In elementary school I was always told, “You are what you eat,” however I never knew just how true this is or the implications it has until very recently. The law of conservation of mass states that matter cannot be created nor destroyed. So, as beings made up of matter, where did we come from? Biochemically, every atom we have in our bodies has come from ingestion or respiration. All the carbon, nitrogen etc. in our bodies comes from the elements found in our food. Quite literally, we are composed of exactly what we eat.
We take in chemical compounds in our foods such as carbohydrates, which are composed of solely carbon, oxygen and hydrogen. They are broken down in the body’s digestion and used to generate energy through metabolism. As metabolites these compounds give about 4 kcal/g. This extremely diverse class includes small sweet sugars, as well as long carbon chains.
Three important simple carbohydrates, glucose, fructose and sucrose. Sucrose, the combination of the two, is what we commonly call sugar.
Other compounds in food are proteins made of amino acids, which are composed of carbon, nitrogen, oxygen, hydrogen and other elements.
General Amino Acid structure:
Single amino acid, where the R is a functional group giving rise to the compound’s specific properties. The amino group (side with the NH2) bonds to another amino acid’s carbonyl group (COOH) in a peptide bond.
Proteins are useful to the body because as fuel, 4 kcal/g can be obtained, and the amino acids broken down from food proteins in our stomachs are the amino acids our bodies turn into our own human proteins. There are a few essential amino acids, which are so named because our body cannot produce them, and they can only be used if they are ingested. These essential amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and histidine. We must ingest these amino acids, which makes me think of how reliant we are on good, balanced diets, and how we are forced to interact with our natural worlds. We have coevolved to rely on certain foods more than just getting energy because in our bodies the proteins form many structural elements as well as perform many of the biochemical tasks necessary for life. So whether in the form supplied to us in food or in derivative forms, every physical part of us comes from all that we have taken in.
Alright, we are all composed of what we have eaten, and use what we ingest to fuel living, but this has been a reality since animals first came into existence. So why does this matter now?
Well in the last few decades, remarkable changes have occurred in the American diet. Leading the front lines of these changes was a single plant: corn. Not sweet corn as you or I would eat it, but rather ‘commodity corn,’ called number 2 corn. Number 2 corn as it grows is inedible to humans with any nutritional benefit. Instead, commodity corn is grown solely for industrial processes to transform the chemical compounds within the corn kernels into usable processed ingredients. The kernels are broken down into the molecules that compose it, and these are then used to make up nearly every food you or I eat on a daily basis.
There are a few parts of the corn kernel that are useful to industrial processes, and are extracted through the process of wet milling. This fossil fuel-driven process gives rise to the multiplicity of corn products you can see in supermarkets today. The endosperm is rich in starch, fiber, and gluten, while the germ is high in oil. Kernels are first soaked in water and sulfur dioxide to prevent bacterial growth, a time during which the kernels inflate due to osmosis. This allows the starch to be softened within so it may be released in the mill. In the crushing mill, the corn oil containing germ is separated from the endosperm’s starch through a cyclone. The starch will be broken down into glucose, which when combined in mixtures high in fructose become what is known commonly as high fructose corn syrup. The endosperm’s fiber is separated from the mixture over a screen, and finally gluten and starch are separated in a centrifuge. From here, the starch can be chemically transformed into many smaller sugars used as sweeteners such as glucose or fructose. Other products of the corn processing are used in animal feed for large industrial farms with thousands of cows packed in tight spaces together. Ethanol, another major corn product, can be found mixed in most gasoline now.
So every part of the corn kernel has been found useful to us in some way. This plant is unique in this way, that it can be broken down so heavily and used in such a multiplicity of ways. It makes sense then how humans have taken this plant and used it so widely, because it is an easy and cheap source of so many things that we need. When we go to a grocery store, we are hoping that the store will have everything we need, and we then won’t have to go from store to store to find our week’s groceries. Corn is much the same way; we can extract so much out of it and convert it all industrially in so many ways to create so much of what we need.
You might think to yourself, “But I only eat corn on the Fourth of July or when we go to visit my uncle and have barbeques during the summer.” But you are really eating corn whenever you eat any conventionally grown chicken or beef, drink conventional milk, or eat anything with corn syrup, xanthan gum, cornstarch and many other compounds. Corn in beef and chicken!? Well, yes actually, and lots of it. As I said before, “you are what you eat,” and cows and chickens on conventional farms (where most supermarket meat comes from) are fed primarily if not entirely corn-produced meal. Nutrients are often pumped into a carbohydrate and oil rich mixture fed to cows and chickens. These animals are then entirely made up of old corn, so when we eat the animals we are actually eating recycled corn that has been biologically processed into proteins (in the animals’ bodies). All of the proteins our body now makes come from animals that were built on corn! So we eat corn-meat, but the milk we drink, cheese we eat, and eggs for breakfast all come from corn-fed animals, and so we consume corn in nearly every meal. Sodas contain corn syrup, and companies such as Coca-Cola are major purchasers of processed commodity corn. Processed food that contains fructose and glucose also is likely derived from corn. Try going out to a local supermarket and look for all the products that might have corn in them, you might be surprised where you will find some corn.
We are essentially corn people. Not only are we made of corn because of its prevalence in our diet, but we also use it to clean ourselves, and get us from home to work.
In nature there are three naturally occurring isotopes of carbon. There is 12C, which is the most common form, with six neutrons and six protons. The 13C isotope has one extra neutron, and the 14C isotope, which has two additional neutrons, is a radioactive isotope used in carbon dating. Corn is what is known as C-4 plant, meaning that it will take in more carbon than other plants during photosynthesis, creating molecules containing four carbon atoms. While doing this, more isotopic 13C is used than plants that only use three carbon atom-containing molecules. This means that molecules that come from corn will have a very high specific ratio of isotopic 13C. When average Americans are analyzed, this isotopic ratio can be seen explicitly, showing how high our diet must be in corn-derived products. As Michael Pollan states on page 23 of his book The Omnivore’s Dilemma, we are “processed corn, walking.”
So we are a people primarily made up of corn-derived compounds. What implications does this have? Chemically speaking, it doesn’t matter much, there is no known danger to us having high 13C isotopic ratios. But being made entirely of recycled corn seems kind of far-fetched right? Well it’s a reality, and our diet does not seem like it will be changing soon. In fact, estimates say that an increase in corn cultivation is expected in the next few years, and we will be relying on corn to build our children for years into the future. There are many ethical issues that may be raised however, and many economic and ecological concerns.
Corn production is heavily subsidized by the government. Companies that rely on corn’s processing (Coca-Cola, McDonald’s, Nabisco, etc.) all have lobbyists working for government officials to help shape these policies. Commodity cornfields currently take up over 95 million acres of US soil. The compounds their milling creates generate cheap food with a very large variety of products available to consumers.
Those of you concerned with GMOs (Genetically Modified Organisms) might wish to know that just short of 75% of commodity cornfields were planted with GMO corn in 2011. Diversity is a measure of health in any ecosystem, and with corn as the only organism growing in 95 million acres, vast swaths of land can be said to ecologically unhealthy. Corn depletes soil nitrogen levels, and so all the land used to grow corn rapidly runs out of nitrogen deposits resulting in infertile soil. To solve this, heavy use of fertilizers has been implemented, both natural and artificial (although often artificial because it is cheaper). These fertilizers are generated using copious amounts of fossil fuels, and also end up running into the Gulf of Mexico creating dead zones where no animal life can survive, killing the fishing industry there. Having nearly our entire food industry built around corn growing in homogeneous fields makes us potentially vulnerable to corn-borne diseases that wipe out crops.
To me, relying to heavily on one plant creates a dependency, one that could potentially be dangerous. If we build our entire food system and energy system around this single plant, we are heavily vulnerable to disaster. I don’t want to sound like a fear-monger, but it is a reality that must be seen. When any system falls entirely dependent on one thing, a single event that destroys that support will cause the whole system to crumble. This could come in the form of a super-resistant parasite, a disease, or industrial breakdown. Additionally, no long-term research has reflected the health risks or benefits of a corn-based diet.
There is a lot that corn does for us as humans. It has allowed us to create the mass amounts of food that we all enjoy regularly. It has grown alongside us and moved us into a new era of food production: industrialization. This has many benefits and well as drawbacks, but it’s ultimately up to us: whether we try to diversify our food sources, or if we choose to remain corn people.
Pollan, Michael. The Omnivore’s Dilemma. New York: Penguin Books. 2006. Print.
“Corn Wet Milling.” Tate & Taylor. <http://www.tateandlyle.com/aboutus/ourindustry/pages/cornwetmilling.aspx> April 25, 2012.