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. "
Many scientists, however, think that focusing public health on one vilified nutrient is the wrong tack to take. Such a strategy has backfired before: for example, doctors once told us all fat is bad, so manufacturers took it out of processed foods (and, interestingly, replaced it with sugar). Today, it’s recommended we eat 20 to 35 percent of calories from fat—most of which should be the healthy, unsaturated kind.
“We certainly agree we should eat less sugar, but I think he’s making a huge mistake from a public health perspective,” says Katz. “We spent the last three decades doing exactly this: we thought just oat bran is good for us, so we put it in everything. Then we just needed to cut fat. Then it was carbs. So I can imagine we’ll soon have a vast proliferation of sugar- or fructose-reduced junk food filled with some unhealthy substitute... I can’t help but roll my eyes and ask, how many times do we have to get this wrong before we get it?”
And Tappy is concerned Lustig’s public message is leaping ahead of the science: “So far, except for triglycerides, the data in the literature linking metabolic syndrome to fructose is pretty weak.”
But Lustig counters that, with the U.S. losing $65 billion in worker productivity and spending $150 billion on medical care for health problems associated with metabolic syndrome each year, “Do we have to wait for those studies to be finished in humans before we can do anything about it? I would suggest that that would be way too late.”
At the end of his YouTube lecture that sparked the sugar firestorm, the camera switches from generic blue PowerPoint slides to a gray-haired, gray-suited Robert Lustig. After 90 minutes of science, Lustig gives the audience some advice: drink only water or milk; exercise; eat your carbs with fiber (fruit’s fiber slows the absorption of fructose so it never overwhelms your liver: “When God made the poison he packaged it with the antidote,” says Lustig); wait 20 minutes before your second portion; use computers and TV for only as long as you exercise each day. It’s all we need to avoid a deadly fructose fate, he says.
At the very end of his lecture, Lustig peers at his captive audience. He pauses a moment, and makes his final appeal. “I’m standing here today to recruit you in the war against bad food,” he says. “And this [added sugar] is what’s bad.”
The storyteller closes his book. It’s up to us to write the final chapter.
Contributing editor Rachael Moeller Gorman won a James Beard Award for her EatingWell article "Captain of the Happier Meal" (May/June 2010).