By Marc Braman, MD, MPH
MB (Marc Braman, MD, MPH):
A recent major news headline claims “magnesium cream could combat high blood pressure without the need to take pills.” Further bullet points include “good news for people who do not like taking pills or have difficulty ingesting them”, as well as “magnesium cream could be used as an alternative or in addition to medication to combat high blood pressure a study has found.” The story goes on to claim only 86% of the population currently meet recommended magnesium levels in their diet (which by the way is the vast majority?) according to the researchers from the University of Hertfordshire. They say that supplementation is proven to improve immune function and our heart health as well as lower risks for metabolic syndrome, the medical term for a combination diabetes, high blood pressure and obesity.
So this gets us thinking that all I need to do is put on some magnesium cream and I can treat my high blood pressure and all will be well. Well it turns out what they call a significant rise in blood magnesium from using this cream is only “statistically” significant — meaning that mathematically it meets certain criteria. It does not mean it makes sense in real-world life. The story talks about how most people don’t meet magnesium intake recommendations and that low magnesium is associated with multiple medical problems, including high blood pressure. Now these factors are true but some of the conclusions and the direction they take with this does not hold water.
So if we turn back to the original research article it turns out that we can learn a lot. The actual original article from which this new story is based — which the new story does not cite or give you any links to — was not actually about using magnesium as treatment for high blood pressure. It was about “can you get magnesium into the body through the skin?”. And there are some pretty interesting details in this study.
It’s just a pilot study. They say it’s the first study ever to see if you can get magnesium into the body through the skin in a measurable way — measuring the blood and the urine. It turns out they had use a LOT of cream. You would be so gooey you wouldn’t be able to stand yourself with the amount of cream that they had to use. Interestingly enough, whenever you use a cream to try to get medication or something of nutritional value into the body, you end up absorbing a lot more of the cream base or ingredients into your bloodstream than you do of the active ingredients you’re trying to get in.
They also couldn’t get the results to be significant until they excluded athletes. This is fascinating! Obviously we should be exercising. Exercise is far and away proven to have HUGE health benefits and is one of the big problems in our society — the lack of it. So what are we going to conclude? If you are going to use the cream you need to stop exercising? Why would it only work in non-exercisers? This is backwards to what we know for sure we should be doing.
Scientific studies typically start with the background rationale for why they are doing the study. In this case they state that “magnesium supplementation has been shown to significantly improve blood pressure,” and cite three references. So lets look at the references that prove this. Well it turns out the first reference of the three that are cited supposedly proving supplementation has been shown to significantly improve blood pressure actually says that “the conflicting results of studies evaluating the effects of magnesium supplements on blood pressure and other cardiovascular outcomes indicate that the action of magnesium in the vascular system is present but not yet established. Therefore, this mineral supplementation is not indicated as part of antihypertensive treatment, and further studies are needed to better clarify the role of magnesium in the prevention and treatment of cardiovascular diseases.” So the study being cited in support, actually says the opposite.
Reference number two, supposedly supporting this, is actually by the same author as this study, and it does seem to support the premise. But even in this case the same study author starts the study with saying, “to date there has been inconclusive evidence regarding the effect of magnesium supplements on blood pressure.” So they have to do this big complicated study and all sorts of special statistical methods to finally put things together in a way that shows a small effect on blood pressure with magnesium supplements.
Study number three supposedly supporting supplemental magnesium to lower blood pressure is specifically, blatantly, at-face-value about dietary magnesium, as in from food, not magnesium supplements at all. Okay…enough…we don’t need to look at this study any further. The foundation of this house of cards has completely collapsed…we don’t need to waste any further time.
It is very important to realize that high blood pressure is actually a symptom. Yes, in and of itself it is not good for the body. It is bad for organs, our cardiovascular system, and so forth. But it is a symptom of a problematic lifestyle, such as poor nutrition. And yes the research does support that a richer magnesium diet is associated with lower blood pressure and many other diseases, coming back to, “Eat your veggies.”
This became very clear to me at one point when I attended an NIH consensus development conference on exercise and cardiovascular health. They presented research in people with high blood pressure and randomly divided them into two groups. One group got medication. One group got put on an exercise program. Well surprisingly enough it was the medication group that lowered their blood pressure numbers more. However, who had fewer heart attacks and fewer deaths? The exercisers. Exercise is one of the fundamental causative factors or forces producing either health or disease and blood pressure is just a symptom. What really matters, is, well, what really matters.
There is another important detail noted at the end of this study this news article is about. It turns out the second author on the study being cited in this fake news headline, “may receive royalties on a magnesium cream for which she has signed an agreement.” They even tell us that the name of the cream is “Natural Calm Cream.” Now I’m grateful to know about conflicts of interest. This is really important. And I’m all in favor of having the best experts possible involved in creating the best products for consumers. But…: A) this is a royalty arrangement. That means that the more that gets sold, the more this researcher makes. Whenever you incentivize someone based on the quantity sold, you create very problematic dynamics, to say the least. And…B): look at the name of the cream: “Natural Calm Cream”. That has nothing whatsoever to do with high blood pressure, diabetes, cardiovascular disease, or anything else that any of this research is relative to. This product is being marketed under a false pretense, not supported by the science involved in these studies. Again, a very problematic dynamic for any credible researcher to be involved in.
So, don’t waste your time. Don’t waste your money. Eat your veggies.
Forget about the magnesium cream for high blood pressure, and get on with real healthy living and truly enjoying living well.
The relationship between dietary magnesium intake, stroke and its major risk factors, blood pressure and cholesterol, in the EPIC-Norfolk cohort. Bain LK, Myint PK, Jennings A, Lentjes MA, Luben RN, Khaw KT, Wareham NJ, Welch AA. Int J Cardiol. 2015 Oct 1;196:108-14. doi: 10.1016/j.ijcard.2015.05.166. Epub 2015 May 31.
Magnesium and vascular changes in hypertension. Cunha AR, Umbelino B, Correia ML, Neves MF. Int J Hypertens. 2012;2012:754250. doi: 10.1155/2012/754250. Epub 2012 Feb 29.
Effect of magnesium supplementation on blood pressure: a meta-analysis. Kass L, Weekes J, Carpenter L. Eur J Clin Nutr. 2012 Apr;66(4):411-8. doi: 10.1038/ejcn.2012.4. Epub 2012 Feb 8. Review.
The relationship between dietary magnesium intake, stroke and its major risk factors, blood pressure and cholesterol, in the EPIC-Norfolk cohort. Bain LK, Myint PK, Jennings A, Lentjes MA, Luben RN, Khaw KT, Wareham NJ, Welch AA. Int J Cardiol. 2015 Oct 1;196:108-14. doi: 10.1016/j.ijcard.2015.05.166. Epub 2015 May 31.
Effect of transdermal magnesium cream on serum and urinary magnesium levels in humans: A pilot study. Kass L, Rosanoff A, Tanner A, Sullivan K, McAuley W, Plesset M. PLoS One. 2017 Apr 12;12(4):e0174817. doi: 10.1371/journal.pone.0174817. eCollection 2017.
