Alzheimers is a disease that effects roughly 6 million Americans over the age of 65. Researchers have discovered that are genes (genes :APOE-2, APOE-3, and APOE-4) that are directly associated with the increased risk of developing Alzheimer's, as well as genes that directly cause the disease (genes: APP, PS1, and PS2). 40-65% of people diagnosed with the disease are found to have the APOE-4 gene, meaning that only 1% of people with Alzheimers actually inherit the disease. Alzheimer's happens because the brain is made of billions of neurons that communicate through charges from one neuron to another, Inside the neuron, there is a tau protein which helps provide nutrients to the cell. In Alzheimer's, it is believed that there is abnormal tau proteins causing an inability of the nutrients reaching the cell which then causes cell death. With the death of so many cells, the brain eventually shrinks. There is no known way to cure or prevent Alzheimer's, but it is believed that life style changes such as, quitting smoking, controlling blood pressure, maintaining a healthy weight, reducing alcohol consumption, etc. can reduce the risk of Azheimer's.