This is one of the most interesting studies I have ever read. Coming from Yale University, the results are short and sweet:

People who regard aging and all that surround the concept of aging in a negative way  are much more likely to develop brain distortions associated with Alzheimer’s disease than those who have a more positive outlook on life.

The reverse  has also been found to be true.

Since virtually the beginning of time, the greatest masters have talked about the idea of thoughts being THE most influential factor in one’s life. Now, modern science has finally caught up with what has been known for thousands of years.