Are common garden chemicals a health risk?

Gardening in Australia requires, to varying degrees depending where in the country you are, pesticides, herbicides and fertilisers. From shutterstock.com

Ian Musgrave, University of Adelaide

As the weather warms and days lengthen, your attention may be turning to that forgotten patch of your backyard. This week we’ve asked our experts to share the science behind gardening. So grab a trowel and your green thumbs, and dig in.

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Gardening is good for your health, but it can pose some risks if you’re not careful. For example, you should use sensible protection against the sun to prevent cancer, a significant cause of death in Australia.

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Further reading: The science is in: gardening is good for you

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Gardening in Australia also requires, to varying degrees depending where in the country you are, pesticides, herbicides and fertilisers. There is an enormous number of agents with multiple formulations, depending on what you are doing, what plants you are tending, the size of your garden and the kind of soil.

These garden treatments are designed to be specific and potent, so they can be applied less often and work (mostly) only on the things you want them to work on. All of them – even the “natural” ones such as sulfur dusts to control caterpillars and mildew – are chemicals, which means they have health risks.

Even sulfur dusts are chemicals, which means they have health risks. Yates Tomato and Vegetable Dust product webpage/Screenshot

Regulation of chemicals

While not perfect, gardening product safety is regulated in Australia. Let me introduce you to the Australian Veterinary Medicines and Pesticides Authority. This body regulates pesticide (a substance that kills pests such as insects and weeds) and herbicide (a substance that kills only weeds) products sold in Australia.

The AVPMA regularly reviews products for safety concerns, though the reviews may be decades apart. It co-ordinates with World Health Organisation bodies and its counterparts in Europe, Canada and the United States.

Given the sheer number of compounds and formulations available, I can’t possibly cover the safety of all chemicals, or even all groups of chemicals. If you are concerned about a particular product, you can search the AVPMA site for the ingredients in a given pesticide, herbicide or fertiliser.

This may be tricky, as some will not necessarily have a chemical name on them, just the trade name. However, most pesticides and herbicides from reputable companies should have a material safety data sheet (MSDS) with them. This should give you the details you need to check through the AVPMA site.

There are several ways to deal with pests: repel, smother or poison them. From shutterstock.com

Pesticides

There are three ways to deal with pests (well, four if you count laboriously picking them off your plants): repel, smother or poison them. All these can harm people if they are exposed to significant quantities. But in an urban garden, exposure to pesticides is typically small and of limited duration.

Common smothering pesticides are oils such as petroleum oils used to control, say, leaf pests on citrus, or pests in a variety of other circumstances. If you apply these often, without gloves, you might get skin irritation; or lung irritation if you breath the spray in. So always follow the directions, which include wearing gloves and spraying so the wind doesn’t blow the spray back into your face.

Pyrethrums are found naturally in some chrysanthemum flowers. From shutterstock.com

Modern poisoning insecticides include the pyrethrums which are found naturally in some chrysanthemum flowers. Both the natural pyrethrum and synthetic pyrethroids have low toxicity to humans – particularly at the doses found in garden products. Continuous use of pyrethroid insecticides has no health implications for humans if instructions are followed.

Neonicotinoids are synthetic insecticides that mimic nicotine, which is toxic to insects. These have a place in pest control if used thoughtfully and sparingly. Unlike pyrethroids, these insecticides target a pathway in the insect nervous system shared with humans, so could potentially harm us.

When used as directed, poisoning should not occur and animal studies suggest human exposure should not lead to significant health effects. Neonicotinoids are toxic to bees, although Australia has not had the big bee crash seen in the US and parts of Europe.

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Further reading: Birds, bees and bugs: your garden is an ecosystem, and it needs looking after

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Chronic use of neonicotinoids in a human gardening population has not been assessed for long-term health effects, but a small study of agricultural workers has shown no effect of chronic exposure. Another small study, however, suggests some association with memory loss.

Herbicides

Again, there is a bewildering variety of herbicides, depending on what weedy species is being targeted and how the weed is being killed.

Right out of the gate is glyphosate, used for broadleaf weeds. This chemical, commonly sold as Roundup, caused some controversy after the International Agency for Research on Cancer (IARC) concluded it was a probable human carcinogen.

The Lawn Care Advice site/Screenshot

However, the IARC’s determination was based on only a small number of animal studies and didn’t include a number of animal studies where glyphosate did not cause cancer. It also said nothing about risk; that is, what is the likelihood glyphosate would cause cancer at the concentrations humans are usually exposed to?

The European Food Safety Authority and the AVPMA have evaluated the evidence and determined that under appropriate handling conditions applicable to general backyard gardeners, there is no risk to humans.

As a comparison, a homemade herbicide of salt, vinegar and soap that is claimed as a replacement for glyphosate is more toxic than glyphosate.

Another herbicide for woody weeds, like blackberry, is Triclopyr. This can cause eye and skin irritation, but has no serious long-term health impacts if proper safety procedures are followed.

When using garden chemicals, always wear gloves to avoid irritation. From shutterstock.com

Fertilisers

There are many formulations and varieties of fertilisers depending on soil type and location (where I live is basically sand). Health risks are basically related to long-term inhalation of fine particles, which could cause breathing difficulties. Once again follow the safety instruction.

Caveat

Just because a given product is not, or minimally, toxic to humans, that does not mean you should apply it to your garden by the bucket load. Always apply any garden chemical with care and thought, using the right amount at the right time for the right purpose.

Any agent you apply or spray can cause adverse reactions if you don’t use it as directed. Getting “organic” garlic and soap insecticide spray in your eyes will hurt like billy-o, just like the latest you-beaut synthetic pyrethrum spray, even though both are pretty much non-toxic to humans.

Inhaling dusts can irritate your lungs. Always make sure you are wearing gloves, apply sprays and dusts downwind and wear goggles if necessary. Always follow the directions.

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You can read the other articles in our gardening series here.

Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

No, nanoparticles in baby formula will not harm your baby

The health scare surrounding nanoparticles might lead to people abandoning formula unnecessarily, with serious impacts on babies’ health. from www.shutterstock.com

Ian Musgrave, University of Adelaide

If you watched Channel 7 news this week, you would have learnt about a study commissioned by Friends of the Earth that found “potentially toxic” nanoparticles in Australian baby formula.

The study’s spokesperson said calcium phosphate nanoparticles (nano-hydroxyapatite, also known as nano-hydroxylapatite) caused kidney and liver damage. That claim was, how shall I put it kindly, just a little misleading.

https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2F7NewsAdelaide%2Fvideos%2F1606605372703445%2F&show_text=0&width=560

I have the study the spokesperson mentioned before me, which was conducted in rats, not humans.

The researchers injected calcium phosphate nanoparticles directly into rats’ body cavities (instead of oral administration as happens with baby formula) at concentrations around a million times higher than found in the baby formula.

Let me quote from the study’s findings:

The normal levels of AST, ALT and A/G [liver enzymes indicating liver damage] in the n-HA [nano-hydroxyapatite] group suggested no inflammation and necrosis induced by accumulation of 100 mg of n-HA particles. In the liver function there was almost no damage. Moreover, no significant change on values of BUN and CR [urea and creatine] than the control, which also suggested n-HA has no effect on renal function.

In other words, there were no ill effects on liver or kidney function, the direct opposite of what the media reports were claiming.

Even if you injected 100 milligrams of pure nano-hydroxyapatite directly into a newborn baby’s body (equivalent in baby terms to the dose given to the rats) there would be no significant effect on liver or kidney function.

The spokesperson’s misleading message caused unwarranted concern. On a now deleted Sunrise Facebook post discussing this report, the commentors’ concern and fear was palpable. Causing unreasonable fear is irresponsible.

Nanoparticles occur naturally

Nanoparticles have become the latest bogeyman, despite nanoparticles occurring naturally. The media report that fuelled the controversy failed to put nanoparticles in their natural biological context, provide any significant support that particles detected in milk are engineered nanomaterials, nor provide evidence of harm for the levels found.

Infant formula is based on milk, which naturally contains calcium and phosphorus (as calcium phosphates). Milk is an important source of calcium, which forms the basis of bones and teeth. The calcium and phosphates are in a complex balance between soluble and protein-bound forms.

One of the forms of calcium phosphate in milk is hydroxyapatite (also found in tooth enamel). So it is unsurprising that hydroxyapatite is found in dried infant formula, which is mainly dried milk powder.

Nanometre-sized particles of calcium phosphate also form naturally in drying milk.

Other studies have found no effect

Researchers have studied the safety of consuming hydroxyapatite nanoparticles before.

Animals who ate the nanoparticles (added to their food, as opposed to having them injected) showed no toxicity at levels well above those present in milk (up to 100 milligrams per kilogram of body weight a day for a year).

Even if you inject them (into veins or into body cavities), you need levels well above those found in infant formulas to cause damage (50 milligrams nano-hydroxyapatite per kilogram body weight in rats).

To give you an idea of how much higher this is with respect to infant formula, the highest levels of hydroxyapatite nanoparticles in any formula is 287 particles in 10 grams of formula.

Yes, that’s particles not milligrams, not micrograms but actual particles. We are talking nano- to femtograms here, amounts so small it is hard to visualise. These levels are a million times or more less than levels found to have produced no effects in animals (and even lower than levels that do cause damage).

Hydroxyapatite nanoparticles have been widely developed to aid bone repair, deliver drugs and have been extensively tested. All results suggest that even levels required to be drug delivery agents, well above those found in baby formula, have no significant adverse effects.

The body dissolves the nanoparticles anyway

These nanoparticles will also not stay nanoparticles: they dissolve in the stomach fluids, allowing their calcium to be absorbed.

Newborns and very young babies’ stomach fluids are less acidic than older babies and young children (pH5), but still acidic enough to dissolve hydroxyapatite.

And particles are more easily dissolved the smaller they are. So, nanoparticles are likely to be even more rapidly dissolved into their component calcium and phosphate ions than larger particles.

What’s the take-home message?

There are no significant public health implications for these small crystals of naturally occurring calcium phosphates in milk-based baby formula.

The way the Friends of the Earth study results have been presented, with misleading references to irrelevant studies, has caused unnecessary fear and concern, and may lead some to abandon formula unnecessarily, with negative impacts on baby health.

Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

New evidence for BPA and obesity? Not so fast!

Ian Musgrave, University of Adelaide

The headline image of the University of Melbourne’s Facebook link to its press release about recent research on Bisphenol A (BPA) is of a takeaway coffee cup. The kind that does not have any BPA in it at all ^[1]. The headline “Obesity Link to BPA” directly below the image of the cup is guaranteed to cause unwarranted consternation in consumers of our favourite takeaway beverage which I’m sure the researchers did not intend.

Bisphenol A (BPA) is one of the most recognizable chemicals to the general public. A component of some kinds of hard plastics, plastic liners for tins (but not paper cups) and certain kinds of thermal paper, it has generated quite a lot of concern as BPA is a mimic of the hormone estrogen.

However, it is a very weak mimic of estrogen (and some other hormones). BPA is typically 10,000 to 100,000 times weaker than estrogen (see for example here). BPA may also act through some other pathways, but again it is not very strong. Studies of our exposure to BPA have consistently shown that we have a safety margin of about 100-1,000 fold between the threshold for BPA to produce biological effects and the levels in our bodies.

Still, we are not cavalier about BPA’s presence in our environment and studies continuously reevaluate BPA’s potential for harm, which is where this latest study from the University of Melbourne comes in.

So what did the researchers do?

They took cow embryos and placed them in tissue culture conditions. They then exposed them for four days to either BPA at 1 or 10 nanogram per millilitre of tissue culture solution (1ng/mL) or estrogen at 1 or 10 ng/mL ^[2]. To make sure that BPA was working through estrogen receptors they also exposed some of the embryos to a combination of BPA and a specific blocker of estrogen receptors.

What did they find?

Both 10 ng/mL BPA and estrogen reduced the number of 8 cell embryos that progressed to blastocysts by around 7% (1 ng/ml of BPA and estrogen had no significant effect). Roughly 10% fewer of the 10 ng/mL treated blastocysts were of implantation quality.

What about obesity – where does that fit in?

In embryos treated 10 ng/mL of either BPA or estrogen, there was a roughly 50% increase in glucose uptake and lactate production. This increase was prevented by the selective estrogen receptor blocker (the 1 ng/mL concentration of BPA had no effect).

That’s it?

While there is no direct evidence that increased glucose uptake and utilisation in the embryo will cause obesity later in life, it is at least plausible that this could somehow predispose organisms to obesity later in life.

So should we be worried?

Not really, as well as the link being weak, there are two key issues which means that the relevance to humans is limited.

One is that the concentrations used in the study are very unlikely to be achieved in the human body under normal conditions. 10 ng/mL is a really tiny quantity, and it is hard to visualise this ^[2], but the quantities in the human body are even smaller, on the order of picograms/mL (that is a thousand times less).

Measuring the levels of BPA in blood and biological fluid accurately is very difficult. BPA is very rapidly metabolised, most of BPA in the circulation is inactive metabolites. Not only do the low levels stretch the limits of our measuring devices, but BPA present in the plastics that are used to draw and store blood and other biological fluids can contaminate these fluids, giving spuriously high readings.

Very careful measurements and studies using BPA where the hydrogen atoms have been replaced with a heavier isotope of hydrogen (deuterium) have shown that levels of BPA in blood (and hence other body fluids) are well below the 1ng/mL concentration that had no effect in this study (see also here). This is backed up by back calculation from measurement of urinary excretion of BPA and its metabolites.

Another check is calculation of intake from foods and the environment. These show that intake of BPA is 100 to 1,000 times less than the new, temporary European Food Safety tolerably daily intake of 4 micrograms per kilogram body weight (which is 1,000 times lower than the lowest levels that show no effect in animal studies).

Recent studies of food exposure from Australian foods showed very low intake levels (with the new limits, you only need to consume 10 cans of soup a day of the soups with the highest BPA content to reach the tolerably daily intake).

So, altogether the evidence is that human levels of BPA are well below the levels that produce these metabolic effects in these cow embryos.

Another issue is the response to BPA. Remember how I said that BPA is 10,000-100,000 times weaker than estrogen? This has been shown in numerous receptor and functional studies, including studies on human estrogen receptors. In the current cow embryo studies BPA and estrogen were approximately equally effective, and the blocker study confirmed that the effect of BPA was through the estrogen receptor, not some novel mechanism (as in this study).

This implies that cow embryo estrogen receptors are different to human receptors and that any extrapolation to humans must be made very carefully.

The take home message?

Don’t panic over BPA and obesity. You are very unlikely to reach the bodily levels of BPA that will cause disruption of glucose metabolism in early embryos. Of course, as I have said before, the best way to reduce BPA intake is to eat fresh, rather than pre-prepared foods, especially fresh fruit and vegetables as Australians in general do not eat enough fresh fruit an vegetables (and eat too many calories, and don’t exercise enough).

Another take home message is to make sure the containers you use to illustrate your press release actually do have BPA in them. You may be consuming too many calories from the milk and sugar in your takeaway coffee, but BPA? No.

[1] I can’t link directly to the Facebook advertisement. The main illustration on the University of Melbourne press release webpage is cans of soft drink, these do not measurably contribute to BPA intake. It also has the takeaway coffee cup, which is lined with polyethylene, not BPA containing plastic.

[2] A milligram will cover the head of a pin, a microgram would be a single speck on the head of a pin, you would need a microscope to see a nanogram. In contrast, a teaspoon full of sugar is around 4 grams, one teaspoon in a 250 mL coffee will result in 20 milligrams per millilitre (mg/mL) coffee. Now dilute that a million times and you will get 20 ng/mL.

Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

Even better news: Australian honey is not likely to make you sick

Ian Musgrave

Those of us who consume honey as a tastier alternative to refined sugar would have been disturbed to see headlines proclaiming Australian honey could be making us sick. Why, you might wonder, could this wholesome and all natural product be a threat to our health?

It is all because plants, famously, can’t run away from predators.

To stop animals eating them plants often use toxic chemicals. An example is the bitter alkaloid caffeine, which deters or can even kill insects trying to munch on the plants that contain it. A far less pleasant herbivore deterrent is the class of toxic chemicals are the pyrrolizidine alkaloids. These are a large group of related compounds that can cause severe liver and lung damage. Long term consumption of pyrrolizidine alkaloids may increase the risk of cancer.

Pyrrolizidine alkaloids are present in many plants ranging from comfrey to Patterson’s curse (Salvation Jane), and small amounts of pyrrolizidine alkaloids may be found in comfrey containing salads and herbal medicines. Importantly, one source is honey.

In many parts of Australia, especially southern Australia, the weed Patterson’s Curse/Salvation Jane is a significant source of nectar for foraging bees. Patterson’s Curse produces high levels of pyrrolizidine alkaloids. Indeed it is called Patterson’s Curse in part because of it poisoning stock. Honey produced from Patterson’s Curse nectar can have high levels of pyrrolizidine alkaloids, and must be diluted with honey from other sources to reduce the levels.

To date no adverse health effects, either acute or chronic, have been attributed to consumption of Australian honey.

The headlines were generated by a recent report that shows that Australian honey has on average four times more pyrrolizidine alkaloids than European honeys. Depending on how much you ate, consumption of some of the honeys would exceed recommended European intake guidelines.

Several European guidelines recommend that people be exposed to no more than 0.007 micrograms pyrrolizidine alkaloid per kilogram body weight per day, while Australian guidelines state that people should consume no more than 1 microgram pyrrolizidine alkaloid per kilogram body weight. Australian guidelines have set the intake limits as one hundred times lower than levels that show no evidence of toxicity or carcinogenicity in animal studies. Thus there is a substantial safety factor.

European guidelines are more stringent than Australian guidelines, due to a more conservative estimate of cancer risk. While pyrrolizidine alkaloids are able to produce cancer in rats, evidence for cancer in humans is indirect. As well, the human risk is likely lower as the mechanism of carcinogenicity are likely different to that in rats. However, the European guidelines take a “zero tolerance approach” and thus have lower intake limits.

Even with this more stringent approach for most Australian honeys the risk is low. Australian honey has on average 149 micrograms of pyrrolizidine alkaloids per kilogram honey (compared to 40 micrograms per kilogram for European honeys, to give you an idea of how small that is, a single grain of sugar weighs around 600 micrograms, now imagine a third of a single grain of sugar dissolved in a kilogram of honey).

For a 70 Kg person eating the average amount of honey (around three grams per day, roughly three teaspoons^[1], this is around double the average European consumption) consumption of most of the Australian honeys would be safe at both European and Australian guidelines.

There were a few exceptions where the levels were quite high, and would have exceeded the EU, but not Australian, limits substantially. Out of 59 honeys tested five had double the EU limit and one had nearly ten times the EU limit (ironically this was an “organic” honey) these honeys are of concern.

While for the average consumer the risk is low, people who are high consumers of honey are at much greater risk. The average Australian may consume only three teaspoons of honey a day, but a small proportion of Australians consume much more.

Around 5% of Australians consume around 57 grams of honey a day. When consumed at these levels several honeys come close to the current Australian limits and substantially exceed the European guideline limits. The impact on children with lower body mass is likely to be greater as well.

On a brighter note the honey that was assayed in the headline-generating study was purchased in 2011 and 2012. Since then there has been a substantial campaign to reduce Patterson’s Curse infestation. While Patterson’s curse is not the only source of pyrrolizidine alkaloids (eg. weeds of the Heliotropium genus also contribute) this should reduce the amount of pyrrolizidine alkaloids entering into our honeys.

To reiterate, for the average consumer the risk from honey is low. However, further investigation and assays of more recent honey supplies will be needed to understand the risk to more vulnerable groups.

The bottom line is that there is no need to throw away your honey, but do eat sensible amounts of it, and make sure the kids are not eating too much.

[1] As pointed out in the comments, this may not be correct, I took this value from a FSANZ document, however, honey from different sources has different densities, according to what I can find, 2.74 grams of European honey will be two teaspoons, and 2.74 grams of Manuka honey will be around half a teaspoon.

Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

What’s in your herbal medicines?

by Ian Musgrave and Michael Bunce

Many people take herbal medicines, including traditional Chinese medicine (TCM) thinking they are doing something positive for their health. Ironically, in many cases they may be doing just the opposite.

Have you ever wondered what is actually in the herbal medicine products you buy? Has the herb on the label been replaced with another herb? Have pharmaceuticals been snuck in?

Making sure that a tablet claiming to have 500 milligrams of paracetamol really does contain 500 milligrams of paracetamol is relatively easy, there are established assays to measure paracetamol routinely. But how do you test for herbs?

Most herbal medicines are pills or powders that have removed all trace of structure we would normally use to identify plants, and many plants have no chemical signature that is able to definitively identify them. And what about all the other possible contaminants and adulterants that could hide in the complex brew of chemicals from herbal medicines?

Our research, which has just been published in the journal Nature Scientific Reports, goes a long way to answering that.

For the first time, our group of researchers from Curtin University, Murdoch University and the University of Adelaide have combined some of the most cutting-edge and sensitive analytical techniques to screen a set of traditional Chinese medicines available in Australia.

We used a three-pronged approach, combining DNA sequencing, toxicology and heavy metal testing to elucidate the true composition of 26 TCMs purchased at random from the Adelaide Markets; most were either for colds and flu’s or for general wellness.

What did we find?

Summary of the contaminants in traditional Chinese medicines (TCMs) tested in this study that contained toxic metals, undeclared or illegal contents as determined by DNA, toxicological, and heavy metal screening methods. Each TCM tested is represented in the diagram as a tablet; blue shading on tablets indicate AUST L listed medicines, red shading are not-listed with the TGA regulatory body. TCMs deemed non-compliant
for DNA (green), toxicology (pink) and heavy metals (yellow) or a combination thereof, are represented within the Venn diagram. Coglan et al.,Sci Reports 2015

Nearly nine in ten of these medicines had some form of undeclared substance in them as either adulteration or contamination. Sixteen of TCM’s had more than one contaminant or adulterant.

While around half of these medicines were not listed with the Therapeutic Goods Administration (TGA), and should not have been available for purchase, contaminants were found in both TGA-listed and non-listed medicines. These adulterants/contaminants included pharmaceuticals and toxic heavy metals.

Plant and/or animal DNA from species not listed on the labels were also found. The most concerning finding was snow leopard DNA (snow leopards are an endangered species), which was detected in one medicine. DNA from pit viper, frog, rat, cat and dog was also detected in several medicines.

Among the pharmaceuticals found were paracetamol, antihistamines, anti-inflammatories and antibiotics, and stimulants such as pseudoephedrine. Of particular concern were drugs such as warfarin, which have significant potential for harm if not taken under medical supervision, and ephedrine, which is banned in Australia.

Significant levels of toxic heavy metals such as arsenic, cadmium and lead were found in over half the medicines. In at least four of these medicines following the directions on the label would expose you to over ten times the TGA’s regulatory limit for heavy metals in medicines.

What does this mean?

Herbal Medicines. Megan Coglan

Are the levels of undeclared materials in these products adulteration or contamination? In adulteration, the material is added deliberately. In contamination, the material is added inadvertently, for example, through unclean workplaces or herbs grown on contaminated soil.

Whether a compound is a result of deliberate adulteration or contamination has different regulatory implications. It can mean the difference between banning a substance or cleaning up the workplace.

It can be tricky to decide which is which. In TCM materials, for instance, heavy metals or toad venom may be added as part of the treatment. However, by looking at the patterns of materials we found, we can get some hints.

One TCM claiming to enhance weight gain with appetite stimulation contained pharmaceutically relevant levels of the drug cyproheptadine, a known appetite enhancer.

In another, ephedrine was found without any evidence of DNA from plants of the Ephedra genus, suggesting that in both cases the drug was deliberately added.

Intriguingly, high levels of arsenic were often found with similar levels of lead. Lead arsenate has been used as a pesticide, and the high levels may come from persistently contaminated soils.

What this means is that you should be very careful about choosing and purchasing TCMs. Definitely avoid any medicine that does not have an ARTG listing (it should have a number like AUST L 123456 on the front of the bottle). But even medicines with these AUST L labels are no guarantee of safety.

This also highlights the importance of informing your health practitioner if you are taking TCMs as adulterants might interact with conventional medication to cause adverse effects.

What are the regulatory implications?

Unlike countries such as the United States, where many herbal medicines are regulated as dietary supplements, in Australia, herbal medicines are regulated through the TGA as medicines.

TGA-regulated medicines can be approved as either “registered” or “listed”. Most herbal medicines are classified as “listed”. Unlike registered medicines such as paracetamol and warfarin, the evidence required for approval is much less stringent.

In many ways it is an honour system, where the herbal medicines sponsor says there’s no evidence of harm, and they hold documentation that shows this. Mostly, the evidence is historical, claiming that people have been using it for generations without evidence of harm. As well, if the compounds are on the TGA’s list of “generally recognised are safe” materials extensive safety testing is not required.

The TGA uses post marketing follow-up to check for compliance with the “listed” medicine regulations. This follow-up consists of random surveys as well as targeted surveys from concerns raised by consumers.

In Australia, nearly 2,000 new herbal medicines are registered each year.
In a TGA survey in 2012-2013, 145 complementary medicines were tested. Around 83% of complimentary medicines surveyed were deemed to be non-compliant, with 6% failing due to product composition, formulation or manufacturing.

Using a combination of new molecular approaches, our survey found a much higher level of adulteration and contamination in TCMs than found in the TGA’s surveys. Adding DNA ingredient screening to the TGA’s armoury of analytical methods would help ensure that undeclared ingredients are not included in the herbal medicines we consume.

And Finally:

The herbal medicine industry is a billion dollar international industry, with products travelling all over the world.

Globally, we need a better auditing “toolkit” to ensure consumers of herbal medicines, as well as people testing their efficacy, are not being misled.

This research, we think, provides a roadmap to more effective regulation of the herbal medicine sector.

* The results of our screening have been passed on to the TGA, which is following this up.

Ian Musgrave, Senior lecturer in Pharmacology

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.
 

In the vaccine debate, science is just getting its boots on

Ian Musgrave

There is an old saying that a lie will be heard around the world while truth is still getting its boots on. This was brought home to me during a radio interview I did on Tuesday night in the wake of the Federal Government’s decision to remove the conscientious objection exemption for vaccination. I was astonished that in 2015, some of these pieces of misinformation are still out there, and still believed, if the passionate radio callers (and several posts in my Facebook feed) are any indication.

Here is a sample of some of the misinformation and misunderstandings I encountered on the radio show and on the internet in the past 24 hours (paraphrased slightly).

“Why should we inject our kids with polyethylene glycol/brake fluid?” We don’t. There is no ethylene glycol in our vaccines. We do have harmless traces of a completely different chemical, 2-phenoxyethanol, which is an antibacterial helping keep the vaccines sterile.

“Why are we injecting our kids with formaldehyde?” Formaldehyde is used to inactivate viruses in some vaccines. After clean-up, minute traces are left, but the amount you would get from a vaccine injection is much less that is circulating naturally in your blood. Yes, your body makes formaldehyde. If you are seriously worried about formaldehyde, don’t eat apples or pears, which contain much more formaldehyde than vaccines. For details see here and here.

“Why are we injecting our kids with mercury?” We aren’t, there has been no mercury in kids vaccines in Australia since 2000. Especially those in the vaccination schedule. Note that the amount of mercury in the Thiomersal preservative is less than what you would get from eating a can of tuna and no one seems to be advocating a fish free diet for kids.

“Why are we still giving kids small pox vaccine when small pox is extinct?” We are not. And I am astonished that anyone would think that we did, but this (paraphrased) was an actual question.

Measles vaccination conquers measles. Source: Epidemiol Rev (2002) 24 (2): 125-136. doi: 10.1093/epirev/mxf002

“But we don’t need vaccines, these diseases were going before vaccines”. Nope, see that graph? That’s the incidence of measles in the UK before and after the vaccine, note the strong correlation between the fall in measles and the vaccine coverage of the population. Similar graphs are seen for the US and Canada (see here for the most dishonest anti-vaccination graph ever).

Australia stopped collecting data on measles incidence so there is a big gap in our data, but the incidence of the disease was higher before the vaccine than after. Same goes for pertussis (we had just had an epidemic when the vaccine was introduced), diptheria and Heamophilus Influenza B (and if you want to claim it’s all hygiene and diet, the HIB vaccine was introduced in the ‘90’s where nutrition and hygiene was at modern standards). See the Australian Academy of Sciences “science of vaccination” for graphs and details.

“There have been no deaths from measles since 2000”, this is actually a false statement about US data. 2000 was the year that endemic measles was declared extinct in the US. In Australia, we haven’t has a measles death since 1995. Unsurprisingly, since vaccination has been so effective.

However, in the US the has been 8 deaths during the epidemics caused by unvaccinated people catching measles overseas and bringing it back to the US, where it spreads mostly amongst the unvaccinated. In the US, it is usually linked to the heinous meme “no measles deaths since 2000, hundreds of measles deaths from the measles vaccine”. This pernicious statement is untrue, there have been no deaths due to the measles vaccine.

“What about that study that showed vaccines cause autism”. No, just no. Andrew Wakefield’s study, since retracted for unethical conduct, was so sloppy that it was meaningless, and may even be fraudulent. This unethical study has caused thousand of people to forgo measles vaccines, with kids getting caught in epidemics that should never have happened.

In the debate about our response to under vaccination, it is assumed that people refusing vaccines are making rational choices, weighing up the pros and cons of vaccination versus side effects with the best available data.

The controversial Leunig cartoon that shows a mother fleeing a barrage of syringes inadvertently sums up what it is really about.

Fear

As the talking points I’ve encountered show, people are coming up with objections that are either wildly distorted or flat out untrue but they all have one thing in common. They all directly stoke the fear that by vaccinating our children we will harm them. A rational choice is difficult to make in this environment.

That a lie can travel around the world before truth gets its boots on is never truer than in this debate. This recent article contains talking points not covered above that are either not true or wildly distorted (Fluarix does not contain foetal bovine serum, the virus for the vaccine is grown in eggs; vaccinations are not intravenous and so on). But I’ve already spent three days and over 1,000 words to cover the standard false or misleading claims and I have to stop at some point.

All the items I talked about have been dealt with long ago. But if you do an internet search for “Australian vaccine information” three of the top five hits are vaccine denialist sites. In this age of Dr. Google sites that play on fears will trump the more sober (and boring) official sites.

My approach to vaccine refusers (the people whose decisions have been influenced by misinformation and fear, as opposed to hard core vaccine denialists) is to provide them with better and more accessible information.

This may not work as well as it might be naively imagined, a study on the best way to provide accurate vaccine information to parents who had previously failed to vaccinate their children found that although the parents understanding of vaccine safety improved, they were no more likely to have their children vaccinated. Some parents became even less likely to vaccinate their children.

Even in the light of this somewhat depressing knowledge, we should not stop trying to get truth out there. One of the difficulties in communicating vaccine facts is that these may leave a gap in peoples beliefs (accounting for their reluctance to accept the facts). An approach I’ve mentioned before is replacing the gap with an alternative narrative. Whichever approach we use, we need to keep the facts front and centre.

Remember, this is not just abstract knowledge, or “cute science facts”, but information that will keep real kids out of hospital and in some case save lives.

Truth (and science) may take time to get its boots on, but those boots were made for walking, and the journey has just begun.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

Still no good evidence that most complementary medicine works

Ian Musgrave

The complementary medicine industry has been quick to respond to an opinion piece by Cassandra Wilkinson in The Australian newspaper on the lack of evidence for many complementary medicines, and particularly complementary medicines for children.

Alan Bensoussan of the National Institute of Complementary Medicine claimed in a follow-up letter to the Australian that complementary medicines included many well-established medicines (scroll down for the letter). He claimed that these well-established complementary medicines include medicines that prevent spina bifida in newborns, osteoporosis in the elderly, macular degeneration, cognitive decline, and childhood bronchitis.

Except, well, they don’t. You can search for clinical trials of complementary medicines for the above complaints that show them to be “well-established” and you will come up empty handed. You will find one or two studies suggesting that there might be a beneficial effect of some complementary medicine (see here for the inconsistent evidence for Ginkgo and macular degeneration), but nothing “well-established”.

Similarly, a search of systematic reviews, which look at the overall evidence from multiple studies, turns up nothing, although one treatment for osteoarthritis (not osteoporosis) glucosamine, might be beneficial in some patients. This is hardly “well-established” though.

If you go to the web site of the National Center for Complementary and Alternative Medicine and look up “bronchitis” you get the following “There is not enough evidence to support the use of any complementary health practices for the relief of asthma”. If you look up cognitive decline, you get a page that shows all current complementary therapies either do not help (and this includes the favoured herb, Gingko) or have not enough evidence.

So where does Alan Benoussan’s claim come from? Some clarification comes from an article in Pharmacy News, where Steve Scarff, regulatory and scientific affairs director of the Australian Self Medication Industry, also claimed that there is a growing evidence base to support the use of complementary medicines. Mr Scarff used as examples of clinically-supported complementary medicines “calcium and vitamin D for osteoporosis, omega-3 fish oil for heart disease, folate for pregnant women in preventing spina bifida, iron supplementation for anaemia, and evidence to support St John’s Wort for depression”.

One problem here, all but one (St. John’s Wort) of these are conventional medicine, not complementary medicine. It was conventional medicine that researched the physiology, did the clinical trials and developed the therapies and approaches, not complementary medicine (calcium and vitamin D for osteoporosis (note that this is not “one size fits all” medication), omega-3 fish oil for heart disease, folate for pregnant women in preventing spina bifida). Just because you sell vitamin pills doesn’t mean you get to appropriate the hard work of medical researchers and clinicians.

“Complementary” use of vitamins is usually use of high dose vitamins, such as high dose vitamin C for colds and flu’s (which doesn’t really work) or high dose antioxidant vitamins (high dose fat soluble antioxidant vitamin are actually associated with slightly worse outcomes and in some cases a slight increase in death). And vitamin supplementation of healthy, non-vitamin deficient people also has no benefit.

St. John’s Wort does have a modest anti-depressant effect (although very variable due to wide differences in composition). It also has significant side effects and very serious interactions with conventional medicines, so is not recommended for therapy. People have died because of it. Information on the side effects of St. John’s Wort from points of sale are generally very poor and most consumers will be unaware of them (see also here)

The claims from the National Institute of Complementary Medicine and the Australian Self Medication Industry does nothing to address the issues brought up in the opinion piece, namely that there is no evidence that complementary medicine works for children and that between 70-90% of complementary medicines surveyed did not meet regulatory requirements (71% had manufacturing or quality problems). As well, complementary medicine sponsors drag their feet when asked to remove non-compliant medicines (see here and here).

This is what the National Institute of Complementary Medicine and the Australian Self Medication Industry should be dealing with, not claiming the work of conventional medicine as complementary medicine.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

So, the NHMRC has found homeopathy doesn’t work. Now how do we get the message across?

By Ian Musgrave

The NHMRC has released its final statement on homeopathy. To no ones great surprise, the report concluded that there was no evidence that homeopathy was effective in treating any of 63 separate medical conditions.

I have already dealt with aspects of the interim report, and articles in The Conversation have already dealt with the report in general (see here and here), so I would like to look at it from a different angle; how do we effectively communicate the science behind the report?

Sure, the report is on the web, and has been mentioned in a variety of media and radio programs, but is this going to be effective? The need to effectively communicate these findings is highlighted by two separate occurrences, the recent debate over vaccination in the light of measles outbreaks overseas, and the recent CSIRO report that up to 40% of Australians are “disengaged” or actively distrust science.

After all, the target audience for this information is not the people who have been following the evidence, and are well aware that homeopathy is ineffective. To some degree the people who want to treat mild or self limiting conditions, for example insomnia, and who think that homeopathy is some form of herbal medicine are also not the target audience.

What we are worried about most is those people with serious conditions who abandon standard therapy for ineffective homeopathy (for example, trying to treat diabetes with homeopathic dilutions of uranium salts). We accept that adults should be able to choose (or reject) their therapies. But we also expect that people choose or reject therapies based on the best available evidence. What happens when people reject that evidence?

A recent paper looked at various ways to communicate with parents to increase vaccination rates. They found that parents accepted that the MMR vaccine did not cause significant side effects after the various communication strategies, but were not inclined to get their children vaccinated. One subset of parents, those who had the least favourable views on vaccination at the beginning of the study, were now LESS likely to vaccinate their children.

This is consistent with other studies (see also here) showing that when people with deeply entrenched beliefs are confronted with facts that disprove those beliefs, paradoxically they become firmer in their beliefs.

So how do we effectively communicate the science in the report? The NHMRC site has meticulous information on what they did, summaries and a FAQ, but we have to get people to read them. Most news articles and radio shows do not provide the information to find the report.

From a science communication point of view, most of the information on the NHMRC site is too technical for the general public. As an example of a good way to convey science around a contentious issue, the Australian Academy of Sciences has a great web accessible document that simply and clearly explains the science behind vaccines.

However, if you google “Vaccine Information Australia” you will see 4 of the top 10 results are vaccine denialist sites (and 3 of the top 5), and the AAS report is nowhere to be found.

As well as finding information in a format accessible to the general public, we need to consider that those most at risk of ignoring conventional medicine for homeopathy are also very likely to be in that 20% that the CSIRO found to be disengaged from or distrustful of science. As well, peoples perception of health and their health philosophy can make this a very emotionally charged issue.

We need to carefully consider how to approach this audience. In the light of the pediatrics paper, referenced above, where factual information led people to be less likely to vaccinate, merely giving people the facts is unlikely to be enough.

However, there are a variety of approaches that can be tried. Most of these have been developed in relation to politics or global warming, but the processes that are involved are similar.

In view of how homeopathy may be deeply linked with peoples world views, and showing homeopathy is no more than placebo may leave a gap in peoples beliefs (accounting for their reluctance to accept the facts), an approach such as replacing the gap with an alternative narrative may be the best approach.

Whatever the approach we use, the publication of the NHMRC report on homeopathy is the beginning of a long process of engagement, not the end of the matter.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.