Contributors

Wednesday, January 02, 2013

All Calories are Not Created Equal

A study in the Journal of the American Medical Association reports that the brain reacts differently to fructose than it does to glucose (via USA Today):

For the study, scientists used magnetic resonance imaging, or MRI, scans to track blood flow in the brain in 20 young, normal-weight people before and after they had drinks containing glucose or fructose in two sessions several weeks apart.

Scans showed that drinking glucose "turns off or suppresses the activity of areas of the brain that are critical for reward and desire for food," said one study leader, Yale University endocrinologist Robert Sherwin. With fructose, "we don't see those changes," he said. "As a result, the desire to eat continues — it isn't turned off."
That means the two sugars have different biological effects on the body. Even though they may contain the same number of calories, someone consuming products made with high-fructose corn syrup (HFCS) instead of glucose (regular sugar) may wind up eating more and gaining more weight.

This is not the first such finding. Many studies have found that artificial sweeteners also fail to trip the satiety switch. That means nearly all soft drinks, even diet sodas that contain zero calories, may contribute to weight gain by failing to trip the mechanisms that tell us to stop feeding our faces.

But fructose is the sugar that's in fruit. Does that mean fruit's bad for you? No.

An apple has 116 calories, 31 grams of carbohydrates, 5 grams of fiber (20% of your daily recommended value), vitamin C and trace amounts of vitamin A, iron and calcium. A 12-ounce Coke has 140 calories, 39 grams of carbohydrates, 50 mg sodium and phosphoric acid, which is linked to bone loss. The apple provides nutritional value, which Coke does not, as well as fiber that provides a satiety mechanism.

According to a Gallup poll from last year, the average person who drinks soda consumes 2.6 glasses a day (48% of Americans said they consumed soda, and 7% said they drank four or more glasses per day). It's hard to find anyone who eats 2.6 apples a day, even though doctors tell us we should eat five to thirteen servings of fruits and vegetables daily. The average American eats just three total servings of fruits and vegetables.

Last year everyone went ballistic when New York banned sugared soft drink sizes greater than 16 ounces. I've always been baffled that anyone could down 16 ounces of soda at a sitting, much less 20 or 32. But these scientific findings, if duplicated, may indicate a tangible reason: people don't feel sated when they drink HFCS- and aspartame-sweetened beverages, so they drink and eat more.

Maybe we haven't become gluttons because we're weak-willed: maybe it's the biochemistry of the highly-engineered stuff coming out of food industry labs. HFCS is in everything, from chips to cereal to soda to ice cream to Sarah Lee cakes. Which makes you wonder: is the food and beverage industry aware of this effect? Are they engineering products to make us eat more, the way cigarette companies intentionally engineered their products to make them more addictive? HFCS was originally used because it was cheaper due to sugar import restrictions, but is there a darker reason for using it?

The food industry has been trying to rehabilitate HFCS's image for years. They lobbied the FDA to call it "corn sugar" to get away from its bad rep, an initiative that was ultimately denied. The industry's attempt at subterfuge, reminiscent of the tobacco industry, calls into question their motives.

This debate recalls the revolt against New Coke when it came out in 1985: everyone hated it. Some people went to Mexico to get Old Coke, which was still made with cane sugar. After three months Coke relented and introduced Classic Coke. But it wasn't quite the same: it was made with HFCS instead of cane sugar. Was Classic Coke just a Trojan horse for HFCS?

On the plus side, the study's findings suggest an alternative that we may actually enjoy. Instead of drinking gallons of "diet" or high-fructose soda, perhaps we would eat fewer calories overall if we indulged in one glass of truly classic Coke made with cane sugar, or one rich, dark chocolate bar made with real sugar, or one ice cream cone made with real cream and real sugar. And who can eat anything more after two bites of real cheesecake?

1 comment:

Juris Imprudent said...

Ah, the resident classically trained scientist weighs in...

Are they engineering products to make us eat more, the way cigarette companies intentionally engineered their products to make them more addictive?

Yep, that just screams science. Oh, and the link to the USAT article (that had no link to the actual study) also had this to say:

Waldrop and many nutritionists say there is little evidence the body treats corn syrup and table sugar differently.

and

The corn refiners group has science on its side, "but so what?" says Marion Nestle, a professor of nutrition at New York University. "This isn't about science, this is about people eating too much sugar" of all kinds — 120 pounds a year — leading to obesity, diabetes, heart disease and cancer.

YEAH - fuck science, this is about progressive moralizing!

Table sugar is not pure glucose - it is 50/50 mix of glucose and fructose. You would know that if you actually read your own link. HFCS is a 45/55 mix.