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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Puking pumpkins: more hydrogen peroxide

It was Halloween yesterday and, unusually for the UK, it fell in school term time. As it turned out, I was teaching chemistry to a group of 12-13 year olds on that day which was too good an opportunity to miss.

Time for the puking pumpkin!

A side note: there’s loads of great chemistry here, and the pumpkin isn’t essential – you could easily do this same experiment during a less pumpkin-prolific month with something else. Puking watermelon, anyone?

Carve a large mouth, draw the eyes and nose with marker pen.

First things first, prepare your pumpkin! Choose a large one – you need room to put a conical flask inside and put the pumpkin’s “lid” securely back in place.

Carve the mouth in the any shape you like, but make it generous. Draw the eyes and nose (and any other decoration) in waterproof marker – unless you want your pumpkin to “puke” out of its nose and eyes as well!

Rest the pumpkin on something wipe-clean (it might leak from the bottom) and put a deep tray in front of it.

To make the “puke” you will need:

  • 35% hydrogen peroxide (corrosive)
  • a stock solution of KI, potassium iodide (low hazard)
  • washing up liquid

The puking pumpkin!

You can also add food colouring or dye, but be aware that the reaction can completely change or even destroy the colours you started with. If colour matters to you, test it first.

Method:

  1. Place about 50 ml (use more if it’s not so fresh) of the hydrogen peroxide into the conical flask, add a few drops of washing up liquid (and dye, if you’re using it).
  2. Add some KI solution and quickly put the pumpkin’s lid back in place.
  3. Enjoy the show!

Check out some video of all this here.

What’s happening? Hydrogen peroxide readily decomposes into oxygen and water, but at room temperature this reaction is slow. KI catalyses the reaction, i.e. speeds it up. (There are other catalysts you could also try if you want to experiment; potassium permanganate for example.) The washing up liquid traps the oxygen gas in foam to produce the “puke”.

The word and symbol equations are:

hydrogen peroxide –> water + oxygen
2H2O2 –> 2H2O + O2

There are several teaching points here:

  • Evidence for chemical change.
  • Compounds vs. elements.
  • Breaking the chemical bonds in a compound to form an element and another compound.
  • Balanced equations / conservation of mass.
  • The idea that when it comes to chemical processes, it’s not just whether a reaction happens that matters, but also how fast it happens…
  • … which of course leads to catalysis. A-level students can look at the relevant equations (see below).

Once the pumpkin has finished puking, demonstrate the test for oxygen gas.

Some health and safety points: the hydrogen peroxide is corrosive so avoid skin contact. Safety goggles are essential, gloves are a Good Idea(™). The reaction is exothermic and steam is produced. A heavy pumpkin lid will almost certainly stay in place but still, stand well back. 

But we’re not done, oh no! What you have at the end of this reaction is essentially a pumpkin full of oxygen gas. Time to crack out the splints and demonstrate/remind your students of the test for oxygen. It’s endlessly fun to put a glowing splint into the pumpkin’s mouth and watch it catch fire, and you’ll be able to do it several times.

And we’re still not done! Once the pumpkin has completely finished “puking”, open it up (carefully) and look inside. Check out that colour! Why is it bluish-black in there?

The inside of the pumpkin is blue-black: iodine is produced which complexes with starch.

It turns out that you also get some iodine produced, and there’s starch in pumpkins. It’s the classic, blue-black starch complex.

Finally, give the outside of the pumpkin a good wipe, take it home, carve out the eyes and nose and pop it outside for the trick or treaters – it’s completely safe to use.

Brace yourselves, more equations coming…

The KI catalyses the reaction because the iodide ions provide an alternative, lower-energy pathway for the decomposition reaction. The iodide reacts with the hydrogen peroxide to form hypoiodite ions (OI). These react with more hydrogen peroxide to form water, oxygen and more iodide ions – so the iodide is regenerated, and hence is acting as a catalyst.

H2O2 + I –> H2O + OI
H2O2 + OI –> H2O + O2 + I

The iodine I mentioned comes about because some of the iodide is oxidised to iodine by the oxygen. At this point we have both iodine and iodide ions – these combine to form triiodide, and this forms the familiar blue-black complex.

Phew. That’s enough tricky chemistry for one year. Enjoy your chocolate!

Trick or treat!

 


 

 


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Hydrogen peroxide: another deadly alternative?

I’m sure most people have heard of hydrogen peroxide. It’s used as a disinfectant and, even if you’ve never used it for that, you probably at least know that it’s used to bleach hair. It’s where the phrase “peroxide blonde” comes from, after all. Hydrogen peroxide, and its formula, is so famous that there’s an old chemistry joke about it:

(I have no idea who to credit for the original drawing – if it’s you, leave me a message.)

To save you squinting at the text, it goes like this:
Two men walk into a bar. The first man says, “I’ll have some H2O.”
The second man says, “I’ll have some H2O, too.”
The barman brings the drinks. The second man dies horribly.

Now I think about it, it’s not a terribly funny joke.

Hydrogen peroxide has an extra oxygen atom in the middle.

Never mind. You get the idea. H2O2 (“H2O, too”) is the formula for hydrogen peroxide. Very similar to water’s formula, except with an extra oxygen atom in the middle. In fact, naturopaths – purveyors of alternative therapies – often refer to hydrogen peroxide as “water with extra oxygen”. But this is really misleading because, to torture a metaphor, that extra oxygen makes hydrogen peroxide the piranha to water’s goldfish.

Water, as we know, is pretty innocuous. You should try not to inhale it obviously, or drink more than about six litres in one go, but otherwise, its pretty harmless. Hydrogen peroxide, on the other hand, not so much. The molecule breaks apart easily, releasing oxygen. That makes it a strong oxidising agent. It works as a disinfectant because it basically blasts cells to pieces. It bleaches hair because it breaks down pigments in the hair shaft. And, as medical students will tell you, it’s also really good at cleaning up blood stains – because it oxidises the iron in haemoglobin to Fe3+, which is a pale yellow colour*.

Dilute hydrogen peroxide is readily available.

In its dilute form, hydrogen peroxide is a mild antiseptic. Three percent and even slightly more concentrated solutions are still readily available in high-street pharmacies. However, even these very dilute solutions can cause skin and eye irritation, and prolonged skin contact is not recommended. The trouble is, while it does destroy microbes, it also destroys healthy cells. There’s been a move away from using hydrogen peroxide for this reason, although it is still a popular “home” remedy.

More concentrated** solutions are potentially very dangerous, causing severe skin burns. Hydrogen peroxide is also well-known for its tendency to react violently with other chemicals, meaning that it must be stored, and handled, very carefully.

All of which makes the idea of injecting into someone’s veins particularly horrific.

But this is exactly what some naturopaths are recommending, and even doing. The idea seems to have arisen because hydrogen peroxide is known to damage cancer cells. But so will a lot of other dangerous substances – it doesn’t mean it’s a good idea to inject them. Hydrogen peroxide is produced by certain immune cells in the body, but only in a very controlled and contained way. This is definitely a case where more isn’t necessarily better.

The use of intravenous hydrogen peroxide appears to have begun in America, but it may be spreading to the UK. The website yestolife.org.uk, which claims to empower people with cancer to “make informed decisions”, states “The most common form of hydrogen peroxide therapy used by doctors calls for small amounts of 30% reagent grade hydrogen peroxide added to purified water and administered as an intravenous drip.”

30% hydrogen peroxide is really hazardous stuff. It’s terrifying that this is being recommended to vulnerable patients.

Other sites recommend inhaling or swallowing hydrogen peroxide solutions, both of which are also potentially extremely dangerous.

If anyone ever suggests a hydrogen peroxide IV, run very fast in the other direction.

In 2004 a woman called Katherine Bibeau died after receiving intravenous hydrogen peroxide treatment from James Shortt, a man from South Carolina who called himself a “longevity physician”. According to the autopsy report she died from systemic shock and DIC – the formation of blood clots in blood vessels throughout the body. When her body arrived at the morgue, she was covered in purple-black bruises.

Do I need to state the obvious? If anyone suggests injecting this stuff, run. Run very fast, in the other direction. Likewise if they suggest drinking it. It’s a really stupid idea, one that could quite literally kill you.


* As anyone who’s ever studied chemistry anywhere in my vicinity will tell you, “iron three is yellow, like wee.”


** The concentration of hydrogen peroxide is usually described in one of two ways: percentage and “vol”. Percentage works as you might expect, but vol is a little different. It came about for practical, historical reasons. As Prof. Poliakoff comments in this video, hydrogen peroxide is prone to going “flat” – leave it in the bottle for long enough and it gradually decomposes until what you actually have is a bottle of ordinary water. Particularly in the days before refrigeration (keeping it cold slows down the decomposition) a bottle might be labelled 20%, but actually contain considerably less hydrogen peroxide.

What to do? The answer was quite simple: take, say, 1 ml of hydrogen peroxide, add something which causes it to decompose really, really fast (lots of things will do this: potassium permanganate, potassium iodide, yeast, even liver) and measure the volume of oxygen given off. If your 1 ml of hydrogen peroxide produces 10 ml of oxygen, it’s 10 vol. If it produces 20, it’s 20 vol. And so on. Simple. 3% hydrogen peroxide, for the record, is about 10 vol***. Do not mix up these numbers.


*** Naturally, there are mole calculations to go with this. Of course there are. For A-level Chemists, here’s the maths (everyone else can tune out; I’m adding this little footnote because I found this information strangely hard to find):

Hydrogen peroxide decomposes as shown in this equation:
2H2O2 –> 2H2O + O2

Let’s imagine we decompose 1 ml of hydrogen peroxide and obtain 10 mls of oxygen.

Assuming the oxygen gas occupies 24 dm3 (litres), or 24000 mls, at standard temperature and pressure, 10 mls of oxygen is 10 / 24000 = 0.0004167 moles. But, according to the equation, we need two molecules of hydrogen peroxide to make one molecule of oxygen, so we need to multiply this number by two, giving us 0.0008333 moles.

To get the concentration of the hydrogen peroxide in the more familar (to chemists, anyway) mol dm-3, just divide that number of moles by the volume of hydrogen peroxide. In other words:

0.0008333 mols / 0.001 dm3 = 0.833 mol dm-3

If you really want to convert this into a percentage by mass (you can see why people stick with “vol” now, right?), then:

0.833 mol (in the litre of water) x 34 g mol-1 (the molecular mass of H2O2)
= 28.32 g (in 1000 g of water)

Finally, (28.32 / 1000) x 100 = 2.8% or, rounding up, 3%

In summary (phew):
10 vol hydrogen peroxide = 0.83 mol dm-3 = 3%


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Unsafe slime? How bad is borax, really?

Slime is a fun bit of chemistry that anyone can do – but how safe is it?

It’s August, which means it’s the school summer holidays in the UK and, as is traditional, it’s been pouring with rain. This has left many a cabin-fevered child searching for ways to amuse themselves.

Start hunting around the internet for things to do and it’s not long before the concept of the “kitchen science” experiment turns up. There are actually loads of these, and it’s even possible to do some of them without permanently damaging anyone’s eardrums, dusting every surface with cornflour and leaving a parent rocking in the corner muttering “why did I encourage this?” over and over to themselves.

Which brings me to slime – surely the go-to fun science experiment. What’s not to love about taking some of that white, runny PVA glue found in gallon bottles in school classrooms everywhere and magically turning it into glorious, gloopy slime? Add some food colouring and you can even have coloured slime! Add glitter and… well you get the idea.

Many YouTubers love this stuff. A quick search for “make your own slime” turns up pages and pages of videos, giving instructions as to how to do just that.

In fact, it seems that slime-making is currently a bit of a craze, with children all over the world making all kids of different types. There’s unicorn slime, rainbow slime, fluffy slime – you name it. Brilliant, you might think, a whole generation of youngsters interested in chemistry. What’s not to like about that?

Well, as a few news reports have recently pointed out, there might be a problem if children are handling lots of borax, or certain other chemicals.

Polyvinyl alcohol

Slime, you see, is a really nice example of polymerisation – the same process that goes on when plastics are made. PVA glue, the usual starting material, is a polymer itself. The letters PVA stand for polyvinyl alcohol (its systematic name is poly(1-hydroxyethylene)), but literally no one calls it that, not even A-level chemistry teachers forced, kicking and screaming, to follow IUPAC naming conventions).

PVA is a long chain of carbon atoms with alternating CH2 groups and alcohol, OH, groups. As anyone who’s ever handled it will know, it’s quite runny. Thick, yes, but still runny. Basically, it’s a liquid.

But if you mix it with borax, aka sodium tetraborate, some magic happens. And when I say magic, I mean chemistry. The chains of atoms become linked together (essentially via hydrogen bonds), and as a result the new substance is a lot more solid. But it’s not quite solid. At least, not in the sense of something that keeps its own shape. No, this is weird, peculiar, stuff that sits somewhere in between solid and liquid.

Borax joins the chains of PVA together.

There’s something tactilely pleasing about slime. Put it in your hands and it feels cool and slightly moist – your fingers slide over and through it with a sort of squeaky sensation. Leave it alone for a few minutes and it flows to take the shape of its container, forming a perfect, mirror finish on its surface. Tip the pot over, and it will gradually creep toward the edge.

It is safe to handle. Here are my hands, handling it (we made this at the March for Science in Bristol back in April). You will notice that my skin is not falling off.

It’s white unless you dye it. We went for red, which is pleasingly disturbing.

I did, though, wash my hands after I took that photo. And that’s because, while the PVA is pretty harmless (as you know if, like me, you spent your primary school days painting your hands with glue just so you could peel it off later) the borax isn’t. At least, not entirely.

Before I go any further, let’s be clear: lots of things aren’t “entirely” safe. Most of the cleaning products in the average kitchen and bathroom have warning levels of varying degrees of severity on them, and we don’t think too much about it. Even things that are designed to be in contact with skin, like hand soap and shampoo, usually have warnings about eye irritation and statements like “if irritation occurs, discontinue use”. Even water is deadly in the wrong context (don’t try inhaling too much of it, for example). So when I say not entirely safe, I don’t mean to suggest that panic needs to ensue if your child has so much as looked at a borax solution.

Borax has traditionally been used in several household products, although admittedly more in the US than in the UK. Most people know it as a laundry additive, where it softens water, brightens whites and inhibits the growth of the bacteria and fungi which can make clothes stinky.

It’s not considered a lethal compound, in the sense that you’d have to eat a large quantity – far more than anyone might reasonably consume by accident – before it became deadly, and you’d almost certainly throw up long before then. Borax can irritate the skin (but see note at the end), and inhalation of the dust is well known to irritate the lungs. This is more of a concern for people working with borax on an industrial scale day in and day out – but it could become an issue if, say, someone were making slime every single day using large quantities of borax (not recommended).

Then there’s another concern. If borax is exposed to hydrochloric acid, it forms boric acid. Long-term exposure to boric acid can cause kidney damage and fertility problems, both in men and women. It’s also potentially teratogenic, which means it could cause harm to an unborn child. Borax and boric acid are not the same thing but, of course, our stomachs contain hydrochloric acid. Therefore, if you swallow borax, you’re effectively exposed to boric acid.

Frequent exposure to borax might cause skin irritation (see note at end)

These risks are the reason borax was added to the Substance of Very High Concern (SVHC) candidate list on 16 December 2010, which is the first step in restricting use of the chemical within the European Union. As far as I can establish, it’s still a “candidate”, but the European Chemicals Agency substance information card does state that borax may “damage fertility or the unborn child”.

Now, the chances of achieving the levels involved in “long-term exposure” from occasionally handling borax solutions are slim to none. It’s safe to handle dilute borax solutions (see notes at the end). Indeed, borax is even approved as a food preservative in the EU (E285). To put it into context, alcohol (ethanol) also causes organ damage and is a known teratogen and a carcinogen (which borax isn’t) and that turns up in all sorts of things we’re regularly in contact with, everything from antiseptic hand gels to mouthwashes to drinks (and it’s also approved as a food additive, E1510 – which is good news if you like liqueur chocolates).

I personally have no concerns about handling dry borax in small quantities to make up solutions myself. However, I wouldn’t let children do that part. Once made I’d consider the solution safe, so long as children were supervised and weren’t doing anything really silly like drinking it. I’d also tell children to wash their hands after handling the slime and, if I thought they had sensitive skin for any reason (eczema, say) I’d suggest plastic gloves.

Borax is easy to buy online.

Because of the European Regulations, it theoretically shouldn’t be that easy to get hold of borax in the UK. But I found it for sale on Amazon.co.uk. The listing says that it “can only be purchased by Professionals and by trade and business users,” (sic) but I ordered some and there were no checks. A plastic bag full of borax powder (the decahydrate, Na2B4O7.10H2O) arrived within a few days.

Most of the news reports doing the rounds have involved children suffering from severe skin irritation. For example, in February this year a woman from Manchester posted photos of chemical burns on her daughter’s hands online as a warning to other parents. However, looking into the details of that story it turns out that she wasn’t using borax. In fact, she used fabric detergent “as an alternative”.

Take a look at pretty much type of fabric detergent and you’ll find hazard warnings, usually indicating it’s corrosive and definitely saying “keep out of reach of children”. Those are there for a reason. Fabric detergent is designed to remove grease and  stains. In other words, to break down fats and proteins, and guess what your skin is made of? Yep. Don’t get neat fabric detergent on your hands. Even if your skin isn’t particularly sensitive, it’s almost certainly going to irritate it.

Fabric detergents are usually labelled corrosive.

Bottom line: don’t use fabric detergent as a borax alternative to make slime, because there’s a real risk that enough of it could get onto your (or your child’s) skin that it could irritate.

When it comes to borax itself, if I understand things correctly, it’s not actually restricted in the EU – including the UK – yet. (I might have this wrong – do correct me if you think I have.) It’s not something you can pop to the supermarket and buy, but as we’ve established you can buy it online fairly easily.

Borax solutions are extremely unlikely to cause harm, if used sensibly (boron chemist David Schubert agrees, see note at the end). But, once again: if you’re doing this experiment it’s best not to let children make up the solution – an adult should do that part.

A sensible quantity is about 1 gram of borax in 25 millilitres of warm water (for those without a metric scale: one level teaspoon of borax in half a cup measure of water). This will actually polymerise quite a bit of PVA – you don’t need that much. I recommend making the borax solution in a labelled plastic cup which you should throw away afterwards. Don’t leave it anywhere where someone might mistake it for their drink! Once the solution is made just add a little bit to some PVA in another plastic cup, give it a good stir with a spoon or a lolly stick, and the magic (chemistry) will happen. Add food colouring if you like (be aware that it can stain!) and enjoy the slimy goodness. (See additional note for teachers & technicians at the end.)

Do supervise any and all slime-making, don’t let children handle slime all day, every day, and if you know they have sensitive skin, make them wear plastic gloves. Make them wash their hands before they eat or drink anything.

If a child has made slime somewhere else, at a party or a science club, say, and they bring it home, again, there’s no need to worry. They can play with it perfectly safely. Don’t let them leave it on a radiator, though. That will end in disaster.

I am not a fan of the “it might be a bit dangerous, so no one should ever try it” mentality. I mean, that’s just no fun, is it? But I’m also not a fan of unnecessary risks – because trips to hospital are equally no fun. So if you want to try this experiment, I’ve summarised my guidance in this graphic.

Stay safe with slime by following this guidance

And if you want a even safer slimy experiment, and you can bear the mess, I suggest mixing cornflour with just enough water to make a thick paste in a shallow tray. Then let your kids stick their fingers in it, bounce things off it, and generally play with it. (Check out this link to find out more about why it behaves as it does.) I’m told it makes an even better mixture if you add basil seeds.

Have fun this summer, stay safe, and don’t eat the slime!

Note for teachers and technicians:
This post is aimed at people who might be making slime at home, and hence not have easy access to CLEAPSS guidelines. Anyone doing the experiment with students in school should, of course, refer to their department’s risk assessments and policies. For the record, at the time of writing, CLEAPSS classify 0.2M or 40g/dm³ (or more dilute) borax solutions as “low hazard”.

Edit: 15th August 2017:
After I wrote and published this post I was contacted by someone who specialises in boron chemistry, David Schubert. Now, if anyone knows about boron safety, it’ll be the guy who spends all day working with boron-based chemicals! He told me that borax has been shown to be safe for skin contact. He also said that you absorb less boron through intact skin than you consume by eating a normal, healthy diet (boron is a naturally-occurring trace-mineral – nuts and pulses are good sources), and even provided me with a link to a research paper on the subject. I asked him about the high pH of boron solutions, since alkaline solutions can be irritating in general, and he told me that borax solutions are less alkaline than sodium carbonate and not at all irritating to skin. At this point I will stress that when we’ve seen reports of children suffering skin irritation after making slime, it hasn’t been clear exactly what they’ve been handling. It’s very likely they were adding other chemicals to their slime, and it was actually one of those causing the irritation. Perhaps they developed an allergy to something. It’s impossible to say. Either way, the bottom line is that borax solutions are pretty safe – there’s no need to worry. (Still don’t drink them though!)


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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.


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Hazardous homeopathy: ‘ingredients’ that ought to make you think twice

Would you take a medicine made with arsenic? Or deadly nightshade? Lead? Poison ivy?

You’d ask some serious questions first, at least, wouldn’t you? Is it definitely safe? Or, more accurately, are the odds better than even that it will make me better without causing horrible side-effects? Or, you know, killing me?

There ARE medicines that are legitimately made from highly toxic compounds. For example, the poison beloved of crime writers such as Agatha Christie, arsenic trioxide, is used to treat acute promyelocytic leukemia in patients who haven’t responded to other treatments. Unsurprisingly, it’s not without risks. Side-effects are unpleasant and common, affecting about a third of patients who take it. On the other hand, acute promyelocytic leukemia is fatal if untreated. A good doctor would talk this through with a patient, explain both sides, and leave the final choice in his or her properly-informed hands. As always in medicine, it’s a question of balancing risks and benefits.

Would you trust something with no proven benefit and a lot of potential risk? There are, it turns out, a swathe of entirely unregulated mixtures currently being sold in shops and online which clearly feature the substances I listed at the beginning. And more. Because they are all, supposedly, the starting materials in certain homeopathic remedies.

Homeopaths like to use unfamiliar, usually Latin-based, names which somewhat disguise the true nature of their ingredients. Here’s a short, but by no means comprehensive, list. (You might find remedies labelled differently but these are, as far as I can tell, the most common names given to these substances.)

If you haven’t heard of some of these, I do urge you to follow the links above, which will largely take you pages detailing their toxicology. Spoiler: the words “poison”, “deadly” and “fatal” feature heavily. These are nasty substances.

There are some big ironies here, and I’m not referring to the metal. For example, a common cry of anti-vaccinationists is that vaccines contain animal tissues – anything and everything from monkey DNA to dog livers. But many also seem to be keen to recommend homeopaths and courses of homeoprophylaxis – so-called “homeopathic vaccines” – which use bodily fluids such as pus and blood as starting materials.

Now, at this point I’m sure some of you are thinking, hang on a minute: aren’t you always telling us that “the dose makes the poison“? And aren’t homeopathic remedies diluted so much that none of the original substance remains, so they’re just placebos?

Yes, I am, and yes, they are.

Does anyone test homeopathic remedies to make sure there’s nothing in them….?

In THEORY. But here’s the problem: who’s testing these mixtures to make sure that the dilutions are done properly? And how exactly are they doing that (if they are)?

One technique that chemists use to identify tiny quantities of substance is gas chromatography (GC). This is essentially a high-tech version of that experiment you did at school, where you put some dots of different coloured ink on a piece of filter paper and watched them spread up the paper when you put it in some water.

GC analysis is brilliant at identifying tiny quantities of stuff. 10 parts per million is no problem for most detectors, and the most sensitive equipment can detect substances in the parts per billion range. Homeopathy dilutions are many orders of magnitude higher than this (30c, for example, means a dilution factor of 1060), but this doesn’t matter – once you get past 12c (a factor of 1024) you pass the Avogadro limit.

This is because Avogadro’s number, which describes the number of molecules in what chemists call a “mole” of a substance, is 6×1023. For example, if you had 18 ml of water in a glass, you’d have 6×1023 molecules of H2O. So you can see, if you’ve diluted a small sample by a factor of 1024 – more than the total number of molecules of water you had in the first place – the chances are very good that all you have is water. There will be none of the original substance left. (This, by the way, is of no concern to most homeopaths, who believe that larger dilutions magically produce a stronger healing effect.)

What if the sample ISN’T pure water after it’s been diluted?

If you carried out GC analysis of such a sample, you should find just pure water. Indeed, if you DIDN’T find pure water, it should be cause for concern. Potassium cyanide, for example, is toxic at very low levels. The lethal dose is is only 0.2-0.3 grams, and you’d suffer unpleasant symptoms long before you were exposed to that much.

So what if the dilutions somehow go wrong? What if some sample gets stuck in the bottle? Or on the pipette? Or a few dilution steps get skipped for some reason?

Are these largely unregulated companies rigorously quality-checking their remedies?

Well, maybe. It’s possible some producers are testing their raw materials for purity (ah yes, another question: they CLAIM they’re starting with, say, arsenic, but can we be certain?), and perhaps testing the “stability” of their products after certain periods of time (i.e. checking for bacterial growth), but are they running tests on the final product and checking that, well, there’s nothing in it?

And actually, isn’t this a bit of a conflict? If the water somehow “remembers” the chemical that was added and acquires some sort of “vibrational energy”, shouldn’t that show up somehow in GC analysis or other tests? If your tests prove it’s pure water, indistinguishable from any other sample of pure water, then… (at this point homeopaths will fall back on arguments such as “you can’t test homeopathy” and “it doesn’t work like that”. The name for this is special pleading.)

A warning was issued in the U.S. after several children became ill.

Am I scaremongering? Not really. There’s at least one published case study describing patients who suffered from arsenic poisoning after using homeopathic preparations. In January this year the U.S. Food and Drug Administration issued a warning about elevated levels of belladonna (aka deadly nightshade) in some homeopathic teething products. Yes, teething products. For babies. This warning was issued following several reports of children becoming ill after using the products. The FDA said that its “laboratory analysis found inconsistent amounts of belladonna, a toxic substance, in certain homeopathic teething tablets, sometimes far exceeding the amount claimed on the label.”

Now, admittedly, I’m based in the U.K. and these particular teething remedies were never readily available here. But let’s just type “homeopathy” into the Boots.com (the British high-street pharmacy) website and see what pops up… ah yes. Aconite Pillules, 30c, £6.25 for 84.

What happens if you search for “homeopathy” on the Boots.com website?

Have you been paying attention lovely readers? Aconite is…. yes! Monkshood! One of the most poisonous plants in the garden. Large doses cause instant death. Smaller doses cause nausea and diarrhea, followed by a burning and tingling sensation in the mouth and abdomen, possibly muscle weakness, low blood pressure and irregular heartbeat.

I must stress at this point that there is no suggestion, absolutely none whatsoever, that any of the products for sale at Boots.com has ever caused such symptoms. I’m sure the manufacturers check their preparations extremely carefully to ensure that there’s absolutely NO aconite left and that they really are just very small, very expensive, sugar pills.

Well, fairly sure.

In summary, we seem to be in a situation where people who proclaim that rigorously-tested and quality-controlled pharmaceuticals are “toxic” also seem to be happy to use unregulated homeopathic remedies made with ACTUALLY toxic starting materials.

I wonder if the new “documentary” about homeopathy, Just One Drop, which is being screened in London on the 6th of April will clarify this awkward little issue? Somehow, I doubt it. Having watched the trailer, I think it’s quite clear which way this particular piece of film is going to lean.

One last thing. Some homeopathic mixtures include large quantities of alcohol. For example, the Bach Original Flower Remedies are diluted with brandy and contain approximately 27% alcohol (in the interests of fairness, they do also make alcohol-free versions of some of their products and, as I’ve recently learned, they may not be technically homeopathic). Alcohol is a proven carcinogen. Yes, I know, lots of adults drink moderate quantities of alcohol regularly and are perfectly healthy, and the dose from a flower remedy is minuscule, but still, toxins and hypocrisy and all that.

There are cheaper ways to buy brandy than Bach Flower Remedies.

Amusingly, the alcohol in these remedies is described an “inactive” ingredient. It’s more likely to be the only ACTIVE ingredient. And since Flower Remedies retail for about £7 for 20 ml (a mighty £350 a litre, and they’re not even pure brandy) may I suggest that if you’re looking for that particular “medicine” you might more wisely spend your money on a decent bottle of Rémy Martin?


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