It is predicted that one in five elderly people will have dementia by 2025.According to Takashima, the brains of Alzheimer’s disease patients exhibit three characteristics. “The first is the formation of “senile plaques” on the surface of the brain. In Alzheimer’s disease, there is a buildup of beta-amyloid and tau protein. Second, excessive phosphorylation of tau protein causes neurofibrillary tangles, a lint-like accumulation inside nerve cells. The third is brain atrophy. Neurofibrillary tangles cause the death of neurons and synapses that connect nerves to each other. The death of nerve cells destroys the brain cells in that area, and the brain also atrophies.”   Neurofibrillary tangles first occur in the “olfactory entorhinal cortex,” a region inside the temporal lobe of the brain that, along with the hippocampus, is responsible for learning and memory and spatial perception. The degree of neurofibrillary change is expressed in six stages, with stages I and II being preventable, but stages III and above are no longer preventable. “The olfactory entorhinal cortex is the first to receive information that comes in from the outside. The information is sent to the hippocampus for processing, and then sent back to the cerebral cortex via the olfactory entorhinal cortex. It is a very important part of the brain in terms of information processing.” If you are experiencing a decline in memory, or if you have trouble remembering names quickly, it may be that the cells in the olfactory cortex are already being destroyed.