In part one, sugar was vilified for the role it plays in a host of adverse health outcomes. Sugar is insidiously destructive, slowly killing us with massive amounts of glucose.
But sugar is not the only dietary source of glucose. Glucose is found in many guises in the foods we eat. Starchy vegetables – eventually broken down into glucose during digestion. The sugar found in fruits – fructose is converted to glucose by the liver. The carbohydrates found in non-starchy vegetables – again glucose. Excess protein is converted to glucose in the liver (a process called gluconeogenesis). All of this glucose, regardless of origin, can be used as fuel or stored as body fat.
The difference between glucose from these various sources of glucose and sugar is its ease of digestion. Sugar a simple carbohydrate (remember it is a disaccharide) is easily digested and rapidly absorbed. One swing of the axe, and its ready for absorption. Not so for the sugar in fruits, vegetables or starchy vegetables. These foods contain complex carbohydrates and are considerably harder to digest. Hundreds if not thousands of swings of the axe are needed to cleave off a glucose molecule, ready for absorption.
Protein has a completely different route of absorption and is broken down in the stomach into amino acids (the building blocks of protein), absorbed into the bloodstream in the small intestine, transported around in the blood to wherever new proteins need to be made, and then repackaged into protein. Excess protein building blocks (amino acids) are transported to the liver for conversion to glucose. Protein to glucose, is a long and drawn out process.
A much slower process, the digestion and absorption of these complex carbohydrate containing foods and protein does not flood the bloodstream with glucose anywhere near the same extent as sugar. It’s a gentle stream versus a bursting dam.
Another key difference is complex carbohydrates are packed with nutrients – vitamins, minerals and anti-oxidants – that are essential for our health. Sugar is void of nutrients.
Grains are missing from that list. Whole grains are complex carbohydrates and are packed with fiber. But whole grains are really hard to digest and often our digestive system simply cannot digest it. So we just don’t eat it ‘straight up’ – instead we grind it up.
We grind whole grains into flour, a very fine powder. And the grinding process removes/destroys fiber and any nutrients it may have contained. In flour’s defense, manufacturers have added some vitamins back giving flour its enriched or fortified status. The problem is, refined flour is easily digested and rapidly absorbed. And as a derivative of grains which are complex carbohydrates, it breaks down into glucose (all glucose, no fructose as found in sugar) which is directly absorbed into our bloodstream. Which means – you guessed it – flour floods our bloodstream with glucose and spikes a huge insulin surge. And just as with sugar, insulin goes about the business of removing glucose, pushing it into our cells for all their energy needs and storing the excess as body fat.
Flour and sugar are often combined into delightful sweet treats for a whopping dose of glucose. As far as the body is concerned, a molecule of glucose is a molecule of glucose regardless of origin. And as we learned last week, glucose at massive doses is toxic.
Because flour does contain fructose it is not sweet. But that does not mean it is innocent. Flour spikes glucose in our bloodstream just as effectively, perhaps even more rapidly than sugar. As such, flour is equally responsible for the host of adverse health outcomes (obesity, heart disease, high blood pressure, high cholesterol/dyslipidemia, type 2 diabetes, dementia, stroke, and major depressive disorder) blamed on sugar.
An irresistibly tasty killer combination, sugar and flour perpetuate insulin resistance and all the morbidity and mortality that follows.
Cut the sugar, skip the flour and feel better.
Next in the series, Cut the sugar and skip the flour – it is possible.
Buff it up,
Dr Karen
