Science Questions

Is Blood Magnetic?

Sun, 12th Dec 2010

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Allan Blake asked:

I received a brochure advertising all things magnetic and claiming to cure all sorts for ailments like snoring if this object was put up the nostrils, and all sorts of aches and pains if worn on different parts of the body. Please, can you advise me if there was any evidence at all to prove that magnets have these type of powers and if so, how they work. Thank you.


We spoke to Stuart Richmond from the Department of Health Sciences at the University of York to answer this question for us...Magnetic lines of force of a bar magnet shown by iron filings on paper

Stuart -   The fact that blood contains iron is one of the reasons why some people believe magnetic bracelets might have an effect on the human body.  However, blood is not magnetic in a conventional sense.  In other words, it is not ferromagnetic which is what most people understand as magnetism.  If blood was ferromagnetic, then people would bleed to death or explode in MRI scanners which produce much stronger magnetic forces than those of magnetic bracelets.  So although deoxygenated haemoglobin is paramagnetic and very slightly attracted to a magnet, and also both oxygenated haemoglobin and plasma are diamagnetic or in other words, slightly repelled by a magnet, in theory, wearing a magnetic bracelet shouldn’t have a physiological effect.  Firstly, any influence in the polarity of ions within red blood cells would be lost because blood flows in a pressurised and turbulent way.  Secondly, blood is warm, so for any paramagnetic effect to occur it would need to overcome the forces of brownian motion.  All of which are extremely unlikely.  So, we turn to the second part of the question, do magnetic bracelets actually work?  In my research on magnet therapy in arthritis, I began not by asking how magnetic bracelets might work, but rather by testing whether they had any health effects on humans and by trying to control for the power of imagination.  The best available evidence showed that magnet therapy lacks any meaningful effect other than a placebo effect for arthritis and pain control.  Although there are some contradictory results, it would appear that for those trials which have shown a benefit that have also tended to suffer from problems of blinding which might explain those findings.

Diana -   And when he says that test subjects weren’t blind, that means that they were able to identify if their bracelet was magnetic or not, potentially altering the outcome of the trial.

Stuart -   So, despite this, the effects of positive suggestion should not be discounted if people choose to believe that wearing a magnet might help, then it may well do.  Although there are no known side effects, the danger is however that people may use magnetic bracelets instead of other clinically effective treatments.


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Water (Hydrogen) can be polarized by a very strong magnetic field.

According to Wikipedia, The various oxidation states of oxygen in Hemoglobin (Fe2+, Fe3+, and Fe4+) are diamagnetic, i.e. weakly repelled by magnets.

So, if a person was in an MRI, then it would interact with the blood.

Yet, even so, the interaction is extremely temporary.  So, when the MRI is turned off, the blood essentially will immediately revert to the resting state.

The magnets being used in the bracelets, however, are much less powerful.

They can have a strong Placebo effect.  It is pretty obvious who is in the "magnet treatment" group.  Poorly controlled experiments and the strong Placebo effect have confounded early studies.

Wikipedia has a good summary.

I thought I'd try to find info on the use of pressure wrist bands for motion sickness.  The data seems to be sparse, however, with post operative nausea, there seems to be a slight decrease in nausea with P6 pressure.

So, perhaps there would be effects such as activating pressure points which could be related to some benefits.  But, in this case, it would likely be very specific, rather than a general improvement.

Anyway, consider the magnet thing either a self-delusion, or a hoax. 
Or...  perhaps just consider the strength of the Placebo effect as a benefit in itself. CliffordK, Mon, 6th Dec 2010

I think there is a lot of selective bias in such therapies. but I am of the opinion that a 'therapy' should have benefits for the majority for one to say that it actually works. Anything less is poorly controlled data and or placebo..

the placebo effect is interesting though and is the surrounding argument to all 'alternative' therapies... or so it seems. JnA, Mon, 6th Dec 2010

I think it was Ben Goldacre who humourously pointed out that if haemoglobin were magnetic to an appreciable degree then people would end up getting stuck to the giant magnet they use at the scrapyard!

Is it true that all the oxidation states of iron are equivalently diamagnetic? I thought that part of the way in which MRI BOLD imaging works relied on the relative magnetic difference between oyxgenated and deoxygenated haemoglobin... maybe I've got that wrong...?

Chris chris, Mon, 6th Dec 2010

Oh...  something new every day!!!

I believe the typical MRI is polarizing the Hydrogen atoms in water.  The BOLD seems to take into account both water and hemoglobin.

I was wondering about the Wiki article above.  It seemed to be talking a lot about oxygenated hemoglobin.

Here is what I'm seeing:
Deoxyhemoglobin: paramagnetic; paramagnetic with respect to surrounding tissue
Oxyhemoglobin: diamagnetic; isomagnetic with respect to surrounding tissue.

So, the deoxygenated blood is weakly attracted to a magnet.

However, in the definition of paramagnetism:
Unlike ferromagnets, paramagnets do not retain any magnetization in the absence of an externally applied magnetic field.

Earlier I was trying to understand how a permanent magnet works.  As far as I can tell, it requires two or more atoms or molecules in a close, fixed relation.  The magnetic field induces some sort of resonance in the electron cloud maintaining the orientation or the spin, and thus the magnetic field. 

With hemoglobin, the iron ions are isolated, and thus would be incapable of contributing to such a resonance system.

Keep in mind, an MRI is way more powerful than the bracelets, although may provide some examples for discussing theory. CliffordK, Mon, 6th Dec 2010

If a magnet doesn't stick to you, it won't do you any good. If it does stick, run screaming! SteveFish, Tue, 7th Dec 2010

Since water is mildly diamagnetic, it is possible to "levitate" frogs and mice over VERY STRONG magnets.

Levitating Frog (video)

Levitating Mouse: (description and photos)

Wait long enough, and someone will big a large enough magnet to do it with people  CliffordK, Sun, 12th Dec 2010

I read a paper, about 40 years ago, about the development of a submarine motor/artificial heart. It was a transformer with a tube through it. Presumably the magnetic fields moved the salt-water/blood. David, Sun, 20th Feb 2011

I have placed such magnets on animals in the past. Dogs, cats, cows, calves and horses ALL with a positive result. I have also supplied many hundreds to humans with good but admittedly less than a 100% success rate.Some of the results achieved were quite surprising. In the case of one of our dogs, a Pug, a magnet was placed around her neck following a spinal injury which left her unable to use her back legs. Our Vet offered to put her down as there was no way that she was going to walk again. After a couple of months she was back on her feet walking and a few weeks after that her tail resumed its curl. The Vet found it hard to believe and unable to be explained. A dressage pony also had its navicular arrested. And there are many more results we have seen and heard of with animals. It seems unlikely in the extreme, that these results were due to a placebo effect.I am unable therefore to agree with the scientific explanation offered here. I am however searching for answers as to the effects of magnetic fields upon this and many other functions. If there is anyone who is able to assist me in my search I would appreciate any assistance you feel able to give me. Thank you. Roger Martin, Tue, 11th Nov 2014

I don't know much about this, but wish to point out that the exact circumstances of the application may matter.  That would involve what part of the body to which applied,  the field strength, quite possibly the field direction (this may matter if the effect is upon neurons rather than blood cells, because neurons have a strongly directional structure).  Such details need to be carefully noted when evaluating experimental results. Atomic-S, Thu, 13th Nov 2014

There are actually two distinct questions here.

The magnetic susceptibility of blood is indeed small and almost certainly irrelevant to any curative effect of an external magnetic field. But there is a significant professional veterinary market (particularly equine - and the owners of working horses are pretty savvy) in the magnetic stimulation of healing, usually with pulsed magnetic fields. As has been pointed out above, it's very easy to control for a placebo effect in nonhuman medicine. AFAIK the jury is out on this one. Pulsed magnetic stimulation has an effect in all species with a nervous system, but whether or why this promotes healing is not obvious.      alancalverd, Thu, 13th Nov 2014

That depends; it can often be more difficult because of the caregiver placebo effect. dlorde, Thu, 13th Nov 2014

Thank you to the authors of replies 10 11 12. The explanation I have for the magnetic bracelet helping with pain relief etc. is that the strong magnetic field applied to the (diamagnetic) blood causes the blood cells which naturally tend to bond together in a coin roll formation, to separate from one another whereby they are able to absorb more oxygen which is then circulated throughout the body - in a similar way to persons suffering severe pain are immersed in an oxygen rich environment inside a hyperbaric chamber (HBO therapy) The enhanced oxygen also enhances the healing of injuries and I can personally attest to this enhanced healing with my own magnetic bracelet. From my years of research there does not seem to be an authoritative answer to this question by the experts-some say yes others no, despite masses of anecdotal evidence that it does work in many many instances. Further to this, by exposing their (diamagnetic) drinking water to a strong magnetic field it has been found that cows produce more milk, cell count is reduced and their general health is improved. On one farm, it was found that foot rot had become a thing of the past and where it had been normal practice to give anti-biotics to all new born calves to prevent pneumonia as a matter of course. In year one after fitting magnets only 2 calves had been so prescribed and this as a precautionary measure. No manner of placebo effect I suggest, can be responsible for these and many other results I have had in agriculture, horticulture and even with heating appliances. As one scientist I came across in my research pointed out "Magnetism is Natures most Mysterious Force." Again if anyone can help me further I would be most grateful of their help. Thank you. Roger Martin, Sun, 16th Nov 2014

Any "scientific" study needs a randomized control procedure, and sufficient data to tease out some results.

So, rather than putting a magnetic collar on one dog with a spinal injury, find 10 dogs with a similar injury.  Half get a magnetic collar, half get a non-magnetic collar.

Likewise with the calves.  Give the treatment to some, and no treatment to others.  You can use some historical evidence, but if your treatment protocol has changed, or perhaps other caregiving protocols. 

And, of course, you need an objective outcome, rather than a subjective interpretation. CliffordK, Sun, 16th Nov 2014

Roger: If you could find specific citations describing what you have reported, it would be helpful.
Atomic-S, Thu, 27th Nov 2014

I have several. If interested I can forward these to your e-mail address. Look forward to hearing from you. Before we go any further however, I wish to point out that I am NOT scientifically qualified but am extremely interested to discover more in relation to this and other related phenomena. Roger Martin, Sun, 30th Nov 2014

Can you not post up links or relevant excerpts here, so we can all gain?

If you post this information (or links to it) here, those of us that are scientifically qualified can make assessments of what may be going on and tell you more about these phenomena, about which you are so interested. dlorde, Sun, 30th Nov 2014

I have to disagree with all this. My blood is extracted regularly. It is very dark in colour. If the tube is suspended using two cotton threads it swings to face north south. If approached with a piece of thin sheet steel, iit rotates as if attracted magnetically. Simon Ewart-Grist, Wed, 30th Nov 2016

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