Chemical du jour: how bad is BPA, really?

BPA is an additive in many plastics

When I was writing my summary of 2017 I said that there would, very probably, be some sort of food health scare at the start of 2018. It’s the natural order of things: first we eat and drink the calorie requirement of a small blue whale over Christmas and New Year, and then, lo, we must be made to suffer the guilt in January. By Easter, of course, it’s all forgotten and we can cheerfully stuff ourselves with chocolate eggs.

Last year it was crispy potatoes, and the year before that it was something ridiculous about sugar in ketchup causing cancer (it’s the same sugar that’s in everything, why ketchup? Why?). This year, though, it seems that the nasty chemical of the day is not something that’s in our food so much as around it.

Because this year the villain of the piece appears to be BPA, otherwise known as Bisphenol A or, to give it its IUPAC name, 4,4′-(propane-2,2-diyl)diphenol.

BPA is an additive in plastics. At the end of last year an excellent documentary aired on the BBC called Blue Planet II, all about our planet’s oceans. It featured amazing, jaw-dropping footage of wildlife. It also featured some extremely shocking images of plastic waste, and the harm it causes.

Plastic waste is a serious problem

Plastic waste, particularly plastic waste which is improperly disposed of and consequently ends up in the wrong place, is indisputably something that needs to be addressed. But this highlighting of the plastic waste problem had an unintended consequence: where was the story going to go? Everyone is writing about how plastic is bad, went (I imagine) editorial meetings in offices around the country – find me a story showing that plastic is even WORSE than we thought!

Really, it was inevitable that a ‘not only is plastic bad for the environment, but it’s bad for you, too!’ theme was going to emerge. It started, sort of, with a headline in The Sun newspaper: “Shopping receipts could ‘increase your cancer risk’ – as 93% contain dangerous chemicals also linked to infertility. Shopping receipts are, of course, not made of plastic – but the article’s sub-heading stated that “BPA is used to make plastics”, so the implication was clear enough.

Then the rather confusing: “Plastic chemical linked to male infertility in majority of teenagers, study suggests” appeared in The Telegraph (more on this in a bit), and the whole thing exploded. Search for BPA in Google News now and there is everything from “5 Ways to Reduce Your Exposure to Toxic BPA” to “gender-bending chemicals found in plastic and linked to breast and prostate cancer are found in 86% of teenagers”.

Yikes. It’s all quite scary. It’s true that right now you can’t really avoid plastic. Look around you and it’s likely that you’ll immediately see lots of plastic objects, and that’s before you even try to consider all the everyday things which have plastic coatings that aren’t immediately obvious. If you have young children, you’re probably drowning in plastic toys, cups, plates and bottles. We’re pretty much touching plastic continually throughout our day. How concerned should we be?

As the Hitchiker’s Guide to the Galaxy says, Don’t Panic. Plastic (like planet Earth in the Guide) can probably be summed up as mostly harmless, at least from a BPA point of view if not an environmental one.

BPA is a rather pleasingly symmetrical molecule with two phenol groups. (A big model of this would make a wonderfully ironic pair of sunglasses, wouldn’t it?) It was first synthesized by the Russian chemist Alexander Dianin in the late 19th century. It’s made by reacting acetone – which is where the “A” in the name comes from – with two phenol molecules. It’s actually a very simple reaction, although the product does need to be carefully purified, since large amounts of phenol are used to ensure a good yield.

It’s been used commercially since the fifties, and millions of tonnes of BPA are now produced worldwide each year. BPA is used to make plastics which are clear and tough – two characteristics which are often valued, especially for things like waterproof coatings, bottles and food containers.

The concern is that BPA is an endocrine disruptor, meaning that it interferes with hormone systems. In particular, it’s a known xenoestrogen, in other words it mimics the female hormone estrogen. Animal studies have suggested possible links to certain cancers, infertility, neurological problems and other diseases. A lot of the work is fairly small-scale and, as I’ve mentioned, focused on animal studies (rather than looking directly at effects in humans). Where humans have been studied it’s usually been populations that are exposed to especially high BPA levels (epoxy resin painters, for example). Still, it builds up into quite a damning picture.

BPA has been banned from baby bottles in many countries, including the USA and Europe

Of course, we don’t normally eat plastic, but BPA can leach from the plastic into the food or drink that’s in the plastic, and much more so if the plastic is heated. Because of these concerns, BPA has been banned from baby bottles (which tend to be heated, both for sterilisation and to warm the milk) in several countries, including the whole of Europe, for some years now. “BPA free” labels are a fairly common sight on baby products these days. BPA might also get onto our skin from, for example, those thermal paper receipts The Sun article mentioned, and then into our mouths when we eat. Our bodies break down and excrete the chemical fairly quickly, in as little as 6 hours, but because it’s so common in our environment most of us are continually meeting new sources of it.

How much are we getting, though? This is a critical question, because as I’m forever saying, the dose makes the poison. Arsenic is a deadly poison at high levels, but most of us – were we to undergo some sort of very sensitive test – would probably find we have traces of it in our systems, because it’s a naturally-occuring mineral. It’s nothing to worry about, unless for some reason the levels become too high.

When it comes to BPA, different countries have different guidelines. The European Food Safety Authority recommended in January 2015 that the TDI (tolerable daily intake) should be reduced from 50 to 4 µg/kg body weight/day (there are plans for a new assessment in 2018, so it might change again). For a 75 kg adult, that translates to about 0.0003 g per day. A USA Federal Drug and Administration document from 2014 suggests a NOAEL (no-observed-adverse-effect-level) of 5 mg/kg bw/day, which translates to 0.375 g per day for the same 75 kg adult. NOAEL values are usually much higher than TDIs, so these two figures aren’t as incompatible as they might appear. Tolerable daily intake values tend to have a lot of additional “just in case” tossed into them – being rather more guidance than science.

The European Food Standards Authority published a detailed review of the evidence in 2015 (click for a summary)

So, how much BPA are we exposed to? I’m going to stick to Europe, because that’s where I’m based (for now…), and trying to look at all the different countries is horribly complicated. Besides, EFSA produced a really helpful executive summary of their findings in 2015, which makes it much easier to find the pertinent information.

The key points are these: most of our exposure comes from food. Infants, children and adolescents have the highest dietary exposures to BPA, probably because they eat and drink more per kilogram of body weight. The estimated average was 0.375 µg/kg bw per day.  For adult women the estimated average was 0.132 µg/kg bw per day, and for men it was 0.126 µg/kg bw per day.

When it came to thermal paper and other non-dietary exposure (mostly from dust, toys and cosmetics), the numbers were smaller, but the panel admitted there was a fair bit of uncertainty here. The total exposure from all sources was somewhere in the region of 1 µg/kg bw per day for all the age groups, with adolescents and young children edging more toward values of 1.5 µg/kg bw per day (this will be important in a minute).

Note that all of these numbers are significantly less than the, conservative, tolerable daily intake value of 4 µg/kg bw per day recommended by EFSA.

Here’s the important bit: the panel concluded that there is “no health concern for BPA at the estimated levels of exposure” as far as diet goes. They also said that this applied “to prenatally exposed children” (in other words, one less thing for pregnant women to worry about).

When it came to total exposure, i.e. diet and exposure from other sources such as thermal paper they concluded that “the health concern for BPA is low at the estimated levels of exposure”.

The factsheet that was published alongside the full document summarises the results as follows: “BPA poses no health risk to consumers because current exposure to the chemical is too low to cause harm.”

Like I said: Don’t Panic.

What about those frankly quite terrifying headlines? Well, firstly The Sun article was based on some work conducted on a grand total of 208 receipts collected in Southeast Michigan in the USA from only 39 unique business locations. That’s a pretty small sample and not, I’d suggest, perhaps terribly relevant to the readership of a British newspaper. Worse, the actual levels of BPA weren’t measured in the large majority of samples – they only tested to see if it was there, not how much was there. There was nothing conclusive at all to suggest that the levels in the receipts might be enough to “increase your cancer risk”. All in all, it was pretty meaningless. We already knew there was BPA in thermal receipt paper – no one was hiding that information (it’s literally in the second paragraph of the Wikipedia page on BPA).

The Telegraph article, and the many others it appeared to spawn, also weren’t based on especially rigorous work and, worse, totally misrepresented the findings in any case. Firstly, let’s consider that headline: “Plastic chemical linked to male infertility in majority of teenagers, study suggests”. What does that mean? Are they suggesting that teenagers are displaying infertility? No, of course not. They didn’t want to put “BPA” in the headline because that, apparently, would be too confusing for their readers. So instead they’ve replaced “BPA” with “plastic chemical linked to male infertility”, which is so much more straightforward, isn’t it?

And they don’t mean it’s linked to infertility in the majority of teenagers, they mean it’s linked to infertility and it’s in the majority of teenager’s bodies. I do appreciate that journalists rarely write headlines – this isn’t a criticism of the poor writer who turned in perfectly good copy – but that is confusing and misleading headline-writing of the highest order. Ugh.

Plus, as I commented back there, that wasn’t even the conclusion of the study, which was actually an experiment carried out by students under the supervision of a local university. The key finding was not that, horror, teenagers have BPA in their bodies. The researchers assumed that almost all of the teenagers would have BPA in their bodies – as the EFSA report showed, most people do. No, the conclusion was actually that the teenagers – 94 of them – had been unable to significantly reduce their levels of BPA by changing their diet and lifestyle. Although the paper admits the conditions weren’t well-controlled. Basically, they asked a group of 17-19 year-olds to avoid plastic, and worked on the basis that their account of doing so was accurate.

And how much did the teenagers have in their samples? The average was 1.22 ng/ml, in urine samples (ng = nanogram). Now, even if we assume that these levels apply to all human tissue (which they almost certainly don’t) and that therefore the students had roughly 1.22 ng per gram of body weight, that only translates to, very approximately, 1.22 micrograms (µg) per kilogram of body weight.

Wait a second… what did EFSA say again…. ah yes, they estimated total exposures of 1.449 µg/kg bw per day for adolescents.

Sooooo basically a very similar value, then? And the EFSA, after looking at multiple studies in painstaking detail, concluded that “BPA poses no health risk to consumers”.

Is this grounds for multiple hysterical, fear-mongering headlines? I really don’t think it is.

It is interesting that the teenagers were unable to reduce their BPA levels. Because it’s broken down and excreted quite quickly by the body, you might expect that reducing exposure would have a bigger effect – but really all we can say here is that this needs to be repeated with far more tightly-controlled conditions. Who knows what the students did, and didn’t, actually handle and eat. Perhaps their school environment contains high levels of BPA in dust for some reason (new buildings or equipment, maybe?), and so it was virtually impossible to avoid. Who knows.

In summary, despite the scary headlines there really is no need to worry too much about BPA from plastics or receipts. It may be worth avoiding heating plastic, since we know that increases the amound of BPA that makes its way into food – although it’s important to stress that there’s no evidence that microwaving plastic containers causes levels to be above safe limits. Still, if you wanted to be cautious you could choose to put food into a ceramic or glass bowl, covered with a plate rather than clingfilm. It’ll save you money on your clingfilm bills anyway, and it means less plastic waste, which is no bad thing.

Roll on Easter…


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Just what is blk water, and should you drink it?

Christmas is almost here! Are you ready yet? Are you fed up with people asking if you’re ready yet? Have you worked out what to buy for Great-uncle Nigel, who says he neither needs nor wants anything? Always a tricky scenario, that. Consumables are often a safe fallback position. They don’t clutter up the house, and who doesn’t enjoy a nice box of luxury biscuits, or chocolates, or a bottle of champagne, or spirts, or a case of blk water.

Wait, what?

Yes, this mysterious product turned up in my feed a few weeks ago. It’s water (well, so they say), but it’s black. Actually black. Not just black because the bottle’s black, black because the liquid inside it is… black.

It’s black water.

A bit like… cola. Only blacker, and not fizzy, or sweet, or with any discernable flavour other than water.

It raises many questions, doesn’t it? Let’s start with why. Obviously it’s a great marketing gimmick. It definitely looks different. It also comes with a number of interesting claims. The suppliers claim it contains “no nasties” and “only 2 ingredients”, namely spring water and “Fulvic Minerals” (sic). (Hang on, I hear you say, if it’s minerals, plural, surely that’s already more than two ingredients? Oh, but that’s only the start. Stay with me.)

It claims to “balance pH levels” and help “to regulate our highly acidic diets”. Yes, well, I think I’ve covered that before. Absolutely nothing you drink, or eat, does anything to the pH in any part of your body except, possibly, your urine – where you might see a small difference under some circumstances (but even if you do it doesn’t tell you anything significant about the impact of your diet on your long-term health). And bear in mind that a few minutes after you drink any kind of alkaline water it mixes with stomach acid which has a pH of around 2. Honestly, none of that alkaline “goodness” makes it past your pyloric sphincter.

Finally, blk water apparently “replenishes electrolytes”. Hm. Electrolytes are important in the body. They’re ionic species, which means they can conduct electricity. Your muscles and neurons rely on electrical activity, so they are quite important. Like, life or death important. But because of that our bodies are quite good at regulating them, most of the time. If you run marathons in deserts, or get struck down with a nasty case of food poisoning, or have some kind of serious health condition (you’d know about it) you might need to think about electrolytes, but otherwise most of us get what we need from the food and drink we consume normally every day.

Besides which, didn’t they say “only 2 ingredients”? The most common electrolytes in the body are sodium, potassium, magnesium, chloride, hydrogen phosphate and hydrogen carbonate. Most spring waters do contain some, if not all, of these, in greater or smaller amounts, but it’s not going to be enough to effectively “replenish” any of them. If, say, you are running marathons in the desert, the advice is actually to keep a careful eye on your water intake because drinking too much water can dangerously lower your sodium levels. Yes, there are sports drinks that are specifically designed to help with this, but they taste of salt and sugar and/or flavourings which have been added in a desperate attempt to cover up the salty taste. This is apparently not the case with blk water which, to repeat myself, contains “only 2 ingredients”.

And, according to the blk website the drink contains “0 mg of sodium per 500ml” so… yeah.

Speaking of ingredients, what about those so-called fulvic minerals? Maybe they’re the source of those all-important electrolytes (but not sodium)? And maybe they’re magically tasteless, too?

And perhaps, like other magical objects and substances, they don’t actually exist – as geologist @geolizzy told me on Twitter when I asked.

It’s not looking good for blk water (£47.99 for a case of 24 bottles) at this point. But hang on. Perhaps when they said fulvic minerals, what they meant was fulvic acid – which is a thing, or possibly several things – in a the presence of oh, say, some bicarbonate (*cough* 2 ingredients *cough*).

That could push the pH up to the stated 8-9, and didn’t we learn in school that:
acid + alkali –> salt + water
and maybe, if we’re being generous, we could call the salts of fulvic acids minerals? It’s a bit shaky but… all right.

So what are fulvic acids?

That’s an interesting question. I had never heard of fulvic acids. They do, as it turns out, have a Wikipedia page (Wikipedia is usually very reliable for chemical information, since no one has yet been very interested in spoofing chemical pages to claim things like hydrochloric acid is extracted from the urine of pregnant unicorns) but the information wasn’t particularly enlightening. The page did inform me that fulvic acids are “components of the humus” (in soil) and are  “similar to humic acids, with differences being the carbon and oxygen contents, acidity, degree of polymerization, molecular weight, and color.” The Twitter hive-mind, as you can see, was sending me down the same path…

A typical example of a humic acid.

Next stop, humic acids. Now we’re getting somewhere. These are big molecules with several functional groups. The chemists out there will observe that, yes, they contain several carboxylic acid groups (the COOH / HOOC ones you can see in the example) so, yes, it makes sense they’d behave as acids.

“No nasties”, blk said. “Pure” they said. When you hear those sorts of things, do you imagine something like this is in your drink? Especially one that, let’s be clear, is a component of soil?

Oh, hang on, I should’ve checked the “blk explained” page on the blk water website. There’s a heading which actually says “what are Fulvic Minerals”, let’s see now…

“Fulvic minerals are plant matter derived from millions of years ago that have combined with fulvic acid forming rare fulvic mineral deposits. They deliver some of the most powerful electrolytes in the world.”

“Fulvic minerals contain 77 other trace minerals, most of which have an influence on the healthiness of our body. They are very high in alkaline and when sourced from the ground contain a pH of 9.”

I don’t know about you, but I’m not totally convinced. I mean, as @geolizzy says in her tweet here (excuse the minor typo, she means humic, not humid),  it sounds a bit like… water contaminated with hydrocarbon deposits?

Yummy.

And, by the way, the phrase “very high in alkaline” is utterly meaningless. Substances are alkaline, or they contain substances which are alkaline. “Alkaline” is not a thing in itself. This is like saying my tea is high in hot when sourced from the teapot.

There’s one more thing to add. So far this might sound a bit weird but… probably safe, right? What could be more wholesome than a bit of soil? Didn’t your granny tell you to eat a pinch of soil to boost your immune system, or something? At worst it’s harmless, right?

Tap water is chlorine-treated to keep it free of nasty bacteria.

Maybe. But then again… water is often treated with chlorine compounds to keep it bacteria-free. Now, blk water is supposedly spring water, which isn’t usually treated. But hypothetically, let’s consider what happens when humic acids, or fulvic acids, or whatever we’re calling them, come into contact with chlorine-treated water.

Oh dear. It seems that dihaloacetonitriles are formed. (See also this paper.) This is a group of substances (possibly the best known one is dichloroacetonitrile) which are variously toxic and mutagenic. Let’s hope that spring water is totally unchlorinated, 100% “we really got it from out of a rock” spring water, then.

To sum up: it is black, and that’s kind of weird and a fun talking point – although if you like the idea of a black drink you can always drink cola. It doesn’t balance your pH levels – nothing does. I don’t believe it replenishes electrolyte levels either – how can it when it doesn’t contain sodium? – and I’m dubious about the “2 ingredients” claim (could you tell?). And the oh-so-healthy-sounding fulvic minerals are most likely due to contamination from coal deposits.

All in all, whilst it might not be quite such a conversation piece, I think it would be better to get Great-uncle Nigel a nice box of chocolates this year.


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In the fridge or on the windowsill: where’s the best place to keep tomatoes?

Fresh fruit and vegetables are great, but where’s the best place to store them?

I’ve mentioned before that my Dad is a professional plant-wrangler (if you’ve never read the electric daisies post, do go and have a look – it’s a little-read favourite) and he often brings me home-grown fruit and vegetables.

What follows is an inevitable disagreement about storage, specifically, my habit of putting everything in the fridge.

In my defence, modern houses rarely have pantries (boo) and we don’t even have a garage. We do have a shed, but it’s at the bottom of our poorly-lit, somewhat muddy garden. Do I want to traipse out there on a cold, dark, autumn evening? No, I do not. So the fabled “cool, dark place” is a bit of problem. My fridge is cool and dark, I have argued, but here’s the thing – turns out, it’s too cool. And quite probably too dark.

This I have learned from the botanist James Wong (@botanygeek on Twitter), whose talk I attended on Monday this week at the Mathematical Institute in Oxford. James, it turns out, had a rather similar argument with his Mum, particularly regarding tomatoes.

We should’ve listened to out parents, because they were right. A lot of fruit and vegetables really are better stored outside of the fridge, and for tomatoes in particular “better” actually means “more nutritious”.

Lycopene is a very long molecule with lots of double C=C bonds.

Tomatoes, James explained, contain a lot of a chemical called lycopene. It’s a carotene pigment, and it’s what gives tomatoes their red colour.

Lycopene has lots of double bonds between its carbon atoms which form something chemists call a conjugated system. This has some rather cool properties, one of which is an ability to absorb certain wavelengths of light. Lycopene is especially good at absorbing blue and green wavelengths, leaving our eyes to detect the red light that’s left.

Lycopene absorbs blue and green light, which is why tomatoes appear red.

Tomatoes and lycopene also seem to have a lot of health benefits. There’s some evidence that lycopene might reduce the risk of prostate and other cancers. It also appears to reduce the risk of stroke, and eating tomato concentrate might even help to protect your skin from sun damage (don’t get any ideas, you still need sunblock). Admittedly the evidence is currently a bit shaky – it’s a case of “more research is needed” – but even if it turns out to that the causative relationship isn’t terribly strong, tomatoes are still a really good source of fibre and vitamins A, C and E. Plus, you know, they taste yummy!

But back to the fridge. Surely they will keep longer in the fridge, and the low temperatures will help to preserve the nutrients? Isn’t that how it works?

Well, no. As James explained, once tomatoes are severed from the plant they have exactly one purpose: to get eaten. The reason, from the plant’s point of view, is that the critter which eats them will hopefully wander off and – ahem – eliminate the tomato seeds at a later time, somewhere away from the parent plant. This spreads the seeds far and wide, allowing little baby tomato plants to grow in a nice, open space with lots of water and sun.

For this reason once the tomato fruit falls, or is cut, from the tomato plant it doesn’t just sit there doing nothing. No, it carries on producing lycopene. Or rather, it does if the temperature is above about 10 oC. Below that temperature (as in a fridge), everything more or less stops. But, leave a tomato at room temperature and lycopene levels increase significantly. Plus, the tomato pumps out extra volatile compounds – both as an insect repellant and to attract animals which might usefully eat it – which means… yes: room temperature tomatoes really do smell better. As if that weren’t enough, chilling tomatoes can damage cell membranes, which can actually cause them to spoil more quickly.

In summary, not only will tomatoes last longer out of the fridge, they will actually contain more healthy lycopene!

Anecdotally, once I got over my scepticism and actually started leaving my tomatoes on my windowsill (after years of refrigeration) I discovered that it’s true. My windowsill tomatoes really do seem to last longer than they used to in the fridge, and they almost never go mouldy. Of course, it’s possible that I might not be comparing like for like (who knows what variety of tomato I bought last year compared to this week), but I urge you to try it for yourself.

James mentioned lots of other interesting bits and pieces in his talk. Did you know that sun-dried shiitake mushrooms are much higher in vitamin D? Or that you can double the amount of flavonoid you absorb from your blueberries by cooking them? (Take that, raw food people!) Storing apples on your windowsill is likely to increase the amount of healthy polyphenols in their skin, red peppers are better for you than green ones, adding mustard to cooked broccoli makes it more nutritious, and it would be much better if we bought our butternut squash in the autumn and saved it for Christmas – it becomes sweeter and more flavoursome over time.

In short, fascinating. Who wants to listen to some “clean eater” making it up as they go along when you can listen to a fully-qualified botanist who really knows what he’s talking about? Do check out the book, How to Eat Better, by James Wong – it’s packed full of brilliant tidbits like this and has loads of recipes.

And yes, Dad: you were right.


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Absurd alkaline ideas – history, horror and jail time

I’ve written about the absurdity of alkaline diets before, and found myself embroiled in more than one argument about the idea.

To sum up quickly, it’s the notion that our bodies are somehow “acidic”, and if only we could make them “alkaline” all our health problems – cancer included – would disappear. The way you make your body “alkaline” is, mainly, by eating lots of vegetables and some fruits (particularly citrus fruits – yes, I know, I know).

The eating fruit and vegetables bit aside (they’re good for you, you should eat them), it’s all patent nonsense. Our bodies aren’t acidic – well, other than where they’re supposed to be acidic (like our stomachs) – and absolutely nothing we eat or drink can have any sort of effect on blood pH, which is kept firmly between 7.35-7.45 by (mainly) our lungs and kidneys. And if your kidneys or lungs are failing, you need something a little stronger in terms of medical intervention than a slice of lemon.

But who first came up with this crazy idea?

Claude Bernard carried out experiments on rabbits.

Actually, we can probably blame a nineteenth century French biologist and physiologist, Claude Bernard, for kicking the whole thing off, when he noticed that if he changed the diet of rabbits from largely plant-based to largely animal-based (i.e. from herbivorous to carnivorous) their urine became more acidic.

This observation, followed by a lot of speculation by nutritionists and some really quite impressively dodgy leaps of reasoning (by others, I should stress – not Bernard himself), has lead us to where we are now: umpty-million websites and books telling anyone who will listen that humans need to cut out all animal products to avoid becoming “acidic” and thus ill.

Bernard’s rabbits were, it seems, quite hungry when he got them – quite possibly they hadn’t been fed – and he immediately gave them boiled beef and nothing else. Meat contains the amino acids cysteine and methionine, both of which can produce acid when they’re metabolised (something Bernard didn’t know at the time). The rabbits excreted this in their urine, which probably explains why it became acidic.

Now, many of you will have noticed several problems here. Firstly, rabbits are herbivores by nature (they do not usually eat meat in the wild). Humans aren’t herbivores. Humans are omnivores, and we have quite different digestive processes as a result. It’s not reasonable to extrapolate from rabbits to humans when it comes to diet. Plus, even the most ardent meat-lover probably doesn’t only eat boiled beef – at the very least people usually squeeze in a battered onion ring or a bit of coleslaw along the way. Most critically of all, urine pH has no direct relationship with blood pH. It tells us nothing about the pH of “the body” (whatever we understand that to mean).

The notion that a plant-based diet is somehow “alkaline” should really have stayed in the 19th century where it belonged, and at the very least not limped its way out of the twentieth. Unfortunately, somewhere in the early 2000s, a man called Robert O Young got hold of the idea and ran with it.

Young’s books – which are still available for sale at the time of writing – describe him as “PhD”, even though he has no accredited qualification.

Boy, did he run with it. In 2002 he published a book called The pH Miracle, followed by The pH Miracle for Diabetes (2004), The pH Miracle for Weight Loss (2005) and The pH Miracle Revised (2010).

All of these books describe him either as “Dr Robert O Young” or refer to him as “PhD”. But he has neither a medical qualification nor a PhD, other than one he bought from a diploma mill – a business that offers degrees for money.

The books all talk about “an alkaline environment” and state that so-called acidic foods and drinks (coffee, tea, dried fruit, anything made with yeast, meat and dairy, amongst other foodstuffs) should be avoided if not entirely eliminated.

Anyone paying attention will quickly note that an “alkaline” diet is basically a very restrictive vegan diet. Most carbohydrate-based foods are restricted, and lots of fruits and nuts fall into the “moderately” and “mildly” acidic categories. Whilst a vegan diet can be extremely healthy, vegans do need to be careful that they get the nutrients they need. Restricting nuts, pulses, rice and grains as well as removing meat and dairy could, potentially, lead to nutritional deficiencies.

Young also believes in something called pleomorphism, which is a whole other level of bonkers. Essentially, he thinks that viruses and bacteria aren’t the cause of illnesses – rather, the things we think are viruses and bacteria are actually our own cells which have changed in response to our “acidic environments”. In Young’s mind, we are making ourselves sick – there is one illness (acidosis) and one cure (his alkaline diet).

It’s bad enough that he’s asserting such tosh and being taken seriously by quite a lot of people. It’s even worse that he has been treating patients at his ranch in California, claiming that he could “cure” them of anything and everything, including cancer.

One of his treatments involved intravenous injections of solutions of sodium hydrogen carbonate, otherwise known as sodium bicarbonate or baking soda. This common cookery ingredient does produce an alkaline solution (about pH 8.5) when dissolved in water, but remember when I said blood pH was hard to shift?

Screenshot from a BBC article, see http://www.bbc.co.uk/news/magazine-38650739

Well, it is, and for good reason. If blood pH moves above the range of 7.35-7.45 it causes a condition called alkalosis. This can result in low blood potassium which in turn leads to muscle weakness, pain, and muscle cramps and spasms. It can also cause low blood calcium, which can ultimately result in a type of seizure. Putting an alkaline solution directly into somone’s blood is genuinely dangerous.

And this is before we even start to consider the fact that someone who was not a medical professional was recommending, and even administering, intravenous drips. Which, by the way, he was reportedly charging his patients $550 a pop to receive.

Young came to the attention of the authorities several times, but always managed to wriggle out of trouble. That is, until 2014, when he was arrested and charged with practising medicine without a license and fraud. In February last year, he was found guilty, but a hung jury caused complications when they voted 11-1 to convict on the two medical charges, but deadlocked 8-4 on fraud charges.

Finally, at the end of June 2017, he was sentenced. He was given three years, eight months in custody, but due to the time he’s already spent in custody and under house arrest, he’s likely to actually serve five months in jail.

He admitted that he illegally treated patients at his luxury Valley Center ranch without any medical or scientific training. Perhaps best of all, he was also made to publicly declare that he is not microbiologist, hematologist, medical doctor or trained scientist, and that he has no post-highschool educational degrees from any accredited school.

Prosecuting Deputy District Attorney Gina Darvas called Young the “Wizard of pHraud”, which is rather apt. Perhaps the titles on his books could be edited to read “Robert O Young, pHraud”?


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Alkaline water: if you like it, why not make your own?

Me* reading the comments section on the Amazing Alkaline Lemons post (*not actually me)

Alkaline water seems to be a trend at the moment. Not quite so much in the UK, yet, but more so in the US where it appears you can buy nicely-packaged bottles with the numbers like 8 and 9.5 printed in large, blue letters on their sides.

It’s rather inexplicable, because drinking slightly alkaline water does literally NOTHING for your health. You have a stomach full of approximately 1 M hydrochloric acid (and some other stuff) which has an acidic pH of somewhere between 1.5 and 3.5. This is entirely natural and normal – it’s there to kill any bugs that might be present in your food.

Chugging expensive water with an alkaline pH of around 9 will neutralise a bit of that stomach acid (bringing the pH closer to a neutral value of 7), and that’s all it will do. A stronger effect could be achieved with an antacid tablet (why isn’t it antiacid? I’ve never understood that) costing around 5p. Either way, the effect is temporary: your stomach wall contains special cells which secrete hydrochloric acid. All you’re doing by drinking or eating alkaline substances is keeping them busy.

(By the way, I’m not recommending popping antacids like sweeties – it could make you ill with something called milk-alkali syndrome, which can lead to kidney failure.)

Recently, a video did the rounds of a woman testing various bottled waters, declaring the ones with slightly acidic pHs to be “trash” and expressing surprise that several brands, including Evian, were pH neutral. The horror. (For anyone unsure, we EXPECT water to have a neutral pH.)

Such tests are ridiculous for lots of reasons, not least because she had tiny amounts of water in little iddy-biddy cups. Who knows how long they’d been sitting around, but if it was any length of time they could well have absorbed some atmospheric carbon dioxide. Carbon dioxide is very soluble, and it forms carbonic acid when it dissolves in water which, yes, would lower the pH.

Anyway, there’s absolutely nothing harmful about drinking water containing traces of acid. It doesn’t mean the water is bad. In fact, if you use an ion exchange filter (as found in, say, Brita filter jugs) it actually replaces calcium ions in the water with hydrogen ions. For any non-chemists reading this: calcium ions are the little sods that cause your kettle to become covered in white scale (I’m simplifying a bit). Hydrogen ions make things acidic. In short, less calcium ions means less descaling, but the slight increase in hydrogen ions means a lower pH.

So, filtered water from such jugs tends to be slightly acidic. Brita don’t advertise this fact heavily, funnily enough, but it’s true. As it happens, I own such a filter, because I live in an area where the water is so hard you can practically use it to write on blackboards. After I bought my third kettle, second coffee machine and bazillionth bottle of descaler, I decided it would be cheaper to use filtered water.

I also have universal indicator strips, because the internet is awesome (when I was a kid you couldn’t, easily, get this stuff without buying a full chemistry set or, ahem, knowing someone who knew someone – now three clicks and it’s yours in under 48 hours).

The pH of water that’s been through a (modern) ion-exchange filter tends to be slightly acidic.

The water in the glass was filtered using my Brita water filter and tested immediately. You can see it has a pH of about 5. The water straight from the tap, for reference, has a pH of about 7 (see the image below, left-hand glass).

The woman in the YouTube video would be throwing her Brita in the trash right now and jumping up and down on it.

So, alkaline water is pretty pointless from a health point of view (and don’t even start on the whole alkaline diet thing) but, what if you LIKE it?

Stranger things have happened. People acquire tastes for things. I’m happy to accept that some people might actually like the taste of water with a slightly alkaline pH. And if that’s you, do you need to spend many pounds/dollars/insert-currency-of-choice-here on expensive bottled water with an alkaline pH?

Even more outlandishly, is it worth spending £1799.00 on an “AlkaViva Vesta H2 Water Ionizer” to produce water with a pH of 9.5? (This gizmo also claims to somehow put “molecular hydrogen” into your water, and I suppose it might, but only very temporarily: unlike carbon dioxide, hydrogen is very insoluble. Also, I’m a bit worried that machine might explode.)

Fear not, I am here to save your pennies! You do not need to buy special bottled water, and you DEFINITELY don’t need a machine costing £1.8k (I mean, really?) No, all you need is a tub of….

… baking soda!

Yep, good old sodium bicarbonate, also known as sodium hydrogencarbonate, bicarb, or NaHCO3. You can buy a 200 g tub for a pound or so, and that will make you litres and litres and litres of alkaline water. Best of all, it’s MADE for baking, so you know it’s food grade and therefore safe to eat (within reason, don’t eat the entire tub in one go).

All you need to do is add about a quarter of a teaspoon of aforementioned baking soda to a large glass of water and stir. It dissolves fairly easily. And that’s it – alkaline water for pennies!

Me* unconvinced by the flavour of alkaline water (*actually me).

Fair warning, if you drink a lot of this it might give you a bit of gas: once the bicarb hits your stomach acid it will react to form carbon dioxide – but it’s unlikely to be worse than drinking a fizzy drink. It also contains sodium, so if you’ve been told to watch your sodium intake, don’t do this.

If I had fewer scruples I’d set up shop selling “dehydrated alkaline water, just add water”.

Sigh. I’ll never be rich.


Like the Chronicle Flask’s Facebook page for regular updates, or follow @chronicleflask on Twitter. All content is © Kat Day 2017. You may share or link to anything here, including the images, but you must reference this site if you do.


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Is acrylamide in your toast really going to give you cancer?

Acrylamide has been in the news today, and this might be the understatement of the year. Front page newspaper headlines have been yelling everything from “Brits officially warned off chips” to “Over-cooked potatoes and burnt toast could cause cancer” to the marginally more restrained “What is the real cancer risk from eating roast potatoes or toast?” All this has been accompanied by radio interviews with everyone from actual scientists to professional chefs to people keen to share their roast potato recipes. I expect there have been television interviews too – I haven’t had a chance to watch.

Hey, what could be more traditional, or more fun, than a food-health scare in January?

Acrylamide

Acrylamide

Never fear, the Chronicle Flask is here to sort out the science. Let’s get to the facts: what is acrylamide?

It’s actually a rather small molecule, and it falls into a group of substances which chemists call amides. Other well-known amides include paracetamol and penicillin, and nylon is a polyamide – that is, lots of amide molecules joined together. Amide linkages (the CO-NH bit) are a key feature of proteins, which means they appear in all kinds of naturally-occurring substances.

And this is where the food-acrylamide link comes in. Because acrylamide, or prop-2-enamide to give it its official name (the one only ever used by A-level chemistry students), forms when certain foods are cooked.

Acrylamide occurs naturally in fried, baked, and roasted starchy foods.

Acrylamide occurs naturally in fried, baked, and roasted starchy foods.

It begins with an amino acid called asparagine. If you’re wondering whether, with that name, it has anything to do with asparagus, you’d be on the right track. It was first isolated in the early 1800s from asparagus juice. It turns out to be very common: it’s found in dairy, meat, fish and shellfish, as well as potatoes, nuts, seeds and grains, amongst other things.

This is where the trouble begins. When asparagine is combined with sugars, particularly glucose, and heated, acrylamide is produced. The longer the food is heated for, the more acrylamide forms. This is a particular issue with anything wheat or potato-based thanks to the naturally-occurring sugars those foods also contain – hence all the histrionics over chips, roast potatoes and toast.

How dangerous is acrylamide? The International Agency for Research on Cancer have classified it as a Group 2A carcinogen, or a “probable” carcinogen. This means there’s “limited evidence” of carcinogenicity in humans, but “sufficient evidence” of carcinogenicity in experimental animals. In other words (usually) scientists know the thing in question causes cancer in rats – who’ve generally been fed huge amounts under strictly controlled conditions – but there isn’t any clear evidence that the same link exists in humans. It’s generally considered unethical to lock humans in cages and force feed them acrylamide by the kilo, so it’s tricky to prove.

screen-shot-2017-01-23-at-22-10-46At this point I will point out that alcoholic beverages are classified as Group 1 carcinogens, which means there is “sufficient evidence” of carcinogenicity in humans. Alcohol definitely causes cancer. If you’re genuinely concerned about your cancer risk, worry less about the roast potatoes in your Sunday roast and more about the glass of wine you’re drinking with them.

But back to acrylamide. In animals, it has been shown to cause tumours. It’s one of those substances which can be absorbed through the skin, and after exposure it spreads around the body, turning up in the blood, unexposed skin, the kidneys, the liver and so on. It’s also been shown to have neurotoxic effects in humans. BUT, the evidence that it causes cancer in humans under normal conditions isn’t conclusive. A meta-analysis published in 2014 concluded that “dietary acrylamide is not related to the risk of most common cancers. A modest association for kidney cancer, and for endometrial and ovarian cancers in never smokers only, cannot be excluded.” 

The dose makes the poison is an important principle in toxicology (image credit: Lindsay Labahn)

The dose makes the poison (image credit: Lindsay Labahn)

As I so often find myself saying in pieces like this: the dose makes the poison. The people who have suffered neurotoxic effects from acrylamide have been factory workers. In one case in the 1960s a patient was handling 10% solutions of the stuff, and “acknowledged that the acrylamide solution frequently had splashed on his unprotected hands, forearms and face.” The earliest symptom was contact dermatitis, followed by fatigue, weight loss and nerve damage.

Because of these very real risks, the Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have set occupational exposure limits at 0.03 mg/m3 over an eight-hour workday, or 0.00003 g/m3.

Let’s contrast that to the amount of acrylamide found in cooked food. The reason all this fuss erupted today is that the Food Standards Agency (FSA) published some work which estimated the amounts of acrylamide people are likely to be exposed to in their everyday diet.

The highest concentrations of acrylamide were found in snacks (potato crisps etc), and they were 360 μg/kg, or 0.00036 g/kg or, since even the most ardent crisp addict doesn’t usually consume their favoured snacks by the kilo, 0.000036 g/100g. (Remember that those occupational limits are based on continuous exposure over an eight-hour period.)

In other words, the amounts in even the most acrylamide-y of foodstuffs are really quite tiny, and the evidence that acrylamide causes cancer in humans is very limited anyway. There is some evidence that acrylamide accumulates in the body, though, so consuming these sorts of foods day in and day out over a lifetime could be a concern. It might be wise to think twice about eating burnt toast every day for breakfast.

Oh yes, and there’s quite a lot of acrylamide in cigarette smoke. But somehow I doubt that if you’re a dedicated smoker this particular piece of information is going to make much difference.

As the FSA say at the end of their report:

Your toast almost certainly isn't going to kill you.

Your toast almost certainly isn’t going to kill you.

“The dietary acrylamide exposure levels for all age classes are of possible concern for an increased lifetime risk of cancer. The results of the survey do not increase concern with respect to acrylamide in the UK diet but do reinforce FSA advice to consumers and our efforts to support the food industry in reducing acrylamide levels.”

This is not, I would suggest, QUITE the same as “Crunchy toast could give you cancer, FSA warns” but, I suppose, “FSA says risk hasn’t really changed” wouldn’t sell as many newspapers.

One last thing, there’s acrylamide in coffee – it forms when the beans are roasted. There’s more in instant coffee and, perhaps counterintuitively, in lighter-roasted beans. No one seems to have mentioned that today, possibly because having your coffee taken away in January is just too terrifying a prospect to even contemplate. And also perhaps because coffee seems to be associated with more health benefits than negatives. Coffee drinkers are less likely to develop type 2 diabetes, Parkinson’s disease, dementia, suffer fewer cases of some cancers and fewer incidences of stroke. Whether the link is causal or not isn’t clear, but coffee drinking certainly doesn’t seem to be a particularly bad thing, which just goes to show that when it comes to diet, things are rarely clearcut.

Pass the crisps, someone.


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The Chronicles of the Chronicle Flask: 2016

2016 is limping to its painful conclusion, still tossing out last-minute nasty surprises like upturned thumb tacks in the last few metres of a marathon. But the year hasn’t been ALL bad. Some fun, and certainly interesting, things happened too. No, really, they did, honestly.

So with that in mind, let’s have a look back at 2016 for the Chronicle Flask….

January kicked off with a particularly egregious news headline in a well-known broadsheet newspaper: Sugar found in ketchup and Coke linked to breast cancer. Turns out that the sugar in question was fructose. Yes, the sugar that’s in practically everything, and certainly everything that’s come from a plant. So why did the newspaper in question choose ketchup and Coke for their headline instead of, oh, say, fruit juice or honey? Surely not just in an effort to sell a few more newspapers after the overindulgent New Year celebrations. Surely.

octarineThere was something more lighthearted to follow when IUPAC  verified the discoveries of elements 113, 115, 117 and 118. This kicked off lots of speculation about the elements’ eventual names, and the Chronicle Flask suggested that one of them should be named Octarine in honour of the late Sir Terry Pratchett. Amazingly, this suggestion really caught everyone’s imagination. It was picked up in the national press, and the associated petition got over 51 thousand signatures!

In February I wrote a post about the science of statues, following the news that a statue to commemorate Sir Terry Pratchett and his work had been approved by Salisbury City Council. Did you know that there was science in statues? Well there is, lots. Fun fact: the God of metalworking was called Hephaestus, and the Greeks placed dwarf-like statues of him near their Hearths – could this be where the fantasy trope of dwarves as blacksmiths originates?

MCl and MI are common preservatives in cosmetic products

MCl and MI are common preservatives in cosmetic products

My skeptical side returned with a vengeance in March after I read some online reviews criticising a particular shampoo for containing a substance known as methylchloroisothiazolinone. So should you be scared of your shampoo? In short, no. Not unless you have a known allergy or particularly sensitive skin. Otherwise, feel free to the pick your shampoo based on the nicest bottle, the best smell, or the forlorn hope that it will actually thicken/straighten/brighten your hair as promised, even though they never, ever, ever do.

Nature Chemistry published Another Four Bricks in the Wall in April – a piece all about the potential names of new elements, partly written by yours truly. The month also brought a sinus infection. I made the most of this opportunity by writing about the cold cure that’s 5000 years old. See how I suffer for my lovely readers? You’re welcome.

In May I weighed in on all the nonsense out there about glyphosate (and, consequently, learned how to spell and pronounce glyphosate – turns out I’d been getting it wrong for ages). Is it dangerous? Nope, not really. The evidence suggests it’s pretty harmless and certainly a lot safer than most of its alternatives.

may-facebook-postSomething else happened in May: the Chronicle Flask’s Facebook page received this message in which one of my followers told me that my post on apricot kernels had deterred his mother from consuming them. This sort of thing makes it all worthwhile.

In June the names of the new elements were announced. Sadly, but not really very surprisingly, octarine was not among them. But element 118 was named oganesson and given the symbol Og. Now, officially, this was in recognition of the work of Professor Yuri Oganessian, but I for one couldn’t help but see a different reference. Mere coincidence? Surely not.

July brought another return to skepticism. This time, baby wipes, and in particular a brand that promise to be “chemical-free”. They’re not chemical-free. Nothing is chemical-free. This is a ridiculous label which shouldn’t be allowed (and yet, inexplicably, is still in use). It’s all made worse by the fact that Water Wipes contain a ‘natural preservative’ called grapefruit seed extract which, experiments have shown, only actually acts as a preservative when it’s contaminated with synthetic substances. Yep. Turns out some of Water Wipes claims are as stinky as the stuff they’re designed to clean up.

Maria Lenk Aquatic Enter, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

Maria Lenk Aquatic Enter, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

August brought the Olympics, and speculation was rife about what, exactly, was causing the swimming pools to turn such strange shades of green. Of course, the Chronicle Flask knew the correct solution…

August also saw MMS and CD reared their ugly heads on social media again. CD (chlorine dioxide) is, lest we forget, a type of bleach solution which certain individuals believe autistic children should be made to drink to ‘cure’ them. Worse, they believe such children should be forced to undergo daily enemas using CD solutions. I wrote a summary page on MMS (master mineral solution) and CD, as straight-up science companion to the commentary piece I wrote in 2015.

mugsSeptember took us back to pesticides, but this time with a more lighthearted feel. Did you know that 99.99% of all the pesticides you consume are naturally-occurring? Well, you do if you regularly read this blog. The Chronicle Flask, along with MugWow, also produced a lovely mug. It’s still for sale here, if you need a late Christmas present… (and if you use the code flask15 you’ll even get a discount!)

In October, fed up with endless arguments about the definition of the word ‘chemical’ I decided to settle the matter once and for all. Kind of. And following that theme I also wrote 8 Things Everyone Gets Wong About ‘Scary’ Chemicals for WhatCulture Science.

Just in case that wasn’t enough, I also wrote a chapter of a book on the missing science of superheroes in October. Hopefully we should see it in print in 2017.

Sparklers are most dangerous once they've gone out.

Sparklers are most dangerous once they’ve gone out.

I decided to mark Fireworks Night in November by writing about glow sticks and sparklers. Which is riskier? The question may not be as straightforward as you’d imagine. This was followed by another WhatCulture Science piece, featuring some genuinely frightening substances: 10 Chemicals You Really Should Be Scared Of.

And that brings us to December, and this little summary. I hope you’ve enjoyed the blog this year – do tell your friends about it! Remember to follow @ChronicleFlask on Twitter and like fb.com/chronicleflask on Facebook – both get updated more or less daily.

Here’s wishing all my lovely readers a very Happy New Year – enjoy a drop of bubbly ethanol solution and be careful with the Armstrong’s mixture…. 

See you on the other side!

new-year-1898553_960_720