WHAT'S THE BEEF?: As much as 93 percent of the carbon in a fast food hamburger can be traced back to corn, with its attendant environmental impacts.
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If you thought you were eating mostly grass-fed beef when you bit into a Big Mac, think again: The bulk of a fast-food hamburger from McDonald's, Burger King or Wendy's is made from cows that eat primarily corn, or so says a new study of the chemical composition of more than 480 fast-food burgers from across the nation.
And it isn't only cows that are eating corn. There is also evidence of a corn diet in chicken sandwiches, and even French fries get a good slathering of the fat that makes them so tasty from being fried in corn oil.
"Corn has been criticized as being unsustainable based on the unusual amount of fertilizer, water and machinery required to bring it to harvest," says geobiologist Hope Jahren of the University of Hawaii at Manoa's School of Ocean and Earth Science and Technology, who led the research. "We are getting a picture of the American diet on a national scale by using chemistry, which is quite objective."
Eating a diet of meat from corn-fed animals hasn't been linked to any specific health effects in humans. But it has resulted in widespread environmental degradation, including drained water supplies, degraded soils, and reliance on fossil fuels for fertilizer, pesticides and farm machinery fuel, says preventive medicine physician Bob Lawrence, director of the Center for a Livable Future at the Johns Hopkins Bloomberg School of Public Health, who was not involved in the study.
It's also hard on cows, whose stomachs are specially designed to break down the cellulose in grass, leading to an epidemic of antibiotic use. Also, humans may lose out on beneficial omega-3 fatty acids—important for development of the nervous system and heart health—when they consume corn-fed as opposed to grass-fed beef.
"Instead of eating a predominantly whole grains, fruits and vegetables, we are diverting the grain supply to feeding the animals," Lawrence says, arguing for a diet that treats meat as a garnish rather than the main course and corn for human consumption rather than cows. "Corn-finished beef does add to what has become a preferred taste for the American palate. We've acquired that taste at our own peril."
Jahren and her colleague Rebecca Kraft collected hamburgers, chicken sandwiches and fries from three separate Burger King, McDonald's and Wendy's locations in six U.S. cities: Baltimore, Boston, Detroit, Denver, Los Angeles and San Francisco. The scientists were looking for the amount of carbon 13 (13C), a variety of carbon with an extra neutron (known as an isotope) that makes its atom heavier.
Corn tends to have more of this 13C than other plants. That telltale signature persists as the corn travels through the complex system that turns it into feed, which is consumed and processed by cattle to grow tissue. It continues after the animals are slaughtered and the meat is cooked. The result: 93 percent of the tissue that comprised the hamburger meat was derived from corn.
In fact, only 12 samples from the entire country did not show this unique corn signature: all from a Burger King on the west coast. "My best guess is that it represents meat from another country," Jahren says.
And all of the chicken, in addition to being sourced from just one company, Tyson Foods, Inc., had been fed an entirely corn diet, resulting in a chemical composition that was almost exactly the same from coast to coast. Jahren notes that the isotopic composition of this chicken meat varied from restaurant to restaurant and state to state less than if a sample were taken from just one farmyard-raised chicken.
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23 Comments
Add CommentPrehistoric cattle might possibly have eaten grass, but being forest dwellers, the Aurochs ate many kinds of foliage, including bush, scrub and tree leaves.
Reply | Report Abuse | Link to thisModern cattle feeding on corn must find it about as palatable as we find gruel.
Cattle in the Alpine pastures seem happy with their wide diet of wild flora, with much exercise and fresh air. And their milk and meat are excellent.
Has anybody compared the methane production of free-range and intensively raised cattle?
Corporate corn farming may be revealed as one of the great scams of our times. In addition to all the dietary and environmental problems listed in the article, there is the green revolution's hunger for bio-fuels such as corn, which come with myriad of problems. When will science learn that it's not nice to mess with Mother Nature?
Reply | Report Abuse | Link to thisIf you want to know more about how the corn industry is dominating the food chain (and especially fast food) read 'The Omnivores Dilemma' by Michael Pollan. I guarantee it will change the way you think about food forever and it is unlikely that you will ever go near McDonalds again after reading it.
Reply | Report Abuse | Link to thisThanks. I'll pick up that book.
Reply | Report Abuse | Link to thisIntersting article, but aside from a single sentence of less omega-3 fatty acids in corn-fed beef, it doesn't address any detrimental health effects from added corn or corn products in the American diet. Is this really a bad thing?
Reply | Report Abuse | Link to thisI think, too, that the medical effects on humans are vastly underestimated. At 29 years old, I became violently allergic to corn, including anything with corn syrup, etc. I had never had food allergies. It is in almost everything we eat int he US. I've moved to Europe and found that even processed foods here are not made with corn syrup, corn oil, etc. like in the US. Really brought home the likes of Fast Food Nation and The Omnivore's Dilemma.
Reply | Report Abuse | Link to thisR Self, Ph.D.
One of the health effects is that corn-fed cattle have marblized meat(more fat in their meat, saturated fat specifically) and this lends itself to the ingestion of meat with a higher sat. fat content. If your diet consists of consuming such meat often, and taking in other foods with a high sat. fat content, then such a diet, overall, lends itself to many arterial problems.
Reply | Report Abuse | Link to thisNow I know that I shouldn't eat at Burger King on the west coast. People prefer corn fed beef because it tastes better, not because it is cheaper. If American fast food chains' food tasted as bad as at their grass-fed European franchises, they wouldn't be nearly as popular.
Reply | Report Abuse | Link to thiswwmyers- "People prefer corn fed beef because it tastes better, not because it is cheaper." You have failed to understand that Burger joints do not source their meat mased on American's taste, but on the artificially reduced cost of factory farmed meat. Taking this one step further, the factory farms don't choose corn because it makes the meat taste better, they choose it because of its US Taxpayer subsidized low cost and its effect of accelerated bovine growth. We need to get government out of the food system as this trickle down cause and effect pattern does indeed cause havoc on costs, choices, and health. Keep also in mind that Corn Syrup, the waste byproduct of the corn industry is also chosen by the same Burger joints as a primary ingredient in everything from the cola to the bun and this ingredient has been linked to everything from heart disease, diabetes, obesity, and cancer. If it weren't for the massive corn subsidies, plain old sugar (which isn't metabolized in the liver like HFCS and is still used as the primary sweetener in Europe) would still be in use.
Reply | Report Abuse | Link to thisIf you don't like grass fed beef, you have probably never tried it. It is superior not only in terms of taste, quality, and Omega 3's but also in vitamins esp D which together are the 2 most critical fighters of cancer in humans.
Corn-fed beef is optional! Most cows are raised on a grass diet to adulthood; the primarily-corn diet comes only at the feedlot, where the animals spend several months standing in a stall and putting on weight, most of which is fat. We do NOT need to treat meat, especially beef, as a garnish--there is plenty of pasture out there not suitable for growing grains, and properly managed cattle aren't much of a burden on the environment (it's not like the great plains didn't have grazers in the past).
Reply | Report Abuse | Link to thisAs far as taste, you can tell the difference in a good steak (hard to get marbling on a grass diet), but in anything else the only difference you'll notice is in your waistline.
In response nillions, I find it very hard to believe that as an informed person reading scientific american, you actually believe this.
Reply | Report Abuse | Link to thisPlease, Greensleeves, inform me.
Reply | Report Abuse | Link to thisMost freshly slaughtered meat has little taste. The taste comes from the bacterial degradation of the carcasses, which are left to 'mature' four to five days by butchers before being cut into joints. (A little fat helps the process).
Reply | Report Abuse | Link to thisGame is left for much longer! Cattle are killed humanely to prevent 'rigor mortis' stiffening the muscle fibres. The best, tastiest cuts of meat come from non-stressed free-range stock. Leave the corn for the starving...
This is an artifact of the feedlot system. And as soon as economics dictate it, this will change.
Reply | Report Abuse | Link to thisTaste is an acquired thing and is readily changed by experience. As to meat as a garnish --- Thomas Jefferson used those exact words to describe his own preference, and he was consideres a gourmet in his time.
Reply | Report Abuse | Link to thisCorn, even for starving people, has its limitations; in fact Scientific American ran an article a few years back showing archeological evidence that when Native Americans in Florida were forced onto a corn diet by the Spanish "missions" (vs a previous broader diet ), their physical condition became disastrously worse because the protein in natural corn is incomplete. Genetic modification can help that if hysterical politics don't intervene.
It would be interesting to track the protein in farm-raised fish vs wild-caught. Farmed catfish are fed pellets (based on corn?); tilapia,mostly from China, are fed fishmeal from factory ships offshore Chile and Peru.
All these activities have important environmental effects and resource depletion effects as well as dietary ones.
American prairie fed buffalo (you can herd them to wherever they want to go) offer a wonderful red meat replacement to our over-manufactured cattle. They and the native grasses that support them were here before we were, so it would be a restoration of the pre-contact environment, eliminating all our intrusive chemicals, etc. Obviously, buffalo highway and railroad intersections provide an interesting engineering problem. See also "buffalo commons".
Reply | Report Abuse | Link to thisYou guys are so boringly predictable. Diverting corn to ethanol is causing food shortages, so, now, of course, the department of doublespeak must convince the citizens of Eastasia that corn is bad for food.
Reply | Report Abuse | Link to thisAnother facet to having most of your food linked to corn, or feed-corn in particular is the prevalence of GMO corn.
Reply | Report Abuse | Link to this"Corn is commonly modified with the addition of a gene from the bacterium Bacillus thuringiensis; the resulting plant kills maize-devouring caterpillars. Other added genes bestow resistance to certain herbicides, which might otherwise decimate the crop." Brendan I. Koerner (Slate)
I am finding an increasing number of pet animals having digestive and other issues related to corn in their food. For instance, parrot "pellet" food has corn as the #1 ingredient - no matter which major brand you sample. Weaning them off of corn products has made a positive difference on the subjects that I have tracked.
I wonder how many inflammitory and auto-immune disorders are related to the variety-limited diet that our industrial agriculture system has created.
Check out Marion Nestle's site foodpolitics.com if you want to know more about the relationships between food production and marketing, nutrition and health.
Reply | Report Abuse | Link to thisAs for corn, it's one of the least nutritious and most calorie-dense vegetables around. Perfect for the (fast) food industry obviously. Add substantial government subsidies and heavy fertilizer use and you know why somebody (can't remember who) called it "the syphilis of agriculture."
So, THAT's why Mickey D's makes you "pop."
Reply | Report Abuse | Link to thisWho knew?
Stop feeding cattle on corn and give the corn to the World's 860,000,000 starving. In india most people are vegetarians by religion. Indians have far less colon cancer than western meat-eaters. It takes 16 kilos of corn to produce one kilo of beef! The world has plenty of cereals to feed the poor...if only they were fairly distributed.
Reply | Report Abuse | Link to thisCorn Feed meat does not taste better animals are fed corn to fatten them up so the feed lot gets more money, not to make them taste better. I live here in Pa. and the best tasting meat here is raised by the Amish and their diet is mostly grass and they get more money a pound for it but they raise less cattle so in the end they don’t make as much corn fed meat has little taste and a lot of fat, so you eat more if you have ever ate wild game it fills you up on just a little.
Reply | Report Abuse | Link to thisIf you haven't checked it out yet, take a look at the documentary King Corn.
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