Glucose primarily comes from the carbohydrates in your diet, although some is also produced from fat and protein. Digestive enzymes break down the nutrient, transforming it into this vital energy source. But getting glucose into your cells isn't as easy as filling up your car with gas. For that, you need another component—insulin, a hormone produced by cells in the pancreas. Insulin acts as a key, binding to special receptors, or proteins, on cell surfaces and "unlocking" the cell to let glucose in.

As with most things in your body, blood sugar levels fluctuate, always aiming for a balance. They're at the high end when you've just eaten, sending a fresh supply of glucose out; and at the low end when you're hungry. If you've felt the dizziness, irritability and headache that comes on when you haven't eaten in a while, you know the feeling of low blood sugar, also called hypoglycemia.

While everyone experiences occasional episodes of low blood sugar, the problem is particularly prevalent and serious in people with diabetes who use insulin; too much insulin can send too much glucose out of the bloodstream, leading to plummeting blood sugar levels called hypoglycemia. Left unchecked, this could lead to coma or even death.

A far more common problem today, however, is hyperglycemia, or blood sugars that are too high. It's a common problem because so many of us are overweight, and being overweight increases the risk of insulin resistance. Insulin resistance occurs when you don't have enough insulin receptors on cells, or the insulin receptors don't work properly. Maybe they're not formed right, or maybe they're just stubborn and won't let glucose into the cells. That's why they're "resistant" to insulin. Initially your pancreas just pumps out more insulin to compensate and you maintain normal blood sugar levels. Over time, however, even that fails, and blood sugar levels rise. At this point, you're considered "glucose intolerant," or pre-diabetic, with a high risk of diabetes.

Be Blood Sugar Aware

How do you know if you're heading towards problems with your blood sugar? You get tested. The most common blood sugar tests include:

• The fasting plasma glucose (FPG) test, which measures blood sugar levels after you've fasted for a specified time.
• The HgbA1C test, which measures your average blood sugar level over weeks.
• The oral glucose tolerance test (OGTT), in which you drink a sugary liquid and then blood sugar levels are tested several times to see how well glucose moves into cells.

The American Diabetes Association recommends you take the same test twice, at different times, to confirm a diagnosis.

Your Health & High Blood Sugar

You don't have to have diabetes for high blood sugar to cause problems. High levels of sugar increase the number of rogue molecules in your body called free radicals and reduce levels of protective antioxidants, leading to a variety of tissue damage. When you have diabetes, that damage contributes to high levels of "bad" LDL cholesterol making the cells that line your coronary arteries "stickier," increasing the risk of heart disease. These and a multitude of other chemical reactions related to the high blood sugar levels of poorly controlled diabetes can eventually lead to blindness, nerve damage, kidney damage and, of course, heart attack and stroke.

So, enough about the dangers; what can you do if you learn your blood sugar is too high. Two words: Lose weight. It's clear that insulin resistance increases with weight gain and drops with weight loss. One reason is that fat, particularly fat around the abdomen, is very insulin resistant. It also unleashes a chemical cascade that winds up increasing levels of triglycerides in muscle cells, making them more insulin resistant.

You should also change your diet and get physically active. Here's how:

1. Increase the amount of fruits and vegetables you eat. They're high in soluble fiber, which is particularly helpful in controlling blood insulin and glucose levels. Other good sources of fiber can be found in whole grains, especially oats, beans and legumes.
2. Decrease the amount of food choices full of saturated fat (found in animal products) and trans fats (found in many processed foods). These fats also seem to affect the ability of insulin to do its job.
3. Kick your habit of eating foods and beverages high in refined sugar, and also refined starches—those "white" foods like white bread, white pasta and white rice, all of which have been stripped of fiber and other nutrients. Go for whole grain and brown whenever possible!
4. Exercise. Not only does exercise help you lose weight, but even if the scale doesn't budge, exercise can reduce insulin resistance by making muscle cells more sensitive to insulin, thus moving more glucose from your bloodstream into your cells.

How do we know this drill works? In a major diabetes prevention study from Finland with overweight men and women who had impaired glucose tolerance, those who got half an hour of exercise a day, lost five percent of their weight, cut total fat intake to 30 percent and saturated fat intake to less than 10 percent, and ate more fiber, never got diabetes. They didn't even have to do all five; just following four of those steps for at least a year was enough. Conversely, nearly 40 percent of those who didn't reach any of the targets developed diabetes.

So what are you waiting for? Start walking and toss those fatty foods and snacks packed with sugar and starches. Instead, stock up on fresh fruits, veggies and other high-fiber foods.

This information was produced with the support of an educational grant from Nutrition 21.

Create Date: 9/19/06
Date Last Updated: 9/19/06