Updated November 03, 2014.
Lots of people benefit from carbohydrate reduction. People can lose weight and improve many health markers. But there is one group that clearly benefits the most: people who have issues with blood sugar (blood glucose). These are people on the so-called "diabetes spectrum". The unfortunate thing is that most people who fall into this category don't even know it. There are at least three groups of people who have problems related to processing blood sugar (a fourth is actually reactive hypoglycemia, but whether it is actually on the diabetes spectrum is a question of some debate).
1) Diabetes - Type 1 diabetics don't produce their own insulin so have to rely on injected insulin to control their blood glucose. Many people with Type 1 diabetes find that restricting carbohydrate consumption helps them to stay in a safe blood sugar range with less insulin required.
Type 2 diabetics make up the majority of diabetics. Their bodies have reached a point where they can no longer control their blood sugars without intervention, with diet, exercise, and/or medication. Many find that a reduced-carbohydrate diet enables them to control their blood sugar without medication, or at least with less medication.
The latest estimates are that diabetes affects about 8.3 percent of the U.S. population. This number rises with age -- in people over 65, the number is 27%. Over a quarter of people with diabetes don't know it.
2) Prediabetes - In prediabetics, the body's system to control blood sugar is breaking down, but not to the point where diabetes would be diagnosed. However, damage to the beta cells in the pancreas which secrete insulin has already occurred; by the time a person has diabetes, half of those cells are damaged.
A person with prediabetes is at an increased risk of heart disease and the other problems associated with diabetes (see below), but not as high a risk as diabetics. And, of course, they are at a great risk of becoming diabetic.
According to the Centers for Disease Control, at least 86 millions people in the United States have prediabetes. Over a third of adults over 20 in the U.S., and over half of those over 65, are prediabetic (although there have been arguments that these estimates are low, and that the true numbers may be as much as 16% higher). The vast majority of these people probably do not know it.
Can a low-carb diet prevent progression to diabetes? Although the question has not been studied to any great degree, there is preliminary evidence that the answer is "yes".
3) "Pre-prediabetes" - The blood sugar cutoffs for diabetes and prediabetes are really points on a longer line. In recent years, for example, a fasting blood glucose of 100 is considered prediabetic, whereas 99 is "normal". But is it truly normal? When pressed, most would recognize that the answer is "no". The Endocrine Society points to research showing that a fasting blood glucose over 89 is a warning sign of damage in the pancreas. Some argue that this is, in fact, what begins the process that contributes to weight gain and obesity, and that people who think it's the other way around -- that obesity is the cause rather than the result -- simply haven't looked early enough in the process. People who are insulin resistance or have metabolic syndrome without meeting the criteria for prediabetes would be in this category.
Three Categories, or One? Although they are commonly divided up into different categories, really, they are all the same disorder, which is why it is beginning to be called the "diabetes spectrum".
What happens if diabetes spectrum disorders are not addressed? Here are some of the risks of diabetes:
- 2 to 4 times the risk of dying of heart disease
- 2 to 4 times the risk of stroke
- Leading cause of new cases of blindness in adults 20-74
- Leading cause of kidney failure
- 60-70% of diabetics will have some sort of nervous system damage
- In 2006, 65,700 amputations due to diabetes
- Higher susceptibility to other illnesses such as flu, and a worse prognosis from them
- 2 to 3 times more likely to become disabled
The treatment and prevention? Blood glucose control is the one thing that dramatically lowers the risk for these disorders. A reduced-carb diet can help achieve this, without side effects. If you want to live a long and healthy life, there may be no greater investment you can make.
Source: Centers for Disease Control, National Diabetes Fact Sheet, 2011