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Tell Me About Insulin Resistance
What is insulin?
Although we've been talking about Insulin Resistance you shouldn't think that insulin is really the bad guy in all of this. Even though it is a dangerous hormone when it is produced in excessive amounts, as in the case of Insulin Resistance, it is actually vital for the body to function normally and to control how the body uses and stores glucose. Glucose is what gives your muscles and other organs the energy to function. Too little insulin is also just as dangerous, if not fatal, as seen in people who have type I diabetes: they can't produce insulin so they need to regularly inject themselves with this hormone. Without these injections their blood sugar level would be too high, which has serious and indeed fatal consequences. So, as with many things in life, it is a question of balance—too much or too little insulin in the body are just as dangerous for your health.
Too much insulin can make you overweight and tired, and increase your risk of heart disease and diabetes; too little insulin means high blood sugar levels which damages your internal organs.
What exactly does insulin do?
Insulin is one of many hormones in the body, and is also a protein. It is made in and secreted from cells in the pancreas called the Islets of Langerhans, named after the German pathologist who discovered them. The pancreas is one of the most important organs involved in digesting food and storing the nutrients in what you eat in your body's cells. To give you an idea of proportion, about 98 percent of the cells of the pancreas are devoted to digestion, with the Islets of Langerhans cells accounting for the remaining 2 percent. The cells in the Islets of Langerhans that produce insulin are called beta cells, or B-cells. There are also alpha cells, or A-cells, which produce glucagon, a hormone that raises blood glucose levels.
Insulin and carbohydrates
Insulin's main function is storing glucose from the bloodstream into cells. This first involves converting glucose released into the bloodstream from the digestion of foods into glycogen. The body only has a limited capacity to store glycogen—the primary stores of glycogen in the body are the liver and muscles—so all other glucose is then stored as fat, known as adipose tissue. People who have Insulin Resistance typically store this fat around their middles. Either way, insulin lowers the concentration of glucose in the blood.
Insulin and proteins
Insulin doesn't just determine what happens to the carbohydrates that we eat, it also plays an important part in the way that proteins are metabolized. During the digestive process, many proteins are broken down into amino acids, which are then transported into the bloodstream. Insulin promotes the transit of amino acids into the liver and muscle cells. In this way it is involved in storing proteins away in the body, just as it does carbohydrates. It also inhibits the breakdown of protein in muscle for fuel. This is because if insulin is present, the body concludes that there is adequate glucose available and there is no need to break down muscle proteins for energy.
Insulin and fats
Similarly, insulin also has command over how fats are handled in the body. It inhibits the release of fats from fat tissue. This means that insulin prevents the use of your fat for energy in a similar way to how it stops your body from breaking down proteins. Insulin also promotes the production of fatty acids in the liver, which increases the amount of fats (bad cholesterol and triglycerides) circulating in the bloodstream—a potential risk for heart disease when present in excess.
Essentially, what all this means is that insulin prevents the body from overly using itself up and breaking down structural proteins and fats, especially if you do not eat enough food. Obviously this worked well when we were hunter-gatherers—it meant the body did not begin breaking down its reserves at the first sign of hunger. These days, few of us go hungry for any length of time, so insulin's supreme ability to store glucose at fat for future use is not nearly as important. In fact, the modern diet that encourages high insulin levels means that the body stores more glucose as fat, and we are at greater risk of becoming overweight and obese.
How much insulin your body releases depends on what you eat
Under normal conditions, insulin is produced moments after we eat something, so insulin levels will always be higher after we eat than before. As our blood glucose levels increase, the pancreas secretes insulin into the blood and insulin then performs the storage roles described above. The rate at which the blood glucose level increases is primarily determined by the amount of carbohydrate you eat. The volume of amino acids (proteins) you eat also has an effect on insulin production but much less than carbohydrates. If you eat a portion of carbohydrates, for example, this raises your blood glucose more than if you ate the same amount of protein, resulting in more insulin being released to store the glucose away. Once the glucose and amino acids are stored away, levels of insulin reduce accordingly. In this way, insulin levels vary throughout the day depending on the food we eat.
Carbohydrates raise blood sugar more than proteins. This means that your body produces more insulin when you eat carbohydrates than protein
If the body is continuously exposed to high levels of insulin, the insulin receptor cells in the liver, adipose (fat) tissue, and muscle start to become inefficient. The way insulin binds to the receptors in the liver, fat, and muscle tissues becomes partially blunted. In essence, this means some tissues in the body become resistant to the effects of insulin so that insulin is not able to carry out its normal role. The body recognizes that there is too much glucose in the bloodstream so the pancreas produces even more insulin to try and compensate. When your body is consistently producing high levels of insulin it is a sure indication that you are resistant to insulin, hence the term "Insulin Resistance." The pancreas will ultimately become exhausted and unable to produce the insulin needed to maintain optimal glucose levels, and this is when you become diabetic.
The harm Insulin Resistance does
We already touched on this in the introduction but it is worth looking at the subsidiary effects of Insulin Resistance in detail.
You may wonder why it is vital for the body to keep down glucose levels in the bloodstream. As much as we need glucose to function, glucose at too high a level leads to oxidation and this causes tissue damage. This is what happens in poorly controlled diabetes, which can lead to peripheral neuropathy, renal conditions, and cataracts. Because high blood glucose is so damaging to your health, your body will do everything it can to maintain normal glucose levels. The only means the body has to do this is with insulin. As you will see, the list of health conditions associated with Insulin Resistance is long and unpleasant:
Coronary Heart Disease (CHD)
Body Mass Index (BMI) of 30 or over
High blood insulin levels
High blood cholesterol levels Hypercholesterolemia
High blood pressure
NIDDM (noninsulin-dependent diabetes mellitus)
Blood sugar problems
Polycystic ovary syndrome PCOS
High blood fat levels
Hypertriglyceridemia or hyperlipidemia
Low good cholesterol
Impaired Glucose Tolerance
Impaired Glucose Tolerance
Low blood glucose
Fuzzy head after eating carbs Carbohydrate Sensitivity
What causes Insulin Resistance?
While your genes (see chapter 11) can be a contributory cause of Insulin Resistance—there is a higher risk of Insulin Resistance among people of South Asian origin—generally speaking there are numerous controllable factors that cause or exacerbate Insulin Resistance. The most significant one is related to body weight, or more specifically body over-fatness, especially around the middle. This is compounded by a sedentary lifestyle and the resulting lack of muscle tissue, by aging, stress, high blood pressure, and by excess consumption of refined carbohydrates, overprocessed food, saturated fat, and processed vegetable fat. Interestingly, digestive health also plays an important role. Obviously, with the exception of genetic factors and aging, many of these factors are under our control and we can take positive action. You can look at how these factors are playing a part in your health in chapter 3, with the Insulin Resistance questionnaire.
Insulin Resistance results from the body's protective mechanism to prevent high blood glucose. Insulin Resistance is an extremely common problem that can cause disease and limit life span. There are many things that raise blood glucose (e.g. refined carbohydrates, sugar, stress) but just one that lowers it—insulin. Insulin Resistance is reversible if you make changes to your diet and lifestyle.
Summary of key points
* The food you eat directly affects your insulin levels
* Insulin profoundly affects carbohydrate, protein, and fat metabolism
* High levels of insulin are dangerous and contribute to heart disease
* Diet and lifestyle are the main causes of Insulin Resistance; there is no single genetic cause of Insulin Resistance.
Are Refined Carbs and Sugar the Bad Guys?
They're sweet, they're comforting, they give you an instant feel-good high—small wonder that so many of us keep on turning to refined carbohydrates and sugar. We're also surrounded by food products containing these instantly gratifying substances—soft drinks, chocolate bars, bagels, pasta, ice cream, candies to suck, chew, or swallow—and because the "fix" we get from them is sweet and addictive, we are tempted time and time again.
We have been refining foods for centuries, as far back as the ancient Pharaohs who also observed the dangers of excess carbohydrates, but never as intensively since the middle of the 20th century. Too busy, too tired, too dissatisfied, or too depressed, we are easily seduced by the promise of a quick sugar or carb high. So, you may not want to hear it but carbohydrates and sugars really are the bad guys, especially when it comes to Insulin Resistance and all of its indirect effects. Understandably, it is a message most people don't want to hear. We are consuming more sugar in our diets today than ever before. In the USA the average person eats their way through a staggering 195 pounds of sugar in a year. This equates to every American eating nothing except sugar every fourth day!
Captain Cleave on sugar
As early as the 1930s a British Royal Naval doctor, Captain Thomas Latimer Cleave, identified the dangers of refined carbohydrates and sugar. He observed the correlation between rising incidences of heart and bowel disorders, obesity, diabetes, varicose veins, dental decay, hemorrhoids, and related diseases with the underconsumption of dietary fiber and overconsumption of refined carbohydrates. Sailing around the world between different countries and communities, he observed that there was a close correlation between the degree to which a society's diet was refined with cereals, rice, and sugar plants, and the incidences of these diseases. For instance, tribal communities eating a traditional wholefood diet were free from these diseases, whereas tribal communities who had adopted a more refined diet were not. He continued to study the effects of refined foods on health, eventually publishing The Saccharine Disease in 1974.
The sugar–body fat connection
The single most significant cause of being overweight is eating too many refined carbohydrates, for example, white bread, bagels, white pasta, white rice, cookies, cakes, candy, and chocolate. It is virtually impossible to be obese on a natural food diet. It is very easy to overeat refined carbohydrates because they are a denser form of calories—an apple contains the same amount of calories as a single teaspoon of sugar. You could quite easily consume 10 teaspoons of sugar in a fizzy drink but you'd be hard pushed to eat 10 apples in one sitting! The best way to avoid being overweight is to avoid refined carbohydrates. The ultimate refined carbohydrate is white sugar.
The key difference between natural foods and refined sugars is that natural foods contain fiber, vitamins, minerals, and other nutrients, whereas sugar and refined carbohydrates do not. This is why sugar and refined carbohydrates are often referred to as empty calories. What is more, sugar and refined carbohydrates also deplete nutrients in the body when they are metabolized. For example, every time you eat white sugar, you deplete your zinc and chromium levels because your body needs zinc and chromium in order to make insulin.
Fat consumption and exercise play a part in weight control, but they are not as important as you may think. It is quite possible to lose weight by reducing refined carbohydrates and not making any changes to your fat consumption and exercise routine. However, the Insulin Factor Plan does still recommend moderate exercise and emphasizes the need for good-quality fats.
Sugar and diabetes
There is also a strong link between sugar and diabetes. This is because refined carbohydrates encourage the body to produce high levels of insulin, which ultimately exhausts the pancreas so it is unable to make enough insulin to control blood glucose, leading to diabetes.
Sugar and heart disease
Not only does sugar increase your risk of diabetes, but it also increases your risk of heart disease. Interestingly, sugar will actually start affecting the health of your cardiovascular system long before you ever get diabetes. This is because high levels of insulin, normally caused by a diet high in refined carbohydrates, exist for many years before you develop diabetes, and excess insulin is one of the most powerful causes of furred arteries, high cholesterol and blood fats, (triglycerides), and high blood pressure (see chapter 1, page 7). Insulin is as responsible for elevated bad cholesterol and blood fats as dietary fat. As you know, there is a strong link between high cholesterol and blood fats, and heart attacks and strokes.
Sugar and tooth decay
Of course, it will come as no surprise that sugar is also the main culprit when it comes to tooth decay.
Refined carbohydrates are also behind many digestive problems, because they feed unwanted bacteria in the gut. The refined carbohydrates line the wall of the gut and enable bacteria to thrive and survive rather than pass on through. These bacteria contribute to a range of conditions from excess gas, appendicitis, inflammation of the gallbladder, and poor digestion of fats, abdominal bloating, foul-smelling stools, and even cystitis and interstitial cystitis.
The hostile bacteria cause inflammation in the gut provoking the immune system to produce molecules called cytokines. This is a normal self-defense mechanism. However, an excess of these immune defense molecules causes problems in the same way excess insulin causes problems. They can escape the gut and get into the bloodstream and disrupt the binding of insulin to its receptor cells. Research shows that these cytokines are a significant contributory factor to Insulin Resistance.
This is why the health of your digestive system is an important part of the Insulin Factor Plan.
Surprisingly, the health of your digestive system plays an important part in reversing Insulin Resistance.
But if you are completely horrified at the idea of not being able to eat sugar again, don't panic! Firstly, it's more a question of cutting down on foods that contain refined carbohydrates, and secondly it really isn't as difficult as you think, particularly because there are supplements you can take to stop your cravings. Most of my clients who are hooked on sugary things are surprised at how easy it can be to give them up.
Excerpted from THE INSULIN RESISTANCE FACTOR by ANTONY J. HAYNES. Copyright © 2004 Antony Haynes. Excerpted by permission of Red Wheel/Weiser, LLC.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Part One What is Insulin Resistance?
Chapter 1 Tell Me About Insulin Resistance
Chapter 2 Are Refined Carbs and Sugar the Bad Guys?
Chapter 3 What's My Risk of Insulin Resistance?
Part Two Let's take a look at diet
Chapter 4 How Your Digestion Affects Insulin
Chapter 5 Carbs and Proteins—Your Key to Reverse Insulin Resistance
Chapter 6 What's So Essential About Essential Fats?
Chapter 7 Antioxidants: Your Defense Against Excess Insulin
Chapter 8 Key Nutrients to Reverse Insulin Resistance
Part Three Could your lifestyle be contributing to Insulin Resistance?
Chapter 9 Is Stress Affecting You More Than You Think?
Chapter 10 Are You Exercising Enough?
Chapter 11 Is It In My Genes?
Part Four The Insulin Factor Plan
Chapter 12 Your Plan to Reverse Insulin Resistance
Chapter 13 The Insulin Factor Diet Plan
Chapter 14 Which Supplements Should I Take and When?
A Final Word
Glossary of Key Words and Terms