If you’ve arrived at this article, you probably already know what hypertension is, or at least, you have a tiny idea. It’s almost impossible not to, given that high blood pressure (HBP) is one of the most common health conditions worldwide. According to the latest statistics by the Centers for Disease Control and Prevention, high blood pressure affects about one out of three Americans — that’s 75 million people!1
Uncontrolled hypertension is one of the major risk factors for heart attack, stroke, kidney damage and heart failure, not to mention the years of disability, social impact and elevated health-care expenditures that this condition can leave in its wake.23
But what exactly is hypertension, and what are the causes of such a common disease?
Is it just a matter of salt intake?
Keep reading to discover the root cause behind this “silent killer.”
Hypertension at a glance
The American Heart Association (AHA) defines hypertension as a condition when your blood pressure, the force of the blood flowing through your blood vessels, is consistently too high.
Clinically, it is diagnosed when you have a blood pressure (BP) of ≥130/80 mmHg (millimeters of mercury) or are using blood pressure-lowering drugs.2
What is considered a normal blood pressure reading?
When you get your blood pressure tested, the first number you see measures the pressure in your arteries when your heart beats (systolic pressure), and the lower number measures the pressure in your arteries between beats (diastolic pressure). These numbers should typically be below 120 and 80, respectively. If either of these numbers is higher, you may get a diagnosis of high blood pressure. Although you can easily and accurately measure blood pressure at home, it is important to also get tested and diagnosed by a medical professional.
According to the AHA, the following are the different stages defining what is considered normal or when you need to start paying more attention to your blood pressure numbers.
Blood Pressure Stages
|Blood pressure category||Systolic mm Hg (upper number)||Diastolic mm Hg (lower number)|
|Normal||Less than 120||and||Less than 80|
|Elevated||120-129||and||Less than 80|
|High blood pressure (hypertension) stage 1||130-139||or||80-89|
|High blood pressure (hypertension) stage 2||140 or higher||or||90 or higher|
|Hypertensive crisis (consult your doctor immediately)||Higher than 180||and/or||Higher than 120|
What causes high blood pressure?
Many people who struggle with high blood pressure ask themselves: why me?
This is a hard question to answer given that HBP is multi-factorial. You’ve likely heard how lifestyle choices play a big role in hypertension. High salt intake, being obese, drinking too much alcohol and the use of certain medications can all lead to HBP.
Plant based diets are a reliable intervention for reducing HBP as well. For more, see this paper.
On the other hand, genetics can also play a role in who succumbs to high blood pressure.4
But I bet you never imagined that the amount of certain minerals in your body could also be part of the cause. For example, did you know that elements like potassium, magnesium and calcium may influence your blood pressure? As surprising as it may sound, it’s true.
Recent research shows that elevated blood pressure stems from an excess or deficiency of these core minerals, which means that in some cases, restriction of salt intake alone may not be the primary intervention for reducing HBP.56 Instead, just as with omega-6 to omega-3 ratios in controlling inflammation, the overall ratios of mineral intake may be the driving factor behind getting HBP under control.
Mineral imbalance and high blood pressure
About 28 elements have been identified as possibly affecting human blood pressure regulation. The high intake of sodium on one hand and the low intakes of potassium, calcium, and magnesium on the other — produce and maintain elevated blood pressure in most people.
This is because all these nutrients have important roles in both the control of cardiac output and peripheral vascular resistance, the main determinants of blood pressure levels.678 So, as an early action item for controlling hypertension: the focus should be making sure you have adequate dietary potassium, magnesium and calcium, in addition to limiting salt. The ratio of all these minerals together contribute to blood pressure levels, both healthy and unhealthy.
What’s the link between these minerals and healthy blood pressure?
Potassium and blood pressure
It’s very well known that a high-salt diet contributes to the development and maintenance of hypertension. Sodium affects normal function of the renin-angiotensin system, which is a complex mechanism that regulates blood pressure, water and electrolyte balance; likewise, dietary sodium excess increases the excretion of potassium in the urine, which will cause a fall in its plasma concentration. It’s easy to guess that a reduction of salt intake leads to a considerable reduction in BP in people who are hypertensive.9
Aside from sodium, potassium is probably the most important electrolyte for the control of blood pressure, this mineral is effective in lowering both systolic and diastolic BP and increasing the intake is potentially beneficial to most people who don’t have impaired renal function.1011
There are multiple mechanisms for potassium’s blood-pressure-lowering effects, but mostly, is due to the enhancement of natriuresis, direct vasodilatory functions and modulation of the renin-angiotensin-aldosterone system, all mechanisms of which the end result is lowering BP; potassium also seems to confer some protection against the effects of salt excess and it also reduces urinary calcium excretion.126
The greater effect in lowering blood pressure is seen if in addition to sodium reduction, there is an increase in potassium intake, meaning that it’s more important the sodium-to-potassium ratio, than either sodium or potassium alone.1314
The drawback is that the current American diet provides sodium levels that markedly exceed Dietary Reference Intakes (DRIs) for this mineral — 2,500 mg per day – and by contrast, the intake of potassium is extraordinarily lower, let’s say only about 37% of the recommended level of 4,700 mg/day. Just to give you a better idea, the average U.S. dietary potassium-to-sodium ratio is <1:2.78, when it should be a potassium/sodium ratio of >5:1.7
Relevant genes: MAT1A
Magnesium and blood pressure
Just like potassium, magnesium is an essential element in the human body that may have beneficial health effects. It plays a critical role in BP regulation by acting like a natural calcium channel blocker; moreover, magnesium regulates intracellular calcium, sodium, and potassium levels.3 This mineral has antioxidant benefits, attenuates the damage of vasculature from oxidative stress and inhibits the vasoconstriction. On the other hand, high levels of magnesium are correlated with the improvements in hemodynamic status, such as blood flow, vascular resistance and capacitance function of vessels, which contributes to the pathology of hypertension.1516
So, how much magnesium do you need? The daily recommended intake for this nutrient is 420 mg for adult men and about 300 mg a day for women; sadly, modern diets only supply half of these requirements. It’s important to note that magnesium is more effective in reducing BP when there is enough potassium and calcium in the diet as well.7
Calcium and blood pressure
And finally, we have calcium, which works in combination with other ions, providing the correct balance to the vascular membrane and vasodilatation, which results in reduced BP. At optimal concentrations, calcium stabilizes vascular cell membranes and reduces vasoconstriction; thus, it may be of importance in the modulation of blood pressure. (R) If you consume a couple of dairy products per day, green-leafy vegetables or fortified products, you’ll most likely meet your daily calcium requirements: 1,000-1,300 mg.7
With all these huge benefits from calcium, you might be wondering if it would be a good idea to supplement with this mineral. The answer is no. Calcium supplements have been under considerable scrutiny for the last several years, and studies have shown that users of calcium supplements have an increased risk of heart attack and stroke. Therefore, they are not considered safe.
But why do calcium supplements increase heart attack risk and dietary calcium does not? It’s possible that when taking calcium pills, you get a spike of calcium in your bloodstream — which one doesn’t get just by eating calcium-rich foods — producing a hyper coagulable state and increasing the risk of clots in the heart and brain. It doesn’t matter if it’s a high dose or low dose; any calcium supplementation seems to increase cardiovascular disease risk. Individuals should obtain their calcium requirements from their diet as opposed to supplements.17(R)
Sodium plays a role in high blood pressure
To combat high blood pressure, we shouldn’t simply aim for sodium reduction or any single-nutrient approach. Instead, we should widen our view and look at other minerals that have complex interactions and important roles in our body physiology: potassium, calcium, and magnesium. Having said that, sodium does draw down on our potassium stores, so many can benefit from targeting salt, even though HBP is more complicated than just sodium.
In many cases, these nutrient requirements can be met through changes in our diet.
Diets that are rich in lots of fruits and vegetables, low-fat dairy products, whole grains, and nuts will provide many of the nutrients needed to keep your BP under control.