[Catalist] Nanoparticles in Foods

Sat Sep 26 21:10:17 AEST 2015

Greetings Leon, 

Tic-Tacs  are not part of my diet and never will be as I do not wish to add to my intake of nanoparticles.

Leon you continue to amaze me with your demonstrated knowledge of the essential methodology of research in the biological sciences.

Best Regards,

Mike McGarry

> On 26 Sep 2015, at 5:12 pm, Leon Harris <leon at quoll.com> wrote:
> 
> Hi Mike,
> I'd be inclined to take a bit of a chill pill on this one.
> “Titanium dioxide nanoparticles induce DNA damage and genetic instability in vivo in mice” looks like a classic kite-flying biology paper here.
> The experiments were done with quite contrived anastase TiO2 particles, which are not the same as the rutile form used in food and paint products (they are a few hundred times more active). They used only 5 mice per test, which is an unacceptably low number to generate any kind of meaningful data. The 8 hydroxy guanidine assay that those guys used is super sensitive to user error, and if not handled carefully can measure "degradation artifacts" in otherwise ordinary tissue. This means, that unless you have blinded the samples to the assayer, you have the potential for bias (not fraud, not malice, just wanting to believe). If the study is your PhD thesis, you have enough personally invested into it to have big bias issues.
> 
> This isn't to dismiss the value of this paper entirely. But science requires replication, and these findings aren't adequately replicated in the literature yet, despite having a couple of years to do so. I'd wait.
> 
> Many things cause oxidative damage to cells. We are the lucky survivors of the great oxygen catastrophe, some 3.2 billion years ago, and now cope with breathing a gas which is more reactive than chlorine, for breakfast. Early studies suggested something like 2% of electrons that flow through your mitochondria leak out and end up as free radical species (Irwin Fridovich was the author of that), although my old boss reckoned the proportion was much lower than that. Here's a possible scenario for you: If you are treating animals to different levels of TiO2 exposure, and you don't want them to eat each other's poo, you might house them in separate cages for separate dose rates. Well, at least the control ones, that shouldn't get to eat any TiO2. Illness causes a huge surge in oxidative damage, and chronic infection can be easily seen in 8-OH guanidine excretion in the urine. With most of the mice in one of the cages, you can see how the controls get a lower value.  Now I am not saying that this is what happened, but you can see how good-looking studies can get befouled with bias and artifacts. That is why we await some more detailed, larger, blinded and well controlled repetition before we get too excitable over one study.
> 
> Biological research is hard, arguably harder than a lot of the physical sciences, and full of confounding pitfalls, traps and uncontrollable variables. It is so easy to be blindsided by something that in retrospect seems obvious, but actually is unknowable at the time, owing to the complexity, history and well just mess of the systems involved.
> 
> By the way, at the doses of TiO2 fed to those mice, you wouldn't want to be eating tic-tacs while cleaning the cage! To mangle the advert a bit, getting distracted could lead to an un-cool surprise!
> 
> 
> Cheers,
> Leon
> 
> On 26/09/2015 3:50 PM, Michael McGarry wrote:
>> Greetings Science Colleagues,
>> 
>> Focus Question 1: Are the nanoparticles added to foods safe for human consumption?
>> 
>> “Big questions about risk assessment of nano materials"
>> 
>> URL 1: https://theconversation.com/big-questions-about-risk-assessment-of-nanomaterials-44835 <https://theconversation.com/big-questions-about-risk-assessment-of-nanomaterials-44835>
>> 
>> “Nanoparticles and nano safety: the big picture”
>> 
>> URL 2: https://theconversation.com/nanoparticles-and-nanosafety-the-big-picture-22061 <https://theconversation.com/nanoparticles-and-nanosafety-the-big-picture-22061>
>> 
>> “Explainer: Nanotechnology and you”
>> 
>> URL 3: https://theconversation.com/explainer-nanotechnology-and-you-743 <https://theconversation.com/explainer-nanotechnology-and-you-743>
>> 
>> “Titanium Dioxide Nanoparticles in Food and Personal Care Products”
>> 
>> URL 4: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3288463/ <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3288463/>
>> 
>> “Titanium dioxide nanoparticles induce DNA damage and genetic instability in vivo in mice”
>> 
>> URL 5: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3873219/ <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3873219/>
>> 
>> Focus Question 2: Does existing Australian federal government legislation/regulation require the labelling of foods that contain added nanoparticles?   
>> 
>> “Nano material Health Hazard Review: Health effects of titanium dioxide nanoparticles”
>> 
>> URL 6: http://www.nicnas.gov.au/communications/issues/nanomaterials-nanotechnology/nicnas-technical-activities-in-nanomaterials/nano-titanium-dioxide-human-health-hazard-review/nano-titanium-dioxide-technical-information-sheet <http://www.nicnas.gov.au/communications/issues/nanomaterials-nanotechnology/nicnas-technical-activities-in-nanomaterials/nano-titanium-dioxide-human-health-hazard-review/nano-titanium-dioxide-technical-information-sheet>
>> 
>> “Contemporary and Future Challenges for Australian Nano regulation”
>> 
>> URL 7: https://law.anu.edu.au/sites/all/files/users/u9705219/236-ssrn-nanoreg_in_aust.pdf <https://law.anu.edu.au/sites/all/files/users/u9705219/236-ssrn-nanoreg_in_aust.pdf>
>> 
>> A Request to Science colleagues:
>> 
>> Important Question: Do you have a list of specific foods and the added nanoparticles that these listed-foods contain so that I can exclude such foods from my diet?
>> 
>> Thanks and Best Wishes,
>> 
>> Mike McGarry 
>> 
>> 
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