Fighting Hidden Hunger

In the early 1980s researchers from the Johns Hopkins University School of Hygiene and Public Health studying vitamin A consumption and blindness in Indonesia noticed that children with mild night blindness and dry eyes—symptoms of vitamin A deficiency—appeared to be at a higher risk of dying in the next three to four months. To follow up, they studied 30,000 children in 450 villages on the island of Sumatra, giving children in half of the villages a large dose of vitamin A every six months and children in the other villages nothing. The findings were so dramatic that nutritionists could scarcely believe them.

“We found that two cents’ worth of vitamin A twice a year brought down mortality rates by more than 30 percent. It generated a lot of skepticism, but other studies replicated it, and they confirmed the findings,” says Keith West, an associate professor at Johns Hopkins. A lack of vitamin A, it was clear, could be lethal.

This discovery contributed to a fundamental shift in the focus of nutrition projects in developing countries. With respect to diet, instead of being concerned only with whether people were getting enough energy, development practitioners began to also concern themselves about whether people were getting enough micronutrients—the vitamins and minerals that help the body function. In the last decade or so, progress has been made—iodine and vitamin A deficiencies are on the decline—but there is a long way to go. Researchers in a number of fields are working on improving old ways of combating poor nutrition and on developing new methods of delivering nutrients to the people who need them. Their successes could lead to healthier, more productive lives for billions of people.

The Price of Poverty
In industrial countries micronutrients are everywhere. Dozens of foods, like milk, flour, and breakfast cereal, are fortified, and multivitamin supplements are readily available. And most people can afford to eat a varied diet that includes naturally occurring sources of micronutrients.

In developing countries, however, the problem of micronutrient deficiencies is huge. Although data are scarce, available estimates are cause for alarm. More than half of pregnant women and school-age children suffer from iron deficiency anemia, as do more than 40 percent of nonpregnant women and preschool children. Some 100–250 million preschool children alone are affected by severe vitamin A deficiency. And 740 million people are affected by goiter, a symptom of iodine deficiency.

The costs of these deficiencies in terms of lives lost, forgone economic growth, and poor quality of life are staggering. According to Rebecca Stoltzfus, associate professor at the Johns Hopkins University School of Hygiene and Public Health, iron deficiency anemia in children impedes mental and physical development, damages the cardiovascular system, and can lead to death. In women of reproductive age, it can cause preterm births and contribute to maternal mortality during delivery. Susan Horton, professor of public health and economics at the University of Toronto, has found that anemia causes 65,000 maternal deaths a year in low-income countries in Asia. She estimates that iodine deficiency causes losses of adult productivity equal to 3.3 percent of gross domestic product (GDP) in Pakistan, and a group of economists at the Administrative Staff College of India estimates that in India iron deficiency causes losses equal to 1.25 percent of GDP.

Iron and vitamin A deficiencies are often linked to poverty. “Poor people frequently cannot get access to a sufficient quantity and variety of high-quality foods that are rich in nutrients,” says Rafael Flores, an IFPRI research fellow.

Loading Nutrients into Foods
The biggest global micronutrient success story is probably the fortification of salt with iodine. Iodine deficiency leads to mental impairment, even at mild levels. “If you did nothing about iodine deficiency, many schoolchildren would be performing at a level close to mental retardation,” says Werner Schultink, senior adviser on micronutriuents at UNICEF. Fortunately, adding iodine to salt is a cheap process, and 70 percent of the world’s population now consumes iodized salt, according to Schultink.

The appeal of fortification is that it does not require people to change their eating behavior. It does require, however, getting nutrients into the foods they already eat. Most Latin American countries have mandatory fortification of flour, says Venkatesh Mannar, executive director of the Micronutrient Initiative, which organizes and supports micronutrient programs worldwide. “The advantage of wheat flour is that you can add several nutrients, including vitamin D, B vitamins, folic acid, and iron. But the choice of vehicle for fortification is very limited in many countries.” A food to be fortified must be available to and consumed by the entire population, and it must be “fortifiable.”

The greatest micronutrient deficiencies tend to be in South Asia, where rice is a staple. “One problem is you can’t cheaply fortify rice,” says Horton. “You could coat the grain, but people wash rice. Or you can break down the grain, fortify it, and reconstitute it, but this is 10 times more expensive than fortifying wheat flour, and people tend to pick out the broken grains.”

“The other big issue, equally important,” Horton explains, “is that because rice is processed in so many places, often by small processing plants, it is very difficult to use as a fortification vehicle.” Because of these difficulties, some Asian countries are beginning to fortify other local staples, like soy sauce in China, fish sauce in Viet Nam, and noodles in Thailand.

The Micronutrient Initiative is leading a project to fortify salt with iron as well as iodine. “It’s quite a challenge getting both iron and iodine in salt because they compete with each other,” says Mannar. “Our solution was to encapsulate each iron and iodine molecule.” The new double-fortified salt is about to be tested in a few countries.

Vitamin Pills for All?
A range of efforts are underway to fortify foods, but why can’t aid agencies simply circumvent the difficulties of fortification and distribute micronutrient supplements to the people who need them? In some cases, that is what they are doing. Supplementation seems to work best for vitamin A, which can be stored in the body for six months. This means that supplements can be given just twice a year.

“Supplementation used to be considered a short-term solution until dietary solutions kick in, but it now seems to be a longer-term prospect,” says Schultink. This is because varied diets that include a range of nonstaple foods depend on long-term income increases for the poor. Moreover, recent research has shown that vegetable sources of beta-carotene, which is converted to vitamin A in the body, are not as well absorbed by the body as previously thought.

At certain stages of life, supplementation may be the only way to get people all the nutrients they really need, even people who eat a varied and nutritious diet. This is particularly true during pregnancy, when both the mother and the fetus have an enormous demand for a range of nutrients. “We still need to provide iron supplements during pregnancy,” says Stuart Gillespie, research fellow at IFPRI. “It’s a fallacy to think we can phase them out. But by targeting supplements to people who need them the most, we can reduce the number of people getting supplements and reduce costs.”

Even if you can get the pills to the people who need them, individuals will not always take them. “If you give pregnant women iron and make sure they take it every day, their iron status will be much better,” says Mannar. “But in the real world, there are issues of compliance. Communication is a huge part of it.”

New Ways of Eating
Nutritionists agree that part of the solution to micronutrient deficiencies is convincing people to make their diets more nutritious. So far, however, most attempts to change people’s eating behavior have been unsuccessful. “It’s often difficult to make dietary changes using local foods if you’re poor. You can’t afford a nutritious diet,” says Stoltzfus.

One project designed to increase vitamin A consumption among the poor in northeast Thailand showed positive results. The project promoted vitamin A-rich foods as something used by loving and caring mothers, focusing on a locally grown vegetable—ivy gourd—rich in vitamin A that people could cultivate themselves. “It’s not that we were interested in promoting only one green vegetable,” says Suttilak Smitisiri of the Institute of Nutrition, Mahidol University, Thailand. “We promoted the ivy gourd as representing other green vegetables. And we chose green vegetables not because they are the best sources of vitamin A but because they are the most-available sources for northeast Thailand.”

Most projects seeking to change diets, however, end with people’s returning to their old ways. “Dietary approaches have worked in only limited settings,” says Mannar of the Micronutrient Initiative. “They require lots of inputs and education. When they are scaled up, they rarely work, so they tend not to be sustainable.”

Putting the Nutrients in Staple Crops
One new strategy for supplying micronutrients to the poor in developing countries involves making the staple foods they eat more nutritious by using conventional plant breeding and biotechnology. This is potentially a low-cost, sustainable strategy: it would not require people to change their eating habits and would not impose the recurring costs that accompany fortification and supplements. The greatest potential for improving nutrition status on a wide scale probably involves rice, which is a staple for billions of people in Asia.

Howarth Bouis, an IFPRI senior research fellow, leads a collaborative initiative among international agricultural research and nutrition centers to breed for nutritionally improved staple food crops. Because different varieties of a crop can have different levels of micronutrients, plant scientists can breed for this trait, he explains. “Iron is in every rice endosperm, with lots of variation in levels. Plant breeders can take a high-iron rice and cross it with a high-yielding plant,” says Bouis.

In fact, as part of this initiative the International Rice Research Institute in the Philippines has identified an iron-and zinc-dense rice variety that is also high yielding and disease resistant. One potential obstacle to this approach is that plant sources of iron usually contain compounds that impede iron absorption by humans. “In a pilot feeding trial at a Philippine convent, the iron status of the sisters improved after eating this high-iron rice for four months,” according to Glenn Gregorio, IRRI’s coordinator of the research. A larger-scale trial with a control group is planned to see if results can be confirmed.

For vitamin A, a conventional plant breeding approach is out of the question, because there is no known rice variety that contains beta-carotene in the endosperm (the milled rice grain). So researchers at the Swiss Federal Institute of Technology used genetic engineering to transfer beta-carotene from another species into rice. In January 2000 they announced that they had created a so-called golden rice, which contains beta-carotene, by inserting two genes from the daffodil and one gene from a bacterium into the genetic material of a rice plant.

”The benefit of having the beta-carotene in the crop is that the delivery system is already there,” says Gary Toenniessen of the Rockfeller Foundation, which helped fund the research. “The current generation of improved varieties is being grown in rural areas not being reached by supplements, for instance.”

Although golden rice contains only small amounts of beta-carotene, it is an exciting first step in the effort to make staple crops more nutritious. Getting this variety to farmers will still require putting the beta-carotene into rice varieties preferred by farmers and consumers, nutritional and biosafety studies, and field trials. Commercial adoption of golden rice is several years away.

“We hope that our example will encourage other scientists and granting agencies to follow the golden rice case with other traits and other crop plants important for food security in developing countries,” says Ingo Potrykus, who led the Swiss research team.

“Nutrient-dense staple crops could play a major role in reducing malnutrition, but up to this point substantial funds have not been invested in the strategy,” says Bouis.

No Single Solution
Iron, iodine, and vitamin A are not the only micronutrients that need attention in developing countries—they are just the ones that nutritionists know the most about. But evidence is growing that other micronutrient deficiencies may be as serious. Marie Ruel, a research fellow at IFPRI, says, “We have only recently started to pay attention to zinc deficiency, which has symptoms just as serious as those of iron and vitamin A deficiencies.”

No single solution is likely to solve the micronutrients problem. “The consensus among nutritionists now,” says Flores, “is that we need to use a combination of approaches: fortification, supplementation, and food-based approaches, including plant breeding. If we wait for a food-based approach alone to work, we will not solve the problem. The magnitude of the problem is so big that we can’t wait.”

In the end reducing poverty may have the greatest impact on people’s nutrition by giving them access to a variety of foods and making it possible for developing countries to afford fortification and supplementation efforts. In the meantime researchers are pursuing new avenues to broaden the options for combating this persistent problem.

Reported by Heidi Fritschel
All or part of the text of this article may be reprinted without permission but with acknowledgment to IFPRI. Please send copies to IFPRI.

Next article