Eating for the Environment
By Rita E. Carey, MS, RD, CDE
Today’s Dietitian
Vol. 7 No. 9 P. 52

Think our food choices don’t affect the health of the Earth? Think again.

Dietitians talk and think about food, nutrients, wellness, and disease in some fashion every day. We know how food choices impact human health and can expound on the value of choosing wisely from the wide variety of foods—30,000 to 40,000 items in a U.S. supermarket—available to us today.1 Many of us, however, are less likely to be familiar with the impact this variety has on the health of the ultimate source of all we eat: the Earth.

There are many reasons for dietitians to be aware of the environmental impact of food production, including, but not limited to, human health, food security, and a worldwide resurgence of public interest in the subject. Figuring it all out, however, is not an easy endeavor, as the environmental impacts of food production can be far-reaching and not readily apparent. A general understanding of the environmental effects of food production and commerce helps in making decisions at the marketplace and in answering questions patients and clients may have.

The Food Ecology Movement
Food ecology is a relatively new term being used to describe the concern for and study of the social and environmental costs of global commercial food production. The term is new, but concerns over environmental degradation resulting from the production and harvesting of food are not. In fact, the environmental movement in the United States began in the 19th century with hunters who wished to stop unsustainable takings of certain animals and birds, many of which were being driven to extinction. Granted, much of this killing was done for sport, not food, but hunters were concerned with maintaining healthy populations of these creatures, nonetheless. Alarm over the manner in which food was being cultivated began in Europe in the 1920s, after “synthetic manures” were introduced to agriculture there a decade earlier.

After World War II, the use of chemical fertilizers and pesticides in the United States and abroad soared to an all-time high and Americans began to witness both their immediate benefits (improved yields) and chronic, toxic side effects. These chemicals, some unknown in agriculture prior to the war, were produced from surplus ammonium nitrate (used to make bombs) and poisonous gases of which the then-War Department had to dispose.2 The flood of nitrogen and other chemicals into croplands in the form of fertilizers and pesticides, along with technological advances in irrigation and hybridization, produced bumper crops and, thus, marked the beginning of the “green revolution” and of the commercial agricultural system that exists today.

Trouble in Paradise — The Downside of Commercial Agriculture
Early activists questioned the wisdom of dumping large quantities of nitrogen and toxic chemicals into the environment and ignoring time-honored practices for preserving the soil’s fertility and health. They, like many after them, believed the direction commercial agriculture was taking could not be environmentally sustained and would eventually lead to massive losses of soil and soil fertility. Nearly 100 years after the introduction of the first synthetic manures, it is evident that their fears have come true.

Nitrogen, the building block of proteins and nucleic acids, is essential to life on Earth, but the amount of nitrogen available to living beings is limited. Nitrogen becomes available to living organisms only after it is taken from the environment and “fixed” by soil bacteria living on the roots of legumes or is split in the atmosphere by lightning. The amount of fixed or split nitrogen in natural systems serves to limit the organic matter that can be produced. The addition of nitrogen into the environment in the form of artificial fertilizers or manures makes possible the production of ever-increasing amounts of food. This is beneficial, but, unfortunately, synthetic nitrogen is overused in commercial agriculture, often to compensate for poor soil health and fertility.

Of particular concern is what happens to excess nitrogen that is not, or cannot be, taken up by crops. Some of it evaporates into the atmosphere, released elsewhere as acid rain. Some washes into streams, rivers, lakes, and oceans, where it supports the growth of oxygen-depleting algal blooms. For example, a large area in the Gulf of Mexico (roughly the size of New Jersey) is now considered hypoxic and biologically dead, the result of massive amounts of nitrogen washing down the Mississippi River. Excess nitrogen also contaminates surface water and groundwater, making it toxic to humans. In addition, ammonium nitrate, the most common type of chemical fertilizer, converts to nitrous oxide, a greenhouse gas that contributes to global warming.2

Synthetic nitrogen, as well as other minerals in chemical fertilizers, also increases the need for pesticides and contributes to erosion, soil salinization, and topsoil depletion. In The Anatomy of Life and Energy, soil scientist Arden Andersen, DO, PhD, argues that the health of soils and plants is dependent on a complex interaction of electromagnetism, soil bacteria, and bioavailable nutrients that is absent on industrial farms.3

Healthy soil is alive with bacteria and other organisms and carries a specific electromagnetic charge. Living organisms contribute to soil fertility by making nutrients available to plants and adding organic matter to the soil, helping it hold together and retain water, among other things. An electromagnetic charge also helps hold soil particles together.

Chemical fertilizers disrupt this electromagnetic charge, making soil more susceptible to erosion. They also kill soil organisms, thus reducing the availability of nutrients to plants, along with the overall fertility and water-holding capacity of the soil. Fertilizers, especially those containing chlorine, can bind with minerals in the soil to form salts that, over time, can make cropland sterile and incapable of supporting life. The changes chemical fertilizers make to the soil produce plants that are diseased and that then need additional fertilizers to continue to grow and bear fruit. Diseased plants, according to Andersen and many other prominent researchers, attract insects. This results in an increased need for larger applications of pesticides—and so a vicious cycle of fertilizer and pesticide dependence ensues, the typical pattern in commercial agriculture today.

Soil loss caused by erosion is a particularly dangerous environmental consequence, as it takes from 200 to 1,000 years to form 1 inch of topsoil, depending on conditions.4 It is estimated that, worldwide, topsoil is being lost 16 to 300 times faster than it can be replaced. Continued erosion at this rate may result in the loss of more than 30% of the Earth’s topsoil by the year 2050, a rate of loss that is obviously unsustainable and ultimately devastating to global food security.5,6

Since the publication of Rachel Carson’s landmark 1962 book Silent Spring, the impact of pesticides on the environment has been well-studied, and there is no question that pesticides are toxic to all living organisms. Pesticides are known to pollute groundwaters and surface waters, poison farm workers, and accumulate in the tissues of people who eat foods that have been sprayed with them—with no one truly understanding their long-term physiologic and synergistic effects. Even less known is the effect some pesticides have on the atmosphere. Some may play a large role in depleting the stratospheric ozone layer.7

Agriculture: The Options
Addressing all the environmental issues associated with commercial agriculture is beyond the scope of this article. Perhaps it is enough to say that most people concerned with the long-term viability of our system of food production believe current agricultural norms cannot continue much longer without causing widespread food scarcity and irreparable environmental damage. There are sustainable options, however, that have been around and effective for a long time—they just haven’t been profitable (at least until recently) to the large corporations that control most of the agriculture in this country, and therefore haven’t been promoted.

Sustainable agriculture is based on long-term goals of maintaining soil health and fertility rather than a set of specific farming practices. There are several approaches to alternative farming in the United States—including organic, biodynamic, and biological—that rely primarily on biological systems rather than chemicals to supply fertility and pest control.

Organic farming excludes the use of synthetic fertilizers, pesticides, and growth regulators and relies instead on crop rotation, animal and green manures, legumes, and biological pest control to maintain soil productivity and control insects and weeds. Biodynamic farming parallels organic farming in many ways but places greater emphasis on the integration of animals to provide nitrogen and other inputs. Biological farming has become synonymous with the Reams fertility system, which is based on the use of rock phosphate, calcium carbonate, and compost to achieve optimal soil nutrient ratios, among other things. This style of farming allows the use of selected chemical fertilizers but avoids the use of soil-damaging materials such as anhydrous ammonia (nitrogen) and potassium chloride.

Organic agriculture, once a movement on the cultural fringe, is now in the mainstream of food production and is the most recognizable form of sustainable agriculture in the United States. It also represents the fastest-growing sector of the food business and has become highly profitable. This is evidenced by the large number of previously independent organic farms and companies that are now owned by large corporations. Heinz, for example, owns interest in 20 companies that produce organic foods, including Celestial Seasonings, Arrowhead Mills, and Walnut Acres. Cascadian Farms and Muir Glen, two major producers of organic products, are now owned by General Mills. Large corporations would not give these smaller companies a nod if they weren’t productive and profitable.

There is also no question that organic agriculture is as productive (and, in the long run, more productive because soil health is kept intact) as farms that ignore soil health and depend on chemical fertilizers and pesticides to boost their yields. There is some fear that corporate interests will work to weaken organic standards to improve their bottom line. If that happens, “organic” may not be a better option for the environment. Hopefully, consumer awareness and activism will prevent this from happening, and for now organic is a better choice for the health of humans and the environment.

Some farms choose not to be certified organic but still implement important organic principles. These farms may choose to use pesticides and chemical fertilizers when they need them, but they use them judiciously and not as a matter of course. They may rotate crops, avoid monoculture farming (planting just one species over hundreds of acres), and work to improve soil health. Some major wineries choose to operate in this fashion. This may also occur on local farms that cannot afford certification or for other reasons choose not to become organically certified. If you purchase produce at a local farmers’ market, talk to the growers to see what their operation is like.

Eating Oil for Breakfast
Locally grown food, whether or not it is organic, may be more environmentally friendly than organic food grown on the other side of the continent for the miles it did not have to travel. It takes huge amounts of fossil fuels to feed Americans today. One fifth of the petroleum consumed for all purposes in the United States goes toward the production and distribution of food.2 The energy-intensive nature of our diets represents one of the less obvious impacts commercial food production has on the environment.

Researchers have, for decades, calculated the amount of fossil fuel needed to produce the food we eat. They estimate that 7 to 10 calories of fossil fuel energy are needed to produce and deliver every calorie of energy we get from food. So, a 400-calorie breakfast consumes 2,800 to 4,000 calories of ancient energy once stored in the form of oil, coal, or natural gas. Freelance writer Chad Heeter recently wrote an article, “My Saudi Arabian Breakfast,” in which he estimated, using information from the University of Michigan’s Center for Sustainable Agriculture and David Pimentel at Cornell University, the amount of crude, gas, or coal he “ate” each morning with his breakfast of Irish oatmeal, organic raspberries, and Fair Trade coffee. Depending on the fuel calorie/food calorie ratio he used, he “consumed” 1 to 11/2 cups of crude oil each morning in the form of porridge, berries, and java.

Where do all those petrochemicals go? Approximately 20% go into the actual growing and harvesting of food. Some inputs are obvious, such as the fuel used to power ships, tractors, and combines. Others are not so apparent, such as the fuel required to make fertilizers, pesticides, and animal feed. Chemical agricultural inputs (fertilizers and pesticides) take enormous amounts of energy to produce—so much so that organic farms that eschew these products can use one third less fossil fuel than conventional farms to produce the same amount of food.2

Corn-based animal feed also requires a lot of fuel to produce. It takes between one third and one quarter gallon of oil to produce a bushel of corn, a plant that has a hearty appetite for chemical fertilizers. Consequently, a steer that eats approximately 25 pounds of corn per day will, in its relatively short lifetime, have consumed the equivalent of 35 gallons of oil, nearly a barrel of Saudi Arabian crude.2 It is for this reason that many people choose to follow a vegetarian diet—vegetable protein needs a lot less fuel to produce.

The miles traveled by food and the amount of processing it undergoes also contribute to the amount of fossil fuel it takes to bring that food to your table (80% of fuel use). Because of this, it has been argued that locally produced food, even if it is not organic, may be more environmentally friendly and energy-efficient than organic food that has been trucked halfway across the continent or globe.

As Michael Pollan describes in his book The Omnivore’s Dilemma, organic lettuce chilled to 36° from the moment it is picked in California until it reaches the shelves in Whole Foods Market in Manhattan most likely uses a lot more energy than conventional lettuce grown locally in New York’s Hudson Valley. In the same vein, organic steel-cut oats purchased in the bulk section of the supermarket are a more environmentally friendly item than highly processed instant oatmeal packed in little individual-serving envelopes inside a cardboard box.

We all want to live in a clean environment and desire food security. The choices we make every day for breakfast, lunch, and dinner can help ensure that those desires remain fulfilled. In general, buying organic and local foods whenever possible, eating foods that are minimally processed, and being aware of the economics and politics of our food system all help promote sustainable agriculture and a healthy planet. Being informed is important. There are many books on these subjects (see sidebar) and your clients or patients may be aware of or interested in them. Check some of them out. They are all good reads. They may even change what you choose to eat for breakfast.

— Rita E. Carey, MS, RD, CDE, is a clinical dietitian and diabetes educator at Yavapai Regional Medical Center and the Pendleton Wellness Center in Prescott, Ariz.