It's no secret that sugar isn't great for us, and it's even less of a secret that we eat too much of it anyway. But if we're going to continue to consume the sweet stuff in such high quantities, we'd better at least know exactly what it's doing to our brains and bodies, which is where the latest episode of BrainCraft comes in.
Vanessa has broken down the research on what happens throughout the body when you take a mouthful of sugary goodness in order to find out just why we love it so much. And it turns out that a big part of it has to do with our ancestors.
Back in hunter gatherer days, humans would only get sugar from fruit or the occasional mouthful of honey, but these were both only available at certain times of the year. But even back then they were inspired to eat more of them, as thousands of years of evolution has primed our brains to recognise sweet tastes as a signal for lots of calories, which our bodies need to survive.
This is the same reason babies are innately not fans of bitter and sour tastes – throughout our evolution, these tastes were a signal that something was off or toxic and worth avoiding.
But then things changed. In the 13th century sugar made its way from Asia to Europe and in the 16th century sugar plantations were established in Brazil. Gradually sugar went from an exotic spice to an affordable staple, and between the 18th and 19th centuries, sugar consumption in England increased 1,500 percent, as Vanessa explains.
So what is all that sugar doing to us according to scientists? To start with, we have sweetness receptors on our tongues, and in our pancreas and intestines. These can detect two types of sugar – glucose and fructose – and if eaten in moderation and in combination with the natural fibres from fruits, they don't do much other than tell your brain you're full and trigger some feel-good dopamine.
But when we eat fructose without the fibre of fruit, which we often do when we consume sugary snacks or fruit juice, the pathway gets all messed up and your brain doesn't get the message that you're full, so you just keep on eating.
This is a problem because fructose can only be broken down by the liver, and it can only process around six to nine teaspoons of sugar a day. That may sound like quite a lot, but with all the added sugar in our processed food, the average American consumes two teaspoons a day. And so all that un-metabolised sugar just ends up being stored as fat.
Unfortunately, that's not all that happens. Watch the episode of BrainCraft to find out more about the changes sugar triggers in our bodies. And maybe put down the donut first.