Hypertension, also known as high blood pressure, defined as having a blood pressure of 140/90 or higher or taking medication for high blood pressure, is a well-known ‘silent killer.’ According to recent research, it contributes to memory loss in adults over 45. The study determined that those with high diastolic blood pressure (the second number measured) were more likely to experience memory and thinking problems, known as cognitive impairment, when other factors such as age, education, smoking, education, exercise, diabetes and high cholesterol were taken into consideration. 
The research study involved almost 20,000 Americans from across the country individuals 45 years and beyond, was conducted by researchers at the University of Alabama. Almost 8 percent of the participants, 1,505 had cognitive problems and almost have of the participants were taking medication to lower their blood pressure.
Source: American Academy of Neurology