Many years ago when diabetes educators talked to folks about dietary carbohydrate intake lots of emphasis seemed to be placed on sugar intake. I am aware of this because many of my patients who have had diabetes for 20 years or more seemingly can’t take their eyes off of the “sugars” part of the food label.
At some point the American Diabetes Association came out with the position that people with diabetes should worry less about the origin of the carbohydrate and focus their attention more on the total amount of carbohydrate consumed. In my opinion this was a good move as there is enough diabetes associated guilt out there without having to get people bent out of shape because they want to satisfy their sweet tooth now and then.
To me the really cool and frustrating thing about nutrition is that is that the science is so young that even to practitioners “the rules seem to be changing all of the time.” The latest research indicates that increased intake of dietary fructose results in visceral adiposity, lipid dysregulation and decreased insulin sensitivity which ends up increasing the risk for cardiovascular disease. So, is there such a thing as a “good carb” and “bad carb”?
At first glance this fructose discussion seems kind of trivial because very rarely does one consume pure fructose. For example the carbohydrate in an orange is only 25% fructose while sucrose and high fructose corn syrup are 50% fructose. The rub in all of this for the “average” person is volume of fructose containing sugars available for consumption has increased by close to 20% since 1970.
Some of you might be familiar with Robert Lustig who is a pediatric endocrinologist at UCSF. A few months ago he was part of a fascinating 60 Minutes piece on “Sugar.” Dr. Lustig is also well known on the internet for delivering a lecture called “Sugar- The Bitter Truth” where he outlines in great detail why fructose is in his opinion a “poison.” In both of these spots Dr. Lustig very convincingly argues about the metabolic evils of fructose. However, to me, listening to Dr. Lustig is pretty much like listening to an MD version of Newt Gingrich. The messenger is so pompous that it is somewhat difficult for me to hear the message.
Dr. Lustig has a PhD counterpart at UC Davis named Kimber Stanhope who seems to be just as smart as he is, but is quite humble in her delivery. Accordingly, when she told the folks from 60 Minutes that her research has prompted a dramatic drop in her personal consumption of sugar, I listened up and dug into the literature a bit.
Any of you avid Diabetes Care readers might have noticed a July 2012 paper called “Effect of Fructose on Glycemic Control in Diabetes” which is a meta-analysis of how dietary fructose impacts glucose control. My guess is that all of Dr. Lustig’s pontificating on fructose prompted this review. The unfortunate thing about this review is that it only addresses glycemic control; it does not really address sugar and cardiovascular disease risk. However, in 2009 under the veil of controlling calorie intake, the American Heart Association actually recommended that American women and men limit their daily added sugar intake to no more than 100 and 150 calories respectively.
Stay tuned… I am sure that there is much more on this topic coming soon!
References:
60 Minutes Piece on Sugar
http://www.cbsnews.com/video/watch/?id=7403942n
Sugar the Bitter Truth
http://www.youtube.com/watch?v=dBnniua6-oM
Cozma, A. I., et al. Effect of fructose on glycemic control in diabetes. Diabetes Care 35:1611-1620, 2012.
Johnson, R. K., et al. Dietary sugars intake and cardiovascular health: A scientific statement from the American Heart Association. Circulation 120:1011-1020, 2009.
Stanhope, K. L. & Havel, P. J. Fructose consumption: Recent results and their potential implications. Ann N Y Acad Sci 1190:15-24, 2010.