An elevated blood pressure, particularly during the middle age, was recently associated with an increased risk of cognitive impairment later in life, according to the American Heart Association.

Published in AHA's journal Hypertension, the statement is based on multiple study reviews, and it gives an idea on how an elevated blood pressure can negatively impact the brain, resulting in diseases such as stroke, vascular cognitive impairment and Alzheimer's.

"Many observational studies suggest treating hypertension may reduce the cognitive impact of high blood pressure, especially on vascular cognitive impairment, but observational studies are not designed to prove cause and effect," said Dr. Costantino Iadecola, writing committee chair.

The vascular cognitive impairment is defined by multiple mild to severe changes in brain functions, brought on by poor blood flow to the brain.

One conclusion of the review was that heart attacks or strokes can be reduced through treating the elevated blood pressure. According to the statement, more studies are needed in order to scientifically prove a straight causal relation between the two conditions, especially among the people who have been treated for high blood pressure.

Even if observational studies suggest this correlation, the clinical trials reviewed were not directly focused on the investigation of the effects of high blood pressure on cognition. This makes it impossible to establish a straight relation between the two, and also makes it complicated for the AHA to publish a statement suggesting treatments for the diseases, such as dementia.

One of the possible problems that could occur during this type of investigation is the high number of years that passed between a patient's elevated pressure and when the brain malfunctions. A clear line of action is hard to be derived from long-term studies addressing the question of when the treatment for high blood pressure should start, provide a recommended desired blood pressure and medication to prevent the brain condition.

Dementia is one of the most often neurological disorders, affecting approximately 30 to 40 million people around the globe, and it is anticipated to triple by 2050 because of the aging of the population, and the demographic shifts.

Cognitive impairment is caused by one of two factors in roughly 80 percent of the cases: Alzheimer's disease and vascular cognitive impairment. However, patients who suffer from dementia usually experience both these problems in different degrees.

Dementia begins with the hypertension leading to a disruption in the brain's cellular activity. Over time, if the force of the blood flow is often high, the tissue that makes up the walls of the arteries gets stretched beyond its healthy limit and damage occurs. This creates problems in many ways.