What is the link between chronic illness and development of dementia?

People with two or more chronic illnesses have twice the risk of developing dementia, scientists from the University of Paris informed.

The authors of the study found that people aged over 50 who have no health problems are not at risk of developing dementia in most cases. But those who have 2 chronic diseases are twice as likely to develop senile dementia, including Alzheimer's disease.

The study also found that having 3 chronic diseases increases the risk of developing dementia by a factor of 5. The dangerous chronic diseases can range from problems with high blood pressure or hypertension to depression or arthritis, the scientists said.