Monday, January 21, 2008

Issue Spotlight: Is Too Much Corn Making Us Fat?

Everything I’ve been reading lately points to corn and corn-related products as a major culprit in the growing obesity epidemic.

What?

We love corn! Picked fresh, peeled, boiled, flavored with butter and sprinkled with salt? Is there anything better? It’s a peak experience! Anyone who has shared this experience – or purchased fresh Olathe sweet corn from a Local Farmers’ Market -- must share my dismay. And popcorn! Who can get through a DVD rental without it?

Corn now takes up an inordinate amount of space in our food chain. Not the sweet, fresh-picked corn-on-the-cob variety, but the commoditized, mass-produced variety. According to the USDA, in 2007 more than 90 million acres of land in the U.S. were planted to corn, delivering more than 13 billion bushels. Most of the crop is used in livestock feed; in fact, corn accounts for more than 90 percent of the total value and production of feed grains. It is also processed into a multitude of food products, in the form of high fructose corn syrup, glucose and dextrose, starch, beverage alcohol and cereals and other products. About 3.2 million bushels are earmarked for the production of ethanol. Whatever is left (about 20% of the total) is exported to other countries.[1]

The pervasive use of corn is causing alarm in two key areas. First, researchers tell us that livestock and poultry raised on corn produce meat that is higher in saturated fats and lower in essential nutrients than meat from animals fed with grass. (Look for more on this in future postings.) Second, the increased use of high fructose corn syrup (HFCS) – a widely used corn derivative -- is being blamed for everything from obesity, to diabetes, to pancreatic cancer and more.

In 2004, Dr. George Bray and others analyzed food consumption patterns in the U.S. and noted that the dramatic increase in the consumption of HFCS mirrored a rapid increase in obesity. According to Bray, the consumption of HFCS increased more than 1000 percent between 1970 and 1990, far exceeding the changes of any other food or food group.[2] According to the National Center for Health Statistics, over the same period of time, the prevalence of obesity in the U.S. more than doubled, after remaining relatively stable for prior decades.[3] Bray also reported that the digestion, absorption and metabolism of fructose differ from those of glucose, which may contribute to overconsumption and weight gain. While Bray conceded that his hypothesis would require further testing, he concluded that “an argument can now be made that the use of HFCS in beverages should be reduced.”[4]

Since then, a significant number of studies have implicated fructose in increased levels of triglycerides,[5] negative impacts on appetite regulating hormones,[6] insulin resistance,[7] obesity, Type 2 Diabetes,[8] liver damage[9]and even pancreatic cancer.[10] Here’s a sampling:


  • According to University of Minnesota professor John Bantle, people who use HFCS as a sweetener increase their triglycerides 32 percent relative to people who use mostly sugar.[11]
  • Earl Mindell and Virginia Hopkins, authors of Prescription Alternatives, report that studies done at the US Department of Agriculture's Human Nutrition Resource Center reveal that consuming fructose in this form causes chromium levels to drop, in turn raising LDL cholesterol and triglycerides, and impairing immune system function. Mindell states, "As our consumption of high fructose corn syrup has risen 250 percent in the past 15 years, our rate of diabetes has increased approximately 45 percent in about the same time period.” [12]
  • Research by the U. S. Department of Agriculture (USDA) reveals that high fructose diets shorten the life span of laboratory mice from the normal two years to a mere five weeks![13]

Other studies suggest it’s not fructose -- in and of itself -- that creates the problem, but the delivery medium (as in soft drinks and other fructose-sweetened beverages) that is making us fat.[14] This has prompted an aggressive response from members of the food and beverage industries, who are promoting their own studies that show that frequent consumption of soft drinks does not lead to higher obesity rates,[15] that beverages sweetened with HFCS and sucrose affect satiety[16] and blood levels of glucose, insulin, leptin and ghrelin[17] similarly.

On the website of the Corn Refiners Association they present their side of the story:

  • on obesity: “there is currently no convincing evidence to support a link between HFCS consumption and overweight/obesity.”
  • on sugar consumption: “Bottom line: high fructose corn syrup has not changed the sweetener mix in the country's diet.”
  • on insulin production/resistance: “Both [sucrose and fructose] have essentially the same effect on insulin production.”
  • on differences in metabolism: “Some studies claim that the body processes high fructose corn syrup differently than other sugars due to the fructose content. Conclusions from these studies cannot be extrapolated to high fructose corn syrup. That is because the studies looked at the effects of fructose independently.”
I have two things to say here. First, anyone who lived through the “does tobacco cause lung cancer?’ debate will remember similar pronouncements from the Tobacco Industry back in the 70s. Second, they are side-stepping the key issue – that because HFCS is so plentiful and cheap, it is now in nearly every processed food we eat, and the resulting sugar load is killing us!

Let’s look at some facts:

Fructose exists naturally in small amounts in honey, root plants and various fruits. When eaten in small amounts in a regular diet, fructose can be beneficial to your health. A process for producing HFCS was developed in the late 1950s and refined by Japanese researchers in the 1970s. Basically, you mill corn to produce corn starch and process the corn starch to produce corn syrup. (Corn syrup is almost entirely glucose, the human body’s primary source of energy.) Then you subject that glucose to a three part enzymatic process which turns the glucose into fructose. The fructose is then back-blended with glucose (and other sugars) to create high-fructose corn syrups.

HFCS was found to have a number of desirable qualities. It is about 75 percent sweeter than regular table sugar [18]-- and cheaper to produce.[19] It transports well, mixes easily, extends shelf life, retains moisture in foods, enhances flavors, helps breads brown and helps to prevent freezer burn.[20] The food industry has found ways to put it in practically everything, including breakfast cereals, beverages, sauces and marinades, snack foods, fast foods, syrups and sweeteners, meat products, dairy products, canned soups, condiments, and miscellaneous foods. They’re even putting it into cough syrups and antibiotics!

As a result, the use of HFCS has grown rapidly, from 56,000 short tons in 1970 to nearly 8.8 million short tons in 2006[21] -- and per capita consumption in the U.S. has increased from half a pound a year in 1970 to nearly sixty pounds a year in 2006. In 1970, HFCS supplied less than 1 percent of our total sugar intake; now it provides nearly 42 percent.[22] When you add up all sugar consumption (refined sugar, corn sweeteners, honey, etc.), on a per capita basis we’re consuming nearly 140 pounds of sugar every year! [23]

As Jessica Fraser reports, “many people unknowingly consume food and drinks containing ridiculous amounts of sugar. But don't expect labels to help you determine how much sugar is added. Sugar has all sorts of names: dextrose, glucose, fructose, lactose, corn syrup, maple sugar, honey, invert sugar or malt.” [24] In fact, many people get 30 percent or more of their calories from these hidden sugars.[25]

The USDA recommends that people limit themselves to 10 to 12 teaspoons of added sugars a day. With the pervasive use of HSCS, the average American now eats nearly three times that.[26] Drink one 12 oz. Pepsi and you’ve met the daily objective. Eat one Berkeley Farms low-fat yogurt with fruit -- or drink one Hansen’s Super Vita orange-carrot Smoothie -- and you’re done for the day.[27]

If you’re eating a lot of processed and/or fast foods, it adds up quickly. Take a look at the following hypothetical menu and its sugar load.

Breakfast:
· 8 oz. Ocean Spray grape juice – 10 teaspoons[28]
· 1 cup Post/Kellogg’s Raisin Bran cereal – 4+ teaspoons
· 1 grande Starbucks nonfat or soy chai latte – 11+ teaspoons[29]

Lunch:
· MacDonald’s Double Cheeseburger
· Large French Fries
· 2 T Ketchup
· Large Coke
Total – 24 teaspoons[30]

Dinner:
· 4 oz. sweet and sour shrimp – 6 teaspoons
· ½ c. rice – 0
· Mixed green salad with tomatoes – 1 teaspoon
· 1 T red wine vinaigrette – 3 teaspoons
· 2 Fig Newtons – 6 teaspoons

Grand Total: 65 teaspoons of sugar, or 6.5 times the recommended amount!

So, all you corn lovers, you'll be happy to hear that corn -- per se -- is not the culprit. My ear of corn – arguably one of the sweetest vegetables -- has less than one teaspoon of sugar. The real culprit is fast foods and processed foods, which, with all of their affordability, availability and convenience, are tipping the proverbial scales toward disaster.

[1] http://www.ers.usda.gov/data/feedgrains/StandardReports/YBtable1.htm
[2] Bray, G., Nielsen, S.J., and Popkin, B. M., Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity, in The American Journal of Clinical Nutrition 2004; 79:537-43.
[3] http://www.cdc.gov/nchs/nhanes.htm
[4] Bray, et al, 2004.
[5] Elliot, S.S., Keim, N.L., Stern, J.S., Teff, K., and Havel, P. Fructose, weight gain, and the insulin resistance syndrome. American Journal of Clinical Nutrition, Vol. 76, No. 5, 911-922, November 2002
[6] Teff, K.T., Elliott, S.S., Tschoep, M., Rader, D., Heiman, M, Townsend, R.R., Keim, N.L., D’Alession, D., Havel, P.J., 2004. Dietary fructose reduces circulating insulin and leptin, attenuates postprandial suppression of ghrelin and increases triglycerides in women. Clinical Endocrine Metabolism. 89:2963-2972.
[7] Elliott, et al, 2002.
[8] http://www.cornsyrupnews.com/ as accessed Jan 19, 2008
[9] Wikipedia, High Fructose Corn Syrup, http://en.wikipedia.org/wiki/HFCS as accessed 1/11/2008.
[10] Soda warning: High sugar intake linked to pancreatic cancer, Thursday, November 09, 2006 by: Ben Kage, www.newstarget.com
[11] Dangers of High Fructose Corn Syrup - HFCS, http://www.femhealth.com/DangersofHFCS.html
[12] Ibid
[13]Ibid
[14] Mattes, R.D., Beverages and positive energy balance: the menace is the medium, International Journal of Obesity, 2006, S60-S65.
[15] Sun, S.Z., Empie, M.W., Lack of findings for the association between obesity risk and usual sugar-sweetened beverage consumption in adults – A primary analysis of databases of CSFII-1989–1991, CSFII-1994–1998, NHANES III, and combined NHANES 1999–2002. Regulatory, Nutritional and Scientific Affairs Group, James R. Randall Research Center, Archer Daniels Midland Company. 12 February 2007
[16] Monsivais, P., Perrique, M.M., and Drenowski, A., Sugars and satiety: does the type of sweetener make a difference? American Journal of Clinical Nutrition, Vol. 86, No. 1, 116-123, July 2007 (Supported by a grant from the American Beverage Association, by the Corn Refiners Association, and by fellowship T32 DE07132 from the National Institute of Dental and Craniofacial Research)
[17] Melanson, K.J., Zukley, L., Lowndes, J., Nguyen, V., Angelopoulos, T.J., and Rippe, J.M., Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin and hrelin and on appetitie in normal-weight women. Nutrition 23( 2007) 102-112.
[18] High-fructose corn syrup: sugar on crack? By Phil Lempert, Today Food Editor, March 2006, http://www.msnbc.msn.com/id/12058364/, as accessed 1/21/08
[19] Sugar Coated, by Kim Severson, San Francisco Chronicle, February 18, 2004
[20] Ibid.
[21] Sugar and Sweeteners Team, Market and Trade Economics Division, Economic Research Service, USDA. Last updated: 3/15/2007
[22] Sugar and Sweeteners Team, Market and Trade Economics Division, Economic Research Service, USDA. Last updated: 4/11/2007
[23] Ibid
[24] Dangers of High Fructose Corn Syrup - HFCShttp://www.femhealth.com/DangersofHFCS.html
[25] How Much Sugar Is Too Much, by Chris Woolston, CONSUMER HEALTH INTERACTIVE, http://www.ahealthyme.com/topic/toomuchsugar
[26] Sugar and Your Health, the University of Georgia Extension Service, http://www.fcs.uga.edu/pubs/PDF/FDNS-E-67a.pdf, as accessed 1/20/08
[27] http://www.cspinet.org/reports/sugar/popsugar.html, as accessed 1/20/08
[28] http://www.co.mohave.az.us/WIC/sugar.htm, as accessed 1/20/08
[29] Ibid
[30] McDonald’s Web Site, Food and Nutrition, http://www.mcdonalds.com/corp/about/mcd_faq/food_and_nutrition.html, as accessed 1-20-08

2 comments:

Myrto Ashe said...

In my opinion, in addition to high-fructose corn syrup, I think refined carbohydrates paired with fat, especially, are also to blame for the obesity epidemic. I also think anxiety and alienation play a role, as they increase cortisol levels, which also result in weight gain, depression and more emotional eating.
Folks just need to make wholesale change - to plant-based, whole unprocessed foods. This also means less bread (even whole wheat flour is processed), more leaves...IMHO
Myrto

homegrown colorado girl said...

Thanks for the comment.

I agree. As Michael Pollan says .. "Eat food; not too much; mostly plants."

The more I learn about all of this, the more I realize how disconnected we are from food. It's scary!