|July 2, 2004
A large drop in blood pressure may herald the onset of Alzheimer's disease and other forms of dementia in seniors, Swedish researchers report. The finding adds new information about the still poorly understood relationship between blood pressure and the memory wasting of Alzheimer's disease.
High blood pressure has long been linked to heart attacks and strokes, and some studies have linked long-term high blood pressure to Alzheimer's as well. Other reports have linked very low blood pressure to memory problems and dementia also. Maintaining blood pressure in a healthy range- that is, 120/80, where the second number is 80 or lower- helps assure that blood flows normally, supplying oxygen and nutrients to the heart, brain, and other vital organs.
In the current study, investigators from the Karolinska Institute in Stockholm followed nearly 1,000 older men and women in Sweden aged 75 and up. They were given regular exams and memory tests at the start of the study, then again at three and six years later.
At the end of the study, those seniors who had a drop in the upper blood pressure number of 15 points or more had a three-fold increased risk of developing Alzheimer's. Scientists aren't sure why the two are linked. One possibility is that the same factors that damage the brain in Alzheimer's disease may also cause blood pressure to drop. Alternatively, low blood pressure may decrease blood flow to the brain, accelerating the memory loss and brain damage that is a hallmark of Alzheimer's disease. It is important to note, however, that these results do not mean that high blood pressure is better than low blood pressure, or that you should forego your high blood pressure medicine. Nor can you can do anything to prevent this type of drop in blood pressure.
Scientists continue to explore the link between blood pressure and brain health. In the meantime, have your blood pressure monitored regularly and strive to keep it in a healthy range. A sound diet, regular exercise, and proper medical care are essential to maintaining a healthy blood pressure and, possibly, preserving the health of the brain as well.
The report appeared in the July issue of Stroke, a medical journal from the American Heart Association.
Chengxuan Qiu, M.D., et al: Stroke: Journal of the American Heart Association, July 2004.