Healthy Agriculture for Healthy People

May 7, 2006

The development community increasingly recognizes the many links between human health and the practice and products of agriculture. Some policymakers and practitioners are now pursuing opportunities for using these links to achieve both more productive agriculture and better health.

The global health community is bracing for the possibility of a pandemic of avian influenza, or bird flu—a disease that has to date been transmitted to humans through contact with infected poultry. The anxiety over bird flu highlights the previously often-overlooked link between agriculture and human health.

In fact, agriculture is tied to human health at the most basic level. Agricul-ture produces food, fiber, and medicine and provides livelihoods to millions of farmers so that they can purchase other necessities of life that contribute to their good health.

Moreover, the chain of cause and effect goes both ways. Good health affects agriculture by boosting people’s capacity for work and thus increasing how much they can produce. It enhances their ability to take risks with new crops or farming methods—risks that might pay off with better production and income. On the down side, when unhealthy farmers are unable to produce enough agricultural goods to earn a decent livelihood, their poverty and consequent malnutrition further worsen their health.

“The fact that there are two-way linkages between agriculture and health poses an opportunity for the two sectors to work together to help solve each other’s problems,” says Corinna Hawkes, an IFPRI research fellow. “Agricultural systems can be developed to benefit health, and the health sector can take steps to help overcome agricultural problems. Although this approach will involve some trade-offs, greater coordination could ultimately benefit both sectors.”

The connections between agriculture and health have been recognized for years, but health and agriculture professionals still tend to continue working within the limits of their own sectors. In 1988 Michael Lipton, research professor of economics at the University of Sussex, and Emanuel de Kadt wrote a book for the World Health Organization called Agriculture-Health Linkages, but today Lipton says, “I have seen little sign of improved coordination between health-directed and agriculture-directed agencies.”

Some researchers and development practitioners are now working to direct more attention to these links between agriculture and health and to stimulate more joint action to address them. The Consultative Group on International Agricultural Research (CGIAR), for example, is undertaking an initiative, coordinated by IFPRI, to explore these links. “The CGIAR is well positioned to foster the synergies between health and agriculture. Tapping these synergies, however, requires connecting strong research in both agriculture and the health community. With this new initiative we aim to strengthen that especially neglected connection,” says Joachim von Braun, director general of IFPRI.

Animal Health and Human Health

Farmers, pastoralists, and other agricultural workers are constantly and directly exposed to health risks posed by agriculture, and one of these risks originates from contact with farm animals. Seventy-five percent of the emerging infectious diseases affecting humans are zoonotic, meaning they jump from other animal species to humans. Agriculture, which brings humans and animals together in close contact, is an ideal environment for this species jumping to occur.

Bird flu is one in a long list of zoonotic diseases, including bovine tuberculosis, brucellosis, anthrax, and rabies. Currently, though, the spread of a highly pathogenic form of bird flu, its actual impacts on agriculture, and its potential impacts on human health put this disease at the forefront of global human health and development policy. Many resources and specialists in animal and public health have been mobilized as the international community prepares for a possible global pandemic of a human form of bird flu. The Food and Agriculture Organization of the United Nations (FAO) and the World Organization for Animal Health (OIE) have issued a global strategy for controlling the spread of the disease, in collaboration with the World Health Organization (WHO). In recent months the disease has reached Africa and Europe, and authorities still have much to learn about how it spreads.

Although bird flu poses a serious threat of becoming a global pandemic, it is not yet easily transmissible between humans. According to guidelines from the WHO, the best hope for avoiding a pandemic lies in limiting the number of cases in birds, and thereby reducing the number of human cases in which the virus can mutate into a strain capable of human-to-human transmission.

The changes in agricultural practices needed to reduce the risk of bird flu will be just as useful in fighting off other zoonotic diseases that have emerged in the past and that are sure to emerge again in the future. According to Juan Lubroth of the FAO’s Animal Health Section, “The principles for dealing with bird flu are the same as those for dealing with other animal epidemics. You need early detection and warning, early preparedness, better veterinary inspection, and better hygiene at the abattoir and in the marketplace.” Poor countries are far behind on meeting these goals, but bird flu may provide some additional impetus to raise standards.

IFPRI and the International Livestock Research Institute (ILRI) are now undertaking joint research “to help governments make more informed decisions on how to control the spread of a transboundary animal disease such as highly pathogenic avian influenza while minimizing the negative impacts on different socioeconomic groups, particularly the poor,” says IFPRI research fellow Clare Narrod.

More broadly, the challenge of managing both animal and human health has led to some innovative approaches. In some remote, pastoral areas of Africa, veterinarians have a much greater presence than medical personnel, with the result that livestock, which are critical to pastoralists’ livelihoods, have better access to health care than humans. In 2000, the Swiss Tropical Institute set up a pilot program that established simultaneous vaccination for nomadic women and children and for the nomads’ livestock in certain areas of Chad, where children had never received vaccinations of any kind. In addition to vaccinating 136,000 livestock, the pilot program fully vaccinated 4,700 children against polio, diphtheria, tetanus, and whooping cough and fully vaccinated 7,400 women against tetanus. A significant additional number of children received vaccinations against measles and yellow fever. The program is now being integrated into existing agencies and infrastructure in Chad.

“Initiatives to join veterinary and public health services seem to be most effective in remote zones,” says Esther Schelling, a veterinary epidemiologist at the Swiss Tropical Institute. “Costs of vehicles for transportation are very high, especially in the Sahelian countries. In Chad, for example, it is estimated that only about one-fourth to one-half of the rural population lives near enough to a health center to get access to, for example, vaccinations or tuberculosis treatment. And livestock keepers greatly appreciate that the team considers the health of both their animals and their family.”

Creating a Healthier Agricultural Environment

Not only pastoralists, but also farmers find that their health is tied to agricultural practices. Agrochemicals can lead to sizable gains in production, but can also pose serious risks to users. Overuse of fertilizers causes nitrates and nitrites to run off of farmers’ fields and contaminate drinking water supplies. Evidence has shown that in China only 30 percent of fertilizer applications actually reach crops, a situation that not only threatens health, but also needlessly raises farmers’ production costs. The other 70 percent ends up in downstream water bodies or percolates into groundwater.

Pesticides are also used much more than necessary, poisoning thousands of agricultural workers each year. Pesticides and their residues also pollute water resources, and long-term exposure through drinking water is linked to a range of noncommunicable diseases. Researchers from the International Potato Center (CIP) found that pesticide poisonings among potato farmers in the Ecuadorian highlands were 20 times higher than expected. Researchers used computer software that integrates models from different disciplines—agriculture, health, and environment. “The question we’ve tried to answer with the new model is: Which policies can be put into place that will provide adequate levels of protection for the farmers’ potato crop and, at the same time, reduce pollution and improve human health?” says Charles Crissman, an economist at CIP.

The most effective solution, researchers found, was a combination of integrated pest management (IPM) and education about the dangers of pesticide use. A survey had revealed that less than 15 percent of workers who applied pesticides knew, for example, that a skull and crossbones label on a container indicates danger. By using IPM, which relies more on biological control of pests and less on pesticides, farmers were able to maintain their potato yields while reducing their production costs. At the same time, they escaped many of the neurological effects of the pesticides.

This effort to reduce pesticide use among potato farmers in the Andes is part of a broader approach to agriculture and health called “ecohealth,” which tries to create a “virtuous circle” of adequate agricultural production, improved human health, and sustainable agricultural ecosystems. “Instead of targeting the small fraction of the population that is severely affected by a given illness,” says Jean Lebel, director of the Environment and Natural Resource Management Program at the International Development Research Centre (IDRC), “and achieving a very relative success rate, the aim is to attack the root cause of health problems and protect a larger number of people from illness. It is not always easy to convince the communities in difficulty that the proposed solution to their health problems is not large-scale vaccination or some other modern medical program, but simply better management of their natural resources.”

The ecohealth approach has also been tested in the Mwea region of Kenya, a rice-growing region where malaria has persisted in spite of the use of insecticides and antimalarial drugs. Through a project supported by IDRC, a team of specialists from various disciplines worked with villager-researchers to determine the factors behind the high rates of malaria. They found that local farmers, frustrated with government control over irrigation of their rice fields, had recently taken over this responsibility themselves. The result was that farmers then planted when and where they liked, creating many more breeding grounds for mosquitoes. Researchers also found that villages with the highest concentrations of mosquitoes had the lowest rates of malaria—and the largest number of cattle, which the mosquitoes apparently prefer to humans.

The findings suggested several solutions. One is to reduce rice-paddy flooding time and alternate rice with soybean crops, grown on dry land, thereby cutting back on the mosquitoes’ habitat and improving people’s diets at the same time. Others are to maintain the cattle population by using rice husks as animal feed and to place into water sources bacterial preparations that kill mosquito larvae but are harmless to humans. Insecticide-treated mosquito nets would help protect the most vulnerable groups—women and children—from the disease. The Mwea example also illustrates the importance of understanding local ecosystems and social structures before designing interventions.

Agriculture and HIV/AIDS

Because so many people affected by HIV and AIDS depend on agriculture for food and income, especially in Sub-Saharan Africa, agricultural policies and practices loom large in determining how well households cope with the disease. People living with HIV have heightened nutritional needs and less labor capacity, while others in their households require significant amounts of time for care giving. If agricultural policies and programs fail to account for these realities, they are unlikely to meet their objectives and they can worsen the spread and impacts of HIV and AIDS. “Policymakers need to rethink agriculture in the face of AIDS,” says Stuart Gillespie, an IFPRI senior research fellow. “The art is to think across sectoral lines.”

A good example of this kind of cross-sectoral thinking occurred recently when CARE and the Ministry of Agriculture in Lesotho made major changes in a program of agricultural assistance. Beginning in 1995, CARE offered agricultural extension services and participatory planning and learning to help rural households better manage agriculture and natural resources. At the same time the HIV/AIDS crisis was mushrooming. Lesotho is now believed to have one of the highest HIV prevalences in the world: an estimated 29 percent of people aged 15 to 49 were HIV positive in 2003. To respond to the crisis, CARE added messages about HIV and safe sex to its extension activities and began to distribute condoms, with little result.

CARE staff decided to look for a new approach that would do more to support the food security of AIDS-affected households. What could they do that would work for households that lacked easy access to fields, that had limited capacity for labor and often heavy care-giving responsibilities, and that had special nutritional needs related to HIV infection?

They settled on an approach of promoting and supporting homestead gardens. These small plots of land are adjacent to family homes and can be used for growing vegetables. Because they are within sight and earshot of the house, they make it easier to care for ill family members. To contribute to improved nutrition, at least 75 percent of participating households are required to grow at least five different vegetable crops. This program is a small start in the direction of a more holistic response to HIV and AIDS—a response that CARE is now working to promote more broadly in Lesotho.

Agriculture and Obesity and Other Chronic Diseases

Besides the practice of agriculture, the products of agriculture also play an important role in human health. Agriculture is a contributor, for instance, to the world’s current epidemic of chronic, noncommunicable diseases like obesity, diabetes, cardiovascular diseases, and some forms of cancer. Chronic diseases contributed 60 percent of the 58 million deaths worldwide in 2005, according to the World Health Organization, and 80 percent of these deaths occurred in low- and middle-income countries.

One key factor in chronic diseases is diet, and the world’s diet has undergone major, rapid changes in the past half century. As countries, both developed and developing, have become more urban and industrial, people have replaced traditional plant-based diets with high-fat, energy-dense diets that are often poor in essential micronutrients like vitamin A, iron, and zinc. At the same time, people have become more sedentary, exacerbating the health risks of changing diets.

In some cases agricultural policy has exacerbated chronic health problems. In the early 1970s the Brazilian government adopted a range of policies designed to increase production, export, and consumption of soybean oil. The aim was partly to stimulate the soybean industry and generate foreign exchange and partly to provide a cheap source of energy to lower-income families. From a health perspective, the approach succeeded too well. Consumption of vegetable oils soared and today contributes to excessive fat intake in Brazil. “If agriculture is going to contribute to improved nutrition,” says Hawkes of IFPRI, “it faces a real challenge in ensuring a sufficient supply of staples and micronutrient-rich foods without encouraging excessive consumption of energy-dense, nutrient-poor foods.”

The problem, says Tim Lang, professor of food policy at City University, London, is that the agricultural paradigm based on maximizing production to the exclusion of other concerns has outlived its usefulness.

“In the 20th century the basis of agriculture was to produce food to meet need,” he says. “The food industry has brilliantly unleashed capacity to produce food, but now we are overproducing meats and fats and exporting them to developing countries. There are 650 million hungry people in the world, while there are 1.5 billion people who are overweight and obese. We are selling Western diseases to developing countries, and these are expensive diseases.”

Lang sees the world on the brink of choosing between two new paradigms for agriculture. One is what he calls the “life sciences integrated paradigm,” which links genetics, biology, engineering, and nutrition in a science-led integration of the food chain dominated by large life sciences companies. The other he calls the “ecologically integrated paradigm,” driven by environmental concerns and focusing on local, sustainable agriculture. Although most money has gone to promote the life sciences paradigm in the past couple of decades, says Lang, recent awareness of the complexity of managing food and agriculture to meet the needs of all people and of the threat of global climate change have given increased impetus to the ecological paradigm.

Growing—and Eating—Healthier Food

Part of a new paradigm for agriculture may be simply growing healthier foods. For millions of poor people, their daily diet consists of little more than three meals of rice. They may be ingesting calories, but they are not getting the nutrients they need for good health. Lack of micronutrients like iron, zinc, and vitamin A are responsible for poor mental and physical development, disability, disease, and death in hundreds of thousands of poor people worldwide. Yet little research has been conducted on the effectiveness of one of the most obvious approaches: encouraging poor farmers to grow more nutritious foods and educating poor people on why they should eat these foods.

Food-based strategies consist of efforts to increase both the production and consumption of nutritious foods and, when possible, to make the nutrients in foods more easily absorbable by the body.

According to Marie Ruel, director of IFPRI’s Food Consumption and Nutrition Division, a program in Vietnam that included home gardens, fish ponds, and small-animal husbandry, combined with effective nutrition education, increased the iron intake of young children. “Research shows that farmers are likely to experience trade-offs between the income they would gain from selling their home-produced, nutrient-rich foods and the health benefits they would gain from consuming them,” says Ruel, “so strong communication about the benefits of consumption is critical for production-focused agricultural interventions to improve nutrition.”

Another food-based approach is biofortification—creating staple food crops that are more nutritious. The HarvestPlus program, co-convened by IFPRI and the International Center for Tropical Agriculture (CIAT), is working to add micronutrients to rice, wheat, maize, beans, cassava, and sweet potato—crops widely consumed in the developing world—using both conventional plant breeding and modern biotechnology.

“Those most affected by malnutrition, the rural poor, are also the most difficult to reach with traditional nutrition programs,” says Howarth Bouis, director of HarvestPlus. “Biofortified crops have the potential to transform the health of these communities by allowing them to grow crops that are naturally fortified with essential micronutrients.” In addition, biofortification should cost less than vitamin supplements because once seeds are developed, they would cost farmers no more than regular seed.

“Agriculture can be a tool for public health, but developing new technology is only half of the solution,” says Bouis. “The other half lies in effectively getting biofortified foods to the undernourished.” HarvestPlus is now working to reach malnourished people with its first biofortified crop—an orange-fleshed sweet potato high in vitamin A, developed by CIP.

Integrating Health and Agriculture: Can It Be Done?

On a national scale, getting policymakers in the health and agriculture sectors to work together is still an uphill battle. Todd Benson, an IFPRI research fellow, explains that government ministries and agencies are organized strictly along sectoral lines and are normally self-contained. “Instead of collaborating, they may often find themselves competing over budgetary resources,” he says. “In addition, agriculture and health professionals have different objectives—maximizing agricultural production versus providing health services and preventing ill health—and they have entirely different standards for judging their own success.”

It can be easier to tackle joint problems at the community level, says Benson. At that level, development problems are often perceived holistically rather than neatly categorized as “health problems” or “agricultural problems.” These community-level interactions may offer lessons to higher-level professionals from the two sectors. Policymakers should also increase incentives for health and agriculture professionals to work together, says Benson.

One idea for integrating health concerns into agricultural policies and projects is “health impact assessment (HIA)”—an informal process in which experts and affected communities weigh in on the health effects of policy changes. Michael Joffe, an epidemiologist with Wellbeing, Health, and Economic Policy Services in London, gives the example of London’s recent development of a food strategy. “London’s public sector has enormous food-buying power if you consider the hospitals, schools, and so forth,” says Joffe, “and through the HIAwe argued that you can use that buying power to discriminate in favor of healthier foods and sustainable agriculture.”

Although they are gaining popularity in the industrialized world, HIAs are still little used in developing countries, where capacities are limited. “It would help if donors would require HIAs in the planning of development projects they support,” says Robert Bos, scientist in the Water, Sanitation, and Health Program of the WHO. “And it is not just about preventing adverse impacts. In irrigation and dams projects, for example, the opportunities for health promotion are not recognized. When they fail to include access to safe water for drinking or to put in proper drainage that will help control mosquito populations, they are actually transferring hidden costs to the health sector.” Often, the already thin economic benefits of such projects do not allow for investments in designs and measures that promote health. Bilateral donors, says Bos, should offer grants specifically for these health aspects of development projects.

Despite agriculture’s great potential for improving human health, existing ways of managing agricultural policies and projects will leave much of that potential untapped, according to Benson. Exploiting agriculture’s benefits for health will require changing both mindsets and policy processes. Yet growing evidence suggests that the payoffs could be worth the effort. After all, in the end both agriculture and health seek to improve human well-being.

Reported by Heidi Fritschel