Glucose Revolution: The life-changing power of balancing your blood sugar

by Jessie Inchauspé

‘The animal tends to eat with his stomach, and the man with his brain,’ wrote the philosopher Alan Watts.

Exciting discoveries have happened in the past five years in labs around the world: they’ve revealed our body’s reaction to food in real time – and have proven that although what we eat matters, how we eat it – in which order, combination, and grouping – matters too. What the science shows is that in the black box that is our body, there is one metric that affects all systems. If we understand this one metric and make choices to optimise it, we can greatly improve our physical and mental well-being. This metric is the amount of blood sugar, or glucose, in our blood.

You will rarely hear glucose discussed unless you have diabetes, but glucose actually affects each and every one of us.

A recent study showed that only 12 per cent of Americans are metabolically healthy, which means that only 12 per cent of Americans have a perfectly functioning body – including healthy glucose levels. We don’t have this exact number for all countries, but we know that metabolic health and glucose levels are getting worse everywhere. Odds are that you, and nine out of the ten people closest to you, are on a glucose rollercoaster without knowing it.

The more I’ve learned, the more I’ve realised that there is no benefit to extreme diets – especially because dogmas can easily be abused (there is very unhealthy vegan food, and there is very unhealthy keto food).

First, glucose isn’t everything. Some foods will keep your glucose levels completely steady but aren’t great for your health. For instance, industrial processed oils and trans fats age, inflame and hurt our organs, but they don’t cause glucose spikes. Alcohol is another example – it doesn’t spike our glucose levels, but that doesn’t mean it’s good for us.

context is key. My mother often sends me a photo of something she is debating buying at the supermarket. ‘Good or bad?’ she texts. I always respond, ‘It depends – what would you eat instead?’ We can’t say whether a food is good or bad in a vacuum – everything is relative. High-fibre pasta is ‘good’ compared to regular pasta but ‘bad’ compared to veggies.

a paper that finds that 10 minutes of moderate physical activity after a meal reduces the glucose spike of that meal.

It was once common to assume that plants were ‘soil eaters’: that they made themselves out of dirt. In the 1640s, a Flemish scientist by the name of Jan Baptist van Helmont set out to understand whether that was truly the case. He performed a five-year-long test known as the Willow Experiment, from which humanity learned two things: first, that van Helmont was very patient; second, that plants do not make themselves out of dirt. Van Helmont planted a 5-pound baby willow tree in a large pot filled with 200 pounds of soil. For the next five years, he watered it and watched it grow. Then, after those five years had passed and the tree had grown, he took the tree out of the pot and weighed it again: it stood at 169 pounds – 164 pounds heavier than

it had been at the beginning. But most important, the weight of the soil in the pot remained virtually unchanged. That meant that the 164 pounds of tree had to have come from somewhere else. The Willow Experiment proved that plants aren’t made of dirt. So how do plants make their… plant stuff, if it isn’t from soil? Back to the tiny sprout that just saw the light of day on Earth. Let’s call him Jerry. Jerry was the first to put together a very elegant solution: the ability to transform not soil but air into matter. Jerry combined carbon dioxide (from the air) and water (from the soil, but not actually soil), using the energy

of the sun, to make a never-before-seen substance that he used to construct every part of himself. This substance is what we now call glucose. Without glu...

For hundreds of years after the Willow Experiment, hordes of researchers tried to understand how plants did what they did with the help of experiments involving candles, vacuum-sealed jars and many different species of algae. The three men who finally cracked it were American scientists by the names of Melvin Calvin, Andrew Benson and James Bassham. For the discovery, Calvin was awarded the 1961 Nobel Prize in Chemistry. The process was baptised the ‘Calvin-Benson-Bassham Cycle’. Since it’s not the catchiest name...

I’m a bit envious of the way plants do what they do. They don’t have to spend any time at the grocery store. They create their own food. In human terms, it would be like being able to inhale molecules from the air, sit in the sun and create a creamy lentil soup inside our stomachs

without needing to find it, cook it, or swallow it.

Whenever plants need glucose, they use an enzyme called alpha-amylase that heads to the roots and frees some glucose molecules from their starch chains. Snap – glucose is let loose, ready to be used as energy or as a building block.

Another enzyme (there are a number of them) can be called on to perform a different task. Instead of attaching glucose molecules hand to hand to make starch, this enzyme connects glucose molecules hand to foot, and the resulting chain is called fibre. This substance is as important as grout between the bricks of a house. It’s what allows plants to grow tall without falling over. It’s most commonly found in trunks, branches, flowers and leaves, but there is fibre in roots and fruit as well.

Plants concentrate fructose into fruit – apples, cherries, kiwis and more – that they dangle from their branches. The purpose of fructose is to make fruit taste irresistible to animals. Why do plants want their fruit to be irresistible? Because they hide their seeds in them. It’s key to propagation: plants hope that animals will eat their fruit and their seeds will go unnoticed until they come out their eater’s other end. That’s how seeds spread far and wide, thereby ensuring the plants’ survival.

Every second, your body burns eight billion molecules of glucose. To put that into perspective, if each glucose molecule were a grain of sand, you’d burn every single grain of sand on all the beaches of the earth every ten minutes.

but there is no enzyme that can snap the bonds of fibre. It doesn’t get turned back into glucose. This is why when we eat fibre, it remains fibre. It travels from our stomach to our small and large intestines. And this is a good thing. Though it doesn’t turn back into glucose and therefore can’t provide energy to our cells, fibre is an essential part of our diet and plays a very important role in aiding digestion, maintaining healthy bowel movements, keeping our microbiome healthy and more.

it was accepted that the name for this family would be ‘carbohydrates’. Why carbohydrates? Because it refers to things that were made by joining carbon (carbo) and water (hydrate), which is what happens during photosynthesis.

because glucose is so important to our cells, if we can’t find any to eat, our body can make it from within.

we can make glucose from the food we eat – from fat or protein. Our liver, through a process called gluconeogenesis, performs this process.

when glucose is limited, many cells in our body can, when needed, switch to using fat for fuel instead. This is called metabolic flexibility. (The only cells that always rely on glucose are red blood cells.)

some diets such as Atkins and keto deliberately restrict the consumption of carbohydrates in order to keep a p...

low and thus push the body into burning fat for fuel. This is called nutritional ketosis and is met...

Nature intended us to consume glucose in a specific way: in plants. Wherever there was starch or sugar, there was fibre as well. This is important, because the fibre helped to slow our body’s absorption of glucose.

the vast majority of supermarket shelves are packed with products that contain mostly starch and sugar. From white bread to ice cream, sweets, fruit juices and sweetened yoghurts, fibre is nowhere to be seen. And this is on purpose: fibre is often removed in the creation of processed foods, because its presence is problematic if you’re trying to preserve things for a long time.

Place a fresh strawberry in the freezer overnight. The next morning, take it out to thaw on a plate. If you try to eat it, it will be mushy. Why? Because the fibre was broken into smaller bits by the freezing and thawing process. The fibre is still there (and still has health benefits), but the texture is not the same.

Fibre is often removed from processed foods so that they can be frozen, thawed and stored on shelves for years without losing their texture.

why do we like sweetness so much? It’s because in Stone Age times the taste of sweetness signalled foods that were both safe (there are no foods that are both sweet and poisonous) and packed with energy. In a time when food wasn’t easy to find, it was an advantage to eat all the fruit before anyone else could, so we evolved to feel pleasure when we tasted something sweet.

Deep, old evolutionary programming tells us that eating Skittles is a good move. Sheryl Crow sings that if something makes you happy, ‘it can’t be that bad’. We need glucose to live, and it gives us pleasure. So it’s fair to wonder: what’s the big deal if we eat more? In some cases, more isn’t necessarily better. Give a plant too much water, and it will drown; give humans too much oxygen, and they pass out. Similarly, there is an amount of glucose that is just right for us: just enough for us to feel great, jump around, go to work, hang out with other humans, live, laugh and love. But we can have too much glucose. And too much glucose hurts us, often without our realising it.

with a continuous glucose monitor (CGM), I can measure the amount of glucose throughout my body without a blood test: the CGM senses the concentration of glucose between the fat cells on the back of my arm.

we use millimoles per litre, also written mmol/L. Other countries use milligrams per decilitre (mg/dL). Whatever unit is used, they refer to the same thing: how much glucose is freely roaming in the body.

The NHS states that a baseline concentration (also known as your fasting level, that is, your glucose level first thing in the morning before eating) between 4.0 and 5.4 mmol/L is ‘normal’; that between 5.5 and 6.9 mmol/L indicates ...

studies showed that the thriving range for fasting glucose may be between 4 and 4.7 mmol/L. That’s because there is more likelihood of developing health problems from 4.7 mmol/L and up.

we should strive to avoid increasing our glucose levels by more than 1.7 mmol/L after eating.

A glucose spike from a sweet food (cupcake) is worse for our health than a glucose spike from a starchy food (rice). The reason has nothing to do with the glucose measured, though; it has to do with a molecule that’s not visible.

A sweet food contains table sugar, or sucrose – that compound made up of glucose and fructose. A starchy food doesn’t. Whenever we see a glucose spike from a sweet food, there is a corresponding fructose spike that unfortunately we can’t see. Continuous glucose monitors can detect only glucose, not fructose, and continuous fructose monitors don’t exist yet. Until they do, remember that if the food you ate was sweet and it created a glucose spike, it also created an invisible fructose spike, and that’s what makes a sweet spike more harmful than a starchy spike.

Each of us is made up of more than 30 trillion cells. When we spike, they all feel it. Glucose’s primary biological purpose once it enters a cell is to be turned into energy. The powerhouses responsible for this are microscopic organelles found in most of our cells called mitochondria. Using glucose (and oxygen from the air we breathe), they create the chemical version of electricity to give each cell the power to do whatever it needs to. As glucose floods into our cells, it heads straight to the mitochondria to undergo its transformation.

To understand how mitochondria respond to a glucose spike coming their way, imagine this: your grandfather, finally retiring after a long career, is able to fulfil his dream of working on a steam train. Everyone in the family thinks he’s crazy for doing it, but he doesn’t care. After some training, he enlists as a stoker in a train’s engine room: his job is to shovel coal onto the fire to generate the steam that pushes the pistons and makes the wheels of the train turn. He’s the mitochondria of the train, if you will. Periodically throughout the day, as the train speeds along the tracks, coal is delivered to your grandfather. He places it by the furnace and shovels it into the flames at a steady pace to fuel the process that moves the train. The raw material is converted to energy. And when the stock

is used up, another batch is promptly supplied. Just like the train, our cells hum along smoothly when the amount of energy that is provided is equal to the amount of energy needed to function. Now it’s the second day of your grandfather’s new job. A few minutes after the first delivery of coal, he gets a surprising knock on the door. More coal. He thinks, Well, it’s a bit early, but that way I’ll have some extra. He sets it aside next to the furnace. A few minutes later, another knock. More coal. And another. The knocks keep coming, and the coal keeps being delivered. ‘I don’t need all of this!’ he says. But he’s told that it’s his job to burn it, and he’s given no other explanation. All day long, delivery after delivery, unnecessary coal is stuffed into his cabin. The coal being delivered far exceeds what is needed. Your grandfather can’t burn the coal more quickly, so piles build up around him.

In a short while, there’s coal everywhere, stacked to the ceiling. He can barely move. He can’t shovel any more coal onto the fire because there is so much in the way. The train stops, and people get angry. At the end of the day, he quits, his dream sabotaged. Mitochondria feel the same way when we give them more glucose than they need. They can burn only as much glucose as the cell needs for energy, not more. When we spike, we deliver glucose to our cell...

According to the latest scientific theory, the Allostatic Load Model, when our mitochondria are drowning in unnecessary glucose, tiny molecules with large consequences are released by our cells: free radicals. (And some glucose is converted to fat; more on that shortly.) When free radicals appear because of a spike, they set off a dangerous chain reaction.

Free radicals are a big deal because anything they touch, they damage. They randomly snap and modify our genetic code (our DNA), creating mutations that activate harmful genes and can lead to the development of cancer. They poke holes in the membranes of our cells, turning a normally functioning cell into a malfunctioning one. Under normal circumstances, we live with a moderate amount of free radicals in our cells, and we can handle them – but with repeated spikes, the quantity produced becomes unmanageable. When there are too many free radicals to be neutralised, our body is said to be in a state of oxidative stress. Oxidative stress is a driver of heart disease, type 2 diabetes, cognitive decline and general ageing. And fructose increases oxidative stress even more than glucose alone. That’s one of the reasons that sweet foods (which contain fructose) are worse than starchy foods (which don’t). Too much fat can also increase oxidative stress.

Over decades cells become ravaged. Because they’re stuffed, crowded and overwhelmed, our mitochondria can’t convert glucose to energy efficiently. The cells starve, which leads to organ dysfunction. We feel this as humans: even though we’re fuelling up by eating, we suffer from lassitude;

This may come as a surprise to you, but you are currently cooking. More specifically, you are browning, just like a slice of bread in the toaster. Inside our body, from the moment we are born, things literally brown, albeit very slowly. When scientists look at the rib cage cartilage of babies, it’s white. Once a human reaches 90 years old, that same cartilage is brown. In 1912, a French chemist by the name of Louis-Camille Maillard described and gave his name to this phenomenon, now known as the Maillard reaction. He discovered that browning happens when a glucose molecule bumps into another type of molecule, causing a reaction. The second molecule is then said to be ‘glycated’. When a molecule is glycated, it’s damaged.

This process is a normal and inevitable part of life, and it’s why we age, why our organs slowly deteriorate and why we eventually die. We can’t stop this process, but we can slow it down or speed it up. The more glucose we deliver to our body, the more often glycation happens. Once a molecule is glycated, it’s damaged forever – which is why you can’t untoast a piece of toast. The long-term consequences of glycated molecules range from wrinkles and cataracts to heart disease and Alzheimer’s disease.

Fructose molecules glycate things 10 times as fast as glucose, generating that much more damage. Again, this is another reason why spikes from sugary foods such as cookies (which contain fructose) make us age faster than do spikes from starchy foods such as pasta (which doesn’t).

The combination of too many free radicals, oxidative stress and glycation leads to a generalised state of inflammation in the body. Inflammation is a protective measure; it’s the result of the body trying to defend against invaders. But chronic inflammation is harmful because it turns against our own body.

The World Health Organization calls inflammation-based diseases ‘the greatest threat to human health’. Worldwide, three out of five people will die of an inflammation-based disease.