Thursday, September 19, 2013

Sugar: The Bitter Truth

Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin. Series: UCSF Mini Medical School for the Public [7/2009] [Health and Medicine] [Show ID: 16717]


The above video is an in depth look at what went wrong wtih dietary recommendations with regards to low fat diets. It dismisses popular misconceptions about sugar, fructose, fat, and especially what causes obesity.

The following is a brief summary I wrote while watching this. However, this only highlights some major points. the whole video is full of important information, and needs to be watched to appreciate it.
Obesity is not as simple as calories in versus calories burned. The standard model says if you eat it, you better burn it, or you gain weight. This is a mistake. Obesity is not a simple matter of too many calories, and not burning enough off.
Historical trends in fructose consumption:
Before food processing, fructose consumption would be about 15 grams per day.Prior to WWII 16 – 24 g/day.
1977 – 78: 37 g/day
1994 – 54.7 g/day
Adolescents today: 72.8 g/day – 25% consume at least 15% of calories from fructose alone.
It's not just that calories are going up, but fructose is going up.
Why did this happen? Fructose is so cheap, plus something had to be added into the diet to make up for the low fat diets which started in the 1980s. However, a review of the basic science and studies that led to low fat diet, show that theory is wrong. High fat diets do not lead to cardiovascular disease.
These change have led to an adulteration of the food supply through:
  • Addition of fructose
  • Removal of fiber
  • substitution of trans-fats
Key point: fructose is not glucose (table sugar).
  • Fructose forms Advanced Glycation End-Products (AGE's)
  • Fructose does not supress ghrelin (satiation hormone) so people eat more
  • Acute fructose does not stimulate insulin. If insulin doens't go up, leptin doesn't go up, so brain doesn't see you ate.
  • Liver metabolism of fructose is completely different than that of sugar.
  • Chronic fructose expose alone leads to Metabolic Syndrome.
Glucose can be used by every cell in the body. Excess glucose gets converted into glycogen in the liver. Glycogen is not toxic. Some glucose will get converted it fat, but not much. However, fructose can only be metabolized by the liver. Since the liver is forced to metabolized all fructose, this turns fructose into a poison.
He discusses the relationship between fructose, creation of uric acid, gout and hypertension. As sweetened sugared beverages goes up, so does uric acid, gout and hypertension. Studies have shown that reducing uric acid, will lower high blood pressure. Basically, the fructose (not table sugar) is cause hypertension. Fructose will also stimulate creation of fat “High fructose diet is a high fat diet.”
Fructose consumption leads to: hypertension, myocardial infarction, dyslipidemia, pancreatitis, obesity, hepatic dysfunction, fetal insulin resistance and habituation if not addiction.
His interventions:
  • Get rid of all sugared liquids, only water and milk.
  • Eat carbohydrate with fiber.
  • Wait 20 minutes for second portions.
  • Buy your screen time minute for minute with physical activity.
They found this works for childhood obesity, and analysis shows increased sugared beverage consumption is what will make it not work.
Why is exercise important? Not because it burns calories!
  • Makes skeletal muscle more sensitive to insulin.
  • Endogenous stress reducer, and if stress reduce, then appetite goes down.
  • It makes TCA cycle run faster (raises metabolism).
Why is fiber important in obesity?
In nature fructose always comes with fiber. That's why fruit is ok. Fiber limits amount of carbohydrate absorbtion. Increases speed of transit of intestinal content to ileum. Inhibits absorption of some free fatty acids to the colon, which are metabolized by colonic bacteria to short chain fatty acids, which suppress insulin.

He compares fructose to alcohol and called fructose, " ethanol without the buzz.” Makes the point that biochemically, they are basically the same thing in terms of A low fat diet is not really a low fat diet, because the fructose doubles as fat. So its a high fat diet. In addition, fructose is also a toxin.

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