Is Julian Cribb Right?

Last week, during Dr Karl’s segment on 720 ABC radio in Perth, he had a guest by the name of Julian Cribb, who has recently written a book entitled “poison planet”. This book follows up other books with such cheery titles as “The Coming Famine” and “White Death.”

I had never heard of him before last Thursday, but he apparently passes himself off as a “science writer.” When I looked into it, all I could come up with is that he is a journalist, with no mention of any scientific qualifications.

I sent him an email to find out what his qualifications were, but have not as yet received a reply.

Anyhow, over the space of a few minutes on 720 last Thursday he managed to imply that anyone who breastfed babies was giving them “a mouthful of pesticides” and that we shouldn’t use plastic baby bottles as they contain toxic chemicals.

By the end of the show panicked mothers were texting in to ask whether they could use stainless steel bottles to feed their babies, and one mother said “thanks for making me feel like I’m poisoning my baby.”

Let’s look at these two claims and see what the science says.

The use of pesticides in Australia is controlled by the APVMA (Australian Pesticides and Veterinary Medicine Association). Essentially, it is impossible to use a pesticide in Australia without a licence from the APVMA.

This applies to the cans of fly sprays that you buy from the supermarket, commercial pest controllers, and also fruit growers.

Most people don’t know this – they think that fruit growers have open slather to spray whatever the hell they want onto their crops as often as they want, just so long as the fruit gets to market intact. But the very opposite is the case.

They must apply to the APVMA for a licence for any pesticide they wish to use. And this licence does not just refer to the particular chemical, but to every aspect of the procedure. That is, they must specify the exact concentration of chemical used, the coverage rate (litres sprayed per acre), spraying frequency, and withholding period. The withholding period refers to the time period between the last spray and the arrival of the fruit on the supermarket shelves.

Growers must keep a log of their spraying schedule, as it is subject to inspection at any time. And on top of all this, inspectors go to the markets where they take fruit directly off the trucks, and take them to a lab for testing. Any occasions where the level of pesticides on fruit is above the guidelines results in hefty fines.

So can the APVMA be trusted?

Well, it depends who you talk to. Fruit growers see them as the Gestapo, because their extremely conservative approach places a great burden, both practically and in terms of the regulatory requirements on them.

And they are certainly conservative. The amount of pesticide that they allow to be sprayed, or to remain on fruits, has safety factors upon safety factors upon safety factors. For for example, one of the measurements they use is the NOEL (No Observable Effect Limit).

This is a clinical number which tells you what level of a chemical you can have in your bloodstream before any effect whatsoever is observed, no matter how minor. To give you an idea of how conservative the APVMA is, they take this number and divide it by 10. This is a bit like saying that the best way to make sure you don’t get a speeding ticket in a 60 km/h zone is to go no faster than 6 km/h.

And there are other safety factors as well. But from the consumer’s point of view, you can have absolute confidence that none of the fruit that you get off the shelves has anywhere near enough insecticide to remotely approach a level where it could have any possible tiny effect on your health. As a matter of fact when they take the fruit for testing, most results come back as being below the level of detection of the extremely sophisticated insensitive analytical instruments that are used.

And part of this is the actual chemicals that are used. Years ago, chemicals like DDT were popular for the simple reason that they were stable – that is, they didn’t degrade in the environment. The shoe he is now completely on the other foot, and all pesticides used these days are biodegradable – that is, they degrade quickly when exposed to air or sunlight.

So the bottom line is this – Julian Cribb is completely wrong. Under the present regulations, there is just no possible way that any person could ingest pesticides off fruit that they eat to harm either themselves or their children.

The other claim he made was about plastics, and that they are unsafe for children. The implication, I suppose, is that being petrochemical products, these products are inherently evil, as we all know that oil companies are evil.

Again, this does not stack up. The only chemical that has been raised as a concern in plastic bottles or plates is bisphenol A (BPA). In sufficiently high levels, this chemical can act as an artificial hormone, which is similar to the mechanism of DDT.

Many studies buy both American and European food safety authorities, however, have determined that in the levels that BPA finds its way into food, there is simply no argument to suggest that it is a health hazard.

This, however, does not stop people who market baby products selling plastics that are “BPA free”, so if you want to be really, really, really sure, you simply buy these.

The other thing you can do is to look on the bottom of the item, where there will be a little triangle with a number in it. This is a recycling code that recyclers use to sort products into the right categories. The only classes of plastics that could even possibly contain BPA are those in categories 3 (PVC) and 7 (polycarbonate), so if you just avoid these, then you have eliminated even the possibility of your children consuming any BPA.

So if you threw out all your plastic bottles after listening to the show last Thursday, rush out to the SULO and retrieve them. Actually, don’t – buy new ones.

One warning about plastics, however – make sure they are microwave safe before you blast them. If in doubt, put the empty vessel into the microwave and zap it. If it gets hot, it’s not microwave safe.

The Chemistry of Weight Loss #2: Our body’s fuel system

Yesterday we looked at the chemistry of fat. Elsewhere, we have looked at the chemistry of carbohydrates

So which one does our body use?

Our body is a complex reactor which is capable of converting  fuel into energy. rather like our car. If we want our car to run, we have to put the right fuel in.  If we have apetrol car  and we put diesel in, for example,  it won’t run.

In just the  same way,  how body has a fuel system . Now it’s not quiet  as simple as that ,as our body  actually has several fuel  systems ,but there is one major  system that  dominates all others  that will look  at  today.  Essentially, our  body runs on  glycogen .

Glycogen is the  simplest  carbohydrate , and is what any complex carbohydrate must be broken  down  into  in order to act as a fuel . As I have discussed elsewhere,  if the glycogen is coming from  complex carbohydrates, then  this is a simple  process,  as simple as breaking a Lego  structure  into individual blocks. This process  can happen quickly  and it is the fuel that  our body uses most of the time,  particularly when doing anything at  all energetic.

Under sustained periods of exercise ,if how  body runs out of  complex carbohydrate,  it runs out of glycogen ,and this process is called going  “to the wall “. This is something experienced by marathon on runners for example.  And it’s the kind of thing  you experience if you skip  breakfast and lead a  busy morning.  By the time lunch rolls round,  you are very lethargic.

So the  lesson is,  that most of the time we are running on  glycogen.

This means that if we run out  of complex carbohydrate , our body must manufacture glycogen from somewhere else , and this is where it becomes complex,  and also represents ana opportunity for  weight loss.


The Chemistry of Weight Loss #1: The chemistry of fat.

We’re a nation of fatties – well at least that’s the popular view. Weight loss programs are scattered across the internet, TV, and (women’s) magazines.

So who do you believe? Which programs and/or diets work, and why?

Well, it’s not too hard to understand, if we go back to basics and look at the chemical reactions that occur in our body, what fat is, how it is made, and how it is removed. Like most things in life, there is a chemical explanation.

The first point to understand is that your body is an incredibly sophisticated chemical reactor that is able to convert very different chemicals into each other, with an efficiency and specificity that would be impossible in any laboratory. No industrial process in even the most sophisticated pharmacalogical facility in the world would be capable of carrying out the sophisticated and complex chemical reactions that our body does every day, silent and unseen.

Lets start by looking at the chemistry of fat. Essentially any animal or vegetable fat is a triglyceride, which is basically shaped like an E:

Three fatty acid chains are connected to a glycerol backbone, hence the name. Note that the 3 fatty acid chains are all straight, with the carbon atoms linked by single bonds. We call this a saturated fat because you can’t fit any more hydrogens on it.

Contrast that structure with this:

The third fatty acid chain has a double bond (in green). This molecule is no longer saturated, as there is room for two more hydrogens. That is, two hydrogens could be added across this bond, to convert it to a single bond and make it look like the molecule in the upper image. So because it is not saturated, we say it is unsaturated. Specifically, it is monounsaturated, as there is one double bond.

If there is more than one double bond, it is said to be polyunsaturated.

Now, you will note that the carbon chain with the double bond is bent. The implications of this is that the molecules will not stack together very well on top of each other, in just the same way that regular shaped boxes will stack together easier than irregular shaped boxes.

This means that monounsaturated triglycerides are generally liquid (like olive oil) and saturated fats (like lard) are solid at room temperature.

Stay tuned

Are Generic Drugs Safe?

when you walk down the medicine while in your local supermarket looking for a headache tablet, you will see named brands such as Panadol along with several alternatives – Herron and several generic brands.

This raises two questions – firstly, are they safe, and secondly, do they work as well as big-name brands?

The answer to both questions is yes. You can be sure that they are safe simply because any type of drug is very strictly controlled by the various regulatory authorities. Companies such as Coles and Woolworths are unable to put these products up for sale until they have jumped through many hoops, in terms of the composition and manufacture of the drugs, and in fact they have had to meet the exact same conditions as products like Panadol do.

and, in fact, there is a very good chance that they are exactly the same product anyway. This is how it works – company is like Coles and Woolworths don’t actually have any manufacturing facilities  – they are all done under contract. And if you wanted someone to M headache tablets under contract, you would simply go to someone that was already making them. Makes sense, doesn’t it?

Now if you were Glaxo SmithKlineand you will work approached by a supermarket chain to manufacture headache tablets under contract, be easiest way to do it would be to simply supply then with V headache tablets that you were already manufacturing. In other words,if the generic brands contain 500 mg of paracetamol, just the same as the Panadol brand, and if V paracetamol is (obviously) going to be the most expensive component of the tablet, why would you bother coming up with a different formula for the supermarket chain?

Obviously, you wouldn’t. You would just repackage your own product for the supermarket chain. You wouldn’t make as much profit on these as you would on your premium brand, but you’d still make enough profit to making it worth your while.

I don’t know for a fact that this actually happens, mind you, but it is the most likely scenario.

So, because the drugs both contain the same active ingredient, they are both going to work just as well.

And, of course, the drug companies know this.that’s why when they advertise their products, they never have and authority figure telling you that their drugs work better than V generic brands – all they ever have is vox pop interviews with people on the street saying things like “oh, you know, I just trust Panadol.”

The “voice in the street” approach is meant to convince you, since it comes across as a spontaneous opinion (which it may well be), but the point is that no claims are being made about superior performance of the branded product.

So it’s clever marketing,but that’s all it is. Next time you need some headache tablets, go to Coles and by the generic brand for a third of the price of the Panadol. That way you won’t get a headache by paying too much!

Are White Sugar and White Rice Bleached?

I was asked a very interesting question today – are white sugar and white rice white because they have been chemically bleached?

it’s a good question – if chlorine bleach had been used in anything you ate it would obviously be a cause of concern.

And there have been cases of this kind of thing in the past. It used to be the case that decaffeinated coffee was decaffeinated with dichloromethane, a carcinogenic chemical that you certainly don’t want to be ingesting. At that time there was only one brand that was doing it a different way – HAG.

HAG coffee used supercritical carbon dioxide to decaffeinated their coffee. this was a more expensive process, the much safer as the CO2 quickly evaporated. So be other brands abandoned the dichloromethane and now also use supercritical CO2.

Back to sugar and rice.

As it happens, neither of these products have been bleached. The explanation for the white colour is simply the extra processing.

For sugar, all the brown stuff in brown sugar is impurities that are removed as part of the refining process. In other words, white is the natural colour of sugar crystals (sucrose). So it hasn’t been bleached – it has just been further purified.

And with rice, a similar situation is the case. If you take brown rice and polish it further, you eventually get back to white rice. In other words, brown rice is simply white rice with extra coatings on top. Once these coatings are polished away as part of the refining process, they become white.

Eo there you go – white rice and white sugar are perfectly safe to use. even if they may not be perfectly safe for your waistline.