Noting that many Americans' diets lack adequate amounts of essential micronutrients and may be contributing to illness on a large scale, the Cornell scientists are leading an effort to develop agricultural systems that explicitly improve human health and to develop policies that favor such an approach.
"Today, in the United States, we have the safest, most abundant and nutritious diet in the world," said Ross Welch, Cornell professor of soils, crops and atmospheric sciences and a scientist with the U.S. Department of Agriculture's research service. "But it's not good enough. If everyone started today to eat more cereals, more fruits, more vegetables -- as recommended -- our U.S. agricultural system currently may not be able to meet the demand. So we need to find a way to make the foods we eat -- much of it empty calories -- more nutritious and healthy. That's a sustainable 'food systems' approach."
If agricultural research pays off, staving off certain illnesses -- like heart disease and cancer -- may be less than a generation away. For example, agricultural researchers are delving into breeding human disease-preventing crops as part of a total "food systems" approach to link agriculture to health and nutrition, the Cornell scientists said at the annual meeting of the American Association for the Advancement of Science.
Welch and his colleagues, John M. Duxbury, Cornell professor and chair of soils, crops and atmospheric sciences, and Gerald F. Combs Jr., Cornell professor of nutritional sciences, organized and will speak in a symposium, "Creating Healthful Food Systems: Linking Agriculture to Human Needs," beginning at 8:30 a.m. Feb. 18. They called on their colleagues in agricultural science and food policy to adopt this approach, which would change agricultural systems in ways that enrich the availability of micronutrients that now are sorely lacking.
One essential micronutrient is iron. Twenty percent of women of child-bearing age are iron deficient in the United States, while 25 to 30 percent of African-American women suffer from iron deficiency, Welch said. Most men have an over-abundance of iron due to a diet heavy with red meat.
This type of iron (hemoglobin and myoglobin iron) may be a factor in accelerating heart disease and some cancers. A food systems approach may be an answer to the reduction of such health problems, Welch said.
About 20 percent of American heart disease could be avoided with dietary changes -- a disease costing $56.6 billion annually, according to the Economic Research Service (ERS) of the USDA. The American Cancer Society estimates health costs of $104 billion in this country to treat cancer, but the ERS says that could be reduced by 35 percent by "practicable dietary means." Almost $20 billion is spent on stroke, but the American Heart Association estimates that 20 percent of stroke deaths can be avoided with dietary changes.
In a food systems approach, iron nutriture could be balanced among men and women. Plant breeders could begin examining ways to increase non-heme iron into staple crops such as rice, wheat, maize and cassava. The payoff, Welch explained, would be a healthier American diet and healthier diets for people in developing countries as well.
Worldwide, the problem of iron deficiency gets worse. The World Health Organization estimates that 2 billion people -- one-third the global population -- are iron deficient. Iron deficiency can lead to impaired body temperature regulation, detrimental behavioral changes and faulty psychomotor development.
A food systems approach also could help alleviate malnutrition. After the Green Revolution in the late 1960s, longitudinal research compared the dietary energy supply to the amount of iron density in the diets of south Asian cultures. Between 1970 and 1989, the number of average calories consumed each day increased almost 200 calories, but the iron-to-calorie ratio fell from 6:2 in 1970 to 5:7.5 in 1988.
Other nutrients are important as well. Osteoporosis, caused by a calcium deficiency, costs the American health-care system about $11 billion annually, Welch said. Zinc deficiencies have been linked to stunted growth; vitamin A deficiency causes eye problems; and selenium deficiency has been linked to juvenile cardiomyopathy (Keshan disease), and chondrodystrophy (Keshan-Beck disease), and it may impair thyroid hormone metabolism and help prevent certain types of cancer.
Welch and his Cornell colleagues argue that the American diet -- lacking in key micronutrients like iron and zinc -- needs a food systems approach which clearly links to agricultural production to human health issues.
That means a wholesale revision of the way Americans think about their normal diet, Welch said. The researchers believe that with education and a move toward dietary reform, Americans could fill their micronutrient needs with the help of agriculture.
The Cornell scientists called upon their colleagues to adopt this approach, coupled with an education and information campaign to promote it. They called for the U.S. government to develop policies that influence consumers' choices -- which urge consumers to buy micronutrient-rich food and help farmers to meet that demand.
"Instead of medicine trying to solve all of our health problems, perhaps it's time to let agriculture examine how it can help," Welch said.
EDITORS: Ross Welch can be reached at the AAAS meeting Feb. 16-18 at the Crowne Plaza Hotel, (206) 464-1980. After Feb. 23, he can be reached at (607) 255-5434. Larry Bernard of the Cornell News Service can be reached in the AAAS newsroom or at the Sheraton Seattle, (206) 621-9000, Feb. 13-18, or at (607) 255-3651 after Feb. 18.