Tuesday, February 28, 2012

Just how bad for us is sugar?

In his talk, "Sugar: The Bitter Truth", Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, goes on a jihad against sugar. What to make of it?

Lustig argues that fructose and ethanol are two carbohydrates in a class of their own. The metabolism of these two involves products that are not exactly good for the liver. Moreover, these are chronic toxins, the damage starts showing only after a thousand meals. The results are obesity, diabetes and heart disease. (Perhaps cancer, too.)

The only safe form of fructose is in fruits where it comes in relatively small quantities along with fiber, which slows down its absorption, and along with other nutrients whose benefits outweigh any harm from fructose. Fruit juice is a no-no. Sugar and high-fructose corn syrup are both equally bad.

Less convincing is Lustig's arguments about how fructose, which unlike glucose and other carbohydrates doesn't cause the body to send satiety signals, causes overeating. The simple reason is that in the cases where you overdose on fructose, you get an equal amount of glucose, which presumably will make you feel full.

Alan Aragon has a detailed criticism of Lustig's ideas, "The bitter truth about fructose alarmism".

Gary Taubes, in the NYT (April 13, 2011), agrees with Lustig.