Memory Loss: A Casualty of High Blood Pressure

Memory Loss:
A Casualty of High Blood Pressure

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A gradual decline in memory and cognitive function is one of the lesser-known casualties of elevated blood pressure. There's no clear-cut cause of cognitive impairment -- an early indication of dementia -- but research strongly suggests that high blood pressure contributes to the risk.

The onset of damage may be subtle, but the effect is not: High blood pressure leads to stiffened arteries that ultimately deprive brain tissue of proper nourishment. A study in Lancet Neurologyconcluded that vascular brain injury develops insidiously over the lifetime with discernible effects. The findings suggest that high blood pressure prematurely aged the brain by about seven years.

How exactly does high blood pressure lead to cognitive decline? Your brain has two layers. The cortex, an outer layer of gray matter, is packed with brain cells that play a key role in memory, attention, perception, language and consciousness. An inner layer of white matter contains axons, the biological wires that carry information from one part of the brain to the other. Studies indicate that a reduction in blood flow caused by blood pressure–related buildup of plaque in the arteries damages nerve fibers in the white matter and reduces the volume of gray matter.

These changes in the brain structure can lead to cognitive impairment, beginning at age 50 or earlier. In more severe cases, chronic high blood pressure can result in a series of small strokes that damage brain tissue. Over time, the damage caused by multiple little strokes can result in multiinfarct, or vascular, dementia. Vascular dementia is the second most common type of dementia after Alzheimer's disease, and produces symptoms that include confusion, wandering and problems with short-term memory.

The news is not all bad, however: Evidence suggests that treating high blood pressure among people in middle age and the young elderly can help prevent late-life cognitive decline and dementia. The bottom line is that people with high blood pressure need to be proactive about lowering their numbers, through lifestyle changes and/or medication, as early and consistently as possible.