The Food Babe has No Idea how Physiology Works

Originally posted here: https://mcgill.ca/oss/article/quackery/food-babe-has-no-idea-how-physiology-works

Our good friend the Food Babe has published an interesting piece of pseudoscience writing entitled ‘Are Natural Flavors Really That Bad? (MUST WATCH)’. If you’re looking for the quick answer to this superfluous, click-bait title, let me tell you that it’s no: natural flavours are perfectly safe and healthy. But if you’re looking for an explanation of how taste actually works (and why her claims about natural flavours are utter nonsense), then please read on!

Vani Hari bases her distaste for natural flavours off the idea that “flavor in nature doesn’t come without nutrition.” Regrettably I’m here to tell her that this is unequivocally false. Hari thinks that “foods naturally taste amazing to us because they contain the nutrients we need. Flavors are the cue that tells us where to and the nutrients we need”. Not quite, Babe. Taste =/= nutrition. There are poisonous things that taste great, and very healthy foods that taste awful.

Following this same logic, she also believes that food companies add natural flavour to foods to “trick consumers into thinking they are getting nutrition that isn’t there.” Now, for once, this idea isn’t exactly wrong, but it is misleading. Food producers definitely do add natural flavours to all kinds of foods, but they do so in general to make things taste better, not to make them seem healthier. Think about it, do you really think your soda is healthier if its blueberry flavoured instead of cream soda? Doritos list natural flavours on their label, presumably those are natural flavours of tomato and cheese, but did you really think that Doritos are good for you like homemade tomato soup with cheddar on top?

Following your tongue to guide your diet probably isn’t a good idea, but I think we all knew that. If I only ate what I was craving, I’d live off of French fries, and I don’t think that’s because my body needs a lot of sodium and no protein. Besides, what tastes good is fairly subjective, but what’s healthy isn’t.

So what is flavour, if not nutrition? It’s all chemistry. We taste things because of interactions between the chemicals (gasp!) in food and the chemoreceptors in our mouths. You know how they say there are only 5 tastes: sweet, sour, salty, bitter and umami (savoury)? That’s a result of the taste receptorspresent in humans.

Salty and sour tastes are the simplest in many respects. Saltiness is detected by sodium ion channels in our tongues. When sodium ions (usually from sodium chloride or table salt) interact with these taste receptors, they are allowed to enter the cell. Being positively charged, they change the voltage inside the cell, which starts the process of sending an electrical signal to your brain that tells it, ‘hey, this tastes salty’. Sour tastes use a similar process, but with hydrogen ions entering sour taste cells.

The other 3 tastes are a bit more complex in how they’re detected. Instead of ions entering receptors directly and starting the signal to the brain, various molecules (depending on the taste) interact with different G-protein-coupled receptors. This interaction begins a whole pathway of signaling that eventually reaches the brain to convey taste.  Many different molecules may activate these: for sweet tastes, it’s commonly sugars and molecules similar to sugars; for bitter, it’s more than 670 compounds; and for umami, it’s salts ofglutamic acid, the most commonly encountered of which is monosodium glutamate (MSG).

So food produces a taste because of the molecules inside of it, but why does it taste good? Because of physiology!

Our body does use the tastes of foods to get us to eat varying amounts of them, but not because of their nutrient contents like Hari thinks. In general, we find salt to be a pleasant taste because it is necessary to maintain homeostasis. Without salt, our kidneys would cease to function, so in an attempt to get us to ingest it, our brain makes it taste ‘good’.

Sugar, similarly, is absolutely integral to life. Carbohydrates are just chains of sugars and they are rich in calories, so they are desirable for a body that needs energy, hence the enjoyment that sweet tastes elicit. Umami tastes ‘good’ to encourage us to eat necessary fats and proteins.

Both salty and sour tastes are only ‘good’ in certain quantities. This is thought to be a result of evolution, since things that taste too acidic or salty tend to be spoiled, unsafely acidic or not ripe.

Bitter tastes bad to all humans naturally: just try to feed dark chocolate to a baby if you need proof of that, and it’s only through repeated consumption and some trick psychology that we come to enjoy bitter things. This is anevolutionary development due to many poisonous compounds tasting bitter, and why most medicines still taste bitter to us (our bodies think they’re poisons).

Now, there are many exceptions to these broad generalizations of what tastes ‘good’, proven in the fact that some (silly) people dislike dark chocolate, or the fact that I hate papaya, despite it tasting sweet. And in the modern world, as Food Babe warns us, there are artificial and natural flavours added to foods, so, surprise, surprise, there’s more to a healthy diet than just flavour.

Some good example include nightshade, which is incredibly toxic to humans, yet tastes quite sweet (making it even more dangerous to children who may ingest it), and apricot kernels which are quite toxic (as few as 10 of them could kill a child) due to their amygdalin content (this compound is metabolized into cyanide inside humans). But if you want to follow Vani’s logic, some people think they taste quite good, so they must be good for you, right?

Vani might be technically right about natural flavours being added to foods, but she’s wrong about why, and she’s wrong about a few other things too:

She says that “the flavors that humans love in tomatoes are synthesized in tomatoes from essential nutrients like beta carotene, amino acids, and omega 3’s”. Well, beta carotene is not an essential nutrient in humans, and indeedonly 9 of the 20 amino acids are. Studies on tomatoes have determined that there are about 27 compounds that contribute to their taste, 3 of which (geranial, 2-methylbutanal, and 3-methyl-1-butanol) actually influence how sweet a tomato tastes, regardless of sugar content (or ‘trick your brain!’ as she would say). So if the Food Babe believes compounds that alter how foods taste without altering their nutritional content are problematic, she should probably give up bruschetta.

Not to mention she claims that “soda without flavors is just carbonated water and sugar. No one would drink that without the flavor”’ somehow forgetting that the carbonated water industry is huge, and that billions of people do just that.

To recap, flavours are just the result of chemistry, things that are good for us do taste good, sort of, but not because of their nutrient content, and no one thinks that gummy bears are healthy just because they taste kind of like fruit.

So instead of asking yourself, “Did someone engineer this to be delicious or did nature engineer this to be delicious”, as Hari advises, I think I’d rather contemplate why it is I’d be taking diet advice from a blogger without a science degree.

Why Do Old Books Smell So Good?

Originally published here: https://mcgill.ca/oss/article/did-you-know/why-do-old-books-smell-so-good

E-readers might be convenient, but they’ll never have that comforting old book smell. It turns out that the smell of old books is due to the organic materials in books (like cellulose from wood pulp) reacting with light, heat and water, and over time releasing volatile organic compounds or VOCs. What VOCs are released depends on how the book was made and stored, but common scents are toluene or ethylbenzene, which smell sweet, benzaldehyde or furfural, which smell almond-like, or vanillin, which smells like- you guessed it- vanilla. Book VOCs are even being used to date old books, as the rate at which they break down can be used to determine the age of some old tomes.

What is this “isobutylene” I keep hearing pop up in the news?

Originally posted here: https://mcgill.ca/oss/article/did-you-know/i-keep-hearing-isobutylene-newswhat-heck-it

An explosion and fire at a Texas chemical plant fuelled by the extremely flammable gas isobutylene has killed one employee and left the public wondering why such a dangerously flammable gas is produced in such large quantities.

Isobutylene (also called 2-methylpropene, isobutene, and γ-butylene because chemists aren’t wonderful at sticking to a one naming system) is a colourless, gaseous hydrocarbon at room temperature.

Its flash point is -80 ˚C meaning that above this temperature, if an ignition source is present, isobutylene will ignite. Since the coldest temperature ever recorded on Earth was -89 ˚C, isobutylene is only a spark away from flames nearly everywhere on earth at all times.

Isobutylene is widely used in the synthesis of many things, largely because it contains a double bond which can be easily reacted to form other products. It can, for example, react with ethanol to form ethyl tert-butyl ether (ETBE), a gasoline additive that raises the octane number, making the fuel more resistant to knocking, or spontaneous combustion. Or it can be combined with itself in a long chain to form a polymer, butyl rubber.

Butyl rubber is hugely useful. It’s airtight, so it can be used to make seals like O-rings, window seals or cling film, as well as bottle stoppers, kickballs and tires. It’s tasteless and odourless, so it can be added to chewing gum, which, once chewed, can be collected and recycled to recover the isobutylene.

Like other forms of rubber, butyl rubber will break down when exposed to solvents like ammonia but will do so much slower than other rubbers. This has led to its widespread use in protective articles of clothing and gas masks.

Where do we get all this isobutylene from? Natural gas. Butane (the fuel that’s in your Zippo lighter) can be derived from mined natural gas and turned into tert-Butyl alcohol, which can then be turned into isobutylene.

So, while it’s not the most sustainable chemical around, isobutylene’s many varied uses can explain its mass production. Unfortunately, due to its extremely flammable nature, precautions do need to be taken to avoid fires like the one that occurred in Texas.