Tuesday, January 12, 2010

The fructosification (and poisoning) of America

Here’s a “Mini medical school” lecture by Dr. Robert Lustig from UCSF:

In case you don’t have 90 minutes to watch this, this is what I learned:
  • The obesity epidemic in the U.S. has coincided with our drastic increase in consumption of SUGAR (both from fructose in high fructose corn syrup, and sucrose in regular table sugar. See structures below -- sucrose is fundamentally fructose). We now have an epidemic of obese 6 month olds (pregnant women eat more sugar --> crosses the placenta --> changes adiposity in fetus before birth).  

Molecular structure of glucose (in pasta), fructose (in high fructose corn syrup, fruits), and sucrose (table sugar, from sugar cane): 
Sucrose = fructose + glucose --> Sucrose IS fructose. 

  • Our biggest mistake is thinking that calories in = calories out. This is NOT TRUE and we have to stop thinking this way. A calorie is not a calorie. Different molecules act differently in our bodies. There exists good protein and bad protein, good fats and bad fats, good carbohydrates and bad carbohydrates. Glucose (the carbohydrate in pasta) is a good carb, while fructose/sucrose (the carb in high fructose corn syrup and table sugar) is a POISON
  • When we took fat out of our diets (to prevent cardiovascular disease), we replaced it with fructose. High fructose corn syrup is cheap, sweet, and we like it. It is now in nearly all processed foods: snack foods, buns, breads, sauces, ketchup, gatorade, chocolate milk, the list goes on (check out the ingredients list on your food at home – shocking!). There are only 7 things on the menu at McDonalds that do not contain fructose: French fries, hash browns, chicken mcnuggets, sausages, diet coke, coffee, iced tea. (And if you add ketchup or dipping sauce or a sugar packet, it’s off the list.) 
  • Fructose, in particular, is bad for us because:
    • Fructose causes “browning” from advanced glycation end-products. This is why some fruits will turn brown when left out, and this is what it does to our arteries.
    • Fructose does not suppress the hunger hormone, ghrelin. 
    • Fructose does not stimulate insulin, so insulin doesn’t go up, and leptin (the hormone that signals to your brain that you are full so stop eating) does not go up, so you feel hungry despite having adequate calories. 
    • The metabolism of fructose is different. While glucose is used by every cell, fructose can only be metabolized by the liver. Because of the way fructose is metabolized, it eventually turns into fat, and chronic fructose exposure leads to metabolic syndrome (high blood pressure, insulin resistance, obesity, leptin resistance, lipogenesis). It increases lipogenesis while your brain still thinks you’re hungry. 
Summary so far:
***Fructose is poisoning us*** 
  • The ancestral human diet is termed the “Paleolithic Diet” (more on this in a later post, but it basically means eating like a hunter-gatherer: eating everything as it came out of the ground RAW). On this ancestral diet, the fructose intake from fruits and vegetables is about 15 grams/day and fiber intake about 100-300 grams/day. Today, the average fructose intake is over 70 grams/day, and fiber is about 12 grams/day. Dr. Lustig claims that going on this Paleolithic Diet -- and thus increasing intake of fiber to about 300 grams/day -- would CURE Type 2 diabetes. And it would take about a week. 
  • So, what to advise patients (and ourselves): 
    1. CUT OUT SUGARY DRINKS. For all the reasons above. 
    2. EAT FIBER WITH CARBOHYDRATES. Wherever there is fructose in nature, there is fiber (think about how much fiber is in natural sugar cane). Fiber makes us feel satiated, it inhibits absorption of free fatty acids, it suppresses insulin, and it reduces intestinal carbohydrate absorption. This is why eating fructose in fruits and vegetables is okay. 
    3. EXERCISE. But NOT because it “burns calories.” It has nothing to do with that! It’s because exercise improves skeletal muscle insulin sensitivity, increases metabolism, and reduces stress (which reduces appetite). 

Natural sugar cane = fiber. 
Eat fiber with sugar. 


  1. corn syrup(worstest food piece ever invented)

  2. thanks for the summary!!!!! still haven't had time to watch it, but this really helps.

  3. Thanks, Jen! Yeah I think you will like it. Let me know if you or Sean had any more ideas about juicing and all the fructose we consume (without fiber) in that.

  4. Great summary of this presentation. I just watched it yesterday and was lucky enough to find your post. Thank you.

  5. Thanks, Barb, so nice to hear from you and glad you found the post. It's a great presentation and I hope more people watch it!

  6. A point was almost made here. There is no difference in eating high fructose corn syrup and table sugar. Table sugar is hydrolyzed immediately in the stomach to fructose and glucose 50% each. High fructose corn syrup is about 45% fructose and 55% glucose. Honey is mostly fructose. Too much of any simple carbohydrate is not good.