I’m a skeptic when it comes to “alternative medicine.” Often the claims of alternative medicine conflict with the basic laws of physics—and in the end, physics always wins. In particular, there are many dubious health claims about the biological effects of electric and magnetic fields. For instance, I don’t know of any research supporting the idea that magnets in your shoes or jewelry have health benefits, nor can I think of any plausible mechanism underlying such an effect. Are there companies that really promote such silliness? Go to Google and search for “magnetic therapy” and you’ll find that, indeed, there are.
Voodoo Science: The Road from Foolishness to Fraud,
by Robert Park.
“Natural” remedies [such as magnetic therapy] are presumed by their proponents to be somehow both safer and more powerful than science-based medicine. Fortunately, most natural medicine is in itself relatively harmless, aside from the financial damage done by paying eighty-nine dollars for a refrigerator magnet... It can, however, become dangerous if it leads people to forego needed medical treatment. Worse, alternative medicine reinforces a sort of upside-down view of how the world works, leaving people vulnerable to predatory quacks.
Another source of useful information is the magazine Skeptical Inquirer. In particular, see the article “Magnet Therapy, A Billion-dollar Boondoggle” by Bruce Flamm (July 2006), where he claims that there exists “a worldwide epidemic of useless magnet therapy.” Also, see Stephen Barrett’s article “Magnet Therapy: A Skeptical View” published by Quackwatch, Inc., a nonprofit corporation whose purpose is to combat health-related frauds, myths, fads, fallacies, and misconduct. Barrett’s bottom line is that “there is no scientific basis to conclude that small, static magnets can relieve pain or influence the course of any disease. In fact, many of today’s products produce no significant magnetic field at or beneath the skin’s surface.” How can you distinguish the legitimate from nonsense? I suspect the layman will have a hard time telling the difference between “magnetic therapy” (bogus) and “magnetic stimulation” (a well-understood technique to excite nerves in the brain). The only way I know to sort out the good from the bad is to educate yourself on the underlying physics as it applies to biology and medicine. One place to start is the 4th edition of Intermediate Physics for Medicine and Biology. Whether you consult our book or another source of information, beware of suspicious claims about the benefits of electric and magnetic fields. Bioelectricity and biomagnetism are vibrant and important fields of study (see Chapters 6–9 of our book), but there’s a lot of baloney out there too.
Bacteria in the northern hemisphere have been shown to seek the north pole. Because of the tilt of the earth’s field, they burrow deeper into the environment in which they live. Similar bacteria in the southern hemisphere burrow down by seeking the south pole.
Finegold also reviews this topic. The excerpt reproduced below serves both as an up-date to IPMB and as a sample of the style of an American Journal of Physics resource letter.
Certain bacteria move in response to the earth’s magnetic field (Ref. 35), swimming along the field lines, and have been excellently reviewed (Ref. 36). The “sensing” element is magnetite (an iron oxide) or greigite (an iron sulfide) (Ref. 37). The bacteria would swim toward the boundary between oxygenated and oxygen-poor regions. Until recently, there was the comforting idea that there are two groups of bacteria with opposite sensors, depending on which of the earth’s hemispheres they reside. Alas, both groups have now been found in the same place; it appears that their polarity is correlated with the local redox potential (Ref. 38 and 39). In addition, some bacteria use only the axial property of the field (i.e., they swim both with or against the field direction), whereas others use the vector property (i.e., they swim either with or against the field direction). Details of the behavior have been elucidated by applying magnetic fields to bacteria in a spectrophotometer cuvette, with genetic analysis (Ref. 39).
Magnetoreception is a field that often stirs debate. Russ and I outline one such debate in IPMB
Kirschvink (1992) proposed a model whereby a magnetosome in a field of 10−4–10−3 T could rotate to open a membrane channel. As an example of the debate that continues in this area, Adair (1991, 1992, 1993, 1994) argued that a magnetic interaction cannot overcome thermal noise in a 60-Hz field of 5 × 10−6 T. However, Polk (1994) argues that more biologically realistic parameters, including a large number of magnetosomes in a cell, could allow an interaction at 2 × 10−6 T.
For those of you who like this sort of thing, here is another example from Finegold’s resource letter. The debate is about, of all things, if cows align themselves in magnetic fields!
A surprising finding is that cattle and deer seem to align themselves in an approximate north-south (geomagnetic) direction. The evidence is from world-wide satellite photographs from Google Earth, supported by ground observations of more than 10,000 animals, and is hard to rebut. The satellite photographs do not have enough resolution to show the direction (north or south) in which the animals face.
As Usherwood asks, why on Earth should cattle and deer prefer this alignment? Possible interpretations are that the satellite photographs are made close to noon, so there may be physiological reasons (heating, cooling) for animals to align or to view predators better.
Partly to rule out sun compass effects, Burda et al. investigated ruminant alignment under high-voltage (and hence high-current, low-frequency) power lines and found that the geomagnetic north-south alignment was disturbed; the disturbance was correlated with the alternating fields. Such disturbance might instead be because the animals felt protected by (or preferring) the overhead lines or pylons or because of the audible (to humans at least) corona discharge. A good control for this would be to look at ruminants under power lines being repaired, carrying no current; this is difficult to do. The authors ingeniously compared the nonalignment under N-S and E-W trending power lines and found that the nonalignment followed the resultant total magnetic field. Their conclusions have been challenged (Ref. 75), and they have a lively rebuttal (Ref. 76), to which the challengers have replied (Ref. 77). Hence, the initially persuasive evidence, that cattle and deer detect magnetic fields, may need re-examination.
77. “Authors’ Response,” J. Hert, L. Jelinek, L. Pekarek, and A. Pavlicek, J. Comp. Physiol. [A] 197(12), 1135– 1136 (2011). (I)
Finegold also discusses magnet therapy, a topic I am extremely skeptical about, and that I have discussed before in this blog. He cites his own editorial with Flamm
“Magnet therapy,” L. Finegold and B. L. Flamm, Br. Med. J. 332, 4 (2006) (E)
which concludes
Extraordinary claims demand extraordinary evidence. If there is any healing effect of magnets, it is apparently small since published research, both theoretical and experimental, is weighted heavily against any therapeutic benefit. Patients should be advised that magnet therapy has no proved benefits. If they insist on using a magnetic device they could be advised to buy the cheapest—this will at least alleviate the pain in their wallet.
Well, I can’t vouch for the accuracy of this story or the effectiveness of the treatment, but at least the mechanism underlying the feeding of magnets to cows is plausible. Cattle swallow a lot of junk while eating, including some that is magnetic (for example, wires and nails...yikes!). The article says
That's where magnets come in. A magnet about the size and shape of a finger is placed inside a bolus gun, essentially a long tube that ensures the magnet goes down the cow's throat. Then it settles in the reticulum, collecting any stray pieces of metal. The magnets, which cost a few bucks a pop, can also be placed preventatively. To check if a cow already has a magnet, farmers use a compass.
Apparently the “bolus gun” is inserted through the mouth; I wasn’t so sure. Wikipedia has a page about cow magnets, titled “hardware disease.” Companies make money selling cow magnets (these are big magnets, about four inches long). But even though calves eat magnets, kids should not (note the plural: the problems arise when magnets interact).
Consider a spherical cow.
The 4th edition of Intermediate Physics for Medicine and Biology has an entire chapter about biomagnetism, but no mention of magnets in bovine stomachs. What is wrong with Russ and me? The only place we mention cattle at all is in Homework Problem 30 in Chapter 4, where we analyze the temperature distribution throughout a spherical cow. A small-scale analogy of magnets in steers’ stomachs are rows of magnetosomes in magnetotactic bacteria (see Fig. 8.25 in IPMB), but I doubt the bacteria use them to collect nails before they can puncture their membrane. Yet, could we misunderstand the biological purpose of magnetosomes?
Finally, I have some good news and bad news about the 5th edition of IPMB. The good news: we submitted the page proofs and the book should be published in the next few months. The bad news: no more mention of livestock in the revised edition.
3. HUMAN ENERGY FIELD: SCIENTIST, AGE 9, TESTS TOUCH THERAPY.
More than 40,000 health professionals have been trained in TT and it's offered by 70 hospitals in the US. And yet no one had ever checked to see if practitioners can, as they claim, tactilely sense such a field—until now. The Journal of the American Medical Association this week published the research of a fourth-grade girl. For a science fair project, the little girl persuaded 21 touch therapists to submit to a beautifully simple test. In 280 trials, the 21 scored 44%. According to the editor of JAMA, reviewers found the study to be “solid gold.” The James Randi Educational Foundation has been offering $1M to anyone who can pass a similar test—only one tried (WN 27 Mar 98) , but a 9-year old must have seemed less threatening. The girl, Emily Rosa of Loveland, CO, now 11, plans to take on magnet therapy next.
In Therapeutic Touch the protocol requires that a therapist moves his or her hands over the patient’s “energy field,” allegedly “tuning” a purported “aura” of biomagnetic energy that extends above the patient’s body. This is thought to somehow help heal the patient. Although this is less than one percent of the strength of Earth’s magnetic field, corresponds to billions of times less energy than the energy your eye receives when viewing even the brightest star in the night sky, and is billions of times smaller than that needed to affect biochemistry, the web sites of prominent clinics nevertheless market the claims.
Iron, Nature's Universal Element:
Why People Need Iron
and Animals Make Magnets,
by Eugenie Mielczarek.
Let us hope that hope that Bob Park and Eugenie Mielczarek continue to debunk the techniques of “alternative medicine” when they violate the laws of physics.
James Mattiello passed away on March 19, 2017, at the age of 59, in Utica, Michigan. Jim was a friend of mine from when we both worked at the National Institutes of Health, where he contributed to the development of a magnetic resonance imaging technique called Diffusion Tensor Imaging. He was the first graduate of the Oakland University Medical Physics PhD Program, which I now direct. When I was at NIH, I had never heard of Oakland University until Jim
mentioned it as his alma mater. Little did I know that I would have a
20-year career at OU, teaching and doing research.
Jim performed his PhD research with Prof. Fred Hetzel, and graduated with his PhD in 1987. His dissertation described an in vivo experimental investigation on the interaction between photodynamic therapy and hyperthermia. A copy of his dissertation sits in our Physics Department office, and I often show it to prospective students because it is the thickest dissertation on the shelf, over 480 pages. Hetzel, Norm Tepley,Michael Chopp, and Abe Liboff formed the dissertation committee (I didn’t arrive at OU until ten years later). Three journal articles resulting from this work are:
Well actually this was an amazing story too, because there’s so many people involved and activities that had to be done in order to bring this from bench to bedside. So the first thing is Denis and I started corresponding, and Jim Mattiello then, who was working with Denis and who was also working in our program [Biomedical Engineering and Instrumentation Program], was a little frustrated with some of the projects he was working on and decided that he wanted to start working with us. So I was excited about that because Jim had a technical background in MRI, he had been working in the area for a few–maybe a year and a half at that point, and he would provide a lot of experimental help which I really couldn’t provide because my knowledge at that point of the NMRI [Nuclear Magnetic Resonance Imaging] hardware and sequences and things was almost nonexistent. And so we started doing diffusion experiments with water. The first thing that we – in pork loin – the first thing that we started doing was – Denis got us some magnetic time down at the NMRI center and we started to – since we had this mathematical framework that related the signal that we measured to the diffusion tensor the first thing that you want to do is show that the diffusion tensor in water is an isotropic tensor, which means that if you look at the diffusion process along any direction that it appears the same and that has a characteristic – a special form when you write it as a tensor and it’s something that if you can’t do that you can’t look at other materials that are more complex.
I can remember the morning when Peter came in to NIH carrying a pork loin from a local grocery store. I asked him why he brought a chunk of raw meat to work, and he told me that he and Jim were going to use it that day in their first DTI experiment on muscle. Later in the oral history interview, Basser describes this experiment.
We wrote our first abstract describing it [Anisotropic Diffusion Tensor Imaging] at the ISMRM [International Society for Magnetic Resonance in Medicine Conference] I think which we presented in Berlin in 1992, we looked at a sample of pork loin and we showed that we first measured the diffusion tensor for a large region of that pork loin specimen, and then we actually physically rotated that – Jim Mattiello actually physically rotated the pork loin specimen in the magnet. We repeated the experiments, calculated the tensor and we were able to show that the directions that we calculated for the pork loin muscles followed the direction of the rotation that he had applied physically on that sample, so that we were measuring something intrinsic to the tissue. These principle directions that we were able to extract from the diffusion tensor were fundamental to the tissue architecture and were independent of the coordinate system that we made the measurement in, which was really, I think, a very important demonstration then.
Jim is a coauthor on two classic papers about DTI that are widely cited in the medical literature.
I know many scientists who have had long and successful careers, but few
of them can claim they contributed to a paper with over 4000
citations, a significant achievement (that averages to one citation every other day for over two decades). My most cited article, published about the same time, has only 500 citations, and I consider myself to be a successful scientist. Jim was also the lead author on two related papers.
Jim spent the later part of his career teaching physics at St. Clair County Community College in Port Huron, Michigan. I last saw him when he returned to Oakland University in 2002 to give a physics colloquium about DTI.
James Mattiello’s contributions to magnetic resonance imaging, and specifically to diffusion tensor imaging, have had a lasting impact on the field of medical physics. He will be missed.
One of the key ideas in my book is the clinical trial. Critical thinking lies at the heart of such trials. In the chapter about the health effects of magnets, I discuss the importance of clinical trials being double blind, randomized, and placebo controlled. Why are these features crucial? They keep you from fooling yourself. In particular, a study being double blind (meaning that “not only the patient, but also the physician, does not know who is in the placebo or treatment group”) is vital to prevent a doctor from inadvertently signalling to the patient which group they are in. One of Trecek-King’s favorite sayings is the quote by Richard Feynman that “you must not fool yourself—and you are the easiest person to fool.” That sums up why double blinding is so important.
Placebos are discussed several times in my book. My favorite example of a placebo comes from a clinical trial to evaluate a new drug. “If a medication is being tested, the placebo is a sugar pill with the same size, shape, color, and taste as that of the drug.” One reason I dwell on placebos is that sometimes they are difficult to design. When testing if permanent magnets can reduce pain, “this means that some patients received treatment with real magnets, and others were treated with objects that resembled magnets but produced a much weaker magnetic field or no magnetic field at all.” It is hard to make a “fake magnet” or a “mock transcranial direct current stimulator.” Yet, designing the placebo is exactly a situation where critical thinking skills are essential.
Critical thinking overlaps with the scientific method, with its emphasis on examining the evidence. In Are Electromagnetic Fields Making Me Ill?, my goal was to present the evidence and then let the reader decide what to believe. But that’s hard. For instance, the experimental laboratory studies about the biological effects of cell phone radiation are a mixed bag. Some studies see effects, and some don’t. You can argue either way depending on what studies you emphasize. I tried to rely on critical reviews to sort all this out (after all, where better to find critical thinking than in a critical review). But even the critical reviews are not unanimous. I probably should’ve examined each article individually and weighed its pros and cons, but that would have taken years (the literature on this topic is vast).
Trecek-King often discusses the importance of finding reliable sources of information. I agree, but this too is not always easy. For instance, what could be more authoritative than a report produced by the National Academy of Sciences? In Are Electromagnetic Fields Making Me Ill? I laud the Stevens report published in the 1990s about the health hazards (or should I say lack of hazards) from powerline magnetic fields. Yet, I’m skeptical about the National Academies report published in 2020 regarding microwave weapons being responsible for the Havana Syndrome. What do I conclude? Sometimes deferring to authority is useful, but not always. You can’t delegate critical thinking.
I have found that one useful tool for teaching and illustrating critical thinking are the Point/Counterpoint articles published in the journal Medical Physics. In Are Electromagnetic Fields Making Me Ill? I cite three such articles, on magnets reducing pain, on cell phone radiation causing cancer, and on the safety of airport backscatter radiation scanners. Each of these articles are in the form of a debate, and any lack of critical thinking will be exposed and debunked in the rebuttals. I wrote
When I taught medical physics to college students, we spent 20 minutes each Friday afternoon discussing a point/counterpoint article. One feature of these articles that makes them such an outstanding teaching tool is that there exists no right answer, only weak or strong arguments. Science does not proceed by proclaiming
universal truths, but by accumulating evidence that allows us to be more or less confident in our hypotheses. Conclusions beginning with “the evidence suggests…” are the best science has to offer.
One skill I emphasized in my teaching using IPMB, but which I don’t see mentioned by Trecek-King, is estimation. For instance, when discussing the potential health benefits or hazards of static magnetic fields, I calculated the energy of an electron in a magnetic field and compared it to its thermal energy. Such a simple order-of-magnitude estimate shows that thermal energy is vastly greater than magnetic energy, implying that static magnetic fields should have no effect on chemical reactions. Similarly, in my chapter about powerline magnetic fields, I estimated the electric field induced in the body by a 60 Hz magnetic field and compare it to endogenous electric fields due mainly to the heart’s electrical activity. Finally, in my discussion about cell phone radiation I compared the energy of a single radio-frequencyphoton to the energy of a chemical bond to prove that cell phones cannot cause cancer by directly disrupting DNA. This ability to estimate is crucial, and I believe it should be included under the umbrella of critical thinking skills.
In the video I watched, Trecek-King discussed the idea of consensus, and the different use of this term among scientists and nonscientists. When I analyzed transcranial direct current stimulation, I bemoaned the difficulty in finding a consensus among different research groups.
Finding the truth does not come from a eureka moment, but instead from a slow slog ultimately leading to a consensus among scientists.
I probably get closest to what scientists mean by consensus at the close of my chapter on the relationship (actually, the lack of relationship) between 5G cell phone radiation and COVID-19:
Scientific consensus arises when a diverse group of scientists openly scrutinizes claims and critically evaluates evidence.
Consensus is only valuable if it arises from individuals independently examining a body of evidence, debating an issue with others, and coming to their own conclusion. Peer review, so important in science, is one way scientists thrash out a consensus. I wrote
The reason for peer review is to force scientists to convince other scientists that their ideas and data are sound.
Perhaps the biggest issue in critical thinking is bias. One difficulty is that bias comes in many forms. One example is publication bias: “the tendency for only positive results to be published.” Another is recall bias that can infect a case-controlepidemiological study. But the really thorny type of bias arises from prior beliefs that scientists may be reluctant to abandon. In Are Electromagnetic Fields Making Me Ill? I tell the story of how Robert Tucker and Otto Schmidt performed an experiment to determine if people could detect 60 Hz magnetic fields. They spent five years examining their experiment for possible systematic errors, and eventually concluded that 60 Hz fields are not detectable. I wrote “One reason the bioelectric literature is filled with inconsistent results may be that not all experimenters are as diligent as Robert Tucker and Otto Schmitt.”
After listening to Trecek-King’s video, I began to wonder if the Tucker and Schmidt experiment might alternatively be viewed be a cautionary tale about bias. Was their long effort a heroic example of detecting and eliminating systematic error, or was it a bias marathon where they slaved away until they finally came to the conclusion they wanted? I side with the heroic interpretation, but it does make me wonder about the connection between bias and experimental design. The hallmark of a good experimental scientist is the ability to identify and remove systematic errors from an experiment. Yet one must be careful to root out all systematic errors, not just those that affect the results in one direction. The conclusion: science is difficult, and you must be constantly on guard about fooling yourself.
I reexamined Are Electromagnetic Fields Making Me Ill? to search for signs of my own biases, and came away a little worried. For instance, when talking about 5G cell phone radiation risks, I wrote
After listening to Trecek-King’s video, I am nervous that this was an inadvertent confession of bias. Do my past experiences predispose me to reject claims about electromagnetic fields being dangerous? Or am I merely stating a hard-earned opinion based on experience? Or are those the same thing? Is it bias to believe that Lucy will pull that football away from Charlie Brown at the last second?
All this discussion about critical thinking and bias is related to the claims of pseudoscience and alternative medicine. At the end of Are Electromagnetic Fields Making Me Ill? I ponder the difficulty of debunking false claims.
The study of biological effects of weak electric and magnetic fields attracts pseudoscientists
and cranks. Sometimes I have a difficult time separating the charlatans
from the mavericks. The mavericks—those holding nonconformist views based on
evidence (sometimes a cherry-picked selection of the evidence)—can be useful to
science, even if they are wrong. The charlatans—those snake-oil salesmen out to
make a quick buck—either fool themselves or fool others into believing silly ideas
or conspiracy theories. We should treat the mavericks with respect and let peer
review correct their errors. We should treat the charlatans with disdain. I wish for
the wisdom to tell them apart.
I’ll give Trecek-King’s the last word. Another of her mantras, which to me sums up why we care about critical thinking, is:
I am not saying that all of our problems can be solved with critical thinking. I’m saying that it is our best chance.
Critical Thinking in Education, featuring Melanie Trecek-King, Bertha Vazquez, and Daniel Reed
I am an emeritus professor of physics at Oakland University, and coauthor of the textbook Intermediate Physics for Medicine and Biology. The purpose of this blog is specifically to support and promote my textbook, and in general to illustrate applications of physics to medicine and biology.
