Category: Health and Medicine

We probably all know at least one person who swears by their magnetic charm bracelet for preventing travel sickness, reducing arthritic pain or even helping them through situations that induce an attack of social anxiety disorder. These bracelets and other devices (some are in the form of headbands, others pendants, blankets, knee braces, shoe inserts, there’s even one you wear in your pants to improve your sex life) use magnets of a similar strength to those that make shopping lists stick to your refrigerator or let your kids spell out rude words without you realising…

…in other words, they’re not very strong and so probably have absolutely no physiological effect whatsoever. So, this $5billion industry founded in ancient Greek mythology is almost on a par with homeopathy for having no real scientific basis. Or is it?

Serious research, being carried out in a serious university laboratory, with serious financial backing recently hit the headlines with proclamations that a short application of a magnetic field to an inflamed joint could somehow improve blood flow and reduce swelling. Thomas Skalak, chairman of biomedical engineering at the University of Virginia and his colleagues lead the field in the area of microcirculation research, the study of blood flow through the body’s tiniest blood vessels. This status presumably helped them secure $875,000 of US taxpayers’ money from the National Institutes of Health’s National Center for Complementary and Alternative Medicine.

Initially, they set out to examine a claim made by the companies that sell “therapeutic” magnets: that these devices somehow increase blood flow. Skalak’s team used magnets of 70 milliTesla (mT) field strength, which is about ten times stronger than a common refrigerator magnet, but still very weak, the magnetic field of an MRI machine, for instance, is up to about 3000 milliTesla (3 T in other words). The researchers measured blood vessel diameter before and after placing the magnets up against lab rats.

They found that the magnets seemingly had a significant effect on blood vessels. Those that had been dilated became narrower and those that were previously constricted widened. Apparently, this implies that the magnetic field could induce vessel relaxation in tissues with constrained blood supply, ultimately increasing blood flow; how the magnet knows which way to stimulate the effect is not known. In a more recent study, the team treated the hind paws of anaesthetized rats with inflammatory agents to simulate tissue injury. Therapeutic magnets were then applied to the swollen paws immediately. The researchers say they say significant reduction in swelling (oedema), although there was no effect if there was any delay between injury and application.

According to Skalak, “The FDA regulates specific claims of medical efficacy, but in general static magnetic fields are viewed as safe.” So, could magnets be used to improve blood flow following muscle injury, say, as many of the headlines surrounding this press release claimed?

Well, what I’d first like to know, is did the researchers use a double-blind control? Did they, for instance, apply non-magnetic objects of equal size, shape and weight and at the same temperature to a second set of inflamed rat hind paws to examine whether those had any effect on blood vessel dilation? Did they have a set of inflamed rats that were not treated at all? How did those groups respond? The research paper on which the press release is based was published online in November 2007 in the American Journal of Physiology and Heart Circulatory Physiology.

Given that one of the major tenets of sports injury treatment is ice and compression could it be that the very act of pressing an object against the inflamed joint simply acted as a compressive heatsink, reducing local temperature of the inflamed region and at the same time temporarily reducing blood flow during the compression?

It’s just a thought, but couldn’t any metallic object of a reasonable size, 10-20 mm would be adequate for a rat paw, act as a cold compress, asks my good friend Stephan Logan. Logan supplies scientific educational equipment, including neodymium rare earth magnets, and points out that these have a field strength of several thousand milliTesla (1.3 T is typical for the standard neo magnet N42) and so has a keen interest in scientific claims made about much weaker magnets, such as those used in the experiments, knowing that a nasty pinch when flesh is trapped between two neo magnets is one of the well-known physiological effects but has nothing to do with mystical field effects

The Virginia press release, and consequently much of the media, claim that since muscle bruising and joint sprains are the most common injuries worldwide, Skalak’s discovery has “significant implications”. He rightly points out that, “If an injury doesn’t swell, it will heal faster – and the person will experience less pain and better mobility.” The extrapolation of the magnetic research to the notion that “magnets could be used in much the same way ice packs and compression are now used for everyday sprains, bumps, and bruises, but with more beneficial results, is not necessarily supported.

Magnets could be used, but where is the evidence that they reduce swelling any more than a conventional cold compress? Indeed, does injecting a rat’s foot with an inflammatory chemical simulate adequately a sprain or strain? The release says, “The ready availability and low cost of this treatment could produce huge gains in worker productivity and quality of life.” That’s a big extrapolation from a small laboratory study to the whole of sports injury medicine. Anyway, if commercialised are these therapeutic magnet ever likely to be as cheap and readily available as a bag of frozen peas? I doubt it.

Just before the Christmas break, right as my annual winter festival cold kicked in and I was up to my neck in end of year deadlines, I posted a link to a press release in my Geeky Bits science extra column. That page is a repository of the less worthy, but hopefully interesting stuff I come across. Occasionally, I see an intriguing headline, give it a click, give the text a quick read through, add the item to the Bits, and thinking nothing more of it, just as one might with a del.icio.us or StumbleUpon post.

However, one regular Sciencebase reader, Churchill Fellow Grace Filby, was somewhat taken aback by my highlighting a timely press release from the London School of Hygiene and Tropical Medicine (University of London) – and described it as “a load of misguided nonsense”. Unfortunately, there is no online feedback or comments form on that LSHTM press release through which we could open a public debate on its content.

The press release was entitled – “If you don’t want to fall ill this Christmas, then share a festive kiss but don’t shake hands” – not the snappiest of titles but almost certainly one attempting to catch the wave of festive spirit seeing as it was released on December 19. However, both the title and the subheading of the press release (“The fight against all types of infections, from colds and flu to stomach bugs and MRSA, begins at home, with good hand hygiene, says first review of hand hygiene in the community.”) perhaps places too much emphasis on hand hygiene as opposed to the problem of airborne pathogens, believes Filby.

First off, Filby says that the press release “deflects the public’s attention away from a major source of germs which is the air we breathe…handwashing is only a part of it.” She adds that, “It is the germs arriving in the air that need disinfecting or freshening before the germs land on surfaces that could be touched by hands and passed to other people.” Even the British government appears to be acknowledging this to some degree, according to The Times on Christmas Eve in a bulleted item on how air disinfection units can kill MRSA, and C difficile.

The press release states: “But a report just published warns that we may be far more at risk of passing on an infection by shaking someone’s hand than in sharing a kiss.” As far as we can see, the full text of the original 38-page report cited in the release the word kiss or kissing occurs only once. It’s almost as if the press office hoped to catch media attention with the mistletoe and seasonal kissing theme regardless of the science reported in the report itself. Moreover, there is nothing much about handshakes or shaking hands either.

There are several other dubious details about handwashing: “but we believe that this targeted approach to home hygiene…” Is “believe” valid in a heavyweight scientific document of this sort, asks Filby.

The press release concludes that, “Handwashing with soap is probably the single most important thing you can do to protect yourselves and your loved ones from infection this Christmas.” Probably – that’s good, but we also need to deal with airborne germs. Whatever would Florence Nightingale have said? There are plenty of other risk factors out there and ways to reduce the chances of succumbing to winter bugs, such as walks in the fresh air, healthy eating, and more contentiously vitamin C or zinc supplements, although the jury is still out on the benefits of those.

Regardless, the main problem is that the press release ignores the primary source of respiratory infection which occurs from carrier to the next victim before pathogens ever fall onto a surface. In the case of many winter bugs, they spread quickly through sneezes or coughs when people don’t cover their noses and mouths.

Of course, Filby and I could put on our cynical hats at this point and come up with some kind of plausible explanation as to why hand hygiene as opposed to air hygiene is considered important. “Perhaps it is worth noting that funding for research on air hygiene wasn’t forthcoming whereas for hand hygiene there are plenty of interested parties – soap manufacturers, handwash products and water companies,” says Filby.

Hand hygiene is obviously part of the story and in the pre-Xmas rush for headlines one could forgive the LSHTM for highlighting it, but a broader perspective on all-round hygiene education and the promotion of other aspects of hygiene, as opposed to simple hand-wringing in the washroom, would have made more sense.

Fellow freelance journalist James Butcher alerted me to the existence of a clutch of rather verbose guidelines for journalists and others pertaining to the reporting of medical research results.

The guidelines were published in November by the UK’s Academy of Medical Sciences, an organisation that apparently promotes advances in medical science and campaigns to ensure these are translated as quickly as possible into healthcare benefits for society. The report primarily highlights the role of observational research in identifying environmental and lifestyle causes of disease, such as obesity and diabetes, cancer, cardiovascular disease etc, but warns researchers against overstating the importance of their findings.

The guidelines themselves actually formed part of a much wider document entitled not very snappily: Identifying the environmental causes of disease: how should we decide what to believe and when to take action?. The report’s title alone should have warned readers by now that the guidelines themselves are likely to raise a few issues.

Of course, most medical and science journalists will already have their own internal list of guidelines to follow, probably in much clearer and simple English, and directed firmly in the direction of writing the best piece they can rather than aimed at satisfying some higher bureaucratic order. Depending on the writer’s background these internal guidelines will overlap in essence with the fourteen do’s and don’ts listed below and in other areas there will be little common ground.

Some might say that the list of guidelines is a little patronising to journalists and written in an ostentatious and overblown manner. Others might point out that they assume far too much prior knowledge. Do political, legal, financial, and arts correspondents get such lists of guidelines I wonder? Would those correspondents, as opposed to a science or medical writer understand the technicalities of item 1a “What is the sample?” Well, if you know how to answer that question, you probably don’t need the guidelines, and if you don’t know how to answer it then you should maybe stick to covering art gallery openings and ministerial indiscretions. Either that or head back to school for a quick stats course.

This is not the first time an organisation like this has attempted to lay down guidelines for journalists and others. The Royal Society made an attempt at it a few years ago and recently revised them. Ironically, they did not consult the Association of British Science Writers in producing their guidelines and so they went down like the proverbial plumbum inflatable. More to the point, rulez is for breakin’ and if you’re a (tabloid) hack intent on writing a health scare story, then you’re going to write it regardless of any list of guidelines from an organisation of which you have probably never even heard. And, if you’re not a scaremonger, then, as I said before, you will already have your own endogenous list of guidelines.

Perhaps what is needed is some kind of guidance for the public rather than the journalists that allows them to make more sense of the dozens and dozens of health stories on cancer, obesity, estrogen, bird flu, HIV, MMR vaccination. Such advice might help them to see the facts when those internal guidelines have been overridden in the name of great headlines.

It would be an interesting exercise to analyse each of the news articles and others that I cited in a recent post entitled Obesity News Epidemic, to see just how well each of those mesh with the ACMedSci guidelines. Anyone care to take on the research project?

Anyway, with ACMedSci permission I’ve cribbed the guidelines below for your delectation and to save you wading through the 150 pages of the less-than snappy document. They were originally aimed at journalists and others in the media, presumably to help prevent sensationalisation and healthscares. They could be equally useful/useless (del. as applic.) to bloggers and others too.

1. Pay detailed attention to the methodology of all studies being reported. Important questions to consider include: a. What was the sample? b. What were the measures? c. How strong were the effects in both relative and absolute terms? d. Has there been adequate attention to alternative explanations, and to good control of possible confounding variables? e. Has the finding been replicated? f. Is there supporting experimental or quasi-experimental evidence? g. Are the findings in keeping with what is known about disease mechanisms?
2. Whilst it may not be appropriate to offer extensive discussion of all these details when writing or speaking to the general public, key aspects can be communicated successfully using clear, jargon free, language.
3. The science or medical correspondent needs to have an appropriate grasp of the scientific issues in order to know how best to convey what was novel, interesting and important in the research.
4. Exercise appropriate judgment in identifying and drawing attention to those points of design that are particularly relevant to the study in question – especially when ignoring them might lead to misunderstanding.
5. Bear in mind the research track record of the researchers and of their employing institutions.
6. Consider whether there are any conflicts of interest that might lead to possible bias.
7. Seek to determine the theory or set of biological findings that constitute the basis for the research – noting how this fits in with, or forces changes in, what we already know or believe.
8. Whilst paying appropriate attention to competing views, be wary of creating spurious and misleading ‘balance’ by giving equal weight to solid research evidence and weakly supported idiosyncratic views.
9. Be very wary of drawing conclusions on the basis of any single study, whatever its quality.
10. When considering public policy implications, draw a careful distinction between relative risk (i.e. the increased probability of some outcome given the disease causing factor) and absolute risk (i.e. the probability of that disease outcome in those with the disease risk).
11. Use simple counts to describe risk whenever possible, rather than probabilities.
12. Be careful, insofar as the evidence allows, to clarify whether the causal effect applies to everyone or only to a small special sub-segment of the population.
13. Set the causal factor you are describing in the context of all known causal factors, whilst explaining that there may be others, as yet unknown or unsuspected.
14. In writing about research, seek to educate and engage readers with the science and to encourage them to think critically.

The Nobel Prize website was offline at the time of writing presumably unable to take the strain of hacks and bloggers every scrabbling to learn of the winners. Anyway, Mario R. Capecchi (US) and Oliver Smithies (US) and Martin J. Evans (UK) have won the 2007 Nobel Prize in medicine or physiology for their work on gene targeting in mice.

Their research is being used to help scientists understand at the cellular level why certain diseases, such as cystic fibrosis, occur and why otherwise healthy people can succumb to cardiovascular and neurodegenerative diseases, diabetes, and cancer.

The same threesome the Lasker prize in 2001, so in the absence of a Nobel website you can read more about the award-winning work here. Thanks to blogger Luboš Motl for bringing that link to my attention.

You can see a complete list of past winners of the Nobel Prize for Medicine here.