What’s good? What’s bad? How much sugar is too much? Here’s what the latest science says.
"There is no substitute for whole natural foods, a variety of foods, eaten in season. I read that xylitol, which is marketed as a natural sugar, is actually processed using toxic chemicals. "
The Science of Sugar
Tens of thousands of years ago, before two-liter sodas and oversized candy bars, our tongues rarely tasted sweetness. Sugar was extremely hard to come by. Honey had it (but it was protected by bees) and fruit contained it, enveloped in a fiber cage, but otherwise sweetness was a sensation few people experienced, and only in certain months of the year.
But because sugar provides safe calories (almost no plant that tastes sweet is poisonous), we evolved to crave it. Our brains are hard-wired to release a big shot of joy whenever we taste sweetness, by unleashing a chemical called dopamine that sparks our brain’s pleasure center, a region called the nucleus accumbens. We also have a second way to make sure we are constantly on the lookout for this valuable energy: Even the thought of sugar makes us happy. The brain releases dopamine before we eat sugar, while we’re seeking it out and as we anticipate placing it in our mouths. We have an ancient, always-on, deep-brain need to fill our stomachs with sweet calories.
Now, rubbing the magic lamp, we’ve finally gotten our genes’ greatest wish: an endless supply of sugar. In the U.S., sucrose can be found all over the supermarket, but, more insidiously, ubiquitous HFCS is a cheap source of sweetness, a result of subsidies to corn farmers. “High-fructose corn syrup is evil, but it’s not evil because it’s metabolically evil; it’s evil because it’s economically evil,” Lustig says in his YouTube video. Because it’s so cheap it has found its way into nearly every processed food, including crackers, yogurt, tomato sauce, as well as cookies and sweetened beverages like sports drinks, juices, sodas.