High Blood Pressure and Dietary Supplements
Dietary supplements (DS) are literally on everyone's lips - at least that's what advertising wants us to believe. We are constantly reminded that we need product X, Y, or Z to stay or become healthy, fit, young, beautiful, or whatever.
Effects on specific diseases are usually advertised more implicitly than openly. Even though DSs resemble medications in their forms such as capsules, drops, (effervescent) tablets, etc., they are legally classified as food, and their purpose must not be the alleviation or healing of diseases. Of course, they must not have any adverse effects on health either.
However, advertising texts and descriptions suggest corresponding effects. But what is actually behind this? According to our field of expertise regarding blood pressure, we have dealt more extensively with the topic of dietary supplements.
First of all, one should ask whether one actually needs the supplement. Because apart from certain risk groups, it is generally not necessary to supplement the diet. It is much more important to ensure that the diet itself is balanced. The attempt to compensate for a one-sided diet with supplements is not very effective.
The aforementioned risk groups can include pregnant women or people with intestinal diseases who have an increased need for certain nutrients or problems absorbing them in sufficient quantities from food. In these cases, supplementation, i.e., the targeted addition of food, should always be done in consultation with the treating physician.
Of course, there are some dietary supplements that are better researched than others. However, it is generally noticeable that the actual verifiable effects almost always fall far short of the advertising promises. This is especially true for new, freshly "hyped" products that promise a wide range of effects, from hair loss to athlete's foot.
CBD Products
As an example, one could mention CBD oil (cannabidiol oil), for which there are now studies, but many hardly support the advertising claims. You can find our detailed article on this here:
Does CBD or hemp oil help with high blood pressure?
Does CBD or hemp oil help with high blood pressure?
Ashwagandha
Ashwagandha is also a relatively popular example at the moment. The sleep berry known from Ayurveda is said to have great effects.
However, upon closer examination, one finds various studies that have investigated this or that effect. The best-researched effect here is on sleep and a generally stress-regulating effect, although the formulation is already not very specific.
Looking more closely at the individual studies, a critical reader quickly notices that they have limitations. The studies mostly ran over a short period, and the subjects, if they were humans and not animals or test tubes, were young and/or healthy.
Often, one finds limiting formulations such as "should be further researched" listed under limitations. But also, hints about possible side effects can be found after some searching.
For example, people with cardiovascular diseases and those taking blood-thinning medications should consult their doctor before taking ashwagandha.
Potassium
There are a few dietary supplements that are actually relatively well researched, including their effects on blood pressure. However, there is almost always an unwanted (side) effect associated with desired effects. An example here could be potassium, which is currently often marketed as an alternative salt for those suffering from high blood pressure, but is not suitable for people with kidney disease.
Zinc
Another example is zinc, which is not only used as an ointment for injuries but is also used as a dietary supplement in connection with blood pressure. Although there is evidence that a deficiency in zinc promotes high blood pressure, the current state of research is not advanced enough to make a recommendation for supplementation.
The studies so far have been conducted on mice and rats as well as on human-derived vascular pieces. They aim to explore the mechanism of action of zinc to find out whether it can be a future target for vascular-targeting therapeutics, i.e., medications.
And zinc is also usually taken in sufficient amounts through a balanced diet. However, an overdose of zinc, which is classified as a heavy metal, can lead to poisoning symptoms and can impair the absorption of copper in the body. A copper deficiency, in turn, can lead to neurological problems and anemia.
Magnesium
The same applies to magnesium. There is evidence that a deficiency promotes high blood pressure, but this must be demonstrated individually. Studies have shown an influence of magnesium on blood pressure primarily in the presence of magnesium deficiency.
And here too, there is a risk of overdose with potentially more devastating consequences. An excess of magnesium can lead to paralysis symptoms, which can also affect the respiratory muscles, and heart rhythm disturbances up to cardiac arrest.
Therefore, the intake of dietary supplements should always be discussed with the treating physician, especially when medications are taken. These do not necessarily have to be prescribed for the same condition; interactions are also possible with others. Therefore, it is also important to mention not only prescribed medications when asked about medication intake but also to include over-the-counter preparations and "voluntarily" taken dietary supplements.
Dietary Supplements as Effervescent Tablets
Particular attention should be paid to dietary supplements that are administered as effervescent tablets. Due to a high sodium content, these can negatively affect blood pressure. This was discovered by researchers at the Saarland University Hospital. They examined both over-the-counter and prescription dietary effervescent tablets, finding that these contained an average of 283.9 mg of sodium. The leader was a vitamin C effervescent tablet, which contained 564.7 mg of sodium, corresponding to 28% of the recommended daily maximum dose of sodium. Mind you, in a single effervescent tablet. Therefore, people with hypertension should also include any effervescent tablets they may take in the calculation of their daily salt intake.
Overall, most people can obtain all the necessary substances through food. Overdoses of individual substances are virtually impossible with a balanced diet. This is in contrast to dietary supplements, where a reference value for the actual individual need is often missing, and the units of the active ingredient contained are as inconsistent as the intake recommendations.
Overdoses can easily occur. It is often said that the excess will simply be excreted. However, this mainly applies only to healthy (!) people. In individuals with pre-existing conditions, metabolic disorders can occur, among other things. Additionally, one places an additional burden on an already damaged kidney with the excretion of the excess substances, which can worsen an existing kidney disease. People with high blood pressure should be particularly cautious here.
Therefore, talk to your doctor about whether the supplementation of a certain substance is sensible and advisable for you. In the best case, you will only waste money; in the worst case, you may even harm your health.
By Sabine Croci.
This article is medically reviewed. Last updated (03/2024).
Information on the website and within the app cannot replace a consultation with a doctor, but can certainly complement it.
