Much of the recent ‘sugar toxicity chat’ started with an April 1, 2012, 60 Minutes report. Did you miss the 60 Minutes, CBS report, “Is Sugar Toxic?” with Dr. Sanjay Gupta? It’s not too late; you can see the video or read about it.I’ve written a considerable number of articles about sugar (sugar and the heart, sugar and diabetes, sugar and cereals, and so on). If you look at a simple crystal of sucrose (table sugar), it looks so pure, so simple, and so benign; you just have to wonder what’s all the fuss about? It combines two kinds of simple sugars, glucose and fructose. What happens in the body with each simple sugar is important. If you study physiology, anatomy, and metabolism, sugar seems pretty harmless (at first glance, anyway). Your entire body uses it for energy. The brain uses glucose (half of the sugar compound) exclusively. If our brain, which regulates all of our body’s systems, is designed to use only glucose, then it seems to follow that the simple sugar glucose would be something healthy and certainly not toxic.

To take this one tiny step further, most of us Americans have eaten sugar without any apparent side effects; so we’d be even more inclined to say ‘hogwash’ if someone tried to tell us that sugar was toxic.  This will take some explanation about the case for what happens to sugar in the body, especially that other simple sugar, fructose, that has to go through the liver before the body can use it. That simple fact, when fully understood, enables us to understand what much the fuss is about.

Dr. Robert H. Lusting, a pediatrician and researcher at University of California, San Francisco’s Center for Obesity, is one of the key spokespersons who explains how sugar is processed in the body, and how key facts have not been understood.  Dr Lustig is on the board of directors of The American Heart Association’s (AHA) Bay area. He was interviewed in the 60 Minute report. Lustig’s idea is for a drastic reduction in sugar consumption. He is one of the researchers who helped to form the recommendation that men consume no more than 150 calories and women no more than 100 calories a day as added sugar. (In teaspoons those calories are found in 9 teaspoons for men and 6 for women). I’ve quoted this recommendation a number of times since The American Heart Association (AHA) announced it. Lustig points out that the recommendation is less than the amount in just one can of soda. He makes the point that this is a public health crisis and to meet it, the nation will have to take strong and decisive actions. He encourages us to compare sugar’s effects to the effects of tobacco and alcohol. This is putting sugar in some pretty bad company, substances now known to be addictive and commonly abused. His recommendation that sugar belongs in the same wastebasket as tobacco and alcohol is based on considerable evidence. He’s been considered controversial for quite a few years, but the research from many sources keeps getting stronger in validating his and similar work. So today, let’s see if we can clarify the case regarding sugar toxicity – particularly the fructose part.

Dr. Kimber Stanhope’s researchers (a nutritional biologist at the University of California, Davis) found that subjects who lived within a closed hospital setting (where their eating was strictly controlled) had their LDL (bad cholesterol) increase within two weeks after beginning the comparative phase of her study.  This phase required that they drink a controlled volume of sugar-sweetened Kool-Aid. Stanhope’s research supports Lustig’s research showing that the liver goes into overload with too much fructose and converts some of it into fat. Some of it becomes the small dense LDL that makes plaque and is a dangerous risk factor for heart disease and stroke.

Lustig gives compelling evidence that fructose is the most dangerous portion of sugar (sucrose – ½ glucose and ½ fructose). To begin with Lustig shared the fact that we used to get fructose in fruit, which came loaded with fiber that slows absorption and consumption; he said, “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.” On average, Americans now consume about 20 to 24 teaspoons of added sugar per day. (This is not including the sugars found naturally in fruits, vegetables and unsweetened milk products.) You’re right, you are not putting 24 teaspoons of sugar on your food, but others are doing much of that for you. There’s the baker; the food processor (ready-to-eat cereals, soups, sauces, crackers, snacks, frozen meals, frozen treats, candy, cookies, chips, dips); the dairy industry (think chocolate milk and sweetened yogurt); the fast food shop; the restaurant and so on. We don’t need to do it for ourselves. Food manufacturers are more than willing to provide products for us that we seem to crave.

For example, when cold cereals were first popular, we often sprinkled our cereal lightly with a little sugar; my guess is that we used about one teaspoon. Now if you eat a single serving of Honey Smacks (used to be called Sugar Smacks), and who eats a single serving as given on the box?, you get 20 grams (5 teaspoons) of sugar in a one-cup serving. So if we’re trying to meet the AHA’s goal, 80 calories of sugar in the first serving of the day. That is 80% of the goal for women and 53% of the men’s goal. Many need about 2 one-cup servings or more to be full, which of course, takes even men past their goal.

Why is the goal so darn important?

• Heart disease is the number one killer of both men and women. The writing is ‘on the wall’ for sugar-sweetened drinks. A 20% increase risk of coronary heart disease was shown for men in a Harvard’s School of Public Health study. Women in the Nurses’ Health Study were already found to be at greater risk of heart disease.
• In addition, there’s a plethora of evidence, of sugar contributing to the obesity and diabetes epidemics.
• Now cancer is following suit. Dr. Lewis C. Cantley, a cancer researcher was interviewed on the 60 Minutes piece. What he has learned is that when we get the spike in the hormone insulin after eating or drinking sugar, it can serve as a catalyst to fuel certain types of cancers. He says that nearly a third of some common cancers, including breast and colon cancers have insulin receptors on their surface. The insulin binds to the receptors and signals the tumor to start consuming glucose. Cantley’s research team is working on developing drugs that will cut off the glucose supply to cancer cells. But until then, it is just one more reason, albeit a big one, to ‘listen up’ about sugar. Cantley’s advice: Don’t eat sugar. And if you must, keep it to a minimum.
• The addictive quality of sugar.  On the same 60 Minutes Eric Stice PhD, a neuroscientist at the Oregon Research Institute talked about his research using MRIs to discover how sugar affects the brain. Yikes!  Dopamine, a neurotransmitter in the pleasure center of the brain responds to sugar in the same manner it responds to drugs or alcohol. What’s somewhat extra sad is that he has learned from the hundreds of volunteers that he’s scanned, that those who frequently drink sodas or eat ice cream or other sweet foods may be building up a tolerance – which means that the more you eat, the less you feel the reward and then you feel a greater craving to eat more than ever. This too is the way drugs like heroin work.  It takes more and more to obtain the same sense of pleasure.

Note: You might be interested in our previous blogs on the subject of food cravings and addiction: ­Designing Foods for Craving, and ‪A Rat's Eye View of the Recent Junk-Food Study. Our most recent one was this year: Detoxing from Sugar?

There have been over a couple million views of Lustig’s 2009 YouTube posted - Sugar: The Bitter Truth; it’s an hour and a half presentation chock full of facts about how sugar relates to metabolism, obesity, heart disease and on and on. If you really want to understand why we should get serious about cutting out sugar intake, I’d recommend listening to the full presentation. But if you don’t have the hour and a half, I’ll try to share some of the main ideas presented:

• He begins by citing how soft drink and fruit drink consumption has risen since 1981. (41% & 35%)
  • Part of that is due to the growing bottle sizes; now the 20-ounce bottle is fairly standard, even though it is listed as 2.5 servings in the one bottle.
  • He presents a chart showing how many pounds a person would gain for various sized bottles: One 12 oz. soda each day for a year would yield a 16 pound weight gain; One 20 oz. soda each day for a year would yield a 26 pound weight gain; a 44 oz. soda Big Gulp each day for a year would yield a 57 pound gain in fat.
  • One of Lusting’s many discoveries is that we replaced a lot of fat with added sugars; he often uses Snackwell’s as an example. You frequent readers know that we do too. He reminds us that when the fat is removed the food tastes terrible so the food processors add sugar. This is a particularly bad idea because the sugar increases the small dense LDL pattern B cholesterol that is associated with heart disease.
  • Lustig explains how fructose is sweet – glucose on the other hand is not as sweet. He says it’s the fructose that makes you want more.
  • Lustig goes over the metabolism of sugar – this is key. Half of the sucrose molecule or about half of high fructose corn syrup is fructose. This is where a big problem begins. Biology majors all learn that fructose has to make a pass through the liver to be metabolized. It all seemed so harmless when I learned it about three decades ago. But Lustig made it very clear that if we have large amounts of sugar or HFCS, the fructose overwhelms the liver mitochondria. It’s the same way too much alcohol (ethanol) is toxic to the liver – it overwhelms the mitochondria and makes a fatty liver – we call it cirrhosis. He makes it clear that the fructose in fruits and vegetables, found in nature with fiber, is not the problem. The problem is the added sugars. When he is finished with the explanation of fructose metabolism, you know you want to be very careful with how often you want to challenge your liver with a fructose overload.
  • In this blog we promote the Mediterranean style of eating, studied decades ago by Ansel Keyes, who found it the most healthy in the world in the 1950s. Lustig points out that Keyes found fat and sugar consumption in America were both different than in the Mediterranean diet, but Keyes thought that the problem was only the fat. Unfortunately, we’ve made policy for decades, based upon the ‘fat is the problem’ theory. But as it turns out, it’s a two-headed monster. Both fat and sugar are problems. Lustig makes a point in saying that researchers have belatedly found the error in interpreting Keyes findings and now we need to admit the mistake and make it right. Americans are not less healthy than the 1950’s people in Crete just because of the extra fat.  The people in Crete did not consume much if any added sugar. They had low incidence of the serious diseases Lustig has implicated with sugar. We in the US had much higher rate of disease then, and the rates have increased in epidemic proportions as we have consumed more and more of it.
  • Fructose stimulates the production of the LDL pattern B (low density lipoprotein cholesterol) – it’s smaller and denser than the LDL pattern A and gets under the edge of the epithelial cells of our veins and arteries – the plaque problem – arteriosclerosis.
  • Lustig says that fructose is seven times more likely to bind to protein and get stuck in arteries than glucose to form Advanced Glycation End-Products (AGE’s) – a problem in arterial heart disease.
  • Fructose does not suppress fast acting ghrelin (a hormone that tells you to be hungry). If you have a soda, before a meal, you actually eat more, according to a substantial body of research.
  • Lustig lists nine citations that show that chronic fructose exposure promotes the Metabolic Syndrome.
  • One of the fascinating portions of Lustig’s presentation was when he explained the metabolism of fructose in the liver. In short, just as ethanol (beer, wine, hard liquor) has to be metabolized in the liver, so does fructose.  Now I always thought of it as a simple pass through the liver to become glucose, but if you take in lots of fructose (like a soda pop) the liver has to work four times as hard as when you take in starch.  Starch molecules are essentially like a string of glucose pearls, one after another. The starch can be used in all the cells of the body, but the fructose has to be metabolized by the liver.
    • Let me remind you here, that fructose is exactly 50% of the sugar in table sugar (sucrose); and about 50% of honey and high fructose corn syrup HFCS; agave has more fructose than glucose depending upon the source of the agave syrup – it ranges from 56 to 92% fructose. Ouch! It has been recommended (not by me) to diabetics because it is slower to raise the blood sugar, because of this fact. Unfortunately, because diabetics have an increased risk of heart disease this is an extremely good reason not to use agave. Certainly, none of these sweeteners are health foods!
    • Lustig does a fine job of driving home the analogy with alcohol and sugar. Most of us know the damage that alcohol can do to our liver – fatty cirrhotic liver – cirrhosis is, of course, well known. But it is really not well known that fructose is also doing toxic damage to our livers.  The point is, like alcohol, small doses are fine; but big doses are damaging. If you watch Lustig’s YouTube presentation, you will see that chronic high fructose intake shares eight of the twelve diseases of chronic alcoholism. The symptoms are the same because the metabolism of both fructose and alcohol doesn’t convert directly to glycogen as glucose does, but overloads the mitochondria (the cell’s energy-producing organelles.) Lustig has a nice chart showing at the bottom that 150 calories of Coke and 150 calories of beer each yield 90/92 calories that reach the liver and have to be metabolized in the liver’s mitochondria. Calorie for calorie and damage for damage they compare. Maybe this comparison will help those who think drinking sugar-sweetened soda is harmless.

    Lustig points out that fructose is packed with fiber in nature. At Lustig’s department at UCSF, they say: “When God made the poison, he packaged it with the antidote.”  The point is that wherever there is fructose in nature it is in the company of lots of fiber. Have you ever seen a stick of sugar cane – that is one fibery mess. Fruit also is loaded with fiber. Processing takes out the fiber and gives you the fructose in high-octane form.

• What does fiber do?
1. It reduces the rate of carbohydrate absorption, which helps to keep the insulin response down.
2. It increases the speed of transit through the small intestine and results in more satiety – you stop being hungry for more.
3. It inhibits the absorption of some of the free fatty acids until they reach the colon; there they are metabolized by colonic bacteria to short-chain fatty acids (SCFA) – that’s helpful because this process suppresses insulin.
• Lustig speaks extensively about why it’s important that sugar becomes a controlled substance. One of his main points is that like alcohol, sugar is a problem when it is overused. He gives some very compelling statistics about work productivity, absenteeism, increase in health insurance premiums, and waste in health care resources.  He makes a point of the fact that the government pays twice: once for the corn subsidy and then for the increased health care.
• Lustig ends his discussion with suggestions of what may work to get fructose under control.

I think much of the evidence presented by the 60 Minutes report and Lustig’s Sugar: The Bitter Truth is compelling. Should we call sugar, in its various forms toxic? In that, I’m not sure. I’ve always subscribed to Mary Poppins’ adage, “A spoonful of sugar helps the medicine go down.” I do believe that the 150 calories a day from sugar for men and 100 for women is a reasonable goal; although it may seem very difficult for some to achieve. Lustig doesn’t hold much hope for just educating people; but I have hope that if people really know, they may change – they may demand some change. I remember the outrage over trans fats; we’ve make considerable progress. Certainly, we can’t just rely on the food processors to make the change in the name of public health. As I recently pointed out, the food processors are still putting trans fats in many processed foods. But it seems that the huge ‘toxic sugar movement’ surely will demand some change.

I realize that moderation is not an alluring concept. I embrace the idea that a sweetened drink once in a while, can be a nice treat. But like some of the researchers say, “It’s not an everyday treat.” Maybe mothers, fathers and those who care for little ones, will stop offering soda as a beverage option on a regular basis. Maybe dessert could be considered for once or twice a week. In making a transition, we may want to consider sweetening with a sweetener that does not contain fructose. Maybe we can use less sweetener – experiment a little when sweetening foods at home. Consider eating fewer processed, fast foods and restaurant meals. When you cook, you know what is in the pot.

My husband and I have a few friends that don’t eat dessert even when it’s super special. I’ve been thinking about that. They made a decision not to eat desserts and have stuck with it for years. Dr. Lewis C. Cantley at Harvard Medical School said that he rarely eats sugar. When offered a glass of sugar-sweetened soda pop or a glass of juice, we almost always choose water. Once in a while, we succumb to fresh squeezed orange juice as a special treat. But all in all, we learned that if we cut our sugar consumption down, we have gradually lessened our desire for frequent sugar intake.

Watching the 60 Minutes report and Sugar: The Bitter Truth has really motivated me to be even more careful than ever with sugar. At this point, however, I think I’m still planning on enjoying certain special desserts, in moderation, when the occasion arises. And lastly, I’m still planning on enjoying my small piece of chocolate at night. I just assessed my chocolate ‘stash’ – they range from 17 to 22 calories from sugar for a piece. I think I’ll stick with Mary Poppins’ advice and enjoy my little bit of dessert. Now I have a new weapon in my arsenal against sugar craving – the image of my poor liver trying to contend with an overload of fructose, acting in the same way it would with the toxic effects of too much alcohol. A little bit of added sugar does make life a little sweeter, but more than a little, indeed, has bitter consequences.