Glucose the toxin Part 1 – Sugar the con artist

Ahh, sugar!  We love, love, love it.  It’s such a powerful additive.  And what a ubiquitous additive it is – sugar is added to most everything processed.

Sugar is a highly concentrated form of carbohydrate derived from sugar cane, and other plants such as beets and corn (think high fructose corn syrup.) Chemically this delightful white crystal is a disaccharide – a simple sugar molecule composed of one part glucose and one part fructose.  Fructose, is so named because it is the sugar predominantly found in fruits, and is the component that makes sugar attractively sweet.  And when concentrated into high fructose corn syrup it packs one powerful sweet punch.  (High fructose corn syrup is the sweetener used in most soft drinks.)

Sugar is easily digested and is broken down into glucose and fructose then rapidly absorbed into our bloodstream. The glucose floods our bloodstream immediately, but fructose is diverted to the liver for processing and conversion into glucose before entering our bloodstream.  The pancreas, detecting glucose in the bloodstream, almost instantaneously releases insulin, our life saving energy management hormone.  Insulin then goes about the business of removing glucose from our bloodstream, pushing it into our cells for their immediate energy needs, storing a small easily accessible emergency energy supply (called glycogen) in our muscles and storing the excess energy as body fat.  This is all well and good.  Insulin is doing its evolutionary job – storing excess energy as body fat for future famine.

A critical point that seems long forgotten, is the fact that our body is specifically designed to burn predominantly fat for fuel, rather than glucose.  That is why we store excess energy as body fat – it’s for future use!  That is a key factor in our physiology that allowed us to survive when food was scarce during our hunter-gatherer days.  Another key evolutionary fact that contributed to our survival, is that our brain was designed to reward us for eating calorie dense foods.  As hunter-gatherers ‘calorie dense’ meant tubers (underground starchy vegetables), fruits when in season and animal meat after a successful hunt.  Wild blueberries, yum.  Potatoes, yum.  Steak, yum.  Not sugar in its 21st century can’t-get-enough-YUM-YUM-YUM concentration!

Our body is not well designed to handle sugar in this highly concentrated form.  It floods our bloodstream with massive amounts of glucose.  (Remember sugar is ultimately converted to glucose.)  The glucose in our bloodstream is tightly regulated and maintained at a concentration that is roughly the equivalent of 1 teaspoon of sugar.  ONE TEASPOON in our entire bloodstream.  Contrast that with 10 teaspoons of sugar in a single 375ml can of cola.  The amount of sugar we consumed as fruit and tubers as hunter-gatherers is miniscule relative to that can of cola.

The dose of sugar consumed daily in the 21st century is massive.  Just how massive? Roughly, 152 pounds per person per year.   That is just under ½ pound per day!  To put this into perspective in the 1700s sugar consumption was about 5 pounds per year, in the 1800s it was 23 pounds per year.  (Of note in the 1700s and 1800s, obesity and type 2 diabetes were extremely rare, versus the 21st century where both are epidemic and accelerating!)

We eat roughly ½ pound of sugar per day.  There are roughly 55 teaspoons in ½ pound of sugar.  We only need 1 teaspoon of sugar circulating in our bloodstream.  We eat 55 times more sugar than we need – daily.  (Kinda gives new meaning to the idea of a sweet tooth huh?!)

And that massive dose of sugar is converted to glucose.  And glucose at such massive doses is toxic to the body and over the long term wreaks havoc with just about every system in the body – the brain, the eyes, the kidneys, the heart and blood vessels, the nerves, and the gut.

So, instead of using our stored body fat for fuel, our body preferentially burns the incoming sugar for its daily energy requirements.  And insulin doing its evolutionary job, continues to store excess energy as body fat, predominantly around the middle.

Furthermore, because our brain is designed to seek/crave calorie dense foods, sugar in its highly concentrated form is not only toxic, it is addictive.  But unlike other addictive substances (nicotine, cocaine, heroine or alcohol), sugar does not have any obvious short term negative consequences – no hallucinations, no heart palpitations, no slurred speech, and no impaired judgement.  (Though, as a pediatrician in days gone by, I can attest to the hyperactivity inducing qualities of sugar and subsequent sugar withdrawal related behaviour challenges.)

In fact, the opposite is true – sugar soothes.  Sugar stimulates the reward center of our brain, predominantly via dopamine, our “oh-nice” neurotransmitter.  Eat a little sugar, “oh-nice” and we feel relieved, at least briefly.

Unfortunately, while sugar stimulates our brain’s reward center, delivering a nice soothing little bit of relief, the more we use it, the less dopamine our brain produces.  To make matters worse, the brain decreases its number of dopamine receptors (a phenomenon called down regulation) rendering the dopamine that is produced less effective.  And then, just like any other addictive substance, we need more and more sugar to elicit the same response.

Sadly, we have become a society of sugar addicts.

Though the short term consequences of sugar may be minimal, the long term consequences are staggering.  Sugar is insidiously destructive and takes decades to kill.  And if it does not kill us, it certainly causes considerable pain and suffering!  Over consumption of sugar is a known significant risk factor in a multitude of adverse health outcomes – obesity, heart disease, high blood pressure, high cholesterol/dyslipidemia, type 2 diabetes, dementia, stroke, and depression.

Collectively obesity, heart disease, high blood pressure, stroke and type 2 diabetes fall under the umbrella term of Metabolic Syndrome and Metabolic Syndrome accounts for the majority of chronic diseases afflicting western civilization.  And the central tenent of Metabolic Syndrome is insulin resistance.  Which means our cells no longer respond to insulin and as a result, glucose accumulates in our blood to toxic levels and we get sicker and sicker.  In an effort to compensate, but with limited options, our body makes more insulin and we store more energy as body fat, and we get fatter and fatter.   Unfortunately, we also increase our insulin resistance.  It’s a self-perpetuating downward spiral.

Sicker and sicker, fatter and fatter, and addicted.  Thanks sugar.

Except for concentrated calories, sugar is utterly void of nutritive value.  Sugar is sweet but not so innocent.

At the heart of many pathological processes that drive what ails us in the 21st century, over consumption of sugar has been implicated in inflammation (think joint pain), gut dysfunction (think bloating, pain), impaired cognition (think brain fog, dementia), volatile mood (think depression, stress, anxiety), and accelerated aging to name just a few.

So, weight loss aside, if you want to decrease joint pain, think clearer, feel less depressed or stressed or just want to feel better overall – cut the sugar.

Sugar – it’s quite the con artist.  And we are all victims of the con.  Cut the sugar – admittedly no easy feat, but there is so much to gain (or in the case of weight, so much to lose.)

In the next part of this short series – it’s not only sugar that is intoxicating.

Buff it up!
Dr Karen