Dr. Robert Lustig is waging a war on sugar. He calls sugar the culprit behind obesity, and wants the government to regulate sugar the way it does alcohol. But his ideas have stirred up controversy among his medical colleagues who say he has insufficient evidence linking sugar to obesity. Dr. Lustig joins us to talk about his new book, “Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease.”
On the Prevalence of Sugar
"This is not just about high fructose corn syrup. The reason high fructose corn syrup is a problem is because it's cheap. And because it's cheap, it lowered prices on sugar, the entire world wide and that let it start being put into everything.
It started being put into hamburger buns, it started being put into hamburger meat. It started, you know, the barbecue sauce, the salad dressings, bottom line is, you can't find a processed food that doesn't have sugar. Eighty percent of all of the items in the American grocery store are now laced with added sugar, and that is very specifically because the food industry wants it to."
On How the Food Industry Has Changed the Food Supply
"Once fat was taken out of the diet, it was taken out for very [spurious] reasons, the food industry said 'Well, how are we going to make this stuff palatable? How's anyone going to eat it?' And so what they did was they substituted sugar for fat.
The perfect example is the chocolate milk that kids are drinking in the school today. I mean, which was worse, the fat or the sugar? I'll tell you — categorically, no ifs and or buts, the sugar is way worse.
The [ food industry removed] fiber from many foods. They did that for shelf-life, because you can't freeze fiber. Fiber makes food go bad on the shelf. So the things they have done to the food supply are very specifically for them. Adding sugar for palatability and sales, taking out the fiber for shelf life… that's what the book is about — to explain how our food supply has changed, even though we didn't ask for it to change."
On the Fatty Liver Disease Epidemic
"Only the liver can metabolize the sweet part of the molecule called fructose, which causes liver fat to build up. We now have an epidemic of non-alcoholic fatty liver disease that is actually bigger than the obesity epidemic because 33 percent of all adults in America currently have fatty liver: 45 percent of Latinos, 33 percent of Caucasians, 25 percent of African Americans.
Considering that this phenomenom, non-alcoholic fatty liver, hadn't even been diagnosed in anyone until 1980, the fact that one third of all America has it right now, that is actually the biggest epidemic. How did the liver fat get there? The answer – sugar."
On Defining Processed Food
"Processed food is fiberless food. That's basically what it comes down to. Processed food means that you've got to take the fiber out for shelf-life. And there are two kinds of fiber. There's soluble fiber: which is the kind of stuff that holds jelly together, and pectins, and things like that. And then there's the insoluble fiber: the stringy stuff, like, you know, cellulose, like what you see in celery. You need both. What I describe in the book is like it's kind of like your hair-catcher in your bathtub drain. Um, you have this plastic lattice work with holes in it. So, if you take a shower and the hair is coming down, it blocks up the holes, but only if the hair catcher is there. So, imagine that the cellulose is the hair-catcher, and imagine the hair is the soluble fiber, blocking up the little holes. When they're both there, it forms a barrier on the inside of your intestine.
You actually can see it during electron microscopy, that it's a secondary barrier that reduces the rate of absorption of nutrients from the gut, into the bloodstream. And what that does is that it actually keeps the liver safe, because it reduces the rate at which the liver has to metabolize, the stuff. And if you overload the liver, what it does is it has no choice but to turn extra energy into liver fat. And that's what drives this whole process. Is the process of liver fat accumulation, and the thing that does that the worst is sugar, especially when it's not teamed up with fiber."
On the Science Behind Some of His Claims
What we have on cancer and dementia right now is correlation. We do not have causation in humans, and I'm very clear on that, it's why I say it's not for sure. We have causation in animals. We know that these things cause cancer and promote cancer growth in animals. That's an across the board. You can ask Lew Cantley, from Beth Israel, who is now in Mount Sinai, about that. He was the one who did the 60 Minutes piece with us back in April. So, we have the data in animals, no ifs, ands, or buts. And we have the correlative data in humans.
Now, causative data is tough to come by, as you can imagine. Those are hard studies to do. Now, I'm the first one to say that we do not have causative data, in part, because everybody's exposed. There's nobody, who's not exposed. So that means the baseline's pretty darn high. So it's very hard to see an effect, especially since we've only just realized that this is a problem. So, this is going to take a while to get that data. Here's my issue – Medicare will be broke by 2024 — you want to wait?"
Robert Lustig, author, professor of pediatrics in the Division of Endocrinology and director of the Weight Assessment for Teen and Child Health (WATCH) at UCSF Medical Center