Diabetes And Insulin Resistance

Last modified on August 12th, 2009

There has been a lot of talk in the Twitterverse lately regarding diabetes, so I thought I’d write a small entry dedicated to it. While I don’t suffer from diabetes, I do a lot of research in the area of something called metabolic syndrome, which in a lot of ways directly relates to diabetes.

Prior to around 1980 or so, there were two forms of diabetes. The lay public generally referred to these as juvenile diabetes, which many people essentially were born with (or diagnosed with at an early age), and adult-onset diabetes, which was usually diagnosed later in life. Nowadays we call juvenile diabetes Type-I diabetes, and adult-onset diabetes Type-II, mainly because it affects so many children as well.

Nobody is really sure why, unfortunately. Some researchers argue it’s because we now live in what’s called a “Toxic Food Environment”, as evidenced by the fast food establishments on every corner, and the soda pop in all our schools. The basic hypothesis is that our bodies are overloaded by the constant influx of sugars and carbs, and eventually the cells in the body become resistant to the affects of insulin, which in turn results in Type-II diabetes (similarly how constant exposure to very loud sounds will eventually result in hearing impairment).

There’s also evidence that there’s a gestational component — that is, evidence shows that heavy mothers typically produce heavy babies, and often in life those heavy babies will become obese and sometimes diabetic. I’ve read some interesting studies that have related some of these affects to popularity of baby formula decades ago (which nowadays resembles breast milk in terms of its constituents , but long ago used to be primarily carbohydrate).

Along with the obesity epidemic that’s been steadily climbing in North America is a condition known as metabolic syndrome which affects approximately 25% of the population. It also goes by other names, including Syndrome X and hyperinsulinemia. Essentially the root cause is a physiological defect that results in the body becoming insensitive to insulin (i.e. insulin resistant). Because the cells stop responding to it, the pancreas is forced to release more and more insulin into the blood. Eventually the body will require more insulin than the pancreas can release, at which point the person is officially a Type-II diabetic that requires insulin.

Insulin is a catabolic hormone in that it causes cell proliferation (it’s been implicated in the spread of cancers — ever wonder why so many people get cancer nowadays? Well, excess insulin in the population is a viable hypothesis in several cancers, including breast cancer), and it’s also the prime hormone involved in fat storage — in fact, it’s hormonally impossible to store fat without it (which forms the basis for low carb diets — if you can reduce the insulin level in your blood, it’s essentially impossible to store fat — likewise, the hormone that breaks down fat, glucagon, cannot co-exist in the blood at high levels while insulin is circulating). Because insulin promotes the deposition of fat in cells, high levels of circulating insulin also lead to atherosclerosis, or the hardening of the arteries. This in term leads to high blood pressure and ultimately cardiovascular problems.

As an aside, the only real method for prolonging the life of an organism is by calorie restriction. In most organisms (including worms, rats, and non-human primates such as monkeys), calorie restriction can lead to a 30-40% increase in mean lifespan of a population. The main physiological change believed to be responsible for this increase in lifespan is the decrease in insulin levels that goes along with calorie restriction. Ever met someone over 100 years old (technically a centenarian)? Want to know what trait almost all of them have when compared to the population? Low insulin levels.

The combination of obesity, diabetes, hypertension, and hypertriglyceridemia (which is the elevation of triglcyerides in the blood) is often called “The Deadly Quartet” by researchers, since they almost always exist simultaneously. I’ve spent the better part of the last six years reading up on the subject every Sunday night, so I’d like to think I’m fairly well versed.

The best book I’ve read on the subject is a book called “Good Calories, Bad Calories” by Gary Taubes (it’s a rather unfortunate title, as the book is really a look at the underlying science, or lack-of, with regards to the current dietary recommendations). I highly recommend everyone pick up this book and read it, especially if anyone in your family suffers from diabetes. If you don’t have the money or the time, here’s a lecture Gary Taubes gave a while ago that highlights some of the key concepts in his book. Here’s also a video Gary did on Larry King Live when his book came out:

A couple of key arguments Gary makes in his book are:

  • Obesity is primarily caused by an genetically influenced hormonal defect
  • Exercise does not lead to clinically significant weight loss — it leads to hunger
  • Heart disease is not caused by excess fat consumption, it is caused by excess consumption of carbohydrates and elevated levels of insulin
  • The body is a complex homeostatic machine that will adapt to changes in the input. If you eat less, your metabolism slows down. If you eat more, it speeds up. You can no more grow fatter by overeating than you can grow taller — both items are controlled by hormones
  • There are numerous examples of populations in the world where obesity and severe malnutrition coexist simultaneously. The current hypothesis for the cause of obesity — that calories and excess food consumption directly cause obesity — is not supported by these observations.
  • Cause and effect have been confused by researchers: lethargy and overeating are not causes of obesity, they are symptoms of it (at the cellular level obese people are physically starving — the calories them consume get shunted away into fat cells before other cells can make use of the energy)

Given the prevalence of both heart disease and diabetes nowadays, I highly recommend that book, even if you disagree with everything in it.