Hi Janny ,
It is an interesting question . Extensive research has been carried out on the use of Coffee or Caffeine in prevention of Alzheimer’s disease . People with the disease will be more than happy to know that there have been some wonderful findings in the research carried out in mice .
The findings showed a reduction in the levels of Beta – amyloid proteins in mice after the use of Caffeine . Beta-amyloid proteins aggregate into plaques within the brain and are found to be present in the brains of people with Alzheimer's disease.
Amazingly the mice with high levels of the protein already present in the brain showed reversal or reduction in the levels after the consumption of Caffeine .So Caffeine is being considered to have a good potential in not only preventing but also treating Alzheimer’s disease .
That is how the theory of drinking 2-3 cups of coffee everyday for prevention of Alzheimer’s disease is coming up . Hope this helps you . Take care and regards !