Preventing peanut allergies, problems with health professional regulation, and taxing sugary drinks
Norman Swan: Hello, and welcome to the Health Report with me, Norman Swan. Today, food allergy in kids. Could peanut allergy be preventable, and indeed allergies such as milk and egg? Two recent studies suggest there may be some hope. Also, a tax on sugary beverages. It's been called for by a lot of people, but can it work? Well, there is some recent evidence that it can, at least in one country. Stay tuned for that. And trouble at the regulator of health practitioners such as doctors. Could it be that the national agency is over-regulating and too big for its own good. We are going to find out about that later as well.
But let's go back to that food allergy story. On the line is Professor Katie Allen, who is director of the Centre of Food Allergy Research at the Murdoch Children's Research Institute. Welcome to the Health Report, Katie.
Katie Allen: Hello Norman.
Norman Swan: These two studies published in the New England Journal of Medicine are really quite important. And let's go back to a study done last year into peanut allergy, which suggested that early introduction could prevent peanut allergy.
Katie Allen: Yes, this is a fantastic study, it really is very important for changing the way we feed infants.
Norman Swan: The theory is that the increase in peanut allergy is because we have held back on introducing solids too late.
Katie Allen: Yes, there's this concept that you sensitise through the skin to a food, and if you don't eat it that increases the risk of having allergies. So if there's a food that is commonly eaten in the community but not eaten by the infant themselves, and the infant has eczema, then that child will have a really high rate of something like peanut allergy.
Norman Swan: Because they might be wiping the chocolate on themselves or something like that.
Katie Allen: That's a lay interpretation but in fact Gideon Lack who actually is the author of that study went and vacuumed houses that consumed peanut and found that the peanut was in the dust and in the bed. It's a sticky allergen, so it gets into the environment.
Norman Swan: And then there's these his fascinating studies comparing Israeli kids to Jewish kids in Britain, and Israeli kids of the same genetic stock don't get peanut allergy to the same extent.
Katie Allen: Yes, there's arguments about whether it is the same genetic stock or not when you speak to population geneticists, but the observation was what really drove this LEAP study that you are talking about published in the New England Journal last year, and this observation about the difference between time of introduction of solids, peanut in particular was thought to drive the difference in peanut allergy rates.
However, there was a difference in other food allergy rates as well, and peanut was the only real difference in the way that they introduced that food. There has always been a bit of a question mark in our mind about whether that observational study might have been affected by things like reverse causation or other unmeasured factors.
And so this LEAP trial that was published in the New England Journal last year was really astounding as an outcome from a trial point of view because it's the first time that we've got level one evidence, meaning really high-quality evidence, that delaying peanut is harmful and early introduction may be protective, probably is protective.
Norman Swan: What did they do?
Katie Allen: So they took 640 high risk infants, so they are infants with moderately severe eczema, so eczema that needs treatment with steroids and has been diagnosed by a doctor, plus or minus egg allergy. And then they divided them into two groups; those who were to avoid peanut and those who were to consume peanut. There were really quite staggeringly high differences between those who avoided and those who introduced peanut. And these were infants between four and 11 months of age. So it clearly made evidence that that first year of life is the most important with regards to oral tolerance to foods.
Norman Swan: And were they careful about who they introduced to peanut?
Katie Allen: So if a child had a skin-prick test of five millimetres or above, they were excluded from the study because those are the children who probably already had peanut allergy. In fact the study looks at a high risk group of infants, and it also excluded infants who probably already had peanut allergy. Now, the question mark is what we do for those infants? And the other question mark is what to do for the infants who don't have eczema or don't have egg allergy? But of the low level sensitised groups, so the ones with low-level skin-prick tests, or with a negative skin-prick test, they were actually randomised to avoid or consume, and if they were given a food they were given a food challenge first to check the safety.
The ones who avoided the food weren't given a food challenge, so that's a second question mark, maybe they weren't going to have peanut allergy in the first place. But because it's a trial, you should see equal amounts of outcomes in the balanced arm of the study. We know from our Health Nut study, an observational study in Melbourne of 5,300 infants, and we found there were 150 cases of peanut allergy already by age one, and that's 3% of the general community. And the new onset peanut allergic cases were 0.1%, very, very low. So we know after the age of one, new onset peanut allergy is remarkably rare, really it's all over by age 12 months. If you already have peanut allergy, you are in a different kettle of fish from the immune point of view than if you were looking to prevent it in the first place.
Norman Swan: And the other study in these two studies that have just been released is trying to see whether the peanut story can be applied to milk and egg in particular by early introduction of those allergens in the first three months of life. And this is not a high risk group of babies, this is normal breast fed babies.
Katie Allen: Yes, this is really quite an extraordinary study because it was initiated five or six years ago, really way before we were looking at…this is the first cutting-edge studies and the outcomes take years to actually get. But even having these studies in progress has really changed clinical awareness of the issue and what we should be doing. Some clinicians have started changing their practice based on the fact that the studies have already been in progress, which is often the case with science.
But what is extraordinary about this is that before 1972 babies were actually introduced to solids quite early in life, 2 to 3 months of age, in fact 90% of babies had had some form of solids exposure, not in the form of a roast turkey meal but having cereals such as wheat and perhaps rice added to formula to stick in their feeds, probably because the old-fashioned formulas in the '60s and '50s were causing a lot more posseting. So before 1972 when the UK Committee of Toxicology decided to delay the introduction of solids, early introduction was quite normal.
What Michael Perkin and his team has done at the Evelina Hospital in London is they have sat down and said let's go back to that, let's have a go at trying to introduce solids, and they are all softened solids, so developmentally appropriate solids, at 2 to 3 months of age. And that's pretty shocking when you think about we are being told by WHO to introduced solids after the age of six months, and so to turn that around completely and go into an ethics committee and say 'trust us, we know what we're doing' was pretty extraordinary and very brave.
What's fascinating about this study is that this difference between intention-to-treat and per-protocol. So intention-to-treat means you are put into a group and you have to follow that, but per-protocol means what the actual participant did…
Norman Swan: And just to expand on that, so if you analyse this study, you include the dropouts, so parents who didn't follow the advice, you included into that…because it's supposedly a measure of real life. But what you are saying is in this study there was a very different result for the parents who stuck to the protocol of introducing the solids early.
Katie Allen: So what is normally the case with intention-to-treat is that's what we say before we start what we expect people to be sticking with their allocated groups, and that's the correct scientific way to analyse the data. What the per-protocol does is what people end up disregarding and doing what they want to do themselves. So the real-life environment is actually not as scientifically valid. The intention-to-treat is the correct one that you should do because it actually avoids the bias of people doing what they want to do rather than rather than what they've been told to do. So the per-protocol does reflect real life, but the issue is it's scientifically weaker.
So the conclusion of the study is really going to be very interesting going forward because the per-protocol, meaning what people actually did, found a significant effect, but the intention-to-treat did not. And so what it suggests is that there is a bias. If you can eat it you will eat it, and if you can't eat it you won't, so what happens is those who can't eat it are already probably likely to be allergic or have some sort of thing that stops them from eating it.
So the question is you can't use humans as guinea pigs, and rats and mice and guinea pigs don't have the same immune system as us. So it really highlights how difficult these infant feeding trials are, they are really hard to mount properly, that's why the New England Journal is so interested in looking at this, it's a large properly done study, and we will be analysing these results for many years to come because they are so important.
Norman Swan: But the first take is that it looks positive, that introducing solids early can have an effect in preventing food allergy.
Katie Allen: That's absolutely correct. So this will really make WHO and the big policy makers sit up and take notice because now we have this paradoxical problem where delaying the introduction of solids has been thought to be important because it may impact on breastfeeding, which is obviously something that we are very concerned with, we don't want to drop breastfeeding rates. But if you look at the EAT study that Michael Perkin published in the New England Journal, he argues that it didn't have an impact on breastfeeding rates. And so those who are told standard recommendations to delay the introduction of solids to after six months versus those who had early introduction of solids, the breastfeeding rates between the two arms did not appear to be statistically different.
Norman Swan: So the Health Report has a huge audience amongst pregnant women about to have their babies and worried about what the advice is now. What is the advice now?
Katie Allen: So the advice is likely to stay the same, but it's likely to be better informed. So the Australian Society of Clinical Immunology and Allergy recommends the introduction of solids between the age of four to six months. The NHMRC, the National Health and Medical Research Council, has a softer line which is around six months, but that can be interpreted to mean five to six months. So the recommendations remain the same that they were ten years ago before we changed them, which is introduction between four and six months of age is both safe and acceptable, and going forward people may say bring it back earlier, but one study which was not statistically significantly different isn't going to change it to be less than four months at this point in time.
Norman Swan: Katie Allen, thanks for joining us on the Health Report.
Katie Allen: Thanks Norman.
Norman Swan: Professor Katie Allen is director of the Centre for Food Allergy Research at the Murdoch Children's Research Institute in Melbourne.
You're listening to the Health Report here on ABC Radio National with me, Norman Swan.
You probably don't realise it that several years ago the individual medical boards throughout Australia which registered doctors amalgamated, if you like, kind of amalgamated, into one agency, or came under the umbrella of one agency called the Australian Health Practitioners Regulatory Agency, and it also covers several other professions such as nursing, midwifery and chiropractic.
But there has been some variation in how it has worked and some complaints coming through to the Health Report about how it has worked, and also a recent article by Dr Kerry Breen who is a physician and past president of both the Australian Medical Council and the old Medical Practitioners Board of Victoria which I think still exists actually, has been complaining that may be AHPRA has got too big for its boots. Kerry Breen is in our Melbourne studio. Welcome to the Health Report Kerry.
Kerry Breen: Good evening Norman.
Norman Swan: So is this just sour grapes, you know, someone who used to run a medical board saying big and national has gone bad?
Kerry Breen: No, no, I think there will be people who will think that but I certainly don't think that. I've just been a very keen observer of medical regulation since I became involved in 1981, and I think there are structural legislative flaws that the national system has that probably can't be overcome if they continue down the path they are continuing on.
Norman Swan: So what's the problem?
Kerry Breen: I think it's the size. It's enormous bureaucracy. You mentioned three professions but there are actually 14 professions covering 600,000 doctors, and it doesn't extend to New South Wales which covers a third of Australia's doctors. So the bigger the bureaucracy the harder it is for people to get in and out, for getting information et cetera.
Norman Swan: Hold on a second, when you say not New South Wales, New South Wales is under the system, it's just that they do their own disciplining.
Kerry Breen: Exactly, they are co-regulators. So they leave the national register and the registration processes with AHPRA and the New South Wales medical board, and they've renamed their medical board the Medical Council of New South Wales, and it deals with complaints and performance and doctors health and those sorts of issues.
Norman Swan: And in other states you've got to go to AHPRA to complain, is that right? Or you can go through the old medical board but AHPRA deals with it.
Kerry Breen: Well, there's a difference in Queensland again but I'm not quite across the detail in Queensland.
Norman Swan: So two issues, one is that it wasn't that great beforehand because there were some variation. The West Australian medical board was heavily criticised for some GPs being allowed to practice who were clearly problematic. I think the Queensland board has been criticised for delay, that the small medical boards really did seem to have their problems. Registration wasn't portable between states, so if you were registered in New South Wales you had to get reregistered in Victoria. It was the whole railway gauge stuff all over again. Surely it's more efficient to do it the way we are doing it.
Kerry Breen: From a registration point of view, absolutely. The national register is a huge step forward, and the portability is a huge step forward. So I wouldn't suggest unravelling that in the slightest.
Norman Swan: Let's go back then. So your problem is with discipline.
Kerry Breen: Well, it's the complaints process and the way health issues are handled. I think they are the two things that people are most unhappy with. And it's not just myself of course, there have been now three and a fourth pending inquiry into AHPRA. There was a Senate inquiry in 2011. There's a Victorian parliamentary inquiry in 2013. There's a recent Snowball independent assessment of the scheme, and now the Senate is setting up another committee to look at how complaints are handled.
Norman Swan: Can you give me specific examples of what's going wrong?
Kerry Breen: I'll give you two practical ones. Within the legislation there is a power to issue a caution. And a colleague that I know of was issued with a caution but she was never interviewed by anyone and she felt that she was able to put her case. On top of that, that caution is semi-public in that she is forced to tell any employer about it. And on top of that there is no right of appeal. So I think that's a flaw and that left her very, very unhappy.
The second example is a much bigger issue, that is within the state of Victoria since 2001 we've had a very comprehensive doctors health service, doctors health program, and although we've lobbied for five years it's still not in any way certain that the program will be able to continue in its full format. And as a result I think that the national system is very rigid and not able to accommodate variations from state to state. We are a big country, we've got lots of variations in medical culture around the country, and I don't think the big bureaucracy can cope with that.
Norman Swan: But sometimes that variation is a problem.
Kerry Breen: Yes, but if the best program in the country and a program that is basically built on programs that have been established in North America, Canada and the USA for 40 years, then the problem is with the other states they don't believe that sort of program is worth having.
Norman Swan: So what you are suggesting is that the Victorian and New South Wales…because New South Wales has continued with its doctor health program, I take it, which is also…
Kerry Breen: Well, theirs is different, and they are very proud of it, quite rightly, theirs is an entirely voluntary system. I think they've got a secretary that is paid for but the rest of it is voluntary.
Norman Swan: And we should just explain here, this is where a doctor has got an alcohol problem or is depressed, has a mental health issue, they are free to come forward and they will get help without necessarily threatening their registration.
Kerry Breen: Exactly. I mean, the stigma involved of being reported to the board is very, very great, and if you are not impaired, if you've got an illness that might lead to impairment, the best thing you can do is to get early intervention, and you can't do that through the medical boards health committees, so most jurisdictions in Canada and the USA have had these programs, and Victoria has now had it for 15 years. For example, last year they had 150 new people come in to them. Half of those were junior doctors in training. And that has to be really important early intervention for those stressed doctors, and they weren't impaired, they were just stressed out of their mind and wanting help.
Norman Swan: And you are saying then that that should be a national program because it's not uniformly available in the other states, apart from New South Wales.
Kerry Breen: Well, I would like to see it be national but if it can't be national then Victorian doctors who are very happy to pay for it under the old system should still be able to pay for it fully. And in Victoria it was paid for through the annual renewal of registration fees.
Norman Swan: So does this mean you've got to get rid of the Australian Health Practitioner Regulation Agency in your view?
Kerry Breen: I don't think so, no, I think probably, if we come back to the complaint side of things, we've already had a national experiment in that 70% of doctors are covered by AHPRA and the medical board and 30% in New South Wales are covered by the New South Wales Medical Council. I think a simpler way forward would be for all the state health ministers to say we are going to copy New South Wales and become co-regulated. That would reduce the scale of the complaints mechanism and allow greater chance of getting high quality resolution of complaints and notifications.
Norman Swan: But wouldn't it increase cost by reintroducing bureaucracies that have been shown to be wanting, particularly in the smaller states in the past?
Kerry Breen: Well, we could debate whether all the bureaucracies have been wanting, but I certainly agree there would be some further costs in transitioning to that model, absolutely.
Norman Swan: Kerry Breen, thanks for joining us on the Health Report.
Kerry Breen: Thank you Norman.
Norman Swan: Kerry Breen is past president of both the Australian Medical Council and the Medical Practitioners Board of Australia.
Also with me in the Melbourne studio is Martin Fletcher who is the CEO of the Australian Health Practitioner Regulation Agency. You heard what Kerry said. I keep on getting emails from disgruntled doctors saying it's taking a long time, it's been unfair, no right of reply. I'm getting some noise in the system, if you like, which supports what Kerry is saying. What's your response?
Martin Fletcher: Good evening Norman. Well look, I think while the confidence of doctors is obviously important in terms of practitioner regulation in Australia, really at the heart of our work is public and patient safety, and ultimately we are here for the community not the medical profession. So the move to a national registration and accreditation scheme has been an important national reform to the regulation of doctors and other health practitioners, and I believe overall it is working well. It has raised the bar on public safety, and it has addressed some of the unacceptable variation there was in regulatory decision-making across states and territories prior to the national scheme.
Norman Swan: But I suppose the allegation it has gone down to the lowest common denominator.
Martin Fletcher: I don't believe that has been the case. When health ministers decided on the legislation that underpins our work, they actually adopted what was the highest standard in any one state or territory at the time. So overall the national scheme has increased the requirements that there are on practitioners to ensure public safety.
Norman Swan: Kerry Breen quoted one example of a doctor who was given a caution, that goes on the public record with no right of repeal. What's your response to that without re-litigating the case in question?
Martin Fletcher: First of all I'd say that where we issue a caution, indeed any regulatory action that a board takes, we always provide an opportunity for the practitioner to put their case to the board in terms of what they think are the reasons or issues behind the concern that has been raised…
Norman Swan: Why would you get a caution?
Martin Fletcher: You'd get a caution where there may have been something that you have done that has been a departure from an accepted standard of care, for example, there may have been some issue will with your record keeping, or some issue with your communication with the patient. And I think cautions are a very interesting example because although, as we've heard from Dr Breen, that there may be examples in which a practitioner views a caution as being unfair, in fact if we talk to the community, their concern is that a caution is something that isn't on the public register and isn't necessarily something that the public would be aware of. So I think it's a very good example of where there are a range of views about what the right regulatory response would be.
Norman Swan: So you got the right to put forward your position but no right to repeal.
Martin Fletcher: In relation to a caution there isn't a right of appeal, but in relation to other regulatory decisions that the board makes, so for example if there was a restriction placed on registration or you were suspended from registration because of a concern about your conduct, there is a right of appeal in relation to those sanctions.
Norman Swan: And what about the doctors health service? This is a huge issue where doctors in New South Wales and Victoria in particular have really worked hard to gain the trust of doctors, that if they feel they got a mental health issue or a drug and alcohol issue they can come forward, seek help and get monitored in their practice so that patients are kept safe but they've got a chance to actually heal themselves. And the criticism of Kerry Breen is that in Victoria it's insecure, this service, and it is not uniform across Australia.
Martin Fletcher: Dr Breen has made a very important point about the importance of doctor health services and particularly the well-established program in Victoria, and that's a program that we have continued to fund since the start of the national scheme. And in fact what the medical board of Australia in conjunction with AHPRA has done after carefully reviewing the Victorian program has been to agree to fund health programs in every state or territory, because in the past, although we had a very strong program in Victoria, there were a number of different programs to a greater or lesser extent in other states and territories. So the board is in fact funding health programs that will be available in every state or territory and will build on the very good work done by the Victorian program.
Norman Swan: So you are feeling much misunderstood, are you?
Martin Fletcher: I am feeling a bit misunderstood. I welcome scrutiny and I welcome constructive debate, but I think it is important that it's accurately informed.
Norman Swan: So what's the Kim Snowball review? Kim Snowball, former director-general of Western Australia Health Department, has reviewed AHPRA, what has he said?
Martin Fletcher: Overall the review from Kim Snowball highlighted very much the importance of the achievement that there has been in relation to the establishment of the national scheme, andthat was something that was also recognised by ministers in welcoming his review. So in fact what was said, it was a significant and effective reform of health profession regulation. That's not to say that there aren't areas for improvement and he made a number of recommendations in relation to those improvements. But when I look at the scheme over the past six years, and I've been the CEO for six years, we've made enormous improvements in many areas and it keeps on getting better. I wouldn't say it's perfect but it is certainly I think a very important platform and a strong national framework for regulation in Australia.
Norman Swan: We've spent this time talking about doctors. The chiropractors board, who you also cover in your regulatory framework, has come under a lot of criticism for being a toothless tiger, and chiropractors continuing to say that they can cure asthma and almost everything else known to humankind and modern paediatrics, and they still seem to get away with it, and the chiropractors board doesn't seem to crack down.
Martin Fletcher: As you say Norman, there has been a concern about claims that chiropractors are making in their advertising in relation to treatment effectiveness. I'm pleased to say that we have worked very closely with the board and today in fact the board will be issuing a statement setting out its position in relation to advertising in a much tougher and clearer away, that will also include the fact that the board will be writing to every chiropractor in Australia to make sure that they are aware of the obligations around advertising in the national law, and we are and will take action in relation to chiropractors who don't comply with those requirements.
Norman Swan: Good news. Thanks for joining us on the Health Report Martin.
Norman Swan: Thank you Norman.
Norman Swan: Martin Fletcher, who is CEO of the Australian Health Practitioner Regulation Agency.
Let's get to this sugar tax because it has been called for around the world. One of the people calling for it is a rather famous chef, as you'll discover from this special report by the Health Report's Joel Werner.
Jamie Oliver: Sugary sweetened drinks have earned the right to be focused on, and I'll tell you why, because they are the single largest source of sugar in our children's and our teenagers' diet. I haven't said ban sugary sweetened drinks. What I believe in is a sugary drinks tax, a possible billion pounds raised a year, hypothecated and spent in the NHS on proactive initiatives. The conversation of a tax is the hardest one in the world, but I do think that if you want to see a reduction in obesity and diet related disease in our lifetime, one has to fight.
Joel Werner: Jamie Oliver might be the most public advocate for a sugar tax, but the idea itself isn't new. In 2012, France implemented a sugar sweetened beverages or SSB tax, and since then other countries like Chile, Barbados and Mexico have followed suit. The hope is that the higher cost of sugary treats will deter consumption and help slow or eventually reverse the obesity epidemic. This concept of using fiscal policy to influence health behaviour is certainly not new.
Shu Wen Ng: We have tobacco taxes, we have alcohol taxes. Those are some of the products that are perceived as relatively unhealthy products. And increasingly there is recognition that sugars in beverages fall in that realm. Most sugars in beverages don't provide any additional nutrients other than calories and sugar. There's nothing else really very redeeming about many of these products. So it's a basic economic concept. Generally speaking if something becomes more expensive, it's going to affect the amount that people want to buy.
Joel Werner: That's Associate Professor Shu Wen Ng, a health economist from the University of North Carolina who recently investigated the impact of a sugary drinks tax on consumer behaviour in Mexico.
Shu Wen Ng: So in this study we wanted to see if the excise tax on sugar sweetened beverages changed purchasing behaviour among Mexicans. The tax itself was a one peso per litre tax, which is roughly about a 10% price increase relative to 2013, which was when the tax was talked about, and then it came into effect in January 1 of 2014.
We used data on household purchases of beverages, both taxed and untaxed beverages, in the two years prior to the tax being implemented, and then also included one year from when the tax was implemented. So we had two years pre, one year post.
And then we looked at, for the same households over time, how their purchases changed. There was no control group. This is a national tax, so we don't have another Mexico to use as the control group. What we did in that case was then created what we call a counterfactual of what purchases would have looked like in 2014, which was the first year of the tax, under a condition of not having a tax, using the two years pre-tax trends of purchasers to extrapolate out.
Joel Werner: So you projected what sales may have looked like if the tax hadn't have been implemented.
Shu Wen Ng: Exactly.
Joel Werner: So what did you find?
Shu Wen Ng: We found that among Mexicans living primarily in urban areas, purchasers of taxed sugar sweetened beverages fell by 6% relative to the counterfactual. So it was roughly a 10% price increase and that was associated with a 6% reduction in purchases of the taxed beverages. So if you did a back-of-the-envelope calculation, in economic terms we are talking about a price elasticity of -0.6. But there was also a difference in terms of the response by higher versus lower socioeconomic status households. Lower socioeconomic status households actually reduced their purchases of sugar sweetened beverages by 9%, so it was even higher.
Joel Werner: And is that a relative reduction? So it wasn't just that they were buying more of these drinks beforehand, that this was relative to their purchasing behaviour before the tax?
Shu Wen Ng: Correct, so this was relative to the counterfactual, that projected level of purchase if the tax had not been in place.
Joel Werner: And why do you think you saw that difference according to socio-economic status?
Shu Wen Ng: Actually we were not surprised to find this at all. Again, it's a very consistent with economic theory, that lower income households are going to be more responsive to price increases. A dollar or a peso in this case for lower socioeconomic status is a much larger proportion of their budget than for higher socioeconomic status households. So an increase in the price will certainly affect their decision to buy some products that are now more expensive in a different way.
On the flip side, what we were seeing actually was that there was an increase in purchases of untaxed beverages. So there was a bit of substitution that also occurred away from the sugar sweetened beverages towards the untaxed beverages, in particular bottled water, which is something that we want to encourage.
Joel Werner: We want to encourage from a health perspective, but if this was an environment show we might have a different reaction to the increased consumption of plastic bottled water.
Shu Wen Ng: Perhaps. In Mexico it's an interesting context because very few people trust tap water to just drink. Potable water is not something that is available everywhere in Mexico, and most people, even in Mexico City, do not trust to just take water from the tap and drink it. In fact Mexico is the world's highest consumers per capita of bottled water.
One of the arguments that we often hear is that this tax is regressive because of the fact that it affects the lower income households more in a sense. But even though the rates of overweight and obesity are uniformly higher in Mexico across all socio-economic status, lower income, lower socio-economic households have less resources for treatment of diabetes and other cardio metabolic diseases associated with weight gain and increased consumption of sugar that might have resulted in diseases. So it's important to keep that in mind, that the potential cost to the lower socio-economic status households are much higher. So in a sense these households responding more to the tax is a good thing. We want them to reduce their consumption of sugar sweetened beverages because they are the ones who will bear a higher burden of potential health cost.
Joel Werner: Your study showed no indication of health outcomes, so we don't know from this work if they were getting their sugar fix somewhere else.
Shu Wen Ng: Yes, this is a great question, and we can't fully answer that question at this point. We have some other collaborators who are actually working on looking at the food tax. So at the same time that the SSB tax came into place there was a concurrent high-energy non-essential food tax of 8% that was implemented as well.
I have some colleagues who are getting a paper out that is doing the parallel study on the food side, and one of the things that they are going to show in their paper include sweeteners and sugars and purchases of those products as well, because some people argue, well, it's possible that people might just make their own fruit drinks at home and add sugar in their drinks at home. So we don't really know if that's necessarily happening, and there are findings that will speak to that a little bit.
In terms of the health outcomes, it's really too early to tell. If you look in the biological literature, it takes a long time for anything like weight change to occur from reducing caloric or sugar intake. And then for all the other biological changes to occur in terms of affecting biomarkers associated with cardio metabolic outcomes. So it's going to take a couple of years. This is not going to just turn around like that. The obesity epidemic took many, many years to start, and likewise to try to slow it down and then eventually hopefully turn it around, it's going to take decades.
Joel Werner: You mentioned at the top of the interview that this is an excise tax, so the tax is being taken on by the manufacturer. Do you see that tax amount change by the time it reaches the consumer?
Shu Wen Ng: That's a wonderful question. We wanted to see the amount of the taxes actually being transferred onto prices, and that consumers were actually observing and experiencing an increase in the price, because of course you would not expect purchases to change if prices are not changing. So a first study actually that came out in PLOS Medicine looked at this and we found that the pass-through was complete on average. So the pass-through that happened, manufacturers did pass on the tax to consumers.
Joel Werner: I guess with an excise tax you run the risk of the manufacturers passing on an even higher tax than was originally set.
Shu Wen Ng: Yes, that's definitely the case. In fact in some studies in France where they were looking at the sugar sweetened beverage tax there, these studies found that the tax is actually over-passed. Manufacturers and retailers actually increased the price of sodas more than the tax itself. In the case of Mexico, what we saw was that in urban areas the pass-through was more than the one peso per litre for carbonated soft drinks, but it was less than one peso per litre for the noncarbonated sugar sweetened beverages. So they cost-shifted in different ways.
In the rural areas what was found was the opposite in some ways. So the carbonated soft drinks were under-shifted, so it wasn't complete, it was less than one peso per litre price increase, but the noncarbonated sugar sweetened beverages had more than a one peso per litre pass-through. So it was kind of interesting to see why there was some heterogeneity or differences in terms of how the pass-through occurred for the different types of sugar sweetened beverages in urban areas versus rural areas. And it says something about how the manufacturers respond to these taxes in terms of how they cost-shift and what their market share is like in different parts of the country.
Joel Werner: As promising as these results are, a sugar tax alone won't slow, let alone turn around the obesity epidemic.
Shu Wen Ng: It's going to take a myriad of activities and efforts. No one single approach is going to turn things around. I think in the case of Mexico it is effective. I think we have to continue studying it over time to see what the longer term effects are. We don't know how people are going to adapt around this tax and how not just on the demand side in terms of how consumers are responding to it but also how industry might respond to it. Maybe they will start reformulating their products and marketing the lower calorie, lower sugar products, which I think would be wonderful. So industry also can respond, and it will be interesting to see how they do respond. It's just one of the many things that can be done, but it is a critical piece and it is shown, at least in the Mexico case right now, that it can help.
Joel Werner: As successful as a 10% tax has been in Mexico, if anything Shu Wen would like to see what happens when that rate is even higher.
Shu Wen Ng: The original proposal for this tax was a 20% tax, so it was double of what it actually became. I think it would be useful to also consider increasing the tax to 20%, doubling it, to see what kind of additional changes could happen in terms of reducing consumption.
Norman Swan: And that report on sugar tax came from Joel Werner of the Health Report, and that's what you've been listening to. I'm Norman Swan, see you next week.