What Does Your Blood Pressure Have to Do With Your Memory?

February is American Heart Month, which is a reasonable moment to point out that the organ most affected by your blood pressure after your heart is your brain.

Why Would Blood Pressure Affect Memory?

Your brain is supplied by a dense network of very small blood vessels. Years of raised pressure damages them, and damaged small vessels mean parts of the brain are less well supplied than they should be. That shows up on brain scans long before it shows up as forgetfulness.

This is also why blood pressure in your forties and fifties appears to matter more than blood pressure in your seventies. The damage accumulates.

What Has Lowering It Been Shown to Do?

A large trial tested whether treating blood pressure more intensively than usual protected thinking. The result was genuinely positive and genuinely modest: intensive treatment reduced the risk of mild cognitive impairment by about 19%, and the combined risk of mild cognitive impairment or probable dementia by about 15%.

It did not significantly reduce dementia on its own. The trial was stopped early because the heart benefits were so clear, which left less time for dementia to appear.

What Is Worth Doing About It?

Know your number. A great many people with raised blood pressure do not know they have it, because it has no symptoms at all until it causes something serious.

If it is high, treating it is worth doing for your heart regardless, and the evidence suggests your thinking benefits too. That is an unusually easy decision.

More on blood pressure, cholesterol and memory.

Where This Information Comes From

SPRINT MIND Investigators for the SPRINT Research Group. Effect of intensive versus standard blood pressure control on probable dementia: a randomized clinical trial. JAMA 2019;321(6):553-561. doi:10.1001/jama.2018.21442