Alzheimer's is such a common occurrence in ageing that it might be considered a normal variant like hypertension. It used to be called plain "senility."
What factors are associated with increased risk?
- Age (obviously)
- Family history, mainly maternal history, of dementia. The genetic components may be necessary but insufficient predispositions.
- Overweight
- Being female
- Lack of daily exercise
- A wrong diet: The researchers generally recommend a diet which includes daily wine, berries, olive oil, and leafy greens but is low in sweets, dairy, non-berry fruit, and other carbs.
nb: Correlation does not mean causation. These things just represent the current knowledge. Also, medical researchers never include "Bad luck" as a disease risk factor, but it is usually a major one in most ailments.