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.


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, but you must reference this site if you do.


All comments are moderated. Abusive comments will be deleted, as will any comments referring to posts on this site which have had comments disabled.

Advertisements

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%


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, but you must reference this site if you do.


All comments are moderated. Abusive comments will be deleted, as will any comments referring to posts on this site which have had comments disabled.

Black Salve BS

Historically, people weren’t always careful in the sun.

Summer is fast disappearing in the Northern hemisphere and with it, the sunshine. Which is sad, as we all love a bit of sun, don’t we? Even if it doesn’t always love us, particularly those of us with fairer skin. Sunburn is no fun, but these days we also understand that it’s worse than a couple of days of painfully peeling skin: too much sun exposure can cause cancer.

Unfortunately there’s a whole generation – indeed more than one – who didn’t grow up with parents constantly slathering on the factor 50 (easy-to-use transparent sunscreens with very high SPFs didn’t appear on the market until the 1990s). For some sunburn was a regular part of summer, and those people need to be particularly vigilant for changes which might signify something nasty is going on.

On the plus side, these types of cancer are very treatable, and the outlook is hopeful. Often, the growth can be removed by surgery or even cryotherapy with very little scarring. Even the most dangerous kind of skin cancer, malignant melanoma, has a ten-year survival rate of around 90% with appropriate treatment.

But there’s the key: appropriate treatment. If you notice changes in your skin, especially a mole which is changing in colour or shape, you must see a qualified doctor as soon as you can.

What you should absolutely not do is visit the Black Salve page on Facebook (which I am not linking to for reasons which will be come obvious). This page, so Facebook tells me, is followed by nearly 17,000 users. It features a cheery cover photo of a family holding a canoe over their heads, and its profile picture is a pretty white and yellow flower.

Sanguinarine is a toxic salt extracted from the bloodroot plant. It’s infamous for its ability to destroy animal cells.

It’s all very suggestive of a homely, traditional remedy. The sort of thing your grandma had in her medicine cabinet. Very safe and “natural“. But while black salve might be a traditional remedy, it is anything but safe. Most preparations contain bloodroot, a source of the toxin sanguinarine, which kills animal cells.

Applying bloodroot to the skin destroys tissues and causes the formation of a large, black lump of dead flesh. Eventually this mass, called an eschar, falls off, leaving varying degrees of damage behind (internal use is also not recommended: consuming bloodroot can cause vomiting and loss of consciousness).

Bloodroot is easy to buy. Back in May this year the Good Thinking Society reported that eBay had removed “listings for dangerous cancer ‘cure’” following an investigation. Those listings were for black salve, and this was, of course, very positive news. Except for one thing: whilst listings for black salve were removed (and remain absent), listings for bloodroot were not. At the time of writing, a quick search reveals several bloodroot preparations still for sale.

At the time of writing, bloodroot is easy to find on eBay. The listing confirms that this is prepared from the “rhizome of certified organically grown Sanguinaria conadensis plants”.

Why is this such a bad thing? Because it’s easy to find recipes for making homemade black salve with bloodroot online, and using such mixtures can have truly horrific consequences. Last year the story of a woman who applied it to a basal cell carcinoma on her nose was widely reported. The black salve paste she used did so much damage that she ended up with a large hole in her nose through which she could actually draw air. Photos and video are available online (be warned: it’s gruesome).

Many patients turn to black salve as an alternative to what they imagine will be disfiguring surgery to treat their cancer. But, as in this woman’s case, the paste can do so much damage that far more extensive, reconstructive, surgery is ultimately needed.

Black Salve usually contains bloodroot and, sometimes, zinc chloride – another skin irritant.

It won’t surprise anyone to learn that dermatologists don’t recommend black salve. It can do enormous damage to the surface of the skin, resulting in scarring and a high risk of infection, and it does kill cancer cells along the way. But there is no guarantee that all of the cancerous cells deep within the skin will be destroyed. As a result, patients who’ve attempted to cure themselves may end up with cancerous tissue hidden, and growing, beneath a scar.

In fact, exactly this happened to an otherwise healthy 76 year-old woman in 2006. Her case is described in detail in the journal Dermatology Practical Conceptual – in summary, she refused surgery on a small melanoma on her leg. Instead, she bought black salve on the internet and applied it. A few years later the cancer had spread to her lungs, liver and lymph nodes.

Some people even recommend using black salve on breast cancers but this is, if possible, even worse. It’s highly unlikely that the salve will reach the entirety of a tumour which is beneath the skin. It is likely to do some horribly painful and disfiguring damage along the way, though.

Black salve is particularly popular in Australia, which of course has some of the highest rates of skin cancer in the world. But it’s available in the UK too. One online “herbal medicine” site is openly selling various formulations at prices ranging from £25-£100. Ironically, they describe their “Herbactive” product as “chemical free” (it isn’t, nothing is) and then go onto boast that it “now has a stronger concentration of bloodroot”. Fantastic.

They also sell a product which contains zinc chloride along with bloodroot. They claim zinc chloride is safe. It isn’t. It’s well-known to be a skin irritant, and should never be left in contact with skin.

The Black Salve Facebook page is full of anecdotes and testimonials, but light on evidence.

The Black Salve Facebook page is packed full of anecdotes and testimonials from people who claim to have used these mixtures safely. It’s all interspersed, of course, with the usual “Big Pharma” conspiracy theories. Namely, that the “truth” is being suppressed because there’s “no money in it for the pharmaceutical [industry].”

The irony is that reconstructive surgery is incredibly expensive, and the antibiotics, painkillers and other drugs that are inevitably needed to treat black salve victims aren’t free, either.

Given that Facebook’s community standards page states that: “We remove content, disable accounts and work with law enforcement when we believe that there is a genuine risk of physical harm or direct threats to public safety.” one has to wonder why the Black Salve page is still there. People are actually posting pictures of physical harm. What more does Facebook need?

Please, don’t be tempted to use black salve, or anything containing bloodroot. If you think you have a skin tumour see a properly qualified doctor and follow his or her advice.

It might literally save your life.


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, but you must reference this site if you do.


All comments are moderated. Abusive comments will be deleted, as will any comments referring to posts on this site which have had comments disabled.

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.


Like the Chronicle Flask’s Facebook page for regular updates, or follow @chronicleflask on Twitter. In need of a groovy new mug for your oh-so-healthy coffee? Check out this page.


All comments are moderated. Abusive comments will be deleted, as will any comments referring to posts on this site which have had comments disabled.

 

What’s all the fuss about glyphosate?

Glyphosate, the key ingredient in Monsanto’s weedkiller Roundup, has been in the news recently. A few weeks ago it was widely reported that a UN/WHO study had shown it was ‘unlikely to pose a carcinogenic risk to humans‘. But it then emerged that the chairman of the UN’s joint meeting on pesticide residues (who, incidentally, has the fabulous name of Professor Boobis) also runs the International Life Science Institute (ILSI). Which had received a $500,000 donation from Monsanto, and $528,500 from an industry group which represents Monsanto among others.

And then it transpired that there was going to be an EU relicensing vote on glyphosate two days after the (since postponed) UN/WHO report was released, which resulted in another outcry.

Glyphosate molecule

A molecule of glyphosate

So what is glyphosate, and why all the fuss?

It was first synthesized in 1950 by Swiss chemist Henry Martin. It was later, independently, discovered at Monsanto. Chemists there were looking at water-softening agents, and found that some of them also killed certain plants. A chemist called John E. Franz was asked to investigate further, and he went on to discover glyphosate. He famously received $5 for the patent.

Chemically, glyphosate is a fairly simple molecule. It’s similar in structure to amino acids, the building blocks of all proteins, in that it contains a carboxylic acid group (the COOH on the far right) and an amine group (the NH in the middle). In fact, glyphosate is most similar to the smallest of all amino acids, glycine. Where it deviates is the phosphonic group (PO(OH2)) on the left. This makes it a (deep breath) aminophosphonic analogue of glycine. Try saying that when you’ve had a couple of beers.

As is usually the way in chemistry, changing (or indeed adding) a few atoms makes a dramatic difference to the way the molecule interacts with living systems. While glycine is more or less harmless, and is in fact a key component of proteins, glyphosate is a herbicide.

This probably bears stressing. It’s a herbicide. Not an insecticide. A herbicide.

Crop spraying

Glyphosate is a herbicide, not an insecticide.

I say this because people often conflate the two – after all, they’re both chemicals you spray on plants, right? – but they are rather different beasts. Insecticides, as the name suggests, are designed to kill insects. The potential problem being that other things eat those creatures, and if we’re not careful, the insecticide can end up in places it wasn’t expected to end up, and do things it wasn’t expected to do. This famously happened with DDT, a very effective pesticide which unfortunately also had catastrophic effects on certain predatory birds when they ate the animals that had eaten the slightly smaller animals which had eaten the insects that had eaten the other insects (and so on) that had been exposed to the DDT.

Herbicides, on the other hand, kill plants. Specifically, weeds. They’re designed to work on the biological systems in plants, not animals. Often, they have no place to bind in animals and so are simply excreted in urine and faeces, unchanged. Also, since plants aren’t generally known for getting up and wandering away from the field in which they’re growing, herbicide sprays tend to stay more or less where they’re put (unless there’s contamination of waterways, but this can – and should, if the correct procedures are followed – be fairly easily avoided).

Nicotine pesticide

Nicotine is an effective insecticide. It’s also extremely toxic.

Now this is not to say we should be careless with herbicides, or that they’re entirely harmless to humans and other animal species, but we can cautiously say that, in general, they’re rather less harmful than insecticides. In fact, glyphosate in particular is less harmful than a lot of everyday substances. If we simply look at LD50 values (the amount of chemical needed to provide a lethal dose to half of a test population), glyphosate has an LD50 of 4900 mg/kg whereas, for comparison, table salt has an LD50 of 3000. Paracetamol (acetaminophen) has an LD50 of 338, and nicotine (a very effective insecticide, as well as being the active ingredient in cigarettes) has an LD50 of just 9.

Of course, there’s more to toxicity than just killing things, and that’s where it gets tricky. Yes, it might take more than a third of a kilo to kill you outright, but could a smaller amount, particularly over an extended period of time, have more subtle health effects?

But before we go any further down that rabbit hole, let’s take a look at that ‘smaller amount’. Certain campaigners (they always seem to have some sort of stake in the huge business that is organic food, ahem) would have us believe that food crops are ‘drenched’ in glyphosate, and that consumers are eating significant quantities of it every day.

Here’s a great graphic, made by Sarah Shultz of the Nurse Loves Farmer blog (reproduced with her kind permission), that answers this question nice and succinctly:

How much glyphosate?

How much glyphosate is sprayed on crops? (Reproduced with permission of Sarah Shultz)

It’s about 1 can of soda’s worth per acre. Or, if you find an acre hard to visualise, roughly ten drops for every one hundred square feet – the size of a smallish bedroom.

In other words, not a lot. It’s also worth remembering that although there is some pre-harvest spraying – particularly of wheat crops – no farmer is spraying their crops five minutes before harvest. What would be the point of that? Farmers have margins, just like any other business, and chemicals cost money. If you’re going to use them, you use them in the most efficient way you can. The point of spraying pre-harvest is to kill any weeds that might be present so that they don’t get into your harvest. This takes time to happen, so it’s done seven to fourteen days before harvesting takes place. It’s also carefully timed in the growing cycle. Once wheat turns yellow, it’s effectively dead – it’s neither photosynthesising nor transporting nutrients – so if it’s sprayed at this point, glyphosate isn’t moved from the plant into the grain of the wheat. Which means it doesn’t make it into your food.

The long and short of all this is that if there IS any glyphosate in food crops, it’s in the parts per billion range. So is that likely to be harmful?

In March 2015 the International Agency for Research on Cancer (IARC) – the cancer-research arm of the World Health Organisation – announced that glyphosate was ‘probably carcinogenic to humans’, or category 2A. It needs to be pointed out that this outcome was controversial, as this post by The Risk Monger explains. But even that controversy aside, lots of things fall into category 2A, for example smoke from wood-burning fires, red meat, and even shift work. The IARC did note that the evidence mainly involved small studies and concerned people that worked with glyphosate, not the general public, and that recommendations were partly influenced by the results of animal studies (really, go and read that Risk Monger post). The one large-cohort study, following thousands of farmers, found no increased risk.

And by the way, alcohol has been classified as a Group 1 carcinogen, meaning it’s definitely known to cause cancer in humans. If you’re worried about glyphosate in wine and beer, I respectfully suggest you have your priorities the wrong way round.

So, the tiny traces of glyphosate that might be on food definitely aren’t going to poison you or give you cancer. Are there any other health effects?

Gut bacteria

Glyphosate isn’t interfering with your gut bacteria (image: microbeworld.org)

One thing that the health campaigners like to talk about is gut health. Their logic, such as it is, follows that glyphosate passes though our body largely unchanged. Now, you might imagine this would be a good thing, but according to these particular corners of the internet, it’s exactly the opposite. Glyphosate is known to be anti-microbial, and since it’s not changed as it passes through the body, the argument goes that it gets into our guts and starts wiping out the microbes in our digestive system, which have been increasingly linked to a number of important health conditions.

It sort of makes sense, but does it have any basis in fact? Although glyphosate can act as an antimicrobial in fairly large quantities in a petri dish in a laboratory, it doesn’t have a significant effect in the parts per billion quantities that might make their way to your gut from food. Glyphosate prevents bacteria from synthesising certain essential amino acids (it does the same thing to plants; that’s basically how it works) but in the gut these bacteria aren’t generally synthesising those amino acids, because they don’t need to. The amino acids are already there in fairly large quantities; bacteria don’t waste energy making something that’s readily available. In short, glyphosate stops bacteria doing something they weren’t doing anyway. So no, no real basis in fact.

I have so far avoided mentioning GMOs, or genetically-modified organisms. “GMO” often gets muttered in the same breath as glyphosate because certain crops have been modified to resist glyphosate. If they weren’t, it would damage them, too. So the argument goes that more glyphosate is used on those crops, and if you eat them, you’ll be exposed to more of it. But, as I said earlier, farmers don’t throw chemicals around for fun. It costs them money. Plus, not-really-surprisingly-if-you-think-about-it, farmers are usually quite environmentally-conscious. After all their livelihood relies on it! Most of them use multiple, non-chemical methods to control weeds, and then just add the smallest amount of herbicide they can possibly get away with to manage the last few stragglers.

Ah, but even a little bit is too much, you say? Why not eat organic food? Then there will be absolutely no nasty chemicals at all. Well, except for the herbicides that are approved for use in organic farming, and all the other approved chemicals, famously copper sulfate and elemental sulfur, both of which are considerably more toxic than glyphosate by anyone’s measure. And, of course, organic food is much more expensive, and simply not a feasible way of feeding over seven billion people. Perhaps, instead of giving farmers a hard time over ‘intensive’ farming, we should be supporting a mixture of sustainable methods with a little bit of, safe, chemical help where necessary?

In summary, the evidence suggests that glyphosate is pretty safe. Consuming the tiny traces that might be present in food is not going to give you cancer, won’t cause some sort of mysterious ‘leaky gut’ and it’s definitely not to poison you. There is a lot of fuss about glyphosate, but it’s really not warranted. Have another slice of toast.


EDIT 2nd June 2016

After I wrote this post, a very interesting article came my way…

  • Petaluma city suspended use of glyphosate in favour of alternatives. Notable quote:“Having used the alternative herbicides over the past two months, DeNicola said crews have needed to apply the treatments more often to achieve similar results. The plants are also likely to regrow, since the root remains alive underground.The treatments are also said to be extremely pungent during application, with several workers complaining of eye irritation and one experiencing respiratory problems, DeNicola said. Those attributes have required the use of new protective equipment, something that was not required with Roundup.“It’s frustrating being out there using something labeled as organic, but you have to be out there in a bodysuit and a respirator,” he said.”

A classic example of almost-certainly unfounded fear leading to bad decision-making.


Follow The Chronicle Flask on Facebook and Twitter for regular updates and other interesting bits and pieces from around the internet.

No, ketchup does not cause cancer

ketchup and coke

Do these things really cause breast cancer? (Spoiler: no)

Less than two days into the new year, and I’d already found what might well be one of the silliest health headlines of the year. What is it I hear you ask? Well, it was in a national newspaper on New Years Day, and it was this:

Sugar found in ketchup and Coke linked to breast cancer

This, to borrow a favourite line from an online greetings card company, had me rolling my eyes so hard I could practically see my brain. Why? Because even without reading any further, I knew immediately that it was the equivalent of saying, “too much of thing found in most stuff might cause cancer!”

But let’s not be one of the 70% of users that only read the headline, let’s dig a little further. The newspaper article, which in fairness isn’t too bad – it’s just a bit of a silly headline, alludes to work carried out the University of Texas’ MD Anderson Cancer Centre. If you click on the link I’ve added back there, you’ll see that MD Anderson’s headline was:

“Sugar in Western diets increases risk for breast cancer tumors and metastasis”

Note, they just say ‘sugar’, not sugar in two apparently randomly-selected foodstuffs. The researchers divided mice into four groups, fed some a diet high in sucrose (more commonly called table sugar – in other words, the stuff in the sugar bowl) and compared them to others fed a low-sugar, ‘starch-controlled’ diet. They found that the high-sugar diet lead to increased tumour growth, particularly in mammary glands.

I’ve covered forms of sugar before but still, here’s a quick reminder before we go any further: this is a molecule of sucrose:

Saccharose2

Sucrose

Sucrose is made of two ‘bits’ joined together: one unit of fructose and one unit of glucose.

157px-Alpha-D-Glucopyranose

Glucose

These two molecules are what chemists call isomers. They contain the same number and type of atoms, just joined up differently. They’re both sugars in and of themselves. Glucose is used directly by cells in your body for energy. Fructose, on the other hand, is trickier. It has a lower glycemic index than glucose, in other words, it doesn’t raise your blood sugar as rapidly as glucose, but this doesn’t mean it’s healthier. It’s metabolised almost exclusively in the liver and, long story short, invariably ends up being converted into, and stored as, fat.

179px-Beta-D-Fructofuranose

Fructose

Fruit is high in fructose, and fructose tastes very sweet to us (sweeter than either glucose or sucrose). This is nature’s way of telling us, and other animals that might eat the fruit, that it’s high in nutrients. From the plant’s point of view, it’s an incentive to eat the fruit and, ahem, spread the seeds around.

Humans have, of course messed around with this perfectly sensible survival mechanism by stuffing all kinds of easily-available and not particularly nutrient-rich foods with fructose, and herein lies the problem. Co-author of the paper that started all this, Lorenzo Cohen, Ph.D., professor of Palliative, Rehabilitation, and Integrative Medicine, said “we determined that it was specifically fructose, in table sugar and high-fructose corn syrup […] which was responsible for facilitating lung metastasis and 12-HETE production in breast tumors.” Notice that he mentions fructose in table sugar; this is because, once you eat sucrose, it breaks down into units of glucose and fructose.

The article goes on to suggest that sugar-sweetened beverages are a significant problem, so was the newspaper wrong to pick on Coke? It’s a popular drink after all, and a standard can of Coca-Cola contains approximately 35 grams of sugar (which might come from either sucrose or high fructose corn syrup mainly depending on where you buy it). The guidance for adults is no more than 30 grams of sugar per day, so a single can of regular Coca-Cola would take you over that limit, and it’s very easy to drink two or even three cans without giving it a second thought.

sugar

Soft drinks and fruit juice both contain a lot of sugar

However, the same goes for pretty much any non-diet soft drink.  Pepsi, for example, has a similar amount. Lemonade can be even more sugary, with some drinks hitting 40 grams per 330 ml can. Ginger beer might well be the worst; there are 53 grams per 330 ml in Old Jamaica Ginger beer for example. Fruit juice is no better, with many juices containing 35 g of sugar per 330 ml, although at least fruit juice might contain some other nutrients such as vitamin C.

So really, I’d say it’s a bit unfair to single out Coke in a headline like this.

What about the ketchup (note they didn’t pick a specific brand here, just generic ‘ketchup’)?

Well, ketchup IS high in sugar. It contains about 24 grams of sugar per 100 grams. But hang on, 100 grams of ketchup is quite a lot. A more realistic serving size of a tablespoon is only about 15 grams, which works out at about 3.5 grams of sugar. Still quite a lot, but probably a drop in the ocean compared to all the sugar in cake, bread, drinks, fruit juice, breakfast cereals and the tubs of Roses and Quality Street you scoffed over Christmas. Unless you make a habit of drinking ketchup by the bottle (apparently some people do) this is frankly a ridiculous foodstuff to pick on.

I imagine that someone did a quick search for ‘foods that contain fructose’ and picked Coke because, well, everyone knows that Coke’s bad, right? So that sounds credible. And ketchup because we all sort of suspect it’s probably not that healthy, but it hasn’t been the subject of a health scare recently so that makes it stand out. Great clickbait, bad science.

mouse

Mice are not people

Plus, let’s be absolutely clear, the study was in mice. Mice are not people. While a study that shows an effect in mice is an interesting start, and may well be good reason to conduct more studies, quite possibly in humans, it’s not proof that this mechanism exists in humans. Humans have, after all, evolved to eat a very different diet to mice. There might well be a link, but this doesn’t prove it, and even if a link does exist we certainly can’t say anything about the significance or size of it from this research.

I’m not a dietician, but I’m going to go out on a (fairly sturdy) limb here and say that cutting back on sugar will not do you any harm and is likely to be a jolly good thing. Let’s also be clear that sugar in fruit juice, agave, honey etc is still sugar and is no healthier than table sugar. Eating too much of the sweet stuff is almost definitely bad for your waistline and, as we all learned as children, bad for your teeth too – something which is often overlooked but really shouldn’t be, poor dental health having been linked to other serious health problems including diabetes and heart disease.

ketchup on bread

Maybe cut back on the fried ketchup sandwiches

But, and here’s my big problem with the newspaper’s headline, none of this means that Coke and ketchup directly cause breast cancer which is how, I fear, some people will interpret it. Cut out sugary fizzy drinks by all means, and perhaps ditch the ketchup sandwiches (especially fried ones), but please don’t worry that the occasional dollop of red sauce is going to kill you. I’m pretty certain it won’t.

Follow The Chronicle Flask on Facebook for regular updates.

A small edit was made on 6th January to clarify that pure fructose isn’t used as an ingredient in Coke, but rather high fructose corn syrup.

 

 

Does drinking alcohol actually cause dehydration?

alcohol-effects

Today I came across this article: Drinking water doesn’t prevent a hangover, study says, which includes the memorable line: “[the] study concluded, the only way to prevent a hangover is to drink less alcohol.”

Now, at first sight, you might think that surely this simply another piece of work from the University of the Bleedin’ Obvious.

But hang on. Alcohol does dehydrate you, doesn’t it? Everyone knows that! After all, don’t you wee more when you go drinking, and wake up all sweaty and with a dry mouth after a ‘heavy night’? Surely this is all evidence of fluid loss? Am I really about to suggest we should consign ‘alcohol causes dehydration” to the collection of alcohol-based myths such as mixing drinks gives you a worse hangover (only if you drink more as a result), a night cap will help you sleep (only temporarily, overall it tends to disrupt sleep), drinking beer will cause a ‘beer belly’ (too much of any type of drink can cause weight gain), and so on?

Well…

1024px-Ethanol-3D-balls

There are many alcohols; ethanol is the one we drink.

Firstly, what is alcohol or, more specifically (the word ‘alcohol’ actually refers to a group of compounds), ethanol? It’s a simple molecule, containing only two carbon atoms, an oxygen and some hydrogen atoms. It’s produced, as we all learned at school (or possibly when attempting home-brewing), by yeast during the process of fermentation. Feed this clever little single-celled organism some sugar and voilà, it produces ethanol (C2H5OH) and carbon dioxide via a remarkably simple equation:

C6H12O6 –> 2C2H5OH + 2CO2

220px-Marula01

Marula fruit naturally ferments.

Humans learned this trick a long time ago and have been brewing for literally thousands of years. In fact it doesn’t even require human intervention – marlula fruit is particularly famous for becoming naturally alcoholic (although stories of monkeys and elephants using it to get drunk might be somewhat exaggerated).

We like drinking because, of course, of what it does to us. In medical terms, it’s a central nervous system depressant with significant psychoactive effects (sounds fun, eh?) In English, it reduces anxiety, making drinkers feel relaxed and happy. This accompanies a decrease in motor skills of course, which is why drinking and driving is illegal virtually everywhere (although exact definitions of what this means do vary).

But while alcohol is all natural, it’s not what you’d consider healthy. Every now and then someone drags out some data that suggests that low to moderate alcohol intake is good for you, but this sadly appears to be more wishful thinking than good science. In terms of disease, alcohol consumption has been linked with stroke, high blood pressure, several liver diseases, pancreatitis, a weakened immune system and a handful of cancers including mouth, throat, liver and breast cancers.

In fact, alcohol has been categorised by the International Agency for Research on Cancer as a group 1 carcinogen, which puts it in the company of such other delights as asbestos, radium isotopes, ultraviolet radiation, diesel exhaust and tobacco.

Enjoying-Dinner-copy

Give up alcohol before you worry about your latte ingredients.

Of course, the dose makes the poison. Lots of people enjoy low to moderate alcohol consumption quite safely. Still, I have to admit to being amused by health nuts that insist on a diet consisting of little more than raw vegetables, make a fuss about so-called GMOs, campaign for additives (none of which are anywhere close to being group 1 carcinogens) to be removed from food, and then post pictures of themselves drinking wine. You really want to improve your health? Never mind caramel colour IV in your latte, give up the booze.

So, alcohol isn’t a health food, or indeed drink. But to get back to the original question, does it cause dehydration? Well, it would appear that while it does do a lot of bad stuff health-wise, that’s not one of the bad things it does. In a study, men drank six pints of beer and were then subjected to a number of tests. As the subsequent PubMed article states: “All subjects had a slight hangover, but none was fluid depleted”.

Screen Shot 2015-08-29 at 18.22.08

Twin doctors Chris and Xand van Tulleken in a recent BBC documentary.

In a recent BBC Horizon documentary, twin doctors Chris and Xand van Tulleken collected all their urine during a night in which Xand drank 21 units of alcohol in one sitting (while his brother only had one drink), and next morning demonstrated that the volumes were the same. In other words, the excessive alcohol consumption had not, as is widely believed, had a significant diuretic effect.

Admittedly, this was only two people, and the PubMed study only involved six participants – small sample size is often an issue with such work. The Dutch study I mentioned at the start was much larger, which is one reason it’s useful. In that study, drinking water appeared to make little difference to the severity of the hangover experienced. The only thing that really mattered was, not surprisingly, how much alcohol had been consumed.

In fact it’s not well-understood what does cause hangovers. It would appear it’s linked to an immune system response. In very simple terms, getting blind drunk is a little like self-imposed flu. Drinking plenty of fluids won’t do you any harm, but it’s not actually a solution. Of course, there’s no virus involved here to keep the immune system on the warpath, so for most healthy people the best, and probably only, hangover cure is time.

So in summary, yes, we probably can chuck “alcohol causes dehydration” in with all the other alcohol myths floating around out there, but that’s not an excuse to have a pint after your workout.

Follow The Chronicle Flask on Facebook for regular updates.