Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure. If this pressure rises and stays high over a long period, it can damage the body. High blood pressure is deadly serious, it usually has no symptoms so you can have it for years without knowing it. During this time, though, it can damage your heart, blood vessels, kidneys, and yes … your brain.
Impact on brain-volume and risk for dementia
If you are middle-aged you should have your blood pressure measured regularly and if it is elevated, make sure you take actions to control it, as hypertension can quietly damage your brain for years before any symptoms are apparent. High blood pressure has been associated with later development of cognitive impairment, vascular dementia and possibly Alzheimer’s disease.
Hypertension has impact on brain-structure, as many studies have shown that elderly people with chronic hypertension have more brain-volume decline and more damage to their white matter than people with normal blood pressure. Some studies have shown this association to still hold true, when hypertension is controlled with medication. One study on 243 individuals aged 73 – 94 at death showed that raised blood pressure at midlife was related to pathological markers of Alzheimer’s disease in the brain (senile plaques and neurofibrillary tangles). Another research followed its participants for 21 years and found that raised systolic blood pressure in midlife increased the risk of Alzheimer’s disease significantly in later life.
Impact on cognitive skills
The results of several studies suggest that long-standing hypertension in middle-age is associated with cognitive impairment later in life. One research analyzed 10 longitudinal studies that looked at the relationship between hypertension and cognitive skills. Of the 10 studies, 8 found that hypertension had negative impact on cognitive skills. The authors concluded that the weight of evidence suggested that elevated blood pressure predicted cognitive decline. Many cross-sectional studies support that conclusion.
Some studies have even shown associations between hypertension and cognitive decline, irrespective of whether the hypertension is medically treated or not, but others suggest that medically controlled hypertension has no impact on cognitive skills.
Here is a video called “The Silent Killer” by Blood Pressure Canada http://hypertension.ca/bpc/, about the dangers of high blood pressure:
Kivipelto, M., Helkala, E., Laakso, M., Hanninen, T., Hallikainen, M., Alhainen, K. o.fl. (2001). Midlife vascular risk factors and Alzheimer’s disease in later life: longitudinal, population based study. BMJ, 322(7300), 1447 – 1451.
Petrovitch, H., White, L. R., Izmirilian, G., Ross, G. W., Havlik, R. J., Markesbery, W. o.fl. (2000). Midlife blood pressure and neuritic plaques, neurofibrillary tangles, and brain weight at death: the HAAS. Neurobiology of Aging, 21(1), 57-62.
Raz, N., Rodrigue, K. M. og Acker, J. D. (2003). Hypertension and the brain: Vulnerability of the prefrontal regions and executive functions. Behavioral Neuroscience, 117(6), 1169-1180.
Skoog, I. and Gustafson, D. (2006). Update on hypertension and Alzheimer’s disease. Neurological Research, 28, 605-611.