function. In the resting state, the brain, which typically represents only 2 to 5% of total body weight, consumes up to 25% of calories burned.
The brain’s primary fuel is glucose. And one of the hallmarks of Alzheimer’s disease is a progressive failure of the brains ability to use this source of fuel, basically a situation in which brain cells are not able to utilize glucose for energy. In fact, specialized PET scanning of the brain can visualize signature areas of the brain that are less functional in terms of glucose utilization that correlate with Alzheimer’s disease. Continue reading