The belief that magnets increase blood flow is repeated so often, it’s almost established dogma! But read on and see what the evidence says.
From our perspective, the therapeutic effect of quadrapolar and other multipolar magnets results from how they interact with the nervous system and in particular on unmyelinated C-fibres and not necessarily on increasing blood flow. See how Q Magnets work for more information.
We have always been dubious about claims of increased blood flow and have to work hard to not repeat it ourselves.
CAN MAGNETIC FIELDS INCREASE BLOOD FLOW?
Looking at the evidence, it appears static magnetic fields produce microcirculatory homeostasis. That is…
1) where there is trauma, it may cause vasoconstriction, leading to a reduced blood flow and inflammation.
2) in healthy individuals there appears to be no effect on blood flow.
External observations of the effects of Q Magnets on haematomas there is a definite effect which looks more like restricting blood flow.
In addition, a common application for Q Magnets is on the cheek directly over the extraction point after a tooth extraction. Just like in the case of Elizabeth, almost every case we have seen, there seems to be very little pain or swelling. This would support the idea of microcirculatory homeostasis.
The hypothesis “that acute application of SMF to an inflammatory injury may limit the formation of edema and therefore accelerate healing”, was confirmed in the studies by Morris et al., see below in animal studies 5 & 6.
RESEARCH STUDIES:
1. Martel et al. (2002) Comparison of static and placebo magnets on resting forearm blood flow in young, healthy men. J Orthop Sports Phys Ther. 2002 Oct;32(10):518-24. PMID: 12403203
This study had 20 healthy men wear 500 Gauss BIOflex static magnets and then a placebo for 30 minutes on 2 separate occasions. The data suggested that static magnets do not result in significant alterations in resting blood flow.
2. Mayrovitz et al. (2004) Effects of a static magnetic field of either polarity on skin microcirculation. Microvasc Res. 2005 Jan;69(1-2):24-7. PMID: 15797257
This study exposed the fingers of 12 healthy volunteers to the North and South pole of a 4,028 G (0.4 Tesla) molybdenum magnet and then a placebo for 15 minutes each. Measuring skin blood perfusion with a laser-doppler, they found a statistically significant reduction in skin blood perfusion with the active magnet, but no difference between the North and South pole.
Since this was in contrast to two previous studies by the same authors using ceramic magnets, it was postulated the sevenfold greater field intensity may have accounted for the significant result.
ANIMAL MODELS:
1. Xu et al. (1998) Subchronic effects of static magnetic fields on cutaneous microcirculation in rabbits. In Vivo. 1998 Jul-Aug;12(4):383-9. PMID: 9706489
2. Okano et al. (1999) Biphasic effects of static magnetic fields on cutaneous microcirculation in rabbits. Bioelectromagnetics. 1999;20(3):161-71. PMID: 10194558
3. Gimtrov et al. (2002) Effect of 0.25 T static magnetic field on microcirculation in rabbits. Bioelectromagnetics. 2002 Apr;23(3):224-9. PMID: 11891752
These three studies demonstrate a biphasic response from blood flow to static magnetic fields. That is, magnetic fields appear to enhance vasodilation if vessels are relatively constricted and enhance vasoconstriction in vessels that are relatively dilated.
The authors proposed that prolonged exposure to an inhomogeneous static magnetic field probably modifies the macro and microcirculatory homeostasis through effects on smooth muscle on the vascular wall and that vascular tone modulation plays an important role in the cardiovascular effects on both the micro and macrocirculatory level.
4. Steyn et al. (2000) Effect of a static magnetic field on blood flow to the metacarpus in horses. J Am Vet Med Assoc. 2000 Sep 15;217(6):874-7. PMID: 10997160
The results of this study suggested that in horses, the static magnetic field applied with magnetic wraps for 48 hours did not increase blood flow to the portion of the metacarpus that underwent exposure. However, the strength of the magnets used at 7mm from the surface were no greater than the earth’s residual field. Considering the magnetic wraps did not exactly fit the non-uniform surface of the limb covered by hair, there was little chance the field was going to penetrate to envelope underlying blood vessels. You would wonder why they even bothered?
5. Morris et al. (2008) Acute Exposure to a Moderate Strength Static Magnetic Field Reduces Edema Formation In Rats. Am J Physiol Heart Circ Physiol: 2008 Jan;294(1):H50-7. PMID: 17982018
This study claims to be the first to demonstrate that acute, localized static magnetic field exposure of moderate field strength (5-100mT), when applied immediately after an inflammatory injury, can result in significant reduction of edema formation. The methodology did a very good job at measuring the magnetic field dosage and treatment parameters and the results were significant.
There is also a take home message for users of magnetic therapy, as soon as you have an injury – apply your devices. It was observed that the application of the field at the time of injury is important for producing a significant physiological change.
6. Morris et al (2007). Chronic static magnetic field exposure alters microvessel enlargement resulting from surgical intervention. J Appl Physiol : 2007 Aug;103(2):629-36. PMID: 17478604
This research looked at the effects of a localised static magnetic field on edema after trauma in mice. The most significant reduction in arteriolar enlargement was manifested in the smallest vessels. As an example at day 7, sham treated vessels revealed venular enlargement of 91%, whereas magnet treated only 41%. This study contradicts the common assumption, that the healing of SMF’s is induced by increasing blood flow to the injured area.
While we are at it, let’s take a quick look at this myth…
CAN A MAGNETIC FIELD ATTRACT BLOOD THROUGH IRON IN HAEMOGLOBIN?
There are some very weird and wacky claims when it comes to magnetic therapy. One of these being a magnetic field attracts iron in blood.
The first experiment to determine the magnetic properties of haemoglobin was carried out in 1936, by famous Nobel Prize winning chemist Linus Pauling. A Gouy balance (pictured left) was used to weigh samples of venous and arterial blood in the presence of a strong electromagnet.
It can get complicated for those unfamiliar with the physics of magnetism, but see if you can follow…Haemoglobin contains four iron atoms, each of which can bind to an oxygen molecule. The iron in haemoglobin is in the form of either ferrous (Fe2+) or ferric (Fe3+). Arterial blood, the bright red blood having just passed through the lungs is said to be oxygenated (carrying O2). While venous blood, the purple blood having already transported its O2 is deoxygenated (not carrying O2).
Now not all forms of iron are ferromagnetic, what we normally consider as magnetic. Ferromagnetism requires the strong interaction of unpaired electrons, which exists for instance in steel and certain iron alloys. Iron in deoxygenated blood has unpaired electrons, but since they do not interact magnetically, it is paramagnetic. Where as iron in oxygenated blood has no unpaired electrons since they are being shared with the bonded O2 and is diamagnetic.
SO IN SUMMARY:
- Deoxygenated blood is paramagnetic, which means there will be a very tiny and almost negligible force attracting the blood.
- Oxygenated blood is diamagnetic, which means that there will be a very tiny and almost negligible force repelling the blood.
- In no form is iron in haemoglobin ferromagnetic, that required to produce sufficient attractive forces that one might detect.
REFERENCE:
Bren KL, et al (2015). Discovery of the magnetic behavior of hemoglobin: A beginning of bioinorganic chemistry. PNAS October 27, 2015 112 (43) 13123-13127. doi
In an excellent video, YouTuber Brainiac75 demonstrates the concept in an experiment where oxygenated blood is slightly repelled by an extremely powerful neodymium magnet.
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