Archive for category Health & medicine
So, California’s planning a referendum on the labelling of genetically modified food. The Guardian has covered this not in it’s regular news pages, but in its Comment is Free section, under the title “How California’s GM food referendum may change what America eats“.
The article is mostly an opinion piece – fair enough – but there’s one statistic buried in there that leapt out at me.
While researchers have not yet found a “smoking gun”, which would prove that GM foods as a class are dangerous, there are troubling signs that they may be a factor in the recent epidemic of food allergies. Soon after GM soy was introduced to the UK, for example, soy allergies escalated by 50%.
The link there doesn’t go to a scientific paper, but to a piece on “News. Controversy. Opinion.” site Opposing Views, and their figures seem to come, ultimately, from American Academy of Environmental Medicine, a group that has some decidedly quackish views on topics like water fluoridation, vaccines and “Multiple Chemical Sensitivity” (a scientifically unfounded belief that everything in modern society contains toxins). It’s not impossible to support some outlandish ideas while being right about things, of course, but it does ring some alarm bells.
Neither article links to any of the studies it referenced, but with a bit of digging, I found this piece at Academics Review which seems to be dealing with the same statistic. Go there if you want the full takedown, but in a nutshell, it refers to marketing information from a group called “York Nutritional Laboratories” (which sell food allergy testing kits) the rise was in people with a particular antibody, not those who reported allergies and the study didn’t find any connection (the rise simply happened at a similar time to the introduction of GM, although it actually took place before GM soy became mainstream).*
I decided to have a look on Google Scholar for papers looking in the allergenicity of GM soy. There are plenty of studies and review papers looking into this – one, two, three, four, five – and all the ones I’ve found so far suggest that genetic soybeans and GM soybeans pose exactly the same risk of allergy (though as far as I can tell, these are all animal trials. There isn’t much data on human soy allergies out there).
In this case, the claim that GM soy may be responsible for a rise in allergies seems to be simply wrong.
* For the other major claim in Opposing View’s piece, about baby rats dying from eating GM soy, see this peer review of the paper, originally from Nature Biotechnology , which expresses grave concerns about the unusually high numbers of deaths in the control group – it looks like bad care killed the rats, not the soy)
For various largely uninteresting reasons, I’ve not blogged lately. But then I came across this article on The Guardian website today, a for-and-against piece about mitochondria donation with an “against” argument from Peter Saunders that veers from irrelevant to flat out wrong. Let’s get started!
To begin with, this is not about finding a cure. It is about preventing people with mitrochondrial disease being born. These new technologies, even if they work, will do nothing for the thousands of people already suffering from these diseases, or for those who will be born with it in the future.
Now, here’s the first dodgy argument, one that I’m almost tempted to call a dog-whistle. Mitochondrial donations are not about “preventing people with mitrochondrial disease being born“, they’re about “preventing people being born with mitrochondrial disease”. Just look at how moving that phrase “being born” a few words to the right changed a factual statement about the procedure into a non-sequitur about abortion.
It’s of course true that unfortunately, this procedure will do nothing to help people that already have mitochondrial diseases – removing a mutation from the body is perhaps the most impossible thing in all of medicine – but that’s no argument against the procedure.
Also, Saunders claims that there is no need for the procedure when egg donation is already possible. Bear this in mind; it’ll come up again later.
Will it work? This technology uses similar “nuclear transfer” techniques to those used in “therapeutic cloning” for embryonic stem cells – which has thus far failed to deliver, and animal-human cytoplasmic hybrids (“cybrids”). […] Yet cybrids are now a farcical footnote in history. They have not worked. Ironically, it was in that same act of parliament that provision for this new research was also made.
First of all, cybrids were legalised in 2008. 3-4 years is not that long a time in medical research, especially for research into slow-developing, long-term conditions like Alzheimers and Parkinsons. But I decided to have a look on Google Scholar, to see if cybrids were just a “farcical footnote”. Since 2008, there have been at least 362 papers about cytoplasmic hybrids, including 114 in the last year and a half or so. Some of these are papers exploring the ethics of the procedure, but an awful lot are detailing actual breakthroughs made using these cytoplasmic hybrids.
Embryonic stem cell research, being far more mature, is even more successful, with stem cells relieving paralysis in rats and the first clinical trials in humans showing promising results. Hardly a field that has “thus far failed to deliver”.
But even if he was telling the truth, and both fields had proved to be dead ends, this would still be irrelevant to mitochondrial donation. All it says is that mitochondrial donation uses one technique which is also used in stem cell research. As far as arguments go, this is up there with “vegetarians are evil because Hitler was a vegetarian”.
Is it safe? No. Each technique involves experimental reproductive cloning techniques and germline genetic engineering (that is, it affects the genes passed on to children) – both of which are highly controversial and potentially dangerous. Cloning by nuclear transfer has so far proved ineffective in humans and unsafe in other mammals with a large number of cloned individuals spontaneously aborting, and others suffering from physical abnormalities or limited lifespans.
Well, it’s good thing there’s no cloning involved with this technique, thus making that last sentence completely pointless scaremongering.
Also, as the Guardian noted last week, any changes, or unpredicted genetic problems (mutations) will be passed to future generations.
This is true, but the thing is: if a woman with a mitochondrial condition doesn’t use this technique and conceives a child naturally, there is a 100% guarantee that the mitochondrial defect will be passed to the future generation(s). The whole point of this method is to reduce the number of dangerous mutations being passed on.
Is it ethical? No. A large number of eggs will be needed, involving risky and invasive “harvesting” for women donors. How many debt-laden students or infertile women will be exploited by the offer of money, or free IVF treatment, in return for their eggs? How many embryos will be destroyed?
Ok, so, remember how earlier egg donation was a totally ethical alternative to mitochondrial donation? Well, with a deft sleight of hand Saunders is now claiming that egg donation is unethical!
There are concerns about paying people to donate body parts/fluids – it’s one of the most hotly discussed areas of bioethics – but in the UK, donors are not paid to donate eggs. They can have their travel and accommodation expenses paid (up to £750), but that’s it. There’s simply no room for the kind of exploitation Saunders worries about.
As far as I can tell, there is no difference to the egg donor between standard donation and mitochondria donation. The technique doesn’t necessarily require any extra eggs – though I suppose that depends on its success rate, which, since the technique is still experimental, no-one yet knows – and it doesn’t require any more embryo destruction that IVF or standard egg donation.
Then there are the issues of identity confusion for the children, who in effect will have three biological parents. Some mitochondrial diseases are much less serious than others. Once we have judged some affected babies not worthy of being conceived, where do we draw the line?
The mitochondria are, as the standard explanation goes, the little power stations that fuel each cell, and mitochondrial DNA has no effect on the wider body outside these power stations. A baby conceived by mitochondria donation is closer to having two parents than than a baby conceived by standard egg donation (since in mitochondria donation, all the DNA that affects what the baby actually looks like comes from the mother, not the donor), and if “identity confusion” is a concern, it’s odd that he’d endorse adoption either. And this technique does not mean any baby is “not worthy of being conceived” (unless he’s referring to the parents’ choice not to conceive naturally in the first place, in which case his argument is grosser and more unethical than I thought) – conception will still happen, it’s just that egg will be slightly modified first.
This debate is not being handled responsibly. The research scientists involved have financial and research-based vested interests, and getting the regulatory changes and research grants to continue and extend their work is dependent on them being able to sell their case to funders, the public and decision-makers.
I don’t think “I’m a research scientist and I want to continue my research” counts as a vested interest. It’s not like researchers are pretending their research isn’t dependent on this technique being allowed. I genuinely wonder how Saunders would prefer this debate be handled – he certainly never explains. Speaking of not handling debates responsibly, though neither Saunders nor The Guardian point this out, Saunders is the CEO of the Christian Medical Fellowship, a group that speaks out against a variety of medical techniques on religious grounds. As Mark Henderson said on Twitter, “Saunders makes many bad arguments vs mitochondrial transplants, omitting real reason he opposes: religion […] Nothing wrong with opposing embryo research for religious reasons, but those who do should admit it, and that no evidence would convince them”
Let’s concentrate on finding treatments and providing better support for affected individuals, rather than spending limited health resources on unethical, risky and highly uncertain hi-tech solutions that will most likely never deliver.
We already know that, no matter how difficult mitochondrial donation is, finding a cure for mitochondrial disorders is far far harder still – and perhaps impossible with our current knowledge of genetics. A human body contains billions of cells, each one containing at least one and often tens or hundreds of mitochondria. Replacing or fixing all of them would be far more difficult than replacing the mitochondria in a single cell; if you want an efficient way of spending limited health resources (really, limited research resources – the funding for this research would not be directly linked to the NHS), donation research is surely a better route to take.
(I intended to, for balance reasons, point out any inaccuracies in the response from the Nuffield bioethicist arguing for the procedure, but it already seems pretty sensible and fair. Quelle surprise…)
Edit: Also thanks to Mark Henderson for pointing out that the research is being carried out at Newcastle University and entirely publicly funded by the Wellcome Trust and the Medical Research Council – there are no vested business interests involved either.
Hey! I know it’s been a while since I blogged. Hopefully you haven’t missed me too much. Anyway.
Prunes are not a laxative, EU rules, says today’s Telegraph, endowing the EU with frankly godlike powers. Did someone in Brussels snap their fingers and magically prunes suddenly ceased to be laxatives?
Let’s help the Telegraph and suggest a more accurate headline. Perhaps…
Prunes are not a laxative, science suggested two years ago
The laxative effect of prunes is one of those things that “everyone knows”. Certainly MEP and frequent talking head Roger Helmer agrees, claiming:
“The euro is burning, the EU is falling apart and yet here they are: highly-paid, highly-pensioned officials worrying about the obvious qualities of water and trying to deny us the right to say what is patently true.”
Ignoring the fact that this study was carried out in mid-2009, before the Euro crisis kicked off, Roger Helmer has an interesting definition of “patently true”.
The study looked at the scientific evidence for the effectiveness specifically of dried prunes. There were two studies of the effectiveness of dried prunes in humans at the time:
“Daily Consumption of Dried Plum by Postmenopausal Women Does Not Cause Undesirable Changes in Bowel Function” by Edmund Lucas et al and “Consumption of prunes as a source of dietary fiber in men with mild hypercholesterolemia” by Lesley Tinker et al. Lucas found that there was no significant difference between apples and prunes in stool bulk, consistency, frequency or pain, and Tinker found a difference in stool weight between prunes and grape juice, but no effect on consistency or frequency.
A third study they looked at, “Prune juice has a mild laxative effect in adults with certain gastrointestinal symptoms” showed that as you can probably guess from the title, prune juice did appear to have laxative effects – hence why they only talk about dried plums in the report.
Now, it’s possible that dried prunes are laxative – a much more recent study (albeit one funded by the “California Dried Plum Board”) from 2011 found that prunes appear to work better than the laxative psyllium at relieving constipation – but at the time this report was written, it simply would not have been accurate to say that, based on the body of available evidence, prunes were any better at keeping you “regular” than any other sort of fruit.
(The Telegraph also claims that the EU banned claiming that drinking water could prevent dehydration. Read the actual article, and the very last paragraph reveals that they’re talking about clincal dehydration, which is normally caused by disease rather than by not drinking enough fluids and that “This claim is trying to imply that there is something special about bottled water which is not a reasonable claim”)
Edit: Just found this excellent post by Martin Robbins about the dehydration claim.
(Hat tip to @rbhinkley for pointing out the original article)
Imagine a world where CO2 was not a deadly poison in need of urgent regulation by the European Union and the Environmental Protection Agency but a hugely beneficial trace gas which helped plants to thrive… If you’ve read [Delingpole’s tastefully plugged book] Watermelons – or indeed hung around this column for any length of time – you’ll know that that world already exists.
So begins James Delingpole’s latest blog post. Let’s start with the slightly less obvious problem here: governments do not control carbon dioxide because it is a poison, they control it because it has damaging effects on the environment. Whether or not it’s poisonous has no bearing on climate change.
Secondly, carbon dioxide is poisonous. It’s not poisonous at the levels you’ll find in the air around you, assuming you’re reading this from a reasonably well-ventilated room, but at a concentration of around 3% you’ll start to feel drowsy, and as the concentration increases you’ll quickly suffer sensory impairment and eventually black out and can even die. Your body does need a tiny bit of carbon dioxide in the blood, otherwise you suffer what’s known as hypocapnia, but that’s not caused by environmental CO2, that’s caused by hyperventilating (it’s a big problem with divers, which is why you shouldn’t take short, hard breaths before diving).
So why does Delingpole want to claim otherwise? Well, he’s discovered something called the Buteyko Method – supposedly a way of breathing which increases the amount of carbon dioxide in your body, supposedly curing collapsed lungs, ME, MS, depression, arthritis, asthma, emphysema and even Crohn’s disease.
The only evidence Delingpole gives that it works? Well, it works for him. Fair enough – controlled breathing techniques are widelyknown to reduce stress, and if that helps him personally then fine. But remember he’s a journalist – surely before he sells it to his readers (and it does read like a sales pitch – he lists the locations of upcoming workshops… £375 workshops) he should find some concrete evidence that it works – and, crucially, that it has anything to do with CO2?
There’s not much research into whether it works, unfortunately, and a lot of it doesn’t seem to be fantastic quality. Still, here’s a quote from a review paper looking into the method (in particular, its effect on asthma):
Buteyko’s theory relating to carbon dioxide levels and airway calibre is an attractive one, and has some basis in evidence from experimental studies. However, it is not known whether altering breathing patterns can raise carbon dioxide levels significantly, and there is currently insufficient evidence to confirm that this is the mechanism behind any effect that [Buteyko Breathing Technique] BBT may exert. Further research is necessary to establish unequivocally whether BBT is effective, and if so, how it may work. (emphasis mine)
Doesn’t sound fantastic. Maybe the paper “Strengths, Weaknesses, and Possibilities of the Buteyko Breathing Method” will be more promising.
Studies with the Buteyko Method have found that resting carbon dioxide levels do not change after Buteyko training despite reported improvement in symptoms
Ok, how about a study from the same author, “Investigating the Claims of Konstantin Buteyko, M.D., Ph.D.”
The results revealed a negative correlation between BHT and ETCO2 (r = −0.241, p < 0.05), directly opposite to Buteyko’s claims.
[ETCO2 is end tidal CO2, the amount of CO2 released at the end of a breathing cycle]
Or how about this large, randomised controlled study* – again into its effects on asthma.
This study, which we believe to be the largest randomised controlled trial and the first to use a global assessment of asthma control as a primary outcome in a non-pharmacological intervention in asthma, failed to show a difference between the intervention (Buteyko) and control (physiotherapy) groups.
Even Wikipedia, refuge of the lazy journalist, points out that there is no evidence that the CO2 theory is correct and there’s little medical support for the technique!
Where does that leave us? There’s not much evidence that it works, no evidence that it increases CO2 levels, and indeed, some evidence that it may have the exact opposite effect. Does it help with asthma? Perhaps, although apparently no better than any other breathing method. Does it prove that CO2 is unequivocally good for you? Of course not.
* Although as the researchers point out, it was not blinded – which makes the fact that it didn’t work even more striking.
Fresh from their sister paper’s hard-hitting report into scientific ethics (which then ignored scientific ethics completely in favour of plugging The Planet of Apes prequel (direct link)), the Mail on Sunday today claims “150 human animal hybrids grown in UK labs: Embryos have been produced secretively for the past three years“.
That said, the stupidest thing in the article is not The Mail‘s coverage, which overall isn’t as terrible as I thought it would be*, though there’s no attempt at explaining the issues beyond just quoting a spokesperson from each side, and it doesn’t make clear that a lot of the experiments in question – implanting a human nucleus into an empty animal cell – don’t make “hybrids” (more strictly, chimeras or admixed embryos) at all; they just make what is for all intents and purposes a human egg cell (taking eggs out of humans naturally is slightly dangerous, so it’s hard to justify putting women at risk for a science experiment when you can just make egg substitutes in the lab).
No, that prize goes to Lord Alton, who first showed the figures to The Mail. He says:
‘Ethically it can never be justifiable – it discredits us as a country. It is dabbling in the grotesque.
‘At every stage the justification from scientists has been: if only you allow us to do this, we will find cures for every illness known to mankind. This is emotional blackmail.
And those cancer scientists asking for money to invent drugs that cure cancer! Pah! Terrible! It’s emotional blackmail, that’s what it is.
Still, if you’re going to ban scientists from using “curing disease” as a justification then I guess it is pretty hard to justify.
‘Of the 80 treatments and cures which have come about from stem cells, all have come from adult stem cells – not embryonic ones.
‘On moral and ethical grounds this fails; and on scientific and medical ones too.’
I’m not sure where he got that awfully precise figure of 80 from. But yes, all currently approved stem cell treatments have from adult stem cells… because adult stem research has been going strong for over 30 years while embryonic stem cell research is far more recent and has had a troubled history (especially in America); the first embryonic stem cell treatments are just starting to be tested. If in 5 or 10 years there are still no working embryonic stem cell treatments, then it will be time to look at whether embryo research is the best route to take. Right now, though, it’s much too early to say whether this fails scientifically.
* I have very low standards of “terrible” these days, it seems.
A number of papers this week (Daily Express*, Daily Mail, Daily Mirror, Daily Telegraph, Wales on Sunday) have all carried the same story, claiming that, in the words of the Daily Mail, “NHS officials pay £32 for gluten-free bread that costs £2.25 in the shops”.
Though it’s not impossible that a big organisation like the NHS has inefficient bread-buying schemes, it seems a bit unlikely that something as widely prescribed as gluten-free bread is being bought for more than 10 times its shelf price. So where did the figures come from?
Well, it looks like the story comes from this Welsh government data about prescriptions. Sure enough, if you look it says that the 27 prescriptions of a particular type of bread, Lifestyle Gluten-Free High-Fibre Brown, cost £32.27 each.** But doctors aren’t prescribing one loaf of bread at a time.
The important column is the one marked “quantity”, which tells you how many grams of bread were prescribed. For Lifestyle Gluten-Free High-Fibre Brown, doctors prescribed a total of 123,600 grams. Divided between the 27 people, that’s 4,577 grams each, or about 11 loaves of bread per person. So that £32.27 figure is the cost of buying 11 loaves of bread, not 1, and as the Welsh government points out, it works out at around £2.82 per loaf. This is still slightly more than the cheapest online cost of the bread, so I assume there is still room to bring prescription costs down, but NHS Wales is certainly not spending more than £30 on a loaf of bread.
* Turns out James Delingpole writes for The Express too. Huh.
** If you want to check for yourself, it’s in section G-O under the name “Lifestyle_G/f H/fbre Bread Brown”.