Americans: Overfed and Undernourished
To be published in Sustaining People through Agriculture column, Small Farm Today, March-April, 2007.
The epidemic of obesity is obviously related to the American diet. It might be easy to blame these maladies on the sedentary but high-stress American lifestyle, which probably is a significant casual factor. But an even more important cause might be the lack of essential nutrients in many of today's foods. A growing number of scientific studies are finding significant declines in the nutritional value of our foods. And dramatic drops in nutrient density have occurred during a period when American farms were under pressure to specialize, mechanize, get bigger to produce more food cheaper.
Farm policy has always been promoted to taxpayers as being necessary to provide food security. The USDA defines food security as access by all people at all times to enough food for an active, healthy life. Food security, however, includes food quality as well as quantity and affordability. If food isn't nutritious, and healthful, as well as available and affordable, it will not ensure adequate diets for all. Unfortunately, the emphasis of food security programs administered through the USDA including its farm programs has been on food quantity rather than food quality. The agency admits its concept of food security is not adequate to ensure healthy diets, but places most of the burden for food quality on consumers.
During the 1930s, USDA farm programs were justified as means of keeping farmland in the trusted care of family farmers who had very personal reasons for maintaining the fertile and productive of their land. At the time, farmers produced much of their own food and most non-farm consumers were their neighbors. As the population became more urban, price and farm income support programs were promoted as a means of stabilizing prices to ensure a dependable and affordable food supply for all. More recently, the emphasis of agricultural policy has shifted from domestic food production to reliance on the global food economy. The emphasis is on enhancing agricultural exports, but the underlying assumption is that international trade will make food more abundant and affordable for Americans.
Meanwhile the evidence continues to grow that cheap food is abundant in calories but deficient in nutrients. For example, problems of obesity and diabetes are more common among people with lower incomes who logically tend to seek foods providing the cheapest source of energy meaning the most calories for the fewest dollars. Because of time constraints, many such people also rely heavily on highly processed and ready-to-eat foods, including fast foods. On such diets, people can easily end up eating far more calories than they need without getting enough nutrition to meet the minimum requirements of a healthy diet.
When livestock are offered a wide variety of foodstuffs containing a variety of vitamins, minerals, and other nutrients, most will naturally select a healthy balanced diet. When offered a premixed feed containing fixed quantities of the same nutrients, they tend to consumer more of some nutrients than they need, apparently trying to meet their minimum requirements of others. If we humans have this same basic tendency, whenever our food choices are limited we will tend to consume more of some nutrients than we need because we are not getting enough of others. In other words, a lack of nutrient balance in our diets would leave us hungry, even though we are consuming far more calories than is consistent with good health. Many Americans may be obese, sedentary, and stressed out because they are starving for nutritional substance in their foods.
One prominent academic study compared nutrient levels in 43 garden crops in 1999 with levels documented in benchmark nutrient studies conducted by USDA in 1950. The scientists found declines in median concentrations of six important nutrients: protein 6%, calcium 16%, phosphorus 9%, iron 15%, riboflavin 38%, and vitamin C 2%. While these essential nutrients may be lacking in most foods today, they may be found in abundance in foods grown naturally and organically on healthy, productive soils. A 1993 study comparing conventional foods with organic foods, found that organically grown apples, potatoes, pears, wheat, and sweet corn, purchased over a two-year period, averaged 63% higher in calcium, 73% higher in iron, 118% higher in magnesium, 91% higher in phosphorus, 125% higher in potassium, and 60% higher in zinc than conventional foods purchased at the same times.
Other studies establish clear links between declining nutrient density and the industrialization of American agriculture. One such study found that yield-enhancing technologies fertilizers, pesticides, plant density, and irrigation reduce the nutrient content of field crops by amounts generally consistent with declines in nutrient density over the past 50-years and nutrient differences between conventional and organic crops. These results should come as no surprise to anyone who understands that industrial agriculture profits primarily from quantity factors: acres farmed, head produced, yields per acre, rates of gain, and the cost efficiency of large-scale production. Quality factors affecting prices typically are incidental to profits and often related to cosmetic appearance rather than nutrition.
It seems only logical that an industrial agriculture would tend toward selection of crop varieties, livestock breeds, and production systems that rely on organisms having fewer and larger cells that are mostly filled with water. Organisms with smaller cells tend to be more nutrient-dense because they contain more cell walls that are formed from the wide variety of nutrients extracted from the soil or air. In addition, conventional crop production relies heavily on the three basic elements of nitrogen, phosphorus, and potash common in most commercial fertilizers. While these elements are obviously adequate to support high crop yields, they may not be adequate to produce crops containing the wide diversity and balance of nutrients found in crops produced on healthy, naturally productive, organic soils. Even after adjusting for moisture content, less nutrient dense foods appear to be cheaper and more profitable to produce. Regardless, this line of inquiry would appear to be a potentially fertile ground for continuing research into questions of food quality and nutrition. But we don't need a mountain of evidence to conclude that food quality has been compromised in the pursuit of agricultural productivity.
The food processing and distribution industry also must share the blame. The corporations that market our foods are concerned about profits not diet or health. In fact, the managers of the multinational corporations that currently control the American food system have a legal fiduciary responsibility to maximize returns to their stockholders. They have no social or ethical commitment to protecting public health and instead do only those things required by law. Current laws are clearly inadequate to protect the public from diet related illnesses, as is evident in current trends in the diets and health of Americans.
Food industry marketers know that humans have a natural taste preference, probably a genetic predisposition, for foods that are high in fat and sugar. Preferences essential for the survival and health of our primitive ancestors may threaten our health today. Regardless, it's easier to market foods that are higher in calories, particularly when those foods are cheaper to produce. The primary sources of those cheap calories are plants and animals from farms using modern yield-enhancing technologies and thus lacking in nutrient density and encouraging over consumption while enhancing food industry profits. Some logical health consequences of such diets are obesity, diabetes, and heart disease.
The natural link between agricultural policy, overproduction of nutrient deficient food, and unhealthy diets is skillfully documented in Michael Pollan's new best-selling book, The Omnivore's Dilemma. He logically links large government subsidies for corn production with surplus production and depressed corn prices, which subsidize manufacturing of the cheap corn sweeteners that now fill the American diet with empty calories in foods ranging from soft drinks to breakfast cereals, to French fries. Corn subsidies also subsidize large-scale confinement feeding of livestock, resulting in too much unhealthy fat in American diets, in addition to a host of other environmental and social problems. A similar story could be told for virtually every food crop subsidized by government programs in the quest for more and cheaper food. It should be obvious that trade policies currently increasing our reliance on cheap industrial foods from other countries will only exacerbate past problems. In attempting to improve food security through government programs designed to make food more abundant and affordable, we have threatened food security by making it less safe and nutritious.
As in the 1930s, the real food security of our nation still depends on keeping farmland in the trusted care of family farmers who are committed to maintaining the fertility and productivity of the land while producing safe and nutritious foods for all. Rather than subsidizing the industrialization of agriculture and promoting cheap food, our farm policies should be refocused on sustaining our smaller, independent family farmers, people who are personally committed to producing good food for their families, their neighbors, and providing food security for their nation. Our food may cost a bit more and we may consumer a bit less, but only then, will Americans be well nourished and well fed.
For studies of health benefits of natural foods, see The Organic Center, http://www.organic-center.org/
W. M. Jarrell and R. B. Beverly, The Dilution Effect in Plant Nutrient Studies, Advances in Agronomy, 34:197224, 1981.
The Omnivore's Dilemma: A Natural History of Four Meals (