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Strokes are the second leading cause of death in the world. Dementia is the fifth. We often use the terms "Alzheimer's disease" and "dementia" as synonyms, but indeed they are not the same thing.
Much of dementia is vascular dementia. Vascular dementia is the decline of cognitive function due to the interrupted or inadequate circulation of blood to the brain. If you combine the death rates from strokes and from vascular dementia, the total number of deaths in the U. S. is exceeded only by the death rates from heart disease and cancer.
Alzheimer's Disease is complex. Despite all of our efforts to date, we have no clear way of preventing it. We can, however, do much to prevent vascular dementia. There is growing evidence of a link between vascular dementia and Alzheimer's Disease, but even if that link does not pan out, it is still worth doing what we can to prevent vascular brain injury.
Not too long ago, a patient of mine had heard a news story about several new invasive procedures to try to rescue a brain during a stroke. He asked me, "What is the best way to treat a stroke?"
I answered him quite simply, "That is the wrong question. The best way to treat a stroke is to prevent it."
He was somewhat taken aback. He, like so many of us, thought that strokes were something that you hoped to avoid. You lived your life well: You had a good diet, ate kale, didn't smoke, exercised, and did crossword puzzles. You played the odds and hoped for the best.
But "prevent" is an active verb. We can avoid brain injury, but we need to be proactive. You can prevent a stroke.
There are obvious reasons to prevent a stroke. Strokes can kill you. But what can be worse (in some cases) is when they don't kill you. They just leave you damaged. As a practicing invasive-preventive cardiologist, I see thousands of patients over 65 years old. Almost uniformly, they tell me that disability and loss of their physical and mental function are what they fear the most.
Strokes do not have to be big. They can be small, and they can be cumulative. That is to say, you can slowly lose working brain cells over time from interrupted or inadequate blood flow to the brain. That is the essence of vascular dementia.
To me, the brain is a great mystery. To my knowledge, we can't even quite define consciousness. We debate the meaning of intelligence and thought, and we ponder the implications of free will. The heart is fundamentally just a pump, and blood vessels are pipes. This is why I am a cardiologist. It's simpler than being a brain scientist!
What I can tell you is this: If you want to keep a brain, particularly an aging brain, healthy, you need to feed it. You need to regularly, reliably, and adequately provide it with blood. That means you need effective circulation.
Next time, I will begin to explain why, in fact, there is (almost) no such thing as heart and vascular disease — it's mostly just natural aging. Aging is inevitable. No one is immune, but that makes it predictable, measurable, and manageable. That means we can all be empowered to understand how we are aging, and what steps we can take to protect our brains.
