Updated: Apr 18
Most people know that high blood pressure means an increase in pressure in the blood vessels of our body. If we think about a tube with fluid flowing through it at normal pressure, we can then think about what things would cause it to increase in pressure. An increase in the overall volume of fluid in the tubes would do it, like when the kidney gets a signal to retain fluid. An increase in the volume of fluid that needs to flow through the tube at a given time (flow rate) would do it, like if the body got the signal to deliver blood to tissue faster. A decrease in the space in the tube in which the fluid has to flow would also do it, like if the body gets signals to constrict the blood vessels. And lastly, a loss of flexibility of the blood vessels, like when there is a build-up of atherosclerosis, this can also decrease the space in which the blood has to flow as well. Of course, all of these things could happen at the same time too, which is usually the case.
Before we get into why these things could happen resulting in an increase the pressure in the blood, it will be useful to look at how blood pressure is measured and how our body regulates blood pressure. It is measured by taking systolic and diastolic pressure measurements of an artery. The systolic is the pressure measured when the ventricles of the heart are contracting, and the diastolic is the pressure when the ventricles of the heart are not contracting. If you follow my blog, you have read about how the heart is not the main mover of the blood and that a contracting heart is not enough force to move the blood throughout the body. However, the contraction of the heart and opening and closing of heart valves does create momentary pressure changes in the system that give us measurements of blood pressure and the sensation of a pulse in our arteries.
The body regulates blood pressure in an automatic way, meaning it is not under conscious control. The body just does it, just like you breathe without thinking about it. Regulation of blood pressure starts in the kidney. The kidney is always sensing fluctuations in blood pressure and responds accordingly. If pressure gets too low the kidney will secrete a substance called Renin from its juxtaglomerular cells. Renin then goes into the circulation. The liver continuously makes and releases a substance called angiotensinogen into the blood stream, and when renin appears in the blood stream and encounters angiotensinogen it converts it to a substance called Angiotensin I. Once Angiotensin I is present in the blood, then an enzyme called angiotensin converting enzyme (ACE), which is also always present in the blood stream, starts converting Angiotensin I to Angiotensin II. The presence of Angiotensin II then triggers things in the body that raise blood pressure. It stimulates the production of aldosterone in the adrenal gland, which triggers sodium and fluid retention that will increase the volume of blood raising blood pressure. It stimulates vasoconstriction of blood vessels increasing the pressure in them. It also stimulates the sympathetic nervous system which quickens the delivery of blood to tissues by increasing flow of blood and therefore pressure. Once the pressure in the blood has been increased sufficiently, the kidney senses this, lowers the production of renin, and the whole system down regulates.
The system works well, and it is the classic negative feedback loop seen in many regulatory systems in the body. But when the system gets improperly stimulated it creates what we know as chronic high blood pressure, which is associated with atherosclerosis, heart attacks, heart failure, and stokes, as well as dementia, kidney disease, and eye damage. But I want to make something clear, I do not think that high blood pressure causes all of these things. I think the things that cause high blood pressure are also the driving forces behind those chronic diseases. High blood pressure has been associated, or seen at the same time, as many of these conditions, but I have not seen anything that makes me think it is directly the cause of those associated ailments. I do think that higher blood pressure can make some of those diseases worse, but I do not think that high blood pressure can cause them on its own. And high blood pressure usually does not happen unless the other things that cause those chronic diseases are present first.
The first reason I think this is because raising blood pressure is a normal and essential thing that the body is supposed to do. It is one of the ways the body adapts to ever changing environments. One of the best indicators of health is the ability to adapt to different environments. For example, if someone were to go from standing still to a dead sprint, that is a huge environmental change that the body must adapt to. If the average teenager were to do this, they are much more likely to be able to adapt to that change. Whereas the average eighty-year-old would not be able to adapt to this as well, and if they were forced to do this it just might kill them through a failure of the body to adapt. The eighty-year-old has lost the robustness of their adaptive mechanisms. This is why I think things like Heart Rate Variability, which measures your ability to healthily go back and forth between a stress and non-stress state, or being metabolically flexible and having the ability to readily go back and forth between burning carbohydrates and fats, are extremely good measures of health, especially as we age.
If blood pressure is elevated, it is not because the body is doing something it is not supposed to, it is because it is getting the signal to keep the blood pressure elevated. It is doing exactly what it is supposed to, and if it didn’t do it then you probably wouldn’t be alive because your body is not adapting. The problem comes when we get improper signaling telling the body to unnecessarily adapt by chronically maintaining an increase in blood pressure. But it is the things that cause the improper signaling that are the true culprits in the association between high blood pressure and heart disease, eye damage, kidney disease, and dementia.
There are three main culprits when it comes to imbalances in the body that create chronic high blood pressure. The first is that the body does not get enough radiant energy applied to it. In my blog post called “Is the heart really a pump” I go into detail about how the heart is not the main mover of the blood and how the interaction between the formation of 4th phase water on the lining of arteries and the blood in the artery creates an energy gradient that stimulates blood flow without the pumping of the heart. This has been proven by a graduate student at University of Washington, he is awaiting publication. He was able to show that when he stopped the heart of a chick embryo that the blood continued to move for quite some time through these mechanisms and the more radiant energy he applied to the system the faster and longer the blood would continue to flow. The ability of the body to maintain blood flow in this manner is dependent on enough radiant energy being applied to the system. If enough radiant energy (in the form of infrared light from the sun and contact with the Earth) is not provided to the body, then this does not happen as efficiently. If the body cannot create the blood flow it needs due to lack of radiant energy, then it will adapt by constricting blood vessels so that there is less space in them which in turn creates higher pressure and quicker flow. The same thing we see when we put our thumb partially over the outflow of a water hose. The speed at which the water comes out quickens.
We have evidence that this is very likely what is going on through studies done with infrared light exposure. One study that exposed rats to artificial infrared light rays found, “significant decreases in heart rates and systolic and mean blood pressure”. (1) Another study found that average blood pressure was decreased in people through 20 minutes of infrared sauna use 3x/week for 3 months. (2) One last study looked to see if the increase in Vitamin D from sunlight exposure could explain the decreases in blood pressure associated with sunlight exposure. The authors states, “we conclude that although 25(OH)D concentration is inversely associated with [systolic blood pressure], 25(OH)D did not explain the association of greater sunlight exposure with lower blood pressure”. (3) It didn’t explain it because the increase in Vitamin D is not what causes the drop in blood pressure, it is the radiant energy doing this. By applying infrared light to the body, we improve the mechanisms of blood flow by 4th phase water production and the body can relax the constriction of the blood vessels because the blood is flowing just fine without needing to constrict the vessels.
The second cause of improper signaling to increase blood pressure is an imbalance in our Autonomic Nervous System (ANS). The ANS is the system our body uses to interpret our environment with our five senses in order to tell if we are in a safe or threatening situation. I have previously discussed the details of how this system developed in humans in this blog post, but the main idea is that when our body perceives we are in a stressful situation it does things that will help us fight off or flee that situation. One of those things is increased blood flow to tissues to bring oxygen and energy to them. To do this, the body has to raise blood pressure through constriction of blood vessels and increasing blood volume to deliver more needed metabolites. Thus, a stressful situation, or a perceived stressful situation, will turn on the blood pressure increasing system of the body.
The issue we have in society today is that we unnecessarily stimulate the stress state of our ANS just because of our higher-level thinking and ability to worry about things as humans. Dr. Robert Sapolsky says it best, “mobilizing energy while sprinting for your life helps save you. Do the same thing chronically because of a stressful thirty-year mortgage, and you’re at risk for metabolic problems like diabetes and high blood pressure”. An imbalance in our ANS, where the stress state is chronically but incorrectly turned on, is a recipe for creating chronic high blood pressure. This is a result of our evolved stress response physiology dealing with the unnaturally stressful modern-day society we live in.
The best measure of the balance and health of the ANS is Heart Rate Variability (HRV). Studies have shown the relationship between psychological stress with decreases in HRV and increases in blood pressure. (4,5) Another study done on medical students looked at the effects of a stress relieving relaxation therapy on HRV and blood pressure. They concluded that, “short-term practice of relaxation therapy can improve autonomic balance and promote cardiovascular health of medical students. Sympathovagal balance is directly linked to BP status in these individuals”. (6) The imbalance of our ANS by modern-day society is a huge contributor to high blood pressure.
The third cause of improper signaling of our blood pressure regulating system is being metabolically unhealthy. What I mean by this it that the body has become insulin resistant. When we eat it raises our blood sugar and insulin is secreted to take that sugar out of the blood and either put it in cells or store it as fat so that the blood sugar comes back down. When we are insulin resistant, the body does not respond as well to that insulin and this creates metabolic issues. It is no mistake that high blood pressure is highly correlated with things like diabetes, (7) because the characteristic of diabetes is high blood sugar due to insulin resistance. Insulin resistance has been shown to directly upregulate the renin-angiotensin system that raises blood pressure. (8) Insulin resistance is created when we eat fat and carbohydrates at the same time, especially in high amounts and especially the processed forms of these foods (vegetables oil and refined sugar and flour). Sugar and fat eaten together would rarely, if ever, have happened during our evolution and if we do it every day, like many people on the standard American diet do, over time we can wear out our insulin signaling and receiving systems creating insulin resistance.
The things that cause insulin resistance also contribute to oxidative stress, which is an excess of free radicals in the body that can damage the lining of our arteries. Other things, like environmental toxins, endotoxemia, and chronically high blood sugar, can also create oxidative stress. This will damage the artery and lead to the development of atherosclerosis. Once this happens, the arteries lose flexibility and can no longer adapt to changing amount of blood or blood flow which contributes to high blood pressure.
Before we move on to tying up some odds and ends, I want to again emphasize the idea that high blood pressure does not directly cause all the conditions and ailments it is associated with. The things that cause high blood pressure, lack of energy to the body, ANS imbalance, and insulin resistance, are all highly causative of the conditions we listed at the beginning of this post. High blood pressure is just another consequence of these three imbalances, but it is not causative in those conditions. It can make some of those conditions worse, for example increased pressure in the arteries can make atherosclerosis worse because it pushes the things that are damaging the artery wall (oxidative stress cause by insulin resistance) up against it harder, but none of those things would be happening if the insulin resistance wasn’t there in the first place.
Before we end, I want to clear up the misconception that salt causes high blood pressure. The fact that the body starts to hold on to fluid and sodium when angiotensin II is created, and that this results in increased blood pressure, caused doctors and scientists to think that increased salt intake would result in high blood pressure. This is not true. It is also observed that people with kidney failure have trouble holding onto and regulating sodium levels in the body, but that does not mean that high sodium intake causes kidney disease.
One study found that increasing salt intake up to eight times the normal intake for three days in people without diagnosed high blood pressure created only minimal increases in blood pressure. (9) Another study looked at some of the effects of restricting salt intake. They found that, “moderate dietary salt restriction may have adverse effects on both vascular and systemic sensitivity to insulin”. (10) Lastly, a study looked at increase of salt intake in those with high blood pressure and found that mechanisms that increase blood pressure were downregulated with salt intake. They felt that their results gave them, “reasons to search for other mechanisms in the genesis of increases in total peripheral resistance and arterial pressure”. (11) So high salt intake does not cause high blood pressure, restriction of salt could cause insulin resistance, and eating more salt may actually bring blood pressure down in those with high blood pressure.
I want to end by discussing how blood pressure lowering drugs work. These drugs are known as ACE inhibitors. They work by inhibiting the enzyme (ACE) that converts angiotensin I to angiotensin II. When this is prevented the body doesn’t get the signal to hold on to fluid and sodium or constrict blood vessels to increase pressure and blood pressure comes down. However, this is a classic example of chasing a symptom and not correcting the problem. When taking a blood pressure medication, we are lowering the increased pressure in arteries that is merely a symptom of the causes we have discussed here. Those causes are then free to get worse, and then the persons health gets worse as well. What’s more is that, because of the drug, the body is never given the signal to hold on to sodium and other minerals and this can result in mineral deficiency symptoms in people on those drugs. (12,13) We just discussed a study that shows that restricting sodium can actually cause high blood pressure and insulin resistance and taking these drugs can contribute to that loss of sodium. As you can see, the approach of correcting high blood pressure with a medication is very backwards.
I hope that now you understand that high blood pressure is not something that causes the body damage, but instead it is a normal response to our environment. If the environment inside or outside our body gives it signals to increase blood pressure chronically then it will stay elevated. To correct this, we need to change the environment we are in. To do this we need to focus on the same things that will help us combat any chronic condition or ailment. We need to maintain metabolic flexibility by restricting carbohydrates and eating higher fat, provide energy to our body in the form of radiant light, and create balance in our autonomic nervous system.
Stay healthy out there!
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