Main causes of hypertension: low potassium
March 8, 2021
The heart has its own electrical system that controls the rhythm and rate at which it beats. For more on that please read the article on this page entitled “What is Hypertension”. The heart’s electrical panel, so to speak, is operated by electrolytes, chemical elements that conduct electricity when dissolved in water. Each one of them is in charge of both triggering and inhibiting certain body functions as needed. For instance, generally speaking, Calcium is mainly involved in contractions, Magnesium produces relaxation, Potassium and Sodium crucially need to be present in the ratio of 5 to 1 for plasma and cellular fluids to be balanced. In this article we will look at the role Potassium has in influencing blood pressure, and for all intents and purposes, we will only discuss hypokalemia, or low potassium, and its role in hypertension.
First, in order to understand how and why electrolytes seek to exist in the body in balanced amounts, we need to appreciate the concept of homeostasis, which is the body’s spontaneous and continuous effort to maintain a state of stable equilibrium via adaptation responses to changes in the environment. In the case of electrolytes, homeostasis is controlled by the kidneys and several hormones.
Let’s begin by noting that out of all electrolytes Potassium is the one we need in the highest amounts for body functions to run smoothly: a whopping amount of 4,700mg per day is the lowest recommended intake established by the US Dept. of Agriculture. Compare that to Sodium, needed in amounts lower than 2,300mg per day, Calcium, 1,000/1,200mg on average, and Magnesium, needed in the average amount of 400mg (in spite of the fact that it is involved in an abundance of biological functions).
Potassium is in charge of transmitting nerve impulses, controlling muscle contractions, and maintaining normal blood pressure and pulse rate. Studies have shown that low levels of serum potassium and magnesium are associated with a higher risk of atrial fibrillation, also known as AFib, a heart rhythm disorder that can lead to stroke and heart failure. Potassium also keeps the artery walls from becoming stiff by reversing vascular calcification, a marker for many life-threatening conditions.
Too much sodium in your diet will automatically plunge potassium levels down. Sodium is present outside the cells, whereas potassium lodges inside the cells; if sodium is present in excess, cells will inflate and retain water, causing edemas, cellulite and hypertension. So is it excess sodium or a potassium deficiency the actual cause of hypertension? A group of researchers at the Texas Tech University Health Sciences Center (TTUHSC) investigated the role of potassium in hypertension, and isolated a gene, the KNK1 gene, responsible for regulating the relationship between potassium and blood pressure. Low potassium levels signal the organism to crave more sodium (salt); a diet rich in vegetables and low in carbohydrates, which supplies potassium and upregulates its intake, is the best way to ensure optimal expression of this gene.
One interesting and little known fact about Potassium, is that the cell need optimal insulin levels to be able to absorb potassium. This is because insulin regulates the sodium-potassium exchange in plasma and tissues by shifting potassium into the cells, since 98% of our potassium needs to be inside cells for normal body functions to occur (unlike sodium, which needs to be present in the blood in higher concentrations). If you are insulin resistant, your potassium levels drop because potassium uptake is inhibited in cells by blunted insulin receptors. Conversely, optimal potassium levels aid in the resolution of insulin resistance. A high carb/high sugar diet hence may dramatically lower your potassium levels, since potassium absorption is regulated by insulin.
Many other factors can contribute to hypokalemia, including stress-induced alkalosis, or higher-than-normal PH, excess water intake, strenuous exercise (through profuse sweating) and a lack of magnesium in the body, which we will cover in a separate article. The wrong diuretics may also cause the body to flush out potassium.
Bonus info: total potassium is one indicator of lean body mass index, since potassium only lodges itself in fat-free compartments of the body.
The best strategy to maintain optimal potassium levels is a dietary modification to include more potassium rich foods. However, that comes with a caveat: some high-potassium foods such as bananas, sweet potatoes, cereals, rice and juices, touted for their high potassium content, may have an adverse effect on insulin levels, particularly in poor carbohydrate metabolizers (typically apple shaped individuals), defeating the purpose and even worsening the problem. A feeding regime based on green leafy vegetables (beet tops, swiss chard, green salads and artichokes are on the A-list of potassium rich foods), legumes; grains like oats and quinoa; protein from fish like halibut, cod, trout, and seafood like scallops, as well as meat protein like beef, chicken and turkey, is the best strategy.
Note: If you are taking blood thinners it may be a good idea to let your physician know if you are introducing more Vitamin K rich vegetables in your diet, so your dosage may be adjusted to accommodate for the additional clotting factor, if need be. Feel free to contact us for a list of those vegetables. For those who do not have dietary restrictions related to anti-coagulant therapy, taking artichoke extract, which contains high concentrations of nutritional compounds found in the plant, is one way of boosting potassium while supporting liver and kidney detoxification.
As for conventional supplementation, please discuss that with your physician. If needed, your provider will check your potassium levels and determine requirements.
A time-restricted feeding (intermittent fasting) and low carb regime is possibly the best intervention in order to restore insulin sensitivity while increasing intake of potassium rich food, in order to increase absorption. Check out my articles on intermittent fasting and controlled carb regimens for more details.
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References:
https://www.eurekalert.org/pub_releases/2017-10/ttuh-rua102617.php
https://www.ahajournals.org/doi/10.1161/HYPERTENSIONAHA.118.10267