Thursday, March 3, 2011

The Truth About Sugar

Say anything nasty about sugar and folks will swallow it. Sugar caused the recession. Sugar makes your nipples grow. Sugar keyed your car. Sugar's crazy—it knifed my cousin down at the corner bar last Saturday night. Somebody should drop a safe on sugar.

Well, maybe. It's true that sugar is insidious—diabolical, even—and hidden in countless processed foods. It certainly contributes to the obesity crisis. It makes people fat and
diabetic. These claims are correct—to a limited and oversimplified extent. But sugar doesn't point a gun to our heads and force us to eat it. It's only as big a bogeyman as we make it out to be.

We need some truth about sugar. It's too important. The sugar in our bodies,
glucose, is a fundamental fuel for body and brain, says David Levitsky, Ph.D., a professor of psychology and nutritional sciences at Cornell University.

The health threat to the vast American public arises from a very personal level, Levitsky says: "It's that sugars taste good. Sweetened foods tend to make us overeat. And that threatens the energy balance in our bodies."

Read this and learn a few facts about the sweet stuff hiding in some of your favorite meals and drinks. Then, the next time some uniformed punk says sugar's out of line, you won't be tempted to drag sugar behind a dumpster and kick the crap out of it. The fact is, you may be the one who's out of line.

Sugar and Diabetes

Sugar Doesn't Cause Diabetes
Too much sugar does. Diabetes means your body can't clear glucose from your blood. And when glucose isn't processed quickly enough, it destroys tissue, Levitsky says. People with type 1 diabetes were born that way—sugar didn't cause their diabetes. But weight gain in children and adults can cause metabolic syndrome, which leads to type 2 diabetes.

"That's what diabetes is all about—being unable to eliminate glucose," says Levitsky. "The negative effect of eating a lot of sugar is a rise in glucose. A normal pancreas and normal insulin receptors can handle it, clear it out, or store it in some packaged form, like fat."

What matters: That "normal" pancreas. Overeating forces your pancreas to work overtime cranking out insulin to clear glucose. Eric Westman, M.D., an obesity researcher at the Duke University medical center, says that in today's world, "it's certainly possible that the unprecedented increase in sugar and starch consumption leads to pancreatic burnout." But researchers can't be sure; everyone's body and diet are different, so generalization is iffy. One thing that is sure, Dr. Westman says, is that the rise in sugar consumption over the past 100 years is unprecedented.

Your job: Drop the pounds if you're overweight, and watch your sugar intake. Research has shown for years that dropping 5 percent to 7 percent of your body weight can reduce your odds of developing diabetes.

Sugar and High-Fructose Corn Syrup

Simply Avoiding High-Fructose Corn Syrup Won't Save You from Obesity
In the 1970s and 1980s, the average American's body weight increased in tandem with the food industry's use of high-fructose corn syrup (HFCS), a staple because it's cheap. But it's not a smoking gun. "This is a correlation, not a causation," says Levitsky.

"Obesity is about consuming too many calories," says Lillian Lien, M.D., the medical director of inpatient diabetes management at the Duke University medical center. "It just so happens that a lot of overweight people have been drinking HFCS in sodas and eating foods that are high on the
glycemic index—sweet snacks, white bread, and so forth. The calorie totals are huge, and the source just happens to be sugar-based."

Dr. Westman notes that the effect of a
high-glycemic food can be lessened by adding fat and protein. Spreading peanut butter (protein and fat) on a bagel (starch, which becomes glucose in your body), for example, slows your body's absorption of the sugar.

What matters: We can demonize food manufacturers because they produce crap with enough salt and sugar to make us eat more of it than we should—or even want to. But it comes down to how much we allow down our throats. "A practical guide for anyone is weight," says Dr. Lien. "If your weight is under control, then your calorie intake across the board is reasonable. If your weight rises, it's not. That's more important than paying attention to any specific macronutrient." Still, skinny isn't always safe. (Keep reading.)

Sugar and Fat

Too Much Sugar Fills Your Blood with Fat
Studies dating back decades show that eating too much fructose, a sugar found naturally in fruit and also added to processed foods, raises blood lipid levels. And while the relatively modest quantities in fruit shouldn't worry you, a University of Minnesota study shows that the large amounts of fructose we take in from processed foods may prove especially nasty: Men on high-fructose diets had 32 percent higher triglycerides than men on high-glucose diets.

Why? Your body can't metabolize a sweet snack as fast as you can eat it, says Levitsky. So your liver puts some of the snack's glucose into your blood-stream, or stores it for later use. But if your liver's tank is full, it packages the excess as triglycerides. The snack's fructose goes to your liver as well, but instead of being deposited into your bloodstream, it's stored as glycogen. Your liver can store about 90 to 100 grams of glycogen, so it converts the excess to fat (the triglycerides).

What matters: By maintaining a healthy weight, most people can keep their triglycerides at acceptable levels. "If you're overweight or gaining weight, however, they'll accumulate and become a core predictor of heart disease and stroke," Levitsky says.

If you're one of those overweight people, your first step is to lay off sugary and starchy foods, beer, and sweet drinks. Your body wasn't built to handle all that sugar. Consider this: You'd have to eat four apples in order to ingest roughly the same amount of fructose in one large McDonald's Coke.

Oral Glucose Tolerance Test

Too Much Sugar Stresses Your System
Doctors use the oral glucose tolerance test (OGTT) to diagnose prediabetes and diabetes. For an OGTT, you consume 75 grams of glucose to see how your system processes sugar. It's a kind of stress test—downing that kind of sugar load is not something you should normally do.

And yet a 24-ounce soda often contains more than 75 grams of sugar, most of it likely HFCS. Roughly half of that 75 grams is fructose, so that soda shock may be worse than the doctor's test is. "The way people eat and drink these days, unintentional stress tests probably happen quite often," says Dr. Lien.

What matters: Maybe you figure your body can process a big sugar load without damage. But that's like pointing to a man who smokes until he's 90 and dodges emphysema or cancer, Dr. Westman says. Why gamble?

Severe hyperglycemia (high blood sugar) can cause blurred vision, extreme thirst, and frequent urges to urinate. Hypoglycemia (low blood sugar) is easier to spot: You feel weak with cold sweats and anxiety, blurred vision, or tiredness a couple of hours after a sugar binge. Sound familiar? Ask about an OGTT, which is more accurate than the simpler fasting glucose blood test.

Avoid Blood Sugar Spikes

Fewer Blood Sugar Spikes Help You Live Longer
If you live large—big meals, lots of beer, little moderation—you may be shortening your life even if your weight is okay. Repeated blood sugar spikes stress the organs that make up the metabolic engine of your body. That takes a toll.

And you might not notice. "People can live symptom-free for years in a prediabetic state even though they've lost as much as 50 percent of their pancreatic function," says Dr. Lien. "And they don't even know it." People with prediabetes share the same health risks, especially for heart disease, that haunt people with full-blown diabetes.

What matters: Moderation. It's simple, yet difficult. Think about what you put in your mouth. Sugar is diabolical; it tastes great and is less filling. Back off on the high-impact glycemics: beer, sugary soft drinks and sport drinks, potatoes, pasta, baked goods, pancakes. "The less sugar stress you put on your system, the longer it will function properly," says Levitsky. And stop blaming sugar for all the world's problems. Even if it is diabolical.

Thanks to Mike Zimmerman / Rodale Inc. | MensHealth

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