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Sanjay Gupta MD

Is Sugar Toxic?; Role Reversal for Transplant Surgeon

Aired April 28, 2012 - 16:30   ET


DR. SANJAY GUPTA, HOST: More than 30 years ago, there was a big push by the doctors and the government to get people to eat less fat. That was to help lower the rate of heart disease. Low fat they said means heart healthy. So, out went the fat, but in many foods, to keep them tasting good, in went more sugar.

And so, here we are, today, as you've heard me say over and over again, we as a nation are more unhealthy than ever. Not to mention fatter.

You've heard a lot of theories as to why, but one in particular is getting a much closer look.

It's about sugar. Everybody knows too much is bad, but I have been surprised to see just how bad.

I did this investigation with CBS and "60 Minutes" and it begins with this pediatric endocrinologist in California, Dr. Robert Lustig, who says we're literally poisoning ourselves with sugar.


GUPTA: Is sugar toxic?


GUPTA: Do you ever worry that that just sounds a little over the top?

LUSTIG: Sure, all the time. But it's the truth.

GUPTA (voice-over): Dr. Robert Lustig is a pediatric endocrinologist at the University of California, San Francisco, and a pioneer in what is becoming a war against sugar.

LUSTIG: Deep breaths.

GUPTA: Motivated by his own patients, too many sick and obese children, Dr. Lustig has concluded that sugar, more than any other substance, is to blame.

(on camera): What are all of these various diseases that you say are linked to sugar?

LUSTIG: Obesity, type two diabetes, hypertension, and heart disease itself. GUPTA (voice-over): Lustig says the American lifestyle is killing us.

(on camera): And most of it, you say, is preventable.

LUSTIG: Seventy-five percent of it is preventable.

GUPTA (voice-over): While Dr. Lustig has published a dozen scientific articles on the evils of sugar, it was his lecture on YouTube called "Sugar: The Bitter Truth," that brought his message to the masses.

LUSTIG: I'm standing here today to recruit you in the war against bad food.

GUPTA: By bad food, the doctor means the obvious things such as table sugar, honey, syrup, sugary drinks and desserts, but also just about every processed food you can imagine, where sugar is often hidden, yogurts and sauces, bread, even peanut butter.

And what about the manmade often vilified sweetener, high fructose corn syrup?

(on camera): Is it worse than table sugar?

LUSTIG: No, it's the same thing. They're basically equivalent. The problem is they're both bad. They're both equally toxic.

GUPTA (voice-over): Since the 1970s, sugar consumption has gone down nearly 40 percent. But high fructose corn syrup has more than made up the difference. Dr. Lustig says they're both toxic because they both contain fructose. That's what makes them sweet and irresistible.

LUSTIG: We love it. We go out of our way to find it. I think one of the reasons evolutionarily is because there's no food stuff on the planet that has fructose that is poisonous to you. It is all good. So when you taste something that's sweet, it's an evolutionary Darwinian signal this is a safe food.

GUPTA (on camera): We were born this way?

LUSTIG: We were born this way.

GUPTA (voice-over): Central to Dr. Lustig's theory is that we used to get our fructose mostly in small amounts of fruit. Which came loaded with fiber, that slows absorption and consumption. After all, who can eat 10 oranges at a time.

But as sugar and high fructose corn syrup became cheaper to refine and produce, we started gorging on them. Americans now consume 130 pounds per person a year. That's a third of a pound a day. Dr. Lustig believes those sweeteners are helping fuel an increase in the most deadly disease in America, heart disease. For years, he's been a controversial voice.

UNIDENTIFIED FEMALE: Here is our oral isotope.

GUPTA: But now, studies done by Kimber Stanhope, a nutritional biologist at the University of California, Davis, are starting to back him up. She's in the middle of a groundbreaking five-year study which has shown strong evidence linking high fructose corn syrup consumption to an increase in risk factors for heart disease and stroke. That suggests added calories from added sugars are different than calories from other foods.

(on camera): The mantra you hear from most nutritionists is a calorie is a calorie is a calorie.

DR. KIMBER STANHOPE, UNIVERSITY OF CALIFORNIA, DAVIS: And I think the results of the study showed clearly that is not true.

GUPTA (voice-over): Stanhope's conclusions weren't easy to come by. Nutrition studies are expensive and difficult. Stanhope has paid groups of research subjects to live in this hospital wing for weeks at a time under a sort of 24-hour lockdown. They undergo scans and blood tests. Every calorie meticulously weighed and prepared.

STANHOPE: They're never out of our sights, so we do know that they are consuming exactly what we need them to consume.

GUPTA (on camera): And they're not sneaking any candy bars on the side?

STANHOPE: Right. Yes, exactly.

GUPTA (voice-over): For the first few days, participants eat a diet low in added sugars, so baseline blood levels can be measured.

UNIDENTIFIED FEMALE: Remember, you have to finish all of your Kool- Aid.

GUPTA: Then 25 percent of the calories are replaced with sweetened drinks and Stanhope's team starts drawing blood every 30 minutes around the clock. And those blood samples, they revealed something disturbing.

(on camera): And what are you starting to see?

STANHOPE: We found that the subjects who consumed high fructose corn syrup had increased blood levels of LDL cholesterol and other risk factors for cardiovascular disease.

GUPTA: How quickly did the changes occur?

STANHOPE: Within two weeks.

GUPTA (voice-over): Kimber Stanhope's study suggests when a person consumed to much sweet stuff, the liver gets overloaded with fructose and converts some of it into fat. Some of the fat ends up in the blood stream and helps generate a dangerous cholesterol called small dense LDL. These are known to lodge in blood vessels, form plaque, and are associated with heart attacks.

(on camera): Did it surprise you when you first got the results back? STANHOPE: I would have to say I was surprised because when I saw the data, I started drinking and eating a whole lot less sugar. I would say our data surprised me.

GUPTA (voice-over): So, imagine for this healthy young people drinking a sweetened drink might be just as bad for their hearts as the fatty cheese burgers we have been warned about since the 1970s. That's when a government commission mandated that we lower fat consumption to try to lower heart disease.

UNIDENTIFIED MALE: Major coronary risk factors.

GUPTA (on camera): So, with the best of intentions, they say time to reduce fat in the American diet.

LUSTIG: Exactly. And we did. And guess what? Heart disease, metabolic syndrome, diabetes, and death are skyrocketing.

GUPTA (voice-over): Dr. Lustig believes that's primarily because we replaced a lot of that fat with added sugars.

LUSTIG: When you take the fat out of the food, it tastes like cardboard. The food industry knew that, so they replaced it with sugar.

GUPTA (on camera): This idea that sugar increases this particularly bad LDL, the small dens particles associated with heart disease, do most doctors -- do they know this?

LUSTIG: No, they do not knee this. This is new.

GUPTA (voice-over): And it turns out sugar has become a major focus in cancer research, too.

Lewis Cantley is looking at the connections.

(on camera): If you limit your sugar, it decreases your chances of developing cancer?


GUPTA (voice-over): Cantley, a Harvard professor and the head of the Beth Israel Deaconess Cancer Center said when we eat or drink sugar, it causes sudden spike in the hormone insulin, which can serve as a catalyst to fuel certain types of cancers.

CANTLEY: What we're beginning to learn is that insulin can cause adverse effects in various tissues. A particular concern is cancer.

GUPTA: Why? Nearly a third of some common cancers, including breast and colon cancers, has something called insulin receptors on their surface. Insulin binds to these receptors and signals the tumor to start consuming glucose.

CANTLEY: So, this is your body -- GUPTA: Every cell in our body needs glucose to survive, but the trouble is these cancer cells also use it to grow.

CANTLEY: So if you happen to have a tumor that has insulin receptors on it, then it will get stimulated to take up the glucose that's in the blood stream. So rather than going to the muscle, the glucose now goes into the tumor, and the tumor uses it to grow.

GUPTA (on camera): So, you've seen the tumor turn blue, which is essentially reflective of the glucose going into it.

CANTLEY: That's right.

GUPTA: So, these cancers much in the same way that muscle will say, hey, I'd like some of that glucose, the fat says, I would like some of that glucose, the cancers have learned how to do that as well?

CANTLEY: Yes. So, they have evolved the ability to hijack that flow of glucose going by in the blood stream into the tumor itself.

GUPTA (voice-over): Llewis Cantley's research team is working on developing drugs that will cut off the glucose supply to cancer cells and keep them from growing. But until there's a breakthrough, Cantley's advice, don't eat sugar. If you must, keep it to a minimum.

CANTLEY: In fact, I -- you know, I live my life that way. I rarely eat sugar.

GUPTA (on camera): When you see a sugary drink or if I were to offer you one, with all that you know, what's going through your mind?

CANTLEY: I probably would turn it down and get a glass of water.

GUPTA (voice-over): But for most of us, that's easier said than done.

ERIC STICE, OREGON RESEARCH INSTITUTE: Turns out sugar is much more addictive than we had realized early on.

GUPTA: Eric Stice, a neuroscientist at the Oregon Research Institute, is using functional MRI scanners to learn how our brains respond to sweetness.

STICE: Sugar activates the brain in a special way that is very reminiscent of a drug like cocaine.

GUPTA: That's right, cocaine.

(on camera): All right. Let's give it a shot.

(voice-over): I climbed into the MRI scanner to see how my brain would respond. That's a straw that's been rigged to deliver a tiny sip of soda into my mouth.

Just as it hit my tongue, the scanner detected increased blood rushing to certain regions of my brain. In these images, the yellow areas show that my reward region is responding to the sweet taste. Dopamine, a chemical that controls the brain's pleasure center, is being released, just as it would in response to drugs or alcohol.

(on camera): So, dopamine is released. That sort of makes me feel good. I'm experiencing some pleasure from having this.

STICE: That euphoric effect.

GUPTA: So, far be it for people to realize this, because sugar is everywhere, but you're saying this is one of the most addictive substances possibly that we have.

STICE: It's certainly is very good at firing the reward regions in our brain.

GUPTA (voice-over): Eric Stice says by scanning hundreds of volunteers, he's learned that people who frequently drink sodas or eat ice cream or other sweet foods may be building up a tolerance, much like drug users do. As strange as it sounds, that means the more you eat, the less you feel the reward. The result, you eat more than ever.

STICE: If you overeat these on a regular basis, it causes changes in the brain that basically it wants your reward region to respond to the food, so you eat more and more to achieve the same satisfaction you felt originally.

GUPTA: With all these new science emerging, we wanted to hear from the sugar industry. So, we visited Jim Simon who's on the board of sugar association at a sugar cane farm in Louisiana.

(on camera): Would it surprise you that every scientist we talked to, in researching this story, they are eliminating all added sugars, they're getting rid of it, because they're concerned about the health impacts?

JIM SIMON, GENERAL MANAGER, AMERICAN SUGAR CANE LEAGUE: To say that the American consuming public is going to completely eliminate sweeteners out of their diet, I don't think gets us there.

GUPTA (voice-over): Simon cautions that eliminating sugar wrongly vilifies one food rather than working toward the long term solution of reducing calories and exercising.

(on camera): Now, a lot of people, Jim, are saying that sugar is different. That it's bad for your heart and causing a lot of problems that we are talking about. It is addictive and in some cases might even fuel cancers. What would you -- I mean, you have looked at this. You must have looked at some of the studies. What do you say about that?

SIMON: Science is not completely clear here.

GUPTA: But some of the studies exist. I mean, what does a consumer -- what are they make of all that?

SIMON: Well, I would say to them that they've got to approach their diet in balance. GUPTA (voice-over): Dr. Lustig agrees, we need a balanced diet. But his idea of balance is a drastic reduction in sugar consumption. To that end, he co-authored an American Heart Association report recommending men should consume no more than 150 calories of added sugar a day, and women, just 100 calories. That's less than the amount in just one can of soda.

LUSTIG: Ultimately, this is a public health crisis. And when it's a public health crisis, you have to do big things and you have to do them across the board.

Tobacco and alcohol are perfect examples. We have made a conscious choice that we're not going to get rid of them but we are going to limit their consumption. I think sugar belongs in this exact same waste basket.


GUPTA: After that story first ran, we did hear back from the sugar association. They say it boils down to this: you can only fight obesity with a combination of changes to your diet and more exercise. And, of course, I think everyone agrees with that.

They sent us a letter that said we should try to focus on total calories, that too many calories, quote, "remain the cause of a myriad of illnesses facing Americans. To view any single food or ingredients as the main culprit provides little benefit."

Again, that's a statement from the sugar association. Now, one way people try to cut calories is to use sugar substitutes. A question a lot of people ask is: are they better than the real thing or could they be even worse?


GUPTA: You know, a lot of people do try to lose weight by avoiding sugar and using artificial sweeteners instead. We get a lot of questions about the sugar substitutes.

So, here to help me answer a few of them is our friend, Dr. Melina Jampolis, an internist and a board certified physician nutrition specialist.

We give you a lot of questions about these sugar substitutes, especially the sugar piece, you know, that's really -- that message has been getting out there. You say that these sugar substitutes are not all the same. Can you quickly explain the different types?

DR. MELINA JAMPOLIS, PHYSICIAN NUTRITION SPECIALIST: Yes, it's really important to understand that there's both natural and artificial sweeteners and sugar substitutes. And when people are -- most of the concerns that people have are around the five FDA-approved artificial sweeteners.

But it's important to understand that these sweeteners are all different. They have different chemical make-ups and they're handled differently by the body. Some are completely broken down. Some are not. So, you can't lump them into one thing if you have concerns about them.

GUPTA: So, from a more basic standpoint, a nutrition standpoint, is a natural sweetener like Stevia for example, better option than an artificial sweetener?

JAMPOLIS: You know, I think that point is up for debate. And we don't really know. Most people do, most nutrition experts do believe the more natural alternatives are better. But just because something is natural doesn't mean it's good for you, and in larger amounts.

So, I think that, you know, if you tend to prefer more natural products, that's probably the better way to go. But it's not completely risk-free. So, I think with all of these things, you know, you just have to consume things in moderation, which we seem to say all the time.

GUPTA: Yes, I mean, that's a I think it's a message everyone agrees on.

But one of the specific things people ask about our artificial sweeteners or these substitutes is, can they cause cancer? Now, I mean -- this has come up over and over again. It's a controversial topic. Studies I have seen don't seem to support that theory.

I mean, what's your take? Is there any reason people should think sugar substitutes cause it?

JAMPOLIS: You know, I totally agree with you. The studies that I have seen and the studies that the National Cancer Institute has seen and even a new European Food Safety Administration study, they all point to the fact that in humans, there is no compelling evidence. It's really more a very few animal studies.

And in the case of saccharin, there was an animal study in the 70s --

GUPTA: Right.

JAMPOLIS: -- that showed that they cause bladder cancer in rats, but it wasn't even a mechanism that was possible in humans. So, I think, at this point, we don't have convincing research. This is more hype and really a little bit blown out of proportion.

GUPTA: Yes. And a lot of these sweeteners, as you point out, have been around for some time now. So, you know, we've actually --


GUPTA: -- been consuming them.

Does fake sugar make a person crave more food or more calories? And, again, I remember a study a few years back that found people, for example, who drink diet soda often tend to weigh more than people who don't. I mean, is there -- is there a craving component? JAMPOLIS: Yes. You know, that's a great question. And it's really interesting because a lot of studies show diet soda is linked with overweight. But is it that they drink diet soda because they're overweight or because it actually causes weight gain?

And, you know, we know that some of these artificial sweeteners do cause a release of insulin which could drop your blood sugar and make you crave more sugar actually. And they also seem to trigger the same addiction like pathways in the brain. So, there is a potential mechanism, but we don't know the answer at this point.

GUPTA: That's good advice, doctor. Dr. Jampolis, as always, I'll have you back soon. Thanks.

JAMPOLIS: Thanks. Great to see you.

GUPTA: All right. And still ahead, a really fascinating story to share with you. I'm going to introduce you to this transplant surgeon who became a better doctor after needing a transplant himself.

Stay with us.


GUPTA: Dr. Carlos Zayas began his professional life as a priest. But he soon found his true calling in medicine as a transplant surgeon. Little did he know that he would someday need the expertise of his own colleagues to help him overcome a rare and deadly disease.


DR. CARLOS ZAYAS, TRANSPLANT DOCTOR, CANCER SURVIVOR: We just came back from Paris. We celebrated 15 years of wonderful marriage at the Eiffel Tower.

GUPTA (voice-over): For Dr. Carlos Zayas, this wedding anniversary celebration almost didn't happen. You see, three years ago, this transplant surgeon made a shocking discovery. His lymph nodes were swollen and he suspected he had cancer. His fears were confirmed and the diagnosis, a rare form of blood cancer called peripheral T-cell lymphoma.

ZAYAS: It's difficult to treat and has a poor prognosis.

GUPTA: When grueling chemotherapy failed, the transplant doctor needed a transplant himself -- a bone marrow transplant. Now, with bone marrow, a near perfect match is necessary for the treatment to be effective. And that's more likely from a donor of the same ethnicity.

But the pool of potential donors for Hispanics in the United States is very small. They only represent about 10 percent of a national bone marrow registry. In Dr. Zayas' case, a very close match was found, but then the donor backed out.

ZAYAS: People joined the registry for people that they love or they know. But when they get a call about a complete stranger, their answer is, I am afraid I can't do this.

GUPTA: So doctors took another look at his siblings. And while his brother Hector wasn't a perfect match, Zayas got the transplant anyway. Hector's bone marrow started killing the cancer cells and today he's in complete remission, back helping patients find organs. Zayas says it was his faith that helped him through the difficult times and the experience has overall made him a better doctor.


GUPTA: Well;, I'm going to be a better doctor and perhaps a better friend by telling you something that's probably going to be music to your ears. Eat more to weigh less. I'll explain.


GUPTA: As you set out to do your grocery shopping this weekend and plan meals for the week ahead, there's one tip I want you to keep in mind. Now, this is a key to your body's own metabolism and also how you chase live to 100. It's an easy phrase to remember. Eat breakfast like a king. Eat lunch like a prince, and eat dinner like a peasant. Your body can burn that fuel early in the day and not be too overloaded close to bedtime.

Now, some studies have shown eating more food for breakfast can actually help you lose weight. How about that?

Unfortunately, that's going to wrap things up for me today. Follow me at or on Twitter @SanjayGuptaCNN. Also, make an appointment to come back and see us right here on SGMD.

Time now, though, to get a check of your top stories in the CNN NEWSROOM.