Many people continue to suffer from high blood pressure, even though their lifestyle is healthy (low salt intake, low fat diet with lots of fruit and veg, regular exercise, not too much alcohol, losing weight if necessary, reducing caffeine, no smoking), and they are taking all the prescribed medications. This prolonged hypertension can lead to problems such as TIAs (transient ischaemic attacks) with increased risk of a full-scale stroke. When patients have gone through all this and consulted their GP, who may refer them to a stroke centre for comprehensive tests on head and neck blood vessels, the response may be that there is nothing else that can be done, until a more serious episode occurs. 30% of people suffer from arterial hypertension, and of these, 30% cannot be treated sufficiently and so cannot reach a target blood pressure of below 140 mm Hg.
This can lead to problems in lifestyle. Headaches may become more frequent and can be so-called “sentinel headaches” that precede a TIA. Living with this is hard and can lead to a notable reduction in activity. Are there any other ways of reducing blood pressure?
The vagus nerve and blood pressure
Professor Alexander Gourine (University College, London) has developed an instrument that stimulates the vagus nerve by means of a clip on the tragus, the small cartilaginous skin flap on the outer ear, just in front of the ear hole. He says that using this tool for half an hour every evening can reduce blood pressure by 10-15 mm Hg, with effects that last for longer than just the treatment period. The National Institute for Health and Care Research is currently performing clinical research on people, and Professor Gourine hopes that the machines will be commercially available from 2024-2025. Read more about Professor Gourine’s machine here.
But what can sufferers do up until then? Are there other ways of stimulating the vagus nerve? And how does this system work?
Transcutaneous nerve stimulation – using small electric currents applied to the skin – has been used for other conditions as well. One research study was dedicated to fibromyalgia, with an electrostimulation machine “AS Super 4 Digital“, applied to specific points in the outer ear (parameters 25 Hz, 250 microsecs, 20 mA).
The vagus nerve and its functions
The vagus nerve plays an important part in the autonomic nervous system, which controls involuntary body activities such as heart rate, blood pressure, breathing, immune system, saliva production and other processes. This nervous system has two parts, sympathetic (the so-called fight or flight response, which gets your body ready for physical and mental action) and parasympathetic, known as the “rest and digest” system. One of the changes that happens to people’s bodies as they age is that the parasympathetic system’s effect on the heart declines, while sympathetic functions intensify. This causes the autonomic system to get out of balance, and one result is increased blood pressure. A branch of the vagus nerve innervates part of the outer ear. Electrical treatment of the tragus and other parts of the ear is a way of stimulating the parasympathetic nervous system.
In another study, a range of parameters were used with the electrostimulation machine: pulse width 100, 200, 500 microseconds, frequency 1, 10, 25 Hz. The 500 microsecond, 10 Hz settings had the strongest effect on heart rate reduction. Participants in this test also reported better mood, better sleep and better quality of life.
I have purchased an instrument of this type – the German-made TENS ECO 2 (TENS stands for transcutaneous electrical nerve stimulation) with two clips for the tragus. I will start testing it on myself. My hope is that I can reproduce the effects reported by Prof. Gourine.
Isometric resistance training
There are other ways of stimulating the vagus nerve that don’t need electrical devices. In one study, Dr. Matthew Jones (University of New South Wales, Australia) says that isometric resistance training for 12 minutes a day, two or three time a week, can help reduce blood pressure. Isometric resistance training means using a muscle without moving the surrounding joints. Dr. Jones used a handgrip device, but it could even be making a fist and holding it tight for 12 minutes, or holding a squeezed soft rubber ball. The important thing is maintaining the muscular effort without movement. Results are positive but require constancy. At least three weeks is needed before reductions in blood pressure can be seen.
Vagus breathing – a technique that reduces blood pressure
The same sort of pressure-reducing effect can be achieved by a special breathing technique which stimulates the vagus nerve. You breathe more slowly, making sure that you use the diaphragm (the belly) as well as just the chest. To do this, while sitting or lying down, breathe in slowly and gently through your nose, mouth closed, first using your ribcage as in normal breathing, and then completing the inspiration by pushing down your diaphragm. Ideally this inbreath should last four or five seconds. Then hold your breath for two seconds. Then open your mouth and breathe out slowly, for at least five seconds or longer. Say “aaah” or another gentle sound as you breathe out. Try to be conscious of the diaphragm that lifts up again, pulling in your tummy again. Repeat and continue for at least five minutes. It’s a good idea to have a watch with a seconds hand, because it is important to breathe slowly. I have tried this, taking my blood pressure before and after, and saw a reduction from 111 systolic to 93. To reduce blood pressure, one study recommends 25 minutes of vagal breathing per day.
What is the mechanism of vagus breathing? Slow, deep breathing is a cue of safety that the vagus nerve recognizes and transmits to other parts of the body, telling them to turn off their defences activated by anxiety or threat. Soothing sounds also activate the vagus nerve, for example when a mother calms a child.
Walking and blood pressure
A final consideration is related to taking a walk. When my fiancée was having an arterial hypertension episode, we were taking her blood pressure quite regularly, and one morning we went for a half-hour walk. When we returned, her blood pressure had dropped considerably, down to normal levels. Walking is always good, but for some reason, it seems to be better to walk in the morning.
Daily techniques for reducing blood pressure
So my recommendations would be as follows (in addition to the lifestyle factors mentioned above, and taking the prescribed medications):
– when you wake up, in bed, 5 minutes vagus breathing
– before or after breakfast, a walk, half an hour if you can manage that
– mid-morning and mid-afternoon: two more 5-minute sessions of vagus breathing
– evening while watching TV: isometric resistance training, such as squeezing and holding squeezed a tennis ball, or a resistance training handgrip
– transcutaneous nerve stimulation could also be a treatment option. Prof. Gourine recommends half an hour in the evening, perhaps while watching the TV. I will update this section after performing tests.
Please note that I am not a doctor, I have no medical training. This article was written for a family member with high blood pressure.