Many people, especially over a certain age, have high blood pressure (hypertension).

Many don’t know where the boundaries for that lie, so:

What Most People Don’t Know About Blood Pressure ← not only does this have the correct numerical boundaries of what’s healthy and what not, but also, it discusses the symptoms of high blood pressure, which most people also don’t know about and/or have incorrect beliefs about

But what if your numbers are just on the healthy side of the line, that’s good enough, right?

It’s looking a lot like the answer might be “no”:

The wrong side of the blood-brain barrier

The blood-brain barrier (BBB) is a barrier between your brain and [the rest of] your blood. In other words, a filter.

And a big deal in a lot of pharmacology (and pathology) is “does this thing pass the BBB or not?”, and the implications can be very much critical.

New research by Dr. Samantha Schaeffer et al. suggests that when it comes to blood pressure, the answer is “this may be a problem”.

It’s a mouse study, but mouse brains are very much like ours when it comes to cardiac perfusion and the integrity of the BBB, so this is a valid study.

The mice were given drugs that raised their blood pressure. The problem, however, is that hypertension triggered brain damage to endothelial cells, interneurons, and oligodendrocytes by day 3, long before blood pressure rose which was not until day 42—showing that brain injury precedes measurable hypertension.

So, nearly 6 weeks before blood pressure measurably pushed into hypertensive ranges, the following problems were observed in the brains:

• Endothelial cell aging: endothelial cells aged prematurely, with reduced energy metabolism, increased senescence markers, and early weakening of the blood–brain barrier, disrupting nutrient control and allowing harmful molecules to enter
• Interneuron disruption: interneurons showed early damage that disturbed the balance between inhibition and excitation—an imbalance similar to patterns seen in Alzheimer’s disease
• Oligodendrocyte impairment: genes required for myelin maintenance (myelin is the stuff that makes up the protective sheathe around neurons) were under-expressed, setting the stage for future communication breakdown between neurons and later cognitive decline

For how to help guard against that latter thing, by the way: How To Rebuild Your Neurons’ Myelin Sheaths

Back to the mouse study: by day 42, when blood pressure was high, gene expression changes were even more widespread and correlated with measurable cognitive deficits. This suggests that hypertension causes brain damage independent of the system-wide high blood pressure itself—meaning that future medications could target early brain-cell changes to prevent cognitive decline.

In terms of early options that look promising, Dr. Schaeffer and her team found that blocking angiotensin receptors with losartan reversed early endothelial and interneuron damage, which indicates (not proven yet, more studies in the pipeline to know for sure) that this drug class may well offer cognitive protection beyond blood pressure control.

You can find the paper itself, here: Hypertension-induced neurovascular and cognitive dysfunction at single-cell resolution

What to do meanwhile?

Aside from the phosphatidylserine that we suggested for neuronal remyelination, now’s as good a time as any to remember what we often say, “what’s good for your heart, is good for your brain”.

To that end, check out: What’s Your Vascular Dementia Risk?

And, for that matter: Heart-Healthy Lifestyle, Life-Long Healthy Brain

And definitely: What Matters Most For Your Heart? Eat More (Of This) For Lower Blood Pressure ← this discusses factors a lot more relevant than salt consumption, even though everyone talks about salt and fatty foods, but no, the most important thing (statistically!) is actually what most people are not getting enough of. But you can, easily, if you want to 🙂

Take care!