The bullshit about high fructose corn syrup (HFCS) is getting pretty thick. Health care professionals have cautioned us against over-consumption of the stuff, and the corporate public-relations jackals have swooped in to do damage control.
"It's made from corn," they say. "It's nutritionally the same as sugar."
This reminds me of that classic film, Thank You for Smoking, and it only goes to prove that you can support any claim, no matter how ludicrous, if you massage the data enough.
If the warm and fuzzy reassurances of the corn syrup industry have left you unconvinced that their gloopy crap is good for you or your family, then read on. I'm going to lay down the hard facts. HFCS may be sweeter than sugar, but when it comes to your health, it's not so freakin' sweet. At all.
Any sugar that contains fructose is especially problematic from a health perspective. Despite its name, HFCS isn't as "high-fructose" as you might think. Depending on the type, it's generally 42 to 55 percent fructose.[3] The former is common to solid foods, and the latter to beverages. Just as the PR jackals claim, it's chemically similar to table sugar, which is 50 percent glucose and 50 percent fructose.
Sucrose is very similar to corn syrup.
Although these sugars don't have the extremely high glycemic index of raw glucose, they do cause a combination of hyper-insulinemia and aberrant intracellular metabolism, which in turn creates the double-whammy of lipogenesis (fat creation) and glycation (gummed up body proteins). More on all this later. For now, it's enough to know that fructose-containing sugars are not so good.
With the faster gastric emptying [7, 9] and greater blood sugar swings compared to solid meals, liquids are themselves a consideration. Although the literature isn't unanimous on this, simply drinking one's calories creates a positive energy balance.[8] That is, anyone who drinks his calories in fluid form is less likely to down-compensate his intake in later meals.
The natural regulation of daily energy intake gets disrupted. Although this can be used to one's advantage (e.g. bulking), it can also be bad. Whatever you might have heard, all calories are not created equal: carbohydrates as a class are more "fattening" than proteins.[6, 16, 17]
Sure, you can find data that HFCS beverages are not different in satiety value than sucrose drinks, or even milk, [23] but we really need to consider the type of nutrients in those drinks. If they all similarly create positive energy balance, I think I'll choose nutrient-rich milk.
Straight liquid carbs like high-fructose corn syrup or sucrose solutions are digested and metabolized in a particular way, and they're the number one choice of thirsty Americans. Sports supplement drinks and popular beverages are loaded with them. We've all read labels that say, "contains less than 5 percent juice." This is marketing-speak for "fake."
Let me ask you this: where in nature could our hunter-gatherer ancestors quickly guzzle down 100 grams of sugar? You guessed it, nowhere. It just ain't natural. It astounds me that the human body can even deal with a Super Big Gulp. And actually, it doesn't deal with it very well.
The modern-day hunter-gatherer returns with his quarry.
When a human being quickly introduces that much sugar, his body does what it must: turn it into triglycerides (fat). I've seen some disturbing blood work after ingestion of a fat-free, high-fructose meal, in which the subjects' blood values looked like they had just wolfed down some fried chicken. How can this be?
Fructose really turns up the lipogenesis by bypassing the most important regulatory enzyme in our carbohydrate biochemistry, PFK-1. This supplies our bodies with a bountiful supply of acetyl-CoA and glycerol, the building blocks of fat.[5]
Fructose in the cellular metabolism: follow the yellow fat road.
Compared to glucose (which you hardly ever find all by itself in the diet), fructose has a much greater tendency to glycate (or glycosylate if you prefer) surrounding proteins. [12, 21] You've probably heard of glycosylation before. Glycosylated hemoglobin (HbA1c) is a common marker of past glucose tolerance, used to test diabetics.
Glycosylation is more than an indicator of someone's blood sugars running high, however. As a broader phenomenon, it's been linked to disrupted cell function and aging.[12, 13] I used to think fructose appearance in the bloodstream was inconsequential (the liver converts most of it to glucose), but in today's HFCS and sucrose-crazy environment, that little 4-8 mg/dl rise in blood fructose day-in and day-out could become an issue. I don't want my DNA or collagen damaged by glycosylation.[12]
Fructose ingestion is especially problematic for the 10 to 30 percent of the population (and 6 percent of college students) who are already insulin-resistant due to metabolic syndrome.[14, 15] This is a collection of visceral fat accumulation, high triglycerides and LDL-cholesterol, low HDL, high blood pressure, and poor glucose tolerance.
It can creep up on middle-aged guys especially. Their central body fat (visceral fat behind the abs) has a higher turnover rate, which lends some extra fatty acids to the new "building blocks" made available by ingested fructose.[11] The end result is even greater lipogenesis, taking place in an individual who already has surplus fat stored in the worst possible place. Fat begets fat. It's a vicious cycle, which needs to be turned around by sugar reduction, exercise, and medical intervention.
From both a biochemical standpoint, as we've discussed, and from an epidemiological standpoint (obesity trends mirroring HFCS introduction in the food supply), high-fructose corn syrup appears to be a problem.[5, 18]
Epidemiological evidence is not cause-and-effect, of course (a fact the news media overlooks at times), but the HFCS-obesity relationship is suspicious indeed. HFCS consumption has grown 10-fold in recent decades to a whopping 9% of the U.S. calorie intake.[4, 5] And we all know what's happened to the obesity numbers in that time period.
I can barely comprehend that nearly one in ten things Americans now ingest is HFCS. My "health food" granola bars are jam-packed with it. I even tasted some sweetness in some chicken breasts my wife bought. I looked at the label, and you can guess what I found on the ingredients list. HFCS in Chicken breasts! Is nothing sacred?!
But there's more to corn syrup making people fat than just the fact that people eat more of it than ever. We have the uncontrolled glycolytic inundation that we discussed earlier, and here's another fact: fructose actually induces lipogenic enzymes.
According to one study, "long-term absorption of fructose... causes enzyme adaptations that increase lipogenesis and VLDL secretion, leading to triglyceridemia, decreased glucose tolerance, and hyperinsulinemia."[19]
That's right, exposure to fructose prepares the body to do the last thing you want it to do: convert that fructose into fat and store it.
And although there's reason to believe that trained individuals with partly depleted glycogen stores have some capacity to resist fructose's lipogenic effects,[2] even exercise doesn't look like perfect protection, at least in rats: "we conclude that hepatic lipogenic enzyme induction by high carbohydrate meal feeding may be inhibited by exercise training [but] that a fructose-rich diet may attenuate this training-induced down-regulation."[10]
In sum, when something looks like a health problem, and acts like a health problem, guess what? It's a health problem, and public relations be damned. I hope this article has helped you cut through the confusion. Share these facts with your family the next time you see a commercial thanking you for guzzling corn syrup. Corporations have to realize that there are thinking men and women in this world who see their bullshit for what it is, and can answer them back appropriately.
1. Abraha, A., et al. Acute effect of fructose on postprandial lipaemia in diabetic and non-diabetic subjects. British Journal of Nutrition (1998), 80, 169—175.
2. Acheson, K., et al. Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man. Am J Clin Nutr 1988 Aug;48(2):240-7
3. Anderson, H. Much ado about high-fructose corn syrup in beverages: the meat of the matter. Am J Clin Nutr 2007;86:1577— 8.
4. Bantle, J., et al. Effects of dietary fructose on plasma lipids in healthy subjects. Am J Clin Nutr 2000 Nov; 72(5): 1128-34.
5. Bray, G., et al. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. Am J Clin Nutr. 2004 Apr;79(4):537-43.
6. Buchholz AC, Schoeller DA. Is a calorie a calorie? Am J Clin Nutr. 2004 May;79(5):899S-906S.
7. Clarkston, W., et al. Evidence for the anorexia of aging: gastrointestinal transit and hunger in healthy elderly vs. young adults. Am J Physiol. 1997 Jan;272(1 Pt 2):R243-8.
8. DellaValle, D., et al. Does the consumption of caloric and non-caloric beverages with a meal affect energy intake? Appetite. 2005 Apr;44(2):187-93
9. Edelbroek M., et al. Gastric emptying and intragastric distribution of oil in the presence of a liquid or a solid meal. J Nucl Med 33(7): 1283-90.
10. Fiebig, R., et al. Exercise training down-regulates hepatic lipogenic enzymes in meal-fed rats: fructose versus complex carbohydrate diets. J Nutr 128(5): 810-817.
11. Fried S, Rao S. Sugars, hypertriglyceridemia, and cardiovascular disease. Am J Clin Nutr 2003 78(4): 873S-880S
12. Gaby, A., Adverse effects of dietary fructose. Alt Med Rev. 2005 10(4): 294-306.
13. Hipkiss, A. Dietary restriction, glycolysis, hormesis and ageing. Biogerontology. 2006 Sep 13; [Epub ahead of print]
14. Huang, T., et al. Overweight and Components of the Metabolic Syndrome in College Students. Diabetes Care 2004; 27:3000-3001.
15. Israili, Z., et al. Metabolic syndrome: treatment of hypertensive patients. Am J Ther. 2007 Jul-Aug;14(4):386-402.
16. Krieger, J., et al. Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression. Am J Clin Nutr. 2006 Feb;83(2):260-74.
17. Layman, D., et al. (2003). A reduced ratio of dietary carbohydrate to protein improves body composition and blood lipid profiles during weight loss in adult women. J Nutr 133(2): 411-417.
18. Lowery, L. High-fructose corn syrup and the obesity epidemic. Robinson Memorial Hospital Medical Grand Rounds. January 16, 2008, Ravenna, OH, USA.
19. Mayes, P. Intermediary metabolism of fructose. Am J Clin Nutr 1993 Nov;58(5 Suppl):754S-765S fructose lipogenic
20. Phillips, S., et al. Increments in skeletal muscle GLUT-1 and GLUT-4 after endurance training in humans. Am J Physiol. 1996 Mar;270(3 Pt 1):E456-62.
21. Schalkwijk, C., et al. Fructose-mediated non-enzymatic glycation: sweet coupling or bad modification. Diabetes/Metabolism Research and Reviews 20(5): 369-382.
22. Smutok, M., et al. (1994). Effects of exercise training modality on glucose tolerance in men with abnormal glucose regulation. Int J Sports Med 15(6): 283-289.
23. Soenen S, Westerterp-Plantenga MS. No differences in satiety or energy intake after high-fructose corn syrup, sucrose, or milk preloads. Am J Clin Nutr. 2007 Dec;86(6):1586-94
24. Tougas, G., et al. Assessment of gastric emptying using a low fat meal: establishment of international control values. Am J Gastroenterol. 2000 Jun;95(6):1456-62.
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