This is a summary of several interviews and talks by Dr. Robert Lustig, professor of pediatrics in the Division of Endocrinology, University of California, San Francisco.
The good news is that it’s fine to get your sugar embedded in fiber – in fruit that is. It’s processed sugars that are the problem.
The reason fiber is important is that fiber delays the absorption of sugar so your liver has a chance to catch up. Fiber keeps your liver healthy. If your liver is healthy, your pancreas doesn’t have to make as much insulin to help the liver do its job, and you’re far less likely to get Type 2 diabetes, become obese, get hypertension, heart disease, fatty liver disease, polycystic ovarian disease, and some early data indicates, less likely to get cancer and dementia as well.
Lustig makes the following points:
- On average Americans are 25 pounds heavier now than 25 years ago
- It’s not that there’s more food available – food was around tempting people before.
- And we reduced fat consumption from 40 to 30%
- Yet strokes, heart attacks, and type 2 diabetes have gone up!
- We’re eating 450 extra calories of sugar per day, not counting fruit
- Sugar is addictive and needs to be regulated. Lustig says that “Numerous studies, both in animals and humans, show that the area of the brain, the reward center, is affected by sugar the same way it is by tobacco, alcohol, nicotine, cocaine, heroin, and therefore it fosters continued consumption”.
Normally, the hormone leptin tells your brain you’re full and you stop eating. It wasn’t hard at all to maintain a good weight in the past because of this “you’re full” signal. But that’s not happening anymore, leptin isn’t doing its job. Why? What changed?
High fructose sugar was introduced to America in 1975, and was so cheap it found its way into just about every manufactured food product, because low fat processed food tastes like crap. How do you make something with no fat palatable? Add sugar! Which is the worst thing you could do, and we’re still doing it.
Incredibly, the USDA, AMA, and AHA based the need to cut fat on just one study by one person who didn’t interpret the data correctly.
There are 2 types of LDL. The small one is the harmful one, the medium sized is neutral, but the tests are so expensive that they aren’t done. So you should ignore your LDL stats and focus on triglyceride (which should be low) and HDL (which should be high).
It turns out that fructose causes your body to create the bad LDL fat.
It’s okay to have fructose embedded within fruit – fiber protects you from any harm. A long time ago we used to eat 100-300 grams of fiber a day, but now we eat just 12 grams – half the daily requirement, which Lustig thinks ought to be much higher. Why would industry do this? Because by removing fiber, food is easier to freeze, ship, cook, eat, and extends its shelf life. You can almost define fast food as having no fiber.
Fiber ought to be considered an essential nutrient, but the food industry has successfully fought off this requirement, or they wouldn’t be able to sell food abroad.
I’m going to spare you the details of the half hour on the biochemical pathways of how sugars and alcohol are processed in the liver. But this part made me vow to avoid fructose (glucose is okay) and alcohol very much!
The upshot is that fructose harms us in many ways.
- It interferes with the hormones that tell our brain we’re full
- It is processed similarly to alcohol, which is a poison, and causes 8 of the same 12 diseases seen in chronic alcohol consumption
- In the end, it results in the bad LDL that clogs your arteries and promotes Metabolic Syndrome: obesity, type 2 diabetes, hypertension, and heart disease.
- 30% of fructose converts to fats – you’re not consuming carbohydrate, you’re eating fats, a high-fat diet!
Lustig laughs at the idea that exercise helps you burn calories. One cookie is 20 minutes of jogging, a big Mac is 10 hours on the exercycle. Not going to happen. What exercise does is change your metabolism in 3 key ways, one of them is burning fat off in the liver before it can become body fat.
His advice to parents
- Get rid of all sugared liquids – only water and milk.
- Eat your carbohydrate with fiber because fiber is good for you, it’s an essential nutrient
- Wait 20 minutes before 2nd portions
- Buy your screen time with physical activity – 1 hour of exercise to spend 1 hour on the computer or TV
Ira Flatow asked Lustig why we evolved to eat sweet foods like honey and fruit? Lustig’s reply: “We as human beings really only had sugar available to us one month a year, it’s called harvest time. And the fruit would fall to the ground, we’d gorge on it, consume it like crazy. That would increase our adiposity, it would increase our fat stores very specifically. And then what would come after that? Four months of winter, no food at all. And so putting on those extra pounds in advance of a four-month famine was actually adaptive and actually let us make it through winter so that we could repeat the cycle all over again. It was actually metabolically and evolutionary adaptive. The problem is that we now have a maladaptive situation because sugar is available 24/7, 365 in amounts that has never been known to man previously.”
Additional nutrition videos and reading
(see more diet & nutrition videos here: UCTV diet & nutrition videos)
A more nuanced discussion (long) about sugar is at: Gary Taubes. 13 Apr 2011. Is Sugar Toxic? New York Times.
My notes from the video lecture
Coca cola is 10.2% sucrose
The more you expose children to sugar, the more they’ll want it later. In womb, mother’s too much sugar gets into fetus causing problems later.
You’d never give your kid a Budweiser, but sugar and beer belly the same through the same biochemical pathways, sugar is alcohol without the buzz.
Fructose is a carbohydrate metabolized like a fat, it’s a high-fat diet. It’s also a toxin.
What can we do? Anything? How about the FDA? Aren’t they supposed to regulate our food?
High fructose corn syrup (HFCS) was invented in 1965, reached the American market in 1975, because it was half the price of sugar. It is so cheap it’s found its way into everything. Hamburger buns, pretzels, ketchup, out of 32 types of bread, only 1 didn’t have HFCS. It’s added surreptitiously to every packaged food. .
Juice is sucrose, it causes obesity. Increases risk for diabetes type 2.
Soft drink up 35%, fruit drinks up. 1 can of soda a day is 15 lbs per year.
Why doesn’t the leptin work?
“The Coca Cola conspiracy”: salt makes you thirsty, caffeine makes you pee, now you get thirsty again, the sugar hides the salt. They know what they’re doing.
Orange juice and other juices didn’t cause as much weight gain.
63 pounds per year of high fructose corn syrup. Fructose because it’s sweeter than sucrose. Glucose 74, sucrose 100, glucose 120.
Used to get our fructose from fruit.
1977 – 37 gram/day 8% of calories
1994 55 g per day (10.2%)
not just eating more food, eating more sugar
141 lbs of sugar per year per person. Do you think it might have some detrimental effects? Yet it hasn’t stopped you.
If 335 cal/day > than before you wouldn’t be doing it. Our biochemical negative feedback system isn’t working, why?
USDA, AMA, AHA less fat in diet, to stop heart disease.
Why did they tell us to stop eating fat?
LDL. But maybe it’s not so bad. There are 2 types. It does correlate with heart disease, but not pattern A ldl. This kind of LDL is so light, so huge, they float, they never get under the edge of endothelial cells to start plaque. But the other kind, the small ones, do. LDL is BOTH, the neutral and bad one but tests don’t separate them out because it’s too expensive to separate them. But you can guess by looking at triglyceride level.
Low triglyceride, high HDL is GOOD.
Triglyceride to HDL level predicts heart attack way better than LDL ever did.
What raises your small dense LDL? Carbohydrates! We’ve gone on a low fat, high carb diet.
1972 pure white and deadly Yudkin. (about sugar, very prophetic).
Another guy – % calories from fat correlated with coronary disease.
Japan is at the bottom – hey – they don’t eat sugar. Italy low too, not much sugar, their sweets are moderate and expensive. So maybe it wasn’t fat, it was sugar. Well, many problems with his research. We based 30 years of nutrition and policy on this study.
Sugar added also because it’s a Browning agent (contributes to ather)
Removal of fiber from food.
Used to eat 100-300g of fiber a day. Now 12. Why? Too long to cook, eat, and shelf life.
Definition of fast food: no fiber. On purpose. They can freeze it, ship it, fast cooking, fast eating.
Long shelf life
Sub of trans fats for hardening agent, shelf life, now finally being removed.
Fructose is not glucose
What the liver does to fructose is different from glucose
7x more likely than glucose to brown like on your grill and clog your arteries (AGEs Advanced Glycation End-Products)
Fructose does not suppress ghrelin, the hunger hormone.
Acute fructose does not stimulate insulin, if insulin doesn’t go up, then leptin doesn’t go up, so your brain doesn’t register you’ve eaten something, so you eat more
Hepatic fructose metabolism is different
Chronic fructose exposure, alone, promotes the Metabolic Syndrome – obesity, type II diabetes, hypertension, cardiovascular disease, and x
120 calories of glucose – 98% used in body, every cell, every bacteria can use it. What we’re supposed to eat. 20% of those calories will hit the liver. Long biochemical explanation of details of what happens. Glycogen eventually.
How much glycogen can your liver store before it gets sick. Any amount. Not a problem.
Maybe half a calorie ends up as the bad LDL (out of 24). Your brain sees the insulin, knows it’s eating breakfast, doesn’t need lunch. Your body keeps you in balance, not dangerous, what’s supposed to happen.
Ethanol is a carbohydrate. Also a toxin, a poison. You can fry your liver. Not good for you.
Acute ethanol exposure: depression of central nervous system, hypothermia, myocardial depressin, respiratory depression, diuresis, hypoglycemia, tachycardia, loss of motor control.
Chronic ethanol exposure: hematologic disorders, electrolyte abnormalities, hypertension, cardiac dialation (?), cardiomyopathy, dyslipidemia, pancreatitis, malnutrition, obesity, hepatic dysfunction, fetal alcohol syndrome, addiction
Chronic fructose exposure: same as 8 out of the 12 above for ethanol!
Hypertension, myocardial infarcation, Dyslipedimia, Pancreatitis, obesity, hepatic dysfunction, fetal insulin resistance, habituation if not addiction
Why? Because they metabolize the same way. Alcohol is made by fermenting sugar. Sugar and ethanol are the same.
The more soft drinks patients had been drinking the less the above worked.
Why is exercise important in obesity?
Not because it burns calories – 20 minutes of jogging to burn one cookie. You can’t do it. One big mac and mountain bike for 10 hours.
It improves skeletal muscle insulin sensitivity
Reduces stress and resultant cortisol release. Appetite goes down with less stress.
Makes the TCA cycle run faster and detoxifies fructose, improving hepatic insulin sensitivity. You burn the fat off before it becomes fat.
Why is fiber important in obesity?
Fructose is a poison. Wherever there’s fructose in nature, it’s embedded in fiber.
This is why fruit is okay. It limits the amount of fructose and you get some micronutrients.
1) reduces rate of intestinal carbohydrate absorption, reducing insulin response
2) increases speed of transit of intestinal contents to ileum to raise PYY and induce satiety, tells brain you’re full faster.
3) 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
Alcohol gets metabolized in the brain. This is why it’s taxed and 150 years of alcohol control policy because it’s a toxin and we know it. Biochemical talk on 120 calories of ethanol. 96 of 120 calories will hit liver (4x the amount as glucose), this is the rub, a volume issue. Converted to acidaldehyde – bad like formaldehyde, can cause cancer, cross-links proteins. Bad. Generates reactive oxygen species, damages proteins in the liver. This is why alcohol is bad. A whole lot of citrate in the end (also happened with glucose, but much much more to LDL with alcohol). Can make muscles work less well, diabetes. Causes inflammation which does bad stuff to your liver too.
Fructose biochemistry. 120 calories fructose from glass of OJ. Only the liver can metabolize fructose and in the process generates various problems is called a poison. No insulin. Before 24 calories, now 72 that need to be phosphorilated, a problem. Waste product is uric acid, causes gout and hypertension. And it does, it increases gout. And systolic blood pressure (hypertension). Sports drinks high fructose because you’re short on glycogen, can be replaced faster than with glucose. Unless you’re an elite athlete, drinking these makes no sense. 1977 Gatorade. Many biochem steps later bad LDL.
Glucose: almost none ends as fat, fructose, 30% ends up as fat. You’re not consuming a carbohydrate, you’re consuming fat, it’s a high-fat diet!!!!!
Some of the fat won’t make it out of the liver like with ethanol. Bad. Ultimately liver insulin resistance, makes pancreas work harder, higher insulin levels, higher blood pressure, more fat making, and finally the less well your brain can see its leptin, so it doesn’t tell you you’re not hungry anymore and you eat more. You think you’re starving even though your fat cells are full. High insulin generates diabetes. Leptin should turn everything off but insulin gets in the way. And many more bad things. Vicious cycle. Metabolic syndrome.
Hypertension epidemic in our country is caused by FRUCTOSE.
Fructose doesn’t do any of this, it’s not metabolized in the brain.
Can you name the 7 foodstuffs at MacDonald’s that don’t have HCFS or sucrose?
French fries, hash browns, chicken mcnuggets without dipping sauce, sausage, diet coke, coffee, iced tea
Berkeley Farms low fat milk 16g of sugar is okay because not fructose, but 29 g sugars (fructose a lot of it) in chocolate low fat milk
We all know Coca-cola and other sodas have way too much sugar and caffeine, but the reason there’s so much sugar is to hide the huge amount of salt. The salt makes you thirsty, the caffeine makes you pee, so you drink another coke. Lustig looked at the audience and said, “They know what they’re doing,” and said they’re a lot like the tobacco industry.
Best and most recent podcast and transcript of Lustig speaking: NPR. 17 Feb 2012. “Should Sugar Be Regulated Like Alcohol?“. Talk of the Nation.
A review of a Video of Dr Rob Lustig, neuro-endocrinologist at the University of California, San Francisco” Sugar the bitter truth.
Sugar meets all the scientific criteria for being addictive, your cereal may as well be laced with morphine, Dr Lustig implied on KQED’s Forum with Michael Krasny.
One of the two top science journals in the world, Nature, published an opinion piece 2 Feb 2012 by Lustig here: The toxic truth about sugar. Added sweeteners pose dangers to health that justify controlling them like alcohol.