July 12, 2018

Blood pressure: the silent brain killer

By dryeongs

Photo by Val Vesa on Unsplash

How does blood pressure affect your brain? What can we do to optimise our blood pressure?

On my way to work the other day, I heard a report from the UK on the link between blood pressure and dementia. The Whitehall II cohort study is a large-scale ongoing study of men and women, which started in 1985. In this study, the men and women are tracked and followed up every few years to see if any correlations can be made to provide some clues as to what may contribute to certain health conditions.

This particular paper was outlining the relationship the researchers found between blood pressure and dementia. In particular, they found that a systolic blood pressure of 130mmHg and above, at the age of 50 led to an increased risk of dementia. Interestingly, this relationship was not found for similar blood pressure readings at age 60 or 70.

The important thing about this is that us Australian GPs are trained to really start doing something about blood pressures over 140/90mmHg (unless the patient has other medical issues such as diabetes). This study, while not anywhere near conclusive, suggests we should probably be encouraging our patients to aim for lower blood pressures in middle age, if not only for heart health, but also for brain health.

How does blood pressure affect your brain? Well, we already know that high blood pressure causes strokes. This is because over time high pressure in the blood vessels in your brain can cause damage to them, resulting in clots or bleeding, which causes death to brain tissue. This is what causes the stroke symptoms- headaches, paralysis in an arm or leg, difficulty speaking, etc.

However, rather than only causing catastrophic bleeds or clots, researchers think that even just the cumulative effect of moderately high blood pressure can cause problems. Over time, increased resistance in the blood vessels, can cause “micro-infarcts”- sort of like mini-strokes which are so minor you don’t feel anything, but over time they accumulate and can cause problems with cognition and memory. Forgetfulness in older age may have more to do with blood pressure than simply aging.

One of my supervisors when I was a trainee did a research project on dementia which was quite close to home as her own husband had dementia, and the results of her study found that high intensity exercise and controlling blood pressure were two of the best ways to prevent the onset of dementia.

The problem with blood pressure is you can’t feel it getting higher. I commonly get patients coming in worried about their blood pressure because they’re getting headaches or dizziness. However, majority of the time their blood pressure is actually normal, because unless your blood pressure isĀ extremely high, most people don’t feel any symptoms at all.

What about those home blood pressure machines you can buy from the chemist? Those are good, especially for people already on blood pressure medications, or who have a family history of high blood pressure. However, another phenomenon I have noticed are the patients who become extremely anxious about their blood pressure, and check it every day. The other thing about blood pressure is that it fluctuates from minute to minute, and so constantly checking it all the time can provoke anxiety, which can actually raise your blood pressure higher. Other things can affect it as well- being in pain, being sick, having caffeine, recent exercise and so forth. The best thing to do is to measure it once a week, at the same time, and if it’s consistently high then see your GP.

So what can we do about our blood pressure? Firstly, be aware. Have your blood pressure checked at least once a year. Start earlier if you know you have a family history of high blood pressure, heart problems, stroke, or dementia. Do it more often if you have diabetes, or if you’ve had heart problems or a stroke in the past.

Secondly, regular moderate intensity exercise. This is the best way to keep your blood pressure in check, as exercise trains your vascular system to become more pliable and more efficient. Thirdly, if your GP does decide that medication is required, don’t be scared of medication. Yes, none of us like the idea of being on regular medication for the rest of our lives. Some people see it as a failure or a life sentence. Others are afraid of the effects the medications might have on the body. But remember, like all medication, we only use it if there is a need for it. If there wasn’t a problem to treat, then you wouldn’t need it! Sometimes your genetics fight against you. And if a family member is on blood pressure tablets and does not take them regularly, then please encourage them to do so. You might be saving their future brain.

Remember, everything we do today is to help the person we will be many years from now. Good habits set in place at an age where we still have the capacity to start them save many costs and complications in the future.