How the dangers of e-cigarettes extend beyond DNA damage

Studies done on laboratory mice suggest that e-cigarettes can be harmful to humans, although to a lesser degree compared to the traditional tobacco they are supposed to replace. This suggests that  cigarette smokers could do themselves some good in switching to e-cigarettes, although those who have yet to pick up the habit should avoid it because it can actually do the body harm – and is not zero-risk smoking as some might view it.

E-cigarettes have been growing in use over the last few years. Because they are aerosol-based, they use compounds to deliver nicotine to the user. This means they avoid the smoke associated with traditional tobacco cigarettes. In the latter, the burning of tobacco releases carcinogens, which cause cell damage and cancer when they are inhaled. The delivery of nicotine by aerosol in e-cigarettes avoids these, although the recent study proposes that this is not enough.

The most recent research into the use of e-cigarettes suggests that they still cause cancer because they damage string DNA and the body’s ability to repair itself.

Laboratory mice were exposed to the vapour of e-cigarettes for a period that simulated normal human consumption. The vapour of e-cigarettes contains both nicotine and solvent, and while the solvent itself had no effect on the mice, the combination of solvent and nicotine had the same impact as nicotine itself.

The limitations of the study were that it was unclear the vapour inhaled by the mice was equal to the amount a human being would, or pro-rated for the difference in mass! Furthermore, the impact on mice may not be comparable to those on humans.

The research does highlight, nevertheless, that there is a potential danger in e-cigarettes. While guidelines in 2016 recommended them as a safer alternative to tobacco, they are not 100% safe. Various groups of people such as the younger generation, for whom smoking is a perceived sign of maturity, think that just because there is no burnt substance, that they are perfectly safe. Unfortunately, the easy availability of these e-cigarettes, just like nicotine gum, means that rather than getting individuals off cigarettes, they may only be building up a lifelong addiction instead.

The higher cost of body embarrassment

If you were a bloke, would you avoid going to the doctor’s if it meant you had to strip off for the doctor to examine an area of your body you had concern about? Chances are men who have found a lump in their testicles might put off going to the doctor’s for a couple of days, drinking lots of water in the hope that it would go down, and if the lump remained, then work up the courage to make an appointment to see a doctor about it. Why put it off for a few days? It is probably down to the fact that it is slightly awkward and embarrassing to strip off to your private areas in front of someone else, despite the fact that doctors are professional and the health concerns are pressing. Despite the risk that the lumps may need to be operated on, some leave it late – and even a bit too late – because of the embarrassment.

But the embarrassment is not just down to men. Women put off going for tests and checkups because of the awkwardness around their perceived bodies. The BBC News website reported that women were avoiding smear tests to detect cervical cancer, with some either delaying making an appointment, or skipping screening altogether.

Cervical cancer accounts for an average of more than two deaths a day. Over 900 women die annually from it. Each day an average of nine women a day are diagnosed with it. All women aged 25 to 49 are invited for a screening test every three years. From the ages of fifty to sixty-four, this is reduced to once every five years.

Among those aged 25 to 29, more than one in three skip the cervical screening, a statistic that is worrying as the women more likely to get such cancer is the age group most likely to avoid the screening tests meant to catch it.

For what reasons do women avoid such tests?

One survey of around 2000 women found that their embarrssment about body shape was the most largely quoted reason for not attending. In other words, women were not comfortable with their own bodies in front of others. Other women also thought that they were healthy, being regulars of exercise or the gym, and thought that they were of a lower risk than others. A third did not believe that cervical screening reduces the risk of cancer at all. The results of the survey suggest that more importance needs to be placed on educating women of the benefits of screening.

The test only takes five minutes but perhaps one of the biggest barriers facing women was the awkardness if a male doctor or nurse was the one conducting the cervical screening. But women do have the option of asking in advance for a female to carry out the test, and many already do.

Jo’s Cervical Cancer Turst, the only charity in the UK dedicated to women suffers of this form of cancer, is working to improve detection rates and hence reduce the emotional impact of cancer on women and their families. The current screening is the greatest form of protection against such cancer, and helps save the NHS money by preventing the need for later surgery. The treatment of early stage cancer iis estimated by the charity to cost less than a tenth of later stage cancer.

It is not clear from the survery whether the women were representative of different regions, beliefs, or socio-economic groups. Women from certain cultures may find it more socially unacceptable to be naked in front of other individuals, let alone male doctors, and hence not attend screening for such reasons and are likely not to.

Appearance of the body shape and the vulva accounted for 84% or cervical smear absentees. Of these, 38% were also concerned that they might not smell normal, while 31% would not have gone had they not shaved or waxed their bikini area.

A senior nurse mentioned that nurses are aware of the awkwardness of showing an intimate part of the body to someone else but are sensitive to make the procedure less embarrassing so that women continue to have acceptable experiences that do not put them off screening for cancer. A chaperone is always offered and if women prefer to take a friend or partner with them that is fine too. It would be a great shame if women were put off seeking medical advice because of their embarrassment – it would be too great a price to pay for a small period of minimal inconvenience. The same goes for men and visits to their doctors too.

One cigarette a day can cost a lot

According to the newspaper headlines of late, teenagers should be kept away from cigarette exposure because of this worrying statistic.

A survey of over 216,000 adults found that over 60% of them had been offered and tried a cigarette at some point, and of these, nearly 70% went on to become regular smokers. The conclusion drawn was that there are strong links between trying a cigarette ones to be sociable and going on to develop it as a habit.

This of course ended up in the newspapers with headlines such as “One cigarette is enough to get you hooked”. The Mail Online, Britain’s go-to newspaper for your important health news (and I’m being ironic here) went a step further, saying one puff from a cigarette was enough to get you hooked for life. Never mind if you had one draw of a cigarette, felt the nicotine reach your lungs, then coughed in revulsion at the bitter aftertaste and swore that you would never again try a cigarette again. The Mail Online bets you would return to the lure of the dark side, seduced by its nicotine offers.

I digress.

While we all know that any event, repeated many times becomes a habit, the statistics in this case are a little dubious.

The study was conducted by Queen Mary University (nothing dubious in itself) but among the various concerns were what you might call the high conversion rate. Nearly 70% of those who tried a cigarette once went on to smoke regularly as a habit.

I’m not sure why the 70% is worrying. In fact, I wonder why it is not 100%! Surely, if you asked a habitual smoker, “Have you smoked a cigarette before?”, the answer would be a resounding “Yes”!

Unless you have caught someone in the act of sneakily smoking his virgin cigarette. But he wouldn’t yet be a habitual smoker.

Let’s establish the facts of the matter again.

216,000 adults were surveyed.

130,000 of them (60% of the adults) had tried a cigarette before.

86,000 (40%) have never smoked before.

Of the 130,000 who had tried a cigarette before, 81,000 (70%) went on to become regular smokers.

49,000 (30%) of those who tried a cigarette before either did not go on to smoke at all or did not smoke regularly.

Another way of looking at the data would be as follows:

216,000 adults surveyed.

135,000 adults do not smoke regularly or at all. Some did try once in the past.

81,000 adults smoke regularly and these people have obviously tried a cigarette before.

Suddenly the data doesn’t look sexy anymore.

The data was an umbrella studywhich means data was pooled rather than created from scratch through surveys. As previously examined, the final outcome is also dependent on the integrity of the original source.

Bias can also creep in because the data has not been directly obtained and inferences have been drawn.

For example, the influence of e-cigarettes and vaping on the results have not been scrutinised, because some of the data may have existed before then.

Before we leave it at this, here is another example of data bias:
216,000 adults were surveyed.

130,000 of them (60% of the adults) had tried a cigarette before.

86,000 (40%) have never smoked before.

We can conclude that 100% of the 86,000 who have never smoked a cigarette in the past have never smoked a cigarette.

You can see the absurdity more when it’s spelt out more in words than in numbers.

If research is costly and expensive, in terms of money and time, then why is it wasted on these?

One reason is that it keeps academics and researchers in their jobs, if they produce findings that are financially low-cost but can stave off the question of what they actually do, and their purpose.

This kind of research is the academic version of the newspaper filler article, one that columnists generate based on the littlest of information, in order to fill the papers with “news”, that actually mask the fact that they are there to sell advertising space. And in this, columnists and researchers are at times colluding for the same purpose. Vultures who tear at the carcass of a small rodent and then serve up the bits as a trussed up main meal.

Unethical? Who cares, it seems. Just mask the flawed process and don’t make it too obvious.

The bigger issues that come with preventing hearing loss

Is there cause for optimism when it comes to preventing hearing loss? Certainly the latest research into this suggests that if positive effects experienced by mice could be transferred to humans and maintained for the long term, then hereditary hearing loss could be a thing of the past.

It has always been assumed that hearing loss is always down to old age. The commonly held view is that as people grow older, their muscles and body functions deteriorate with time to the point that muscle function is impaired and eventually lost. But hearing loss is not necessarily down to age, although there are cases where constant exposure to loud noise, over time, causes reduced sensitivity to aural stimuli. Over half of hearing loss cases are actually due to inheriting faulty genetic mutations from parents.

How do we hear? The hair cells of the inner ear called the cochlea respond to vibrations and these signals are sent to the brain to interpret. The brain processes these signals in terms of frequency, duration and timbre in order to translate them into signals we know.

For example, if we hear a high frequency sound of short duration that is shrill, our brain interprets these characteristics and then runs through a database of audio sounds, an audio library in the brain, and may come up with the suggestion that it has come from a whistle and may signify a call for attention.

What happens when you have a genetic hearing loss gene? The hairs on the inner ear do not grow back and consequently sound vibration from external stimuli do not get passed on to the brain.

With progressive hearing loss too, the characteristics of sound also get distorted. We may hear sounds differently to how they are produced, thereby misinterpreting their meaning. Sounds of higher and lower frequency may be less audible too.

How does that cause a problem? Imagine an alarm. It is set on a high frequency so that it attracts attention. If your ability to hear high frequencies is gradually dulled then you may not be able to detect the sound of an alarm going off.

As hearing gradually deteriorates, the timbre of a sound changes. Sharper sounds become duller, and in the case of the alarm, you may hear it, but it may sound more muted and the brain may not be able to recognise that it is an alarm being heard.

Another problem with hearing loss is the loss of perception of volume. You may be crossing the road and a car might sound its horn if you suddenly encroach into its path. But if you cannot hear that the volume is loud, you may perceive it to be from a car far away and may not realise you are in danger.

The loss of the hairs in the inner ear is a cause of deafness in humans, particularly those for whom hearing loss is genetic. Humans suffering from hereditary hearing loss lose the hairs of the inner ear, which result in the difficulties mentioned above. But there is hope. In a research experiment, scientists successfully delayed the loss of the hairs in the inner ear for mice using a technique that edited away the genetic mutation that causes the loss of the hairs in the cochlea.

Mice were bred with the faulty gene that caused hearing loss. But using a technology known as Crispr, the faulty gene was replaced with a healthy normal one. After about eight weeks, the hairs in the inner ears of mice with genetic predisposition to hearing loss flourished, compared to similar mice which had not been treated. The genetic editing technique had removed the faulty gene which caused hearing loss. The treated mice were assessed for responsiveness to stimuli and showed positive gains.

We could be optimistic about the results but it is important to stress the need to be cautious.

Firstly, the research was conducted on mice and not humans. It is important to state that certain experiments that have been successful in animals have not necessarily had similar success when tried on humans.

Secondly, while the benefits in mice were seen in eight weeks, it may take longer in humans, if at all successful.

Thirdly, we should remember that the experiment worked for the mice which had the genetic mutation that would eventually cause deafness. In other words, they had their hearing at birth but were susceptible to losing it. The technique prevented degeneration in hearing in mice but would not help mice that were deaf at birth from gaining hearing they never had.

Every research carries ethical issues and this one was no different. Firstly, one ethical issue is the recurring one of whether animals should ever be used for research. Should mice be bred for the purposes of research? Are all the mice used? Are they accounted for? Is there someone from Health and Safety going around with a clipboard accounting for the mice? And what happens to the mice when the research has ceased? Are they put down, or released into the ecosystem? “Don’t be silly,” I hear you say, “it’s only mice.” That’s the problem. The devaluation of life, despite the fact that it belongs to another, is what eventually leads to a disregard for other life and human life in general. Would research scientists, in the quest for answers, eventually take to conducting research on beggars, those who sleep rough, or criminals? Would they experiment on orphans or unwanted babies?

The second, when it comes to genetics, is whether genetic experimentation furthers good or promotes misuse. The answer, I suppose, is that the knowledge empowers, but one cannot govern its control. The knowledge that genetic mutation can be edited is good news, perhaps, because it means we can genetically alter, perhaps, disabilities or life-threatening diseases from the onset by removing them. But this, on the other hand, may promote the rise of designer babies, where mothers genetically select features such as blue eyes for their unborn child to enhance their features from birth, and this would promote misuse in the medical community.

Would the use of what is probably best termed genetic surgery be more prominent in the future? One can only suppose so. Once procedures have become more widespread it is certain to conclude that more of such surgeons will become available, to cater for the rich and famous. It may be possible to delay the aging process by genetic surgery, perhaps by removing the gene that causes skin to age, instead of using botox and other external surgical procedures.

Would such genetic surgery ever be available on the NHS? For example, if the cancer gene were identified and could be genetically snipped off, would patients request this instead of medical tablets and other external surgical processes? One way of looking at it is that the NHS is so cash-strapped that under QALY rules, where the cost of a procedure is weighed against the number of quality life years it adds, the cost of genetic surgery would only be limited to more serious illnesses, and certainly not for those down the rung. But perhaps for younger individuals suffering from serious illnesses, such as depression, the cost of a surgical procedure may far outweigh a lifetime’s cost of medication of anti-depressant, anti-psychotics or antibiotics. If you could pinpoint a gene that causes a specific pain response, you might alter it to the point you may not need aspirin, too much of which causes bleeds. And if you could genetically locate what causes dementia in another person, would you not be considered unethical if you let the gene remain, thereby denying others the chance to live a quality life in their latter years?

Genetic editing may be a new technique for the moment but if there is sufficient investment into infrastructure and the corpus of genetic surgery information widens, don’t be surprised if we start seeing more of that in the next century. The cost of genetic editing may outweigh the cost of lifelong medication and side effects, and may prove to be not just more sustainable for the environment but more agreeable to the limited NHS budget.

Most of us won’t be around by then, of course. That is unless we’ve managed to remove the sickness and death genes.

The financial considerations of investing in medicine and medical research

BBC News reports that a drug that would reduce the risk of HIV infection would result in cost savings of over £1bn over 80 years. Pre-exposure prophylaxis, or Prep, would reduce infection and hence lower the treatment costs for patients in the long term.

The catch? There is one. It’s the long term.

The cost of the treatment and prevention is such that its provision for the first twenty years – bundling together the cost of medical research and production of medicine – would result in a financial loss, and parity would only be achieved after a period of about thirty to forty years; this period is hard to define because it is dependent on what the drug would cost in the future.

Prep combines two anti-HIV drugs, emtricitabine and tenofovir. The medical trials behind it have concluded it has an effective rate of over one in five when it comes to protecting men who have unprotected sex with men from HIV infection. The exact figure is close to 86%.

Prep can be used either on a daily basis, or on what has been termed a sexual event basis – using it for two days before, during and after periods of unprotected sex.

The research model analysed the potential impact of Prep and found that it could reduce infection rates by over a quarter. The cost of the treatment itself, comparative to the cost of treating infection, would result in a saving over one billion pounds over eight years.

However, it does raise a few ethical questions. If the National Health Service is aiming to be a sustainable one – and one of the aims of sustainability is to empower citizens to take responsibility for their own health –  shouldn’t it be considering less about how it will balance the books, but spend more on education for prevention in the first place? The cost of producing Prep on the NHS would be £19.6 billion over 80 years; while the estimated savings from treatment would be £20.6 billion over the same period. Educating people not to have unprotected sex with those at the risk of HIV arguably would result in a higher saving over a lower time period. Perhaps the NHS should consider ways of reducing cost more significantly, rather than latching on to a cheaper prevention drug immediately. If consumer behaviour is not going to change, symptoms are still going to surface, and the provision of Prep on the NHS may only encourage less self-regulation and awareness.

Media’s Marvellous Medicine

When it comes to our health, the media wields enormous influence over what we think. They tell us what’s good, what’s bad, what’s right and wrong, what we should and shouldn’t eat. When you think about it, that’s quite some responsibility. But do you really think that a sense of philanthropic duty is the driving force behind most of the health ‘news’ stories that you read? Who are we kidding? It’s all about sales, of course, and all too often that means the science plays second fiddle. Who wants boring old science getting in the way of a sensation-making headline?

When it comes to research – especially the parts we’re interested in, namely food, diet and nutrients – there’s a snag. The thing is, these matters are rarely, if ever, clear-cut. Let’s say there are findings from some new research that suggest a component of our diet is good for our health. Now academics and scientists are generally a pretty cautious bunch – they respect the limitations of their work and don’t stretch their conclusions beyond their actual findings. Not that you’ll think this when you hear about it in the media. News headlines are in your face and hard hitting. Fluffy uncertainties just won’t cut it. An attention-grabbing headline is mandatory; relevance to the research is optional. Throw in a few random quotes from experts – as the author Peter McWilliams stated, the problem with ‘experts’ is you can always find one ‘who will say something hopelessly hopeless about anything’ – and boom! You’ve got the formula for some seriously media-friendly scientific sex appeal, or as we prefer to call it, ‘textual garbage’. The reality is that a lot of the very good research into diet and health ends up lost in translation. Somewhere between its publication in a respected scientific journal and the moment it enters our brains via the media, the message gets a tweak here, a twist there and a dash of sensationalism thrown in for good measure, which leaves us floundering in a sea of half-truths and misinformation. Most of it should come with the warning: ‘does nothing like it says in the print’. Don’t get us wrong: we’re not just talking about newspapers and magazines here, the problem runs much deeper. Even the so-called nutrition ‘experts’, the health gurus who sell books by the millions, are implicated. We’re saturated in health misinformation.

Quite frankly, many of us are sick of this contagion of nutritional nonsense. So, before launching headlong into the rest of the book, take a step back and see how research is actually conducted, what it all means and what to watch out for when the media deliver their less-than-perfect messages. Get your head around these and you’ll probably be able to make more sense of nutritional research than most of our cherished health ‘gurus’.

Rule #1: Humans are different from cells in a test tube
At the very basic level, researchers use in-vitro testing, in which they isolate cells or tissues of interest and study them outside a living organism in a kind of ‘chemical soup’. This allows substances of interest (for example, a vitamin or a component of food) to be added to the soup to see what happens. So they might, for example, add vitamin C to some cancer cells and observe its effect. We’re stating the obvious now when we say that what happens here is NOT the same as what happens inside human beings. First, the substance is added directly to the cells, so they are often exposed to concentrations far higher than would normally be seen in the body. Second, humans are highly complex organisms, with intricately interwoven systems of almost infinite processes and reactions. What goes on within a few cells in a test tube or Petri dish is a far cry from what would happen in the body. This type of research is an important part of science, but scientists know its place in the pecking order – as an indispensable starting point of scientific research. It can give us valuable clues about how stuff works deep inside us, what we might call the mechanisms, before going on to be more rigorously tested in animals, and ultimately, humans. But that’s all it is, a starting point.

Rule #2: Humans are different from animals
The next logical step usually involves animal testing. Studying the effects of a dietary component in a living organism, not just a bunch of cells, is a big step closer to what might happen in humans. Mice are often used, due to convenience, consistency, a short lifespan, fast reproduction rates and a closely shared genome and biology to humans. In fact, some pretty amazing stuff has been shown in mice. We can manipulate a hormone and extend life by as much as 30%1. We can increase muscle mass by 60% in two weeks. And we have shown that certain mice can even regrow damaged tissues and organs.

So, can we achieve all of that in humans? The answer is a big ‘no’ (unless you happen to believe the X-Men are real). Animal testing might be a move up from test tubes in the credibility ratings, but it’s still a long stretch from what happens in humans. You’d be pretty foolish to make a lot of wild claims based on animal studies alone.

To prove that, all we need to do is take a look at pharmaceutical drugs. Vast sums of money (we’re talking hundreds of millions) are spent trying to get a single drug to market. But the success rate is low. Of all the drugs that pass in-vitro and animal testing to make it into human testing, only 11% will prove to be safe and effective enough to hit the shelves5. For cancer drugs the rate of success is only 5%5. In 2003, the President of Research and Development at pharmaceutical giant Pfizer, John La Mattina, stated that ‘only one in 25 early candidates survives to become a prescribed medicine’. You don’t need to be a betting person to see these are seriously slim odds.

Strip it down and we can say that this sort of pre-clinical testing never, ever, constitutes evidence that a substance is safe and effective. These are research tools to try and find the best candidates to improve our health, which can then be rigorously tested for efficacy in humans. Alas, the media and our nutrition gurus don’t appear to care too much for this. Taking research carried out in labs and extrapolating the results to humans sounds like a lot more fun. In fact, it’s the very stuff of many a hard-hitting newspaper headline and bestselling health book. To put all of this into context, let’s take just one example of a classic media misinterpretation, and you’ll see what we mean.

Rule #3: Treat headlines with scepticism
Haven’t you heard? The humble curry is right up there in the oncology arsenal – a culinary delight capable of curing the big ‘C’. At least that’s what the papers have been telling us. ‘The Spice Of Life! Curry Fights Cancer’ decreed the New York Daily News. ‘How curry can help keep cancer at bay’ and ‘Curry is a “cure for cancer”’ reported the Daily Mail and The Sun in the UK. Could we be witnessing the medical breakthrough of the decade? Best we take a closer look at the actual science behind the headlines.

The spice turmeric, which gives some Indian dishes a distinctive yellow colour, contains relatively large quantities of curcumin, which has purported benefit in Alzheimer’s disease, infections, liver disease, inflammatory conditions and cancer. Impressive stuff. But there’s a hitch when it comes to curcumin. It has what is known as ‘poor bioavailability’. What that means is, even if you take large doses of curcumin, only tiny amounts of it get into your body, and what does get in is got rid of quickly. From a curry, the amount absorbed is so miniscule that it is not even detectable in the body.

So what were those sensational headlines all about? If you had the time to track down the academic papers being referred to, you would see it was all early stage research. Two of the articles were actually referring to in-vitro studies (basically, tipping some curcumin onto cancer cells in a dish and seeing what effect it had).

Suffice to say, this is hardly the same as what happens when you eat a curry. The other article referred to an animal study, where mice with breast cancer were given a diet containing curcumin. Even allowing for the obvious differences between mice and humans, surely that was better evidence? The mice ate curcumin-containing food and absorbed enough for it to have a beneficial effect on their cancer. Sounds promising, until we see the mice had a diet that was 2% curcumin by weight. With the average person eating just over 2kg of food a day, 2% is a hefty 40g of curcumin. Then there’s the issue that the curcumin content of the average curry/turmeric powder used in curry is a mere 2%. Now, whoever’s out there conjuring up a curry containing 2kg of curry powder, please don’t invite us over for dinner anytime soon.

This isn’t a criticism of the science. Curcumin is a highly bio-active plant compound that could possibly be formulated into an effective medical treatment one day. This is exactly why these initial stages of research are being conducted. But take this basic stage science and start translating it into public health advice and you can easily come up with some far-fetched conclusions. Let us proffer our own equally absurd headline: ‘Curry is a Cause of Cancer’. Abiding by the same rules of reporting used by the media, we’ve taken the same type of in-vitro and animal-testing evidence and conjured up a completely different headline. We can do this because some studies of curcumin have found that it actually causes damage to our DNA, and in so doing could potentially induce cancer.

As well as this, concerns about diarrhoea, anaemia and interactions with drug-metabolizing enzymes have also been raised. You see how easy it is to pick the bits you want in order to make your headline? Unfortunately, the problem is much bigger than just curcumin. It could just as easily be resveratrol from red wine, omega-3 from flaxseeds, or any number of other components of foods you care to mention that make headline news.

It’s rare to pick up a newspaper or nutrition book without seeing some new ‘superfood’ or nutritional supplement being promoted on the basis of less than rigorous evidence. The net result of this shambles is that the real science gets sucked into the media vortex and spat out in a mishmash of dumbed-down soundbites, while the nutritional messages we really should be taking more seriously get lost in a kaleidoscope of pseudoscientific claptrap, peddled by a media with about as much authority to advise on health as the owner of the local pâtisserie.

Rule #4: Know the difference between association and causation
If nothing else, we hope we have shown that jumping to conclusions based on laboratory experiments is unscientific, and probably won’t benefit your long-term health. To acquire proof, we need to carry out research that involves actual humans, and this is where one of the greatest crimes against scientific research is committed in the name of a good story, or to sell a product.

A lot of nutritional research comes in the form of epidemiological studies. These involve looking at populations of people and observing how much disease they get and seeing if it can be linked to a risk factor (for example, smoking) or some protective factor (for example, eating fruit and veggies). And one of the most spectacular ways to manipulate the scientific literature is to blur the boundary between ‘association’ and ‘causation’. This might all sound very academic, but it’s actually pretty simple.

Confusing association with causation means you can easily arrive at the wrong conclusion. For example, a far higher percentage of visually impaired people have Labradors compared to the rest of the population, so you might jump to the conclusion that Labradors cause sight problems. Of course we know better, that if you are visually impaired then you will probably have a Labrador as a guide dog. To think otherwise is ridiculous.

But apply the same scenario to the complex human body and it is not always so transparent. Consequently, much of the debate about diet and nutrition is of the ‘chicken versus egg’ variety. Is a low or high amount of a nutrient a cause of a disease, a consequence of the disease, or simply irrelevant?

To try and limit this confusion, researchers often use what’s known as a cohort study. Say you’re interested in studying the effects of diet on cancer risk. You’d begin by taking a large population that are free of the disease at the outset and collect detailed data on their diet. You’d then follow this population over time, let’s say ten years, and see how many people were diagnosed with cancer during this period. You could then start to analyse the relationship between people’s diet and their risk of cancer, and ask a whole lot of interesting questions. Did people who ate a lot of fruit and veggies have less cancer? Did eating a lot of red meat increase cancer? What effect did drinking alcohol have on cancer risk? And so on.

The European Prospective Investigation into Cancer and Nutrition (EPIC), which we refer to often in this book, is an example of a powerfully designed cohort study, involving more than half a million people in ten countries. These studies are a gold mine of useful information because they help us piece together dietary factors that could influence our risk of disease.

But, however big and impressive these studies are, they’re still observational. As such they can only show us associations, they cannot prove causality. So if we’re not careful about the way we interpret this kind of research, we run the risk of drawing some whacky conclusions, just like we did with the Labradors. Let’s get back to some more news headlines, like this one we spotted: ‘Every hour per day watching TV increases risk of heart disease death by a fifth’.

When it comes to observational studies, you have to ask whether the association makes sense. Does it have ‘biological plausibility’? Are there harmful rays coming from the TV that damage our arteries or is it that the more time we spend on the couch watching TV, the less time we spend being active and improving our heart health. The latter is true, of course, and there’s an ‘association’ between TV watching and heart disease, not ‘causation’.

So even with cohorts, the champions of the epidemiological studies, we can’t prove causation, and that’s all down to what’s called ‘confounding’. This means there could be another variable at play that causes the disease being studied, at the same time as being associated with the risk factor being investigated. In our example, it’s the lack of physical activity that increases heart disease and is also linked to watching more TV.

This issue of confounding variables is just about the biggest banana skin of the lot. Time and time again you’ll find nutritional advice promoted on the basis of the findings of observational studies, as though this type of research gives us stone cold facts. It doesn’t. Any scientist will tell you that. This type of research is extremely useful for generating hypotheses, but it can’t prove them.

Rule #5: Be on the lookout for RCTs (randomized controlled trials)
An epidemiological study can only form a hypothesis, and when it offers up some encouraging findings, these then need to be tested in what’s known as an intervention, or clinical, trial before we can talk about causality. Intervention trials aim to test the hypothesis by taking a population that are as similar to each other as possible, testing an intervention on a proportion of them over a period of time and observing how it influences your measured outcome.

Why Asians are more prone to Type 2 diabetes than Westerners

Thirty-four year-old Alan Phua is what you might describe as a typical male Chinese man. He exercises for three to five times a week in a country that places a high emphasis on healthy lifestyles. He also carefully observes what he eats and is strict about his diet.

Alan lives in Singapore. In addition to military service for the duration of two and a half years when they turn eighteen, citizens have annual reservist training for two weeks until they turn forty. Failing to meet targets for physical exercises such as chin ups, standing broad jumps, sit ups, shuttle runs and a 1.5 mile run means remedial physical training every few months until these standards are meet. But not all is negative though. Meeting or exceeding these targets is rewarded by financial incentives. In other words, living in Singapore as a male means there is a strong push to keep fit and maintain it.

The reasons for this are very clear. Singapore is a small country surrounded by two large neighbours in Malaysia and Indonesia. Its population of five million citizens means that like Israel, it has to rely on a citizen reservist force should the threat of war ever loom. While most of the citizens there seem of the mindset that military war would never break out, as the country is so small that any military action would damage the infrastructure and paralyse it; furthermore, the military is only a deterrent force, the readiness to military action gives leverage in negotiations between nation. For example, if the countries disagree over the supply of water that Malaysia gives Singapore to refine, and the discussions escalate towards a military standoff, having a reservist army puts the country in a better negotiating position. But while many may claim that a war is hypothetical, there is a simpler reason for maintaining fitness. A fitter population means less stress on the healthcare system. Singapore is the sustainable healthcare system that many countries are seeking to adopt.

Like many others in Singapore, Alan’s body does not produce enough insulin. This, as a result, causes the accumulation of sugar in the bloodstream. The lack of insulin leads to other health issues, such as general fatigue, infections, or other effects such as the failure of wounds to heal. However, all is not lost. Eating properly and having a good level of exercise can prevent the blood glucose level from rising and developing into diabetes.

Local researchers from the country’s National University Hospital (NUH), working together with Janssen Pharmaceuticals, have discovered that the reason why Asians are moresusceptible than Westerners to developing Type 2 diabetes is the inability of their bodies to produce high enough levels of insulin.

Even though the finding was based only on a small sample size of 140 mostly Chinese participants, the data, if expanded and refined, will point the way and help patients with diabetes to manage it better; not just for local patients but also within the region. Doctors believe that better dietary advice and a better selection of drugs would help patients to treat diabetes. The preliminary findings are part of the country’s largest diabetes study launched last year. The five-year ongoing study has recruited around 1,300 participants, and aims to eventually nearly double that.

The researchers did however notice the ethnicity of the results was fairly restricted and more participants from a wider racial profile will be needed for the results to be applied to the general population.

Currently, the statistics show that one in three Singaporeans has a risk of developing diabetes. Currently, one out of every fourteen Singaporeans are diabetic. Type 2 diabetes comes about because insufficient insulin is produced by the pancreas, or because the body has insulin resistance.

A previous study that 8 per cent of Chinese people with a Body Mass Index (BMI) of 23 have diabetes. A BMI of 23 is within the normal weight range for Caucasians, and the rate of diabetes development within Chinese people is four times more than their European counterparts. The researchers claimed that it highlighted the importance of avoiding too much high-glucose food such as those rich in simple carbohydrates which include white rice and sugar.

The findings could also lay the foundation for efforts to test whether therapies that target insulin secretion and the ability to make more insulin could be more effective in the local population, and lead to customised diabetes treatment.

What bearing does this have on us, and what action can we take? A good start would be to avoid eating high glucose food such as rice too often and managing our diet. Also try adopting a more active lifestyle!