The idea that magnets increase blood flow has been repeated so often it reinforces the mantra, if you repeat something often enough people will start to believe it => established dogma!
From our perspective, the evidence for the therapeutic effect of quadrapolar and other multipolar magnets stems from their unique inhomogeneous magnetic field’s effect on the nervous system and in particular on unmyelinated C-fibres and not 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 at not repeating it ourselves. So what is the evidence?
That is, where there is trauma, it may actually has a vasoconstrictive effect, leading to a reduction in blood flow and inflammation.
In healthy individuals there appears to be no effect on blood flow from static magnetic fields.
At a macro level, when you look at 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.
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.
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 vasoconstricted and enhance vasoconstriction in vessels that are relatively vasodilated.
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 associated with application of magnetic wraps for 48 hours did not increase blood flow to the portion of the metacarpus underneath the wrap. 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 surface of the limb that was 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. While the study doesn’t necessarily relate specifically to magnetic field gradients as they used a bipolar magnet, it does 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 affecting 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 blows away the common assumption that the healing of SMF’s in induced by increasing the blood flow to the injured area.
While we are at it, let’s take a quick look at this myth…
DOES A MAGNETIC FIELD ATTRACT BLOOD THROUGH THE IRON IN HAEMOGLOBIN?
There are some very weird and whacky claims when it comes to magnetic therapy. One of these is that a magnetic field attracts the iron in the blood.
Well, in fact oxygenated blood is diamagnetic which means that there will be a very tiny and almost negligible force repelling the blood. While deoxygenated blood is paramagnetic which means there will be a very tiny and almost negligible force attracting the blood.
In no form is the iron in haemoglobin ferromagnetic which is what would be required to have sufficient attractive forces to have an observable effect.
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