August 05, 2014

What is insulin resistance?

The pancreas secretes insulin in order to help the body use glucose, or sugar, for energy.  When food is eaten during a meal, the glucose concentration in the blood rises, which stimulates the release of insulin.  Insulin helps cells take up and use the blood sugar for energy.

In the liver, insulin promotes the storage of glucose and increases the production of triglycerides.  In the muscles, insulin increases the production of protein, and in the fat, insulin increases the storage of triglycerides.  This is because fat in the form of triglycerides is the most efficient way to store energy.

Insulin resistance occurs when the body cannot utilize insulin properly.  People with insulin resistance have difficulty with the liver, muscle, and fat cells responding appropriately to insulin.  As a result, they need to produce more insulin to make up for this.   People with insulin resistance may have high levels of glucose and insulin in the blood.  The high insulin levels interfere with fat burning.  Remember, one of insulin’s main functions is to increase the production and storage of fat.  So, the more insulin is around, the more fat will be stored, and the greater the difficulty burning fat.

How does one become insulin resistant?

Eating increased  amounts of sugar or refined carbohydrates leads to the production of higher amounts of insulin, which leads to obesity and insulin resistance.  This increases the chances of developing type 2 diabetes and heart disease.  Higher insulin levels are also associated with cancer, high blood pressure, fatigue, dementia, autoimmunity, infertility, among others.

Why is there so much more insulin resistance, diabetes, and obesity now?

Historically speaking,  our hunter gatherer ancestors did not suffer from any of the chronic diseases so entrenched in our modern society.  There was no diabetes, heart disease, or even cancer.  They ate a nutrient dense, high fiber, low sugar diet mostly from fruits and vegetables, and lean meats.

They ate the equivalent of 20 teaspoons of sugar per year.  Everything they ate, they had to work for- by hunting, fishing, and gathering.  The genetic makeup of our Paleolithic ancestors has barely changed at all.  But our environment has.  Now we have the modern conveniences of agriculture, with fast food, supermarkets, and restaurants.  Our ancestors ate no dairy, and no grains.  Now we eat about 22 teaspoons of sugar per day.  Their carbohydrates came from fruits and vegetables with low glycemic indexes, leading to a slower and smaller rise in blood sugar.  It is the refined carbohydrates, grains,  and sugar that lead to rapid increases in blood sugar and therefore insulin production.

What is a refined grain?

A refined grain is made by processing a whole grain, so much of the nutrients are lost. These refined grains have almost no fiber, have bleaching and other chemicals added, and are then enriched with synthetic nutrients.  Some examples of refined grains include white rice, bread, pasta, cookies, pastries, and many cereals.  They are also high in sugar and lead to increases in insulin in our bodies.

Our bodies were not designed to metabolize all these chemicals and sugar, and so the result of all this stress on the human body is manifested as the epidemics of obesity, high blood pressure, insulin resistance, diabetes, cancer, and autoimmune diseases, among others.

Effects of elevated insulin levels

Our bodies have to produce elevated levels of insulin in response to all these sugars and refined carbs we are taking in.  Eventually, we may become insulin resistant, and our bodies need to produce more and more insulin to keep our blood sugar levels under control.  This excessive insulin production can then cause our blood sugar levels to go down, and then we feel the symptoms of low blood sugar, such as hunger, jitteriness, sweating, or rapid heartbeat.  This may cause us to crave more sugar, spiraling our  blood glucose levels out of control.  Having too much insulin around will increase fat storage and interfere with our ability to break down fats, will make us feel hungrier and have more cravings, cause mood changes like irritability and depression, lead to fatigue, poor focus and concentration, increase cholesterol, and even stimulate growth of cancer cells. Cancer feeds on sugar!

Insulin and inflammation

Insulin increases inflammation in our bodies.  It can also interfere with our sex hormones, leading to irregular periods, acne, and abnormal hair growth in women, and low testosterone levels in men.

Sugar is a toxin that promotes insulin resistance

Sugar has been classified as a toxin by many researchers, because the body is not able to utilize what is left when the sugar is refined, unless the depleted nutrients are added back in, or enriched.  Refined sugars are classified as empty calories because they don’t have the natural minerals, and they also remove vitamins and minerals from the body.  Excess sugar is stored in the liver, and when the liver’s capacity is exceeded, the sugars are then released in the blood and stored in fat cells, in places such as the belly, buttocks, and thighs.  Once saturated, fatty acids can then deposit in vital organs such as the heart.  Our blood pressure can become elevated, our immune system can become affected, and our energy levels decrease.

Refined sugar, or sucrose, is made up of glucose and fructose, in a 50/50 combination.  Fructose is highly reactive chemically, and leads to the production of AGEs (advanced glycation end products) which can be very harmful compounds.  It is much sweeter than glucose.  High fructose corn syrup is 55% fructose and 45% glucose.

Refined sugar and high fructose corn syrup do not have any nutrients or fiber, and can displace other nutrients and make us gain weight.  Sugar, which is half fructose and half glucose, is metabolized differently than glucose.  The fructose is metabolized by the liver, while the glucose is metabolized by all of our cells.  This means that there is more work for the liver with fructose, and much of it is converted to fat.  This leads to insulin resistance.  The increased consumption of  sugar that has been occurring is associated with the growing epidemics of diabetes, obesity, and heart disease.

Photo Credit: Flickr User GabrielaMarques.