Now, before we talk about insulin resistance, we first need to talk a little about sugar.
By now I think we all comprehend the fact that sugar isn’t good for us. We know we should eat less sugary foods and exercise a bit more and we assume that by doing this, all will be well.
Unfortunately, it seems the truth may be worse than we were led to believe. Sugar may not be the innocent ‘OK in small doses’ treat we once thought.
I should make it clear at this point, for this article when we make reference to sugar, we are talking about both sucrose and high-fructose corn syrup.
(Photo: Pressbound. via flickr/CC Attribution)
Sucrose contains one molecule of fructose bonded to one molecule of glucose.
High-fructose corn syrup on the other hand contains 55% fructose and only 45% glucose.
This is what makes it sweeter than table sugar (sucrose), as fructose is almost twice as sweet as glucose.
However, when we compare how our bodies reaction to both sucrose and high-fructose corn syrup, we find no difference. This is in stark contrast to how our bodies react to starchy carbohydrates, which contain only glucose.
The difference is this – fructose can only be metabolized by the liver while glucose is metabolized by every cell in the body which means when you eat large amounts of fructose, you end up putting a lot more strain on the liver than if those calories just came from glucose.
Studies in rats looking into this effect have found that if the liver is put under this sort of constant pressure of metabolizing high amounts of fructose, the liver will convert a lot of the fructose (approximately 30%) directly into fat which can eventually lead to non-alcoholic fatty liver disease, which in turn can lead to insulin resistance.
Interestingly, they observed that when you stop feeding rats fructose their livers stopped being fatty and they cease to be insulin resistant.
In humans, a regular large dose of fructose (equivalent to about 9 cans of Pepsi) was seen to make individuals insulin resistant in just a few days.
Scary stuff when you think of how readily available products with refined sugar are and how regularly some people consume them.
What is Insulin Resistance?
In a nutshell, insulin resistance is a condition in which naturally produced insulin is less effective at lowering blood sugar, leading to raised blood sugar levels.
Muscle and fat cells need insulin to absorb glucose, so when they stop responding to insulin, blood glucose levels rise.
To many, the path to insulin resistance and type-2 diabetes was once considered rather straightforward: people ate unhealthy food, became obese and that was it.
That doesn’t seem to account for individuals who are not overweight but have indeed developed diabetes and/or are insulin resistant.
Nowadays, with the aid of more detailed scientific research, the causal links between diet, obesity and insulin resistance appear to be much more complicated.
Negative Effects of Being Insulin Resistant
Insulin is released into the bloodstream by the pancreas after we eat to regulate healthy blood sugar levels.
However, when an individual is resistant to insulin, their pancreas ends up releasing more and more insulin in response to the high blood sugar levels.
If this continues, the pancreas won’t be able to keep up and may experience ‘pancreatic exhaustion’. In most cases, the resulting unregulated blood sugar levels continue to rise unhindered and inevitably type-2 diabetes is often the result.
Some people who are resistant to insulin manage to avoid diabetes as they still able to produce enough insulin to overcome their cells resistance to it.
However, these high insulin levels subject the individual to many other health risks, including heart disease.
If this situation continues, your blood pressure and the fats in your bloodstream (triglycerides) will continue to rise and ‘good’ cholesterol levels will be reduced. This can lead to a more severe insulin resistance, namely metabolic syndrome.
With metabolic syndrome, health conditions including heart disease, diabetes and obesity are usually soon to follow.
More Bad News!
Unfortunately, it doesn’t end there.
There is something else that becomes more likely if a person is diabetic, obese and/or has metabolic syndrome – cancer.
Individuals with insulin resistance secrete more insulin and insulin is one hormone that promotes tumor growth.
Simple Solutions to Pre-Diabetic Insulin Resistance?
Research has led some to suggest that elevated levels of insulin are caused by being overweight(and the factors leading up to this condition) and that the best solution would be to lose weight.
Others however, state that perhaps something other than obesity is causing the initial insulin resistance and that if this is the case, we should trying to avoid this.
The prime suspect of that theory is none other than… SUGAR!
What are the Symptoms of Insulin Resistance?
There are a whole host of noticeable symptoms associated with insulin resistance (although not everyone will display all of these).
They include high blood sugar, problems concentrating, fatigue, weight gain and problems losing weight, bloating, high blood pressure and increased hunger.
Diagnosing Insulin Resistance
If fasting insulin levels are higher than the normal upper limit, this can be seen as evidence of possible insulin resistance. A glucose tolerance test could be taken whereby a fasting individual receives glucose orally and the blood glucose levels are recorded over the next two hours.
The most accurate test is the ‘hyperinsulinemic euglycemic clamp’ which measures the amount of glucose needed to account for elevated insulin levels without causing hypoglycemia. However, this test tends to be reserved for research rather than in clinical practice.
A simpler and newer method of looking into insulin resistance levels is the Quantitative Insulin Sensitivity Check Index (QUICKI).
How to Prevent and Treat Insulin Resistance
At present, the main treatment for insulin resistance is exercise.
Diet has also been shown to play a major role in combating insulin resistance. The prescription drug Metformin is commonly prescribed as a medication for type-2 diabetes and insulin resistance but it is thought that diet and exercise play a much more important role in preventing the development of type-2 diabetes than Metformin.
When you are considering making changes to your eating habits, it seems that a low-carb diet can help improve insulin resistance but only before type-2 diabetes has been established.
**Update – Feb 28, 2013
The authors of Weight Loss Ninja have put together a comprehension guide on how to free yourself from sugar’s grasp in 21 days or less. Visit Amazon for more details.