Saturday, January 2, 2010
Obesity is an epidemic around the world, even, apparently among children as young as 6 months old, and of course, continuing through adulthood. I'm probably going to hear from the corn and cola lobbies, but I just finished watching a talk given by Dr. Robert Lustig, Professor of Clinical Pediatrics, in the Division of Endocrinology Director of the Weight Assessment for Teen and Child Health (WATCH) Program at University of California, San Francisco, www.chc.ucsf.edu/coast/faculty_lustig.htm, It turns out that the chubbers epidemic is not mainly about lack of exercise or fat intake. It's about carbohydrates. Specifically, fructose may be the true villain. And we've put it into so many of our foods and beverages, because it's cheaper and sweeter than regular sugar.
The funny thing is, I remember hearing people say, "fructose is not as bad as sugar because it's fruit sugar." If it's from fruit, it must be good for us. And there's an entire advertising campaign out there right now sponsored by the corn refiners association designed to make you think anything you've heard about fructose being bad for you is, well, just plain ignorant. You can see the ads in the video clip at the bottom of this post. But guess what? Fruit sugars naturally present in the fruit we eat do not have the same effect on us as eating fructose. Fructose is processed differently by your body. Here is a quote I admit that I lifted from Wikipedia, http://en.wikipedia.org/wiki/Fructose, (students, do not cite Wikipedia in your papers without chasing down the original citation and verifying it; even though I did this in my blog, I will grade you down for this!):
"The medical profession thinks fructose is better for diabetics than sugar," says Meira Field, Ph.D., a research chemist at United States Department of Agriculture, "but every cell in the body can metabolize glucose. However, all fructose must be metabolized in the liver. The livers of the rats on the high fructose diet looked like the livers of alcoholics, plugged with fat and cirrhotic." ...
"When fructose reaches the liver," says Dr. William J. Whelan, a biochemist at the University of Miami School of Medicine, "the liver goes bananas and stops everything else to metabolize the fructose." Eating fructose instead of glucose results in lower circulating insulin and leptin levels, and higher of ghrelin levels after the meal. Since leptin and insulin decrease appetite and ghrelin increases appetite, some researchers suspect that eating large amounts of fructose increases the likelihood of weight gain.
Excessive fructose consumption is also believed to contribute to the development of non-alcoholic fatty liver disease."
And the whole thing is made more complicated by the food industry, because it routinely combines fructose with other chemicals - salt and caffeine, for example - that leads both to weight gain through overconsumption of calories, but also something more nefarious -changes in our bodies' ability to process the calories we take in.
Dr. Lustig does a good job of making a pretty complicated scientific topic readily accessible. WARNING: This video is an hour and a half long. But put aside the time, or watch it while you're eating lunch, folding laundry or whatever. PLEASE make the time to watch this video.
While you're at it, go ahead and watch this one, created by Advertising Age, deconstructing the ads by the corn syrup producers, and showing you the vast range of processed foods containing fructose.
54. Forristal, Linda (Fall 2001). "The Murky World of High-Fructose Corn Syrup". Weston A. Price Foundation. http://www.westonaprice.org/motherlinda/hfcs.html.
55. Teff, KL; Elliott SS, Tschöp M, Kieffer TJ, Rader D, Heiman M, Townsend RR, Keim NL, D'Alessio D, Havel PJ (June 2004). "Dietary fructose reduces circulating insulin and leptin, attenuates postprandial suppression of ghrelin, and increases triglycerides in women". J Clin Endocrinol Metab. 89 (6): 2963–72. doi:10.1210/jc.2003-031855. PMID 15181085.
56. Swan, Norman; Lustig, Robert H. "ABC Radio National, The Health Report, The Obesity Epidemic". http://www.abc.net.au/rn/healthreport/stories/2007/1969924.htm. Retrieved 2007-07-15.
57. Ouyang X, Cirillo P, Sautin Y, et al. (June 2008). "Fructose consumption as a risk factor for non-alcoholic fatty liver disease". J. Hepatol. 48 (6): 993–9. doi:10.1016/j.jhep.2008.02.011. PMID 18395287.