sugar, sugar, sugar

I love sugar. I love candy, cake, cookies, pie, all sweets. If it's sweet, I will eat it even if it doesn't taste that good because I love eating sugar. But how does all that sugar affect my body? We know sugar isn't good for you, but is it bad? Recently, I watched a video called "Sugar: The Bitter Truth," which now has over 1.7 million views on You Tube. A video-taped lecture given by Robert H. Lustig, MD a professor of pediatrics at the University of California, San Francisco who is also the Director of the Weight Assessment for Teen and Child Health (WATCH) Program at UCSF, it details sugar on many levels, including chemically, and gives insight into how it affects our bodies. Because the video is an hour and a half long, I decided to summarize it for you. All quotes are from Lustig's lecture unless cited otherwise.

What is sugar?
Chemically speaking, white table sugar is a glucose molecule and a fructose molecule bonded together.

What is glucose?
Besides sugar, glucose is found in many carbohydrates like pasta, bread, and rice. When you eat calories from glucose, "...80% of the total will be used by all the organs in the body...because every cell in the body can use glucose. Every bacteria can use glucose, every living thing on the face of the Earth can use glucose because glucose is the energy of life." The remaining 20% of the calories is metabolized in the liver. There, most of this glucose is transformed into glycogen to be stored. Your liver can store an unlimited amount of glycogen, because it is non-toxic, and it can be reconverted into glucose to be used for energy as needed. The remaining glucose becomes citrate. Enzymes break this down to create very low-density lipoprotein, or vLDL cholesterol. This can cause heart disease and is related to obesity. "[If] You started with 24 calories [of glucose in the liver], maybe a half a calorie will end up as vLDL." Your insulin goes up in this process, and your brain shuts off your hunger urge, so you stop eating.

What is fructose?
Fructose is found in fruit and high fructose corn syrup (HFCS) ("The most widely used varieties of high-fructose corn syrup are: HFCS 55 (mostly used in soft drinks), approximately 55% fructose and 42% glucose; and HFCS 42 (used in many foods and baked goods), approximately 42% fructose and 53% glucose" (Wikipedia)). When you eat calories from fructose, every single calorie will be metabolized in the liver because the liver is the only organ in the body that can metabolize fructose. Similar to glucose, the fructose is processed into citrate, however, in large amounts due to the larger number of total fructose calories being processed by the liver. This leads to the production of large amounts of vLDL cholesterol. Additionally, enzymes act on fructose to transform it into fat to be stored: about 30% of the fructose you eat ends up as fat. "...everybody talks about a high-fat diet. Well a high-sugar diet is a high-fat diet. That's the point." In this process, reactions occur in the liver that interfere with the insulin processes, which means the liver becomes insulin resistant. Other reactions cause problems such as:

• high blood pressure
• gout
• dyslipidemia
• non-alcoholic steatohepatitis
• muscle insulin resistance
• inflammation of the liver
• hepatic insulin resistance
• over-working of the pancreas (due to insulin resistance of the muscles and liver)
• increased fat-making (which leads to obesity)
• interference with brain's response to leptin (a chemical that tells your brain that you are full, and leads to decrease in hunger urge)
• a reward signal released in your brain which continues your appetite and thus consumption: "Your brain gets the signal that it's starving even though your fat cells are generating a signal that says, 'Hey, I'm full like all get-out.'"

"So what do we call it, where, when you take in a compound that's foreign to your body, and only the liver can metabolize it, and in the process, generates various problems... What do we call that? We call that a poison."

What do you mean, "fructose is a poison"?
"...chronic fructose exposure alone, nothing else, causes this thing we call The Metabolic Syndrome... So this is the conglomerate of the following different phenomena: obesity, type II diabetes, lipid problems, hypertension, and cardio-vascular disease." As listed above, all of these problems can be caused by the way fructose is metabolized in the liver. Fructose is causing obesity and a host of other problems.

I thought eating fat made you fat!
While fat intake does affect how calories are stored, overall fat intake among American adults has decreased from around 40% in 1960 to around 30% in 2000, yet prevalence of obesity has gone from around 10% to around 30% in the same span of time. So if we're eating less fat as a whole, why are we getting fatter? "We're all eating more carbohydrate." Specifically, we're all eating more fructose because our low-fat cookies and cakes are packed with high fructose corn syrup and sugar (remember sugar is 50% fructose) to make up for the bland taste caused by removing the fat. Remember that 30% of all fructose consumed is stored as fat. Basically, we replaced our intake from fat calories with sugar calories.

But I don't eat cookies and cakes. I must not be eating much fructose.
Unfortunately, this probably isn't true. Sugar and high fructose corn syrup are in practically every ingredient list you read, especially high fructose corn syrup because it's cheap. "...it's so cheap that it's found it's way into everything. It's found it's way into hamburger buns, pretzels, barbecue sauce and ketchup, almost everything...So we are being poisoned by this stuff, and it's been added surreptitiously to all of our food, every processed food."

Then, how much fructose do I consume in a day?
A lot more than people used to consume. According to a 2008 study, "Adolescents (12 - 18 years of age) had the highest intake (72.8 g/day, or 12.1% of total energy intake). For 25% of adolescents, at least 15% of energy consumed came from fructose." In 1977, data shows that "...mean estimated fructose intake was 37 g/day, or 8% of total intake." Therefore, fructose intake (at least for adolescents) has increased by about 35.8g/day from the invention of HFCS to 2008. "...this [high fructose corn syrup] is something we were never exposed to before 1975, and, currently, we are consuming 63 pounds per person per year."

What about the epidemic of obese infants? How could they eat a lot of fructose?
"We have an epidemic of obese 6-month olds. Now if you wanna say that it's all about diet and exercise, then you have to explain this to me. So any hypothesis that you wanna proffer that explains the obesity epidemic, you've got to explain this one too." (See Kim et al, Obesity 15:1107, 2006 for more information). Baby formula is full of sugar. "It's a baby milkshake. Soda, Coca-cola is 10.5% sucrose. Formula is 10.3% sucrose." While they may also be getting helpful nutrients from formula, they are also ingesting a very high amount of sugar. Additionally it is being shown that the earlier you expose children to sugar, including in the womb, the more they crave it later.

Well why is fructose in everything?
As discussed before, it in part replaced the flavor that was removed when fat was removed from our processed foods. This is not the whole story, however: sugar didn't just replace the fat. "...U.S. farmers now produce 3,900 calories per U.S. citizen, per day. That is twice what we need, and 700 calories a day more than they grew in 1980. Commodity farmers can only survive by producing their maximum yields, so they do. And here is the shocking plot twist: as the farmers produced those extra calories, the food industry figured out how to get them into the bodies of people who didn't really want to eat 700 more calories a day...Most of these calories enter our mouths in forms hardly recognizable as corn and soybeans, or even vegetable in origin: high-fructose corn syrup (HFCS) owns up to its parentage...our HFCS [consumption] is up by 1000 percent" (Kingsolver, 14-15).

Isn't sugar better for you than high fructose corn syrup?
"High fructose corn syrup, sucrose, it's a non-issue. It's a wash. They're the same." "They're both equally bad. They're both dangerous. They're both poison." "The real issue is that excessive consumption of any sugars [as opposed to just high fructose corn syrup] may lead to health problems" (Center for Science in the Public Interest, Press Release Feb 6. 2008). This is important to know when you look at many organic products. They usually contain cane sugar instead of HFCS, but this doesn't make much of a difference (if any) in the health affects caused by the consumption of the product.

If fructose is in fruit, does that mean fruit is bad for you?
No. Why? Because fruit has a lot of fiber. "Wherever there's fructose in nature, there's way more fiber. Did you ever see a piece of sugar cane? It's a stick." This is why fruit is healthy, despite its fructose content. "Fiber: reduces rate of intestinal carbohydrate absorption, reducing insulin response; increases speed of transit of intestinal contents to ileum, to raise PYY 3-36, and induce satiety; inhibits absorption of some free fatty acids to the colon, which are metabolized by colonic bacteria to short-chain fatty acids (SCFA), which suppress insulin." In laymen's terms, this means it lowers your insulin levels (remember high levels cause insulin resistance), causes you to feel full (so you don't overeat), and reduces insulin production (again, helping to counteract insulin resistance).

Well don't processed foods with sugar/HFCS have fiber?
Not really. "We as human beings, walking the Earth 50,000 years ago, used to consume 100 to 300 grams of fiber per day. We now consume 12... We took the fiber out. So why'd we take the fiber out? It takes too long to cook, it takes too long to eat, and shelf-life." Products last longer with less fiber, so most processed foods have great shelf-lives but no fiber.

What about alcohol, isn't alcohol mostly sugar?
Yes. "How do you make ethanol? Naturally. Right, you ferment sugar. Hasn't changed, 'cause it has all the same properties, because it's basically taken care of by the liver in exactly the same way and for the same reason, because sugar and ethanol are the same, every which way you turn." 20% of ethanol (the kind of alcohol we drink) consumed will be absorbed/used by the stomach, intestines, kidney, muscles, and brain. 80% of calories go to the liver. Initially, the ethanol is converted to acetaldehyde, a substance that cross-links proteins (which can cause cirrhosis of the liver) and is carcinogenic (which means it can cause cancer). The more alcohol you consume, the more acetaldehyde is produced. This acetaldehyde is processed into citrate (which we saw in the glucose process as well - remember that citrate is broken down to create vLDL which causes heart disease and affects obesity). While in the glucose reaction only half of a calorie becomes vLDL, in an ethanol reaction, a large amount of vLDL is produced, because 80% of the calories reach the liver, where in a glucose reaction, only 20% of calories reach the liver. In this process, other reactions occur which can lead to such health problems as: dyslipidemia, muscle insulin resistance (which can lead to diabetes), alcoholic steatohepatitis, and inflammation of the liver. Does any of that sound familiar? That's because sugar/HFCS and alcohol consumption cause the same problems on a metabolic level. Sugar/HFCS and alcohol consumption are both linked to:

• hypertension
• myocardial infarction
• dyslipidemia
• pancreatitis
• obesity
• hepatic dysfuction (non-alcoholic/alcoholic steatohepatitis)
• fetal insulin resistance
• habituation, if not addiction

Fructose is "alcohol without the buzz" because it produces the same metabolic health problems, but it is not metabolized by the brain (which causes the buzz). Since both cause weight gain, in some ways it is just "beer belly vs. soda belly." However, it should be noted that while both fructose and alcohol are processed in similar ways in the liver, alcohol itself is a carcinogen, not to mention the carcinogenic substances that are produced as it is processed in the liver or the cells it kills/mutates by being in the body. The major difference between fructose and alcohol lies in the fact that fructose is in no way (as far as I have read/reasearched) a carcinogen. Look for future posts for more information on how alcohol affects the body.

Alcohol is regulated by the government. If it's bad for you, why isn't sugar regulated?
The FDA is in charge of regulating food additives. They give HFCS GRAS (generally regarded as safe) status. According to FDA definitions on what constitutes a safe food additive, "A food shall be deemed to be adulterated if it bears or contains any poisonous or deleterious substance which may render it injurious to health." However, this does not apply to chronic [long-term] disease. The acute [short-term] symptoms of alcohol are many: 

• CNS depression
• decreased BP
• hypothermia
• tachycardia
• myocardial depression
• variable pupillary responses
• respiratory depression
• diuresis
• hypoglycemia
• loss of fine motor control

The acute symptoms of fructose consumption are none. The FDA only regulates acute toxins, and fructose is not an acute toxin.

What about exercise? Even if sugar makes you fat, I can burn it off, right?
Not exactly. We've all been raised on the principle: "If you eat it, you better burn it, or you're gonna store it." However, no one ever really goes into the details of this rule. While you can burn calories through exercise, the amount of activity required to burn off a noticeable number of calories is exorbitant. "Why is exercise important in obesity? Because it burns calories? Come on. 20 minutes of jogging's one chocolate chip cookie. You can't do it!...I mean, one big mac, you know, you've gotta, you know, mountain bike for 10 hours."

Well if I can't burn much fat by exercising, what's the point?
Exercise is still very important. While it doesn't really burn enough calories or fat to be worth the time, it does do the following things:

• improves skeletal muscle insulin sensitivity (which helps bring your insulin levels down)
• reduces stress, and resultant cortisol release (which also reduces your appetite)
• causes the TCA cycle (this is how your body makes energy) to run faster and detoxifies fructose (basically this means your metabolism gets faster, and your liver is less insulin resistant (along with lower instances of all other fructose related problems))

In other words, exercise helps with insulin levels, appetite, metabolism, and processing of sugar intake (all of which can lead to weight loss), but it does not really burn a substantial number of calories.

Then what do I do?
For me, in theory this information means no more sugar. In practice, really it means very little sugar. But how can we go about decreasing the sugar in our diets? Like Lustig said, it's in everything. Well here is what he recommends to start:

• get rid of all sugared liquids--only water and milk
• eat your carbohydrate with fiber
• wait 20 minutes for second portions
• buy your screen time minute-for-minute with physical activity

Lustig has achieved great results with children at combating obesity and other fructose-caused health problems with these methods. What else can you do? See my next post for more tips and tricks to get sugar/HFCS out of your diet. In the mean time, check out these resources:

To see the full video and follow along with the slides:
Sugar: The Bitter Truth
Lustig Slides (be sure to check out all the studies he cites if you want more information, FYI: these are not the exact slides as those used in his lecture, although similar)

To view parts of the video:
Fat makes you fat vs. sugar makes you fat: 29:00-36:20
Glucose vs. Fructose 43:00-45:00
Bio-chemistry of how glucose, fructose, and alcohol are metabolized in the liver: 45:00-1:09:00
Argument that high blood pressure epidemic is caused by sugar: 59:00-1:00:40
Why diet and exercise are important: 1:09:40-1:13:00
Fiber and how it detoxifies sugar: 1:13:00-1:16:00

Other resources:
Substituting Honey for Refined Carbohydrates Protects Rats from Hypertriglyceridemic and Prooxidative Effects of Fructose
Fructose Intake Has Increased to More Than 10% of Daily Energy in U.S. Diet
How bad is fructose? 
Pure, White and Deadly by John Yudkin (recommended in the video)
Animal, Vegetable, Miracle: A Year of Food Life by Barbara Kingsolver with Steven L. Hopp and Camille Kingsolver, HarperCollins, 2007.