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Jul 29th 2004
From The Economist
Nutrition, Food for thought.
Global hunger is on the wane but it is still hampering the growth of people, and of economies
THERE are not enough classrooms at the Msekeni primary school, so half the lessons take place in the shade of yellow-blossomed acacia trees. Given this shortage, it might seem odd that one of the school's purpose-built classrooms has been emptied of pupils and turned into a storeroom for sacks of grain. But it makes sense. Food matters more than shelter.
Msekeni is in one of the poorer parts of Malawi, a landlocked southern African country of exceptional beauty and great poverty. No war lays waste Malawi, nor is the land unusually crowded or infertile, but Malawians still have trouble finding enough to eat. Half of the children under five are underfed to the point of stunting. Hunger blights most aspects of Malawian life, so the country is as good a place as any to investigate how nutrition affects development, and vice versa.
The headmaster at Msekeni, Bernard Kumanda, has strong views on the subject. He thinks food is a priceless teaching aid. Since 1999, his pupils have received free school lunches. Donors such as the World Food Programme (WFP) provide the food: those sacks of grain (mostly mixed maize and soyabean flour, enriched with vitamin A) in that converted classroom. Local volunteers do the cooking—turning the dry ingredients into a bland but nutritious slop, and spooning it out on to plastic plates. The children line up in large crowds, cheerfully singing a song called “We are getting porridge”.
When the school's feeding programme was introduced, enrolment at Msekeni doubled. Some of the new pupils had switched from nearby schools that did not give out free porridge, but most were children whose families had previously kept them at home to work. These families were so poor that the long-term benefits of education seemed unattractive when set against the short-term gain of sending children out to gather firewood or help in the fields. One plate of porridge a day completely altered the calculation.
A child fed at school will not howl so plaintively for food at home. Girls, who are more likely than boys to be kept out of school, are given extra snacks to take home. So are orphans, who are plentiful in Malawi because so many adults have died of AIDS.
When a school takes in a horde of extra students from the poorest homes, you would expect standards to drop. Anywhere in the world, poor kids tend to perform worse than their better-off classmates. When the influx of new pupils is not accompanied by any increase in the number of teachers, as was the case at Msekeni, you would expect standards to fall even further. But they have not.
Pass rates at Msekeni improved dramatically, from 30% to 85%. Although this was an exceptional example, the nationwide results of school feeding programmes were still pretty good. On average, after a Malawian school started handing out free food it attracted 38% more girls and 24% more boys. The pass rate for boys stayed about the same, while for girls it improved by 9.5%.
Better nutrition makes for brighter children. Most immediately, well-fed children find it easier to concentrate. It is hard to focus the mind on long division when your stomach is screaming for food. Mr Kumanda says that it used to be easy to spot the kids who were really undernourished. “They were the ones who stared into space and didn't respond when you asked them questions,” he says.
Richer diet, richer planet
More crucially, though, more and better food helps brains grow and develop. Like any other organ in the body, the brain needs nutrition and exercise. But if it is starved of the necessary calories, proteins and micronutrients, it is stunted, perhaps not as severely as a muscle would be, but stunted nonetheless. That is why feeding children at schools works so well. And the fact that the effect of feeding was more pronounced on girls than on boys gives a clue to who eats first in rural Malawian households. It isn't the girls.
On a global scale, the good news is that people are eating better than ever before. Homo sapiens has grown 50% bigger since the industrial revolution. Three centuries ago, chronic malnutrition was more or less universal. Now, it is extremely rare in rich countries.
For an illustration of how quickly some nations and their diets have grown richer, step into a crowded lift in a Japanese corporate HQ. Etiquette dictates that the most junior employees stand at the front and press the buttons, while the oldest and most senior stand at the back. What is striking, is how much shorter those at the back are. In only a single generation, high-speed economic growth has added centimetres to the national stature. Nutritionists think this kind of thing could happen anywhere.
In developing countries, where most people live, plates and rice bowls are also fuller than ever before. The proportion of children under five in the developing world who are malnourished to the point of stunting fell from 39% in 1990 to 30% in 2000, says the World Health Organisation (WHO). By 2005, this figure is projected to fall below 26%. And the UN's Food and Agriculture Organisation (FAO) estimates that 17% of people in the developing world were undernourished in 1999-2001, a slight drop from 18% in the mid-1990s. The absolute number of undernourished people rose slightly over that period, however, from 780m to 798m.
In recent years, such improvements have stemmed largely from swift economic growth in China and, to a lesser extent, India. Most of the world's malnourished children are still in Asia, but the average Chinese enjoys a third more calories today than he did two decades ago.
Africans are doing less well. A third of Africa's people are undernourished, a figure that barely changed between the mid-1990s and the turn of the millennium. In central Africa, which has been thrown into confusion by the war in Congo, the proportion of hungry people rose from 53% to 58% between 1995 and 2001. More peaceful parts of Africa did much better: and malnourishment is on the retreat in such places as Nigeria, Angola, Ghana, Malawi and Madagascar.
Even those who have never experienced it know that hunger is a bad thing. But can the harm it inflicts be measured? Up to a point, yes. Malnutrition is the largest single contributor to disease, according to the UN's standing committee on nutrition. Hunger weakens the immune system. At the same time, disease can aggravate malnutrition. This may be direct—for example, when infection leads to appetite loss, or impedes the absorption of nutrients into the bloodstream—or indirect, say when a peasant is too sick to work, and so grows less millet.
Inadequate nutrition of mothers and young children alone is responsible for 9.5% of the global burden of disease (see chart). Underweight infants are much more likely to succumb to diarrhoea, malaria or pneumonia. And, by some estimates, more than half of the 10m annual deaths of young children are directly or indirectly attributable to malnutrition. Furthermore, the interaction of hunger and AIDS aggravates matters. HIV infection progresses more quickly to full-blown AIDS in a body weakened by hunger. And hungry women are more likely to sell their bodies to buy food.
Obviously, what hungry people need first and foremost is more food. But they also need better food. The most basic kind of malnutrition is called “protein energy deficiency”. In other words, a diet that is lacking in energy because of a deficit in all the major macronutrients—such as carbohydrates, fats and proteins. Typically, though, such a diet will also be deficient in many micronutrients. As a consequence many lives are blighted for want of tiny amounts of iodine, iron, vitamin A and zinc. Micronutrient deficiencies are ranked eighth among the top ten risks to health worldwide by the WHO.
Take iodine. Nearly 2 billion people consume less of this mineral than they should—usually because the water and soils where they live lack it. The most visible sign of iodine deficiency is a swelling of the thyroid gland called a goitre. The most important effect, though, is on the brain, which cannot develop properly without iodine. Each year, says the UN, some 20m children are born mentally impaired because their mothers did not consume enough iodine. The worst affected suffer cretinism, the symptoms of which include severe mental retardation and physical stunting.
Iron deficiency, meanwhile, is the most common nutritional deficiency in the world, affecting some 4.5 billion people. Iron is essential as it forms the molecules that carry oxygen in the blood. Symptoms of deficiency include fatigue, shortness of breath and lethargy. A lack of iron damages productivity and cuts GDP by 2% in some countries says the WFP. Researchers Sue Horton, of the University of Toronto, and Jay Ross, of the Academy for Educational Development in Washington, estimate that lost productivity due to iron-deficiency anaemia costs Bangladesh 7.9% of GDP each year.
Worse, perhaps, is that iron deficiency impedes cognitive development. Some 40-60% of children in developing countries are impaired in this way. Nevin Scrimshaw, a nutritionist at the United Nations University in New Hampshire, says that iron-deficient children are retarded by the equivalent of five to ten IQ points.
Meanwhile, vitamin A deficiencies compromise the immune systems of a large proportion of those under five in poor countries—increasing their susceptibility to infectious diseases, and ultimately causing 1m infants to die each year. Deficits also cause hundreds of thousands of children to go blind each year, says the Micronutrient Initiative, a lobby group based in Ottawa. Finally, insufficient zinc appears to be linked to a higher risk of dwarfism, diarrhoea and pneumonia.
Of course it is difficult to disaggregate the effects of deficiencies in micronutrients from hunger more broadly. Both hungry and mineral-deficient people tend to be weaker, more prone to illness and less intelligent. This must in turn make them poorer. Weak manual labourers produce less, and so earn less. Clever workers tend to earn more. Thus, malnourishment is not only a consequence of poverty, it is also a cause of it. Only the poor are hungry, and their hunger tends to keep them poor.
Masautso Fraxon, a 13-year-old Malawian boy, dropped out of school last year after his parents died and he was no longer being fed. He supports himself and his grandmother by doing odd jobs in other people's fields. A full day's toil can pay up to 100 kwacha ($1), but if Mr Fraxon has not eaten, he can only put in 20 kwacha-worth before he has to stop, exhausted. He then comes home, spends his paltry wages on food, and rests for the remainder of the day. At the best of times, his wages buy only slightly more calories than he expends to earn them.
Mr Fraxon's ambition, he says, is to set up his own business buying and selling fish. He says he has trouble reading and writing, but is good at sums. Your correspondent asked him what six times six was. He replied: “22”.
Western experts tend to tiptoe around the issue of how malnourishment makes people less intelligent, but local experts sometimes do not. “If your brain is stunted when you are young, that affects the decisions you make in later life. If you can't do simple arithmetic, you won't invest wisely. The cost of that will be very high,” says Tomaida Msisika, a consultant on food security in Malawi.
Sam Chimwaza, an analyst for Malawi's Famine Early Warning Systems Network, says that the reasoning ability of people in rural areas has been affected by malnutrition and it is hard for them to execute simple instructions. “They can work as servants in the city for two or three years and still not figure out how to adjust the temperature on an iron,” he says.
Several pieces of research have shown the broader economic effects of these problems. A study on Zimbabwe found that children exposed to a drought completed on average nearly five months less schooling (and were 2.3cm shorter than expected). It estimated that this resulted in a loss of 7-12% of lifetime earnings. At a somewhat larger scale, the World Bank estimates that in low-income countries, the net present value of causing children to be born of normal rather than low weight would be about $580 per child. That is more than a year's average income in a typical sub-Saharan African country.
Sadly, the battle against hunger is harder to win than it should be. Food shortages tend to occur in countries with callous, despotic rulers. That is why a 14-year-old male North Korean refugee is on average 25cm shorter than his South Korean peer. In the long term, economic growth and improved agricultural technology offer the surest cure for malnutrition. In the meantime, there are several quick, cheap fixes.
Hungry for change
Iodine deficiency, for example, can be eliminated at minimal cost by iodising salt. Progress in this area has been rapid. Since 1990, after sustained efforts by many governments, the proportion of household salt that is iodised has risen from less than 20% to more than 60%. But there is no good reason why it should not be 100%.
Similarly, iron deficiency can be tackled by fortifying flour with iron. And although it is better to get one's vitamins from normal food, pills can help. In places where vitamin A deficiency is rife, supplements can reduce child mortality by 23%.
Some of the harm caused by malnutrition is irreversible, and this is especially likely if it occurs in the womb or during the first two years of life. So it is crucial to get good food into infants early and often. Breastfeeding is the best way to do this, unless the mother is HIV positive. By one estimate, exclusive breastfeeding in the first six months of life, followed by more breastfeeding between six and 11 months, could reduce the number of deaths of children under five by 1.3m a year, or 13% of the global total.
Educating women is also important. As more women go to school, fewer of their children end up malnourished. A study of 63 countries by Lisa Smith and Lawrence Haddad, of the International Food Policy Research Institute in Washington, found that improvements in women's education and life expectancy relative to men's helped to reduce the proportion of children who were malnourished by 50% between 1970 and 1995.
Many mothers, however, still know too little about nutrition to make the best use of the food that is available to them. Poor people are often tremendously knowledgeable about the environment in which they live, but they are also usually reluctant to try anything new. Malawians, for example, have an attachment to nsima (maize porridge) that strikes outsiders as nearly religious in its intensity. Ask a Malawian if he has eaten today, and if he has not eaten nsima, he will probably say “no”.
Patricia Saukila, who works for the WFP in Lilongwe, the Malawian capital, says there is a lot of resistance to dietary change. People do not rear enough chickens and goats, she says, and even if they do they tend to sell them to buy maize rather than eat them. The result is a great deal of protein deficiency, visible in the swollen limbs of so many of the children.
One way to tackle dietary conservatism is to concoct tasty new recipes. Aid workers in Zambia—another southern African country with a maize-porridge fixation—have fooled street children into eating vegetables by dicing them and mixing them with maize porridge. The WFP has even come up with ways to make the “fortified blended foods” it doles out more palatable. Maize-soya porridge can be pepped up with mangoes, tamarind or tomatoes. Blended flour can be baked into cakes and sweetened with bananas or molasses.
Many of the things that would ease hunger are worth doing anyway. Policies that promote economic growth or better education would be desirable even if they had no impact on nutrition. Democracy and freedom of speech are attractive in and of themselves. But it is also worth noting that rich, well-educated countries never go hungry, and that no democratic country with a free press, no matter how poor it may be, has ever suffered a famine. Unfettered reporters provide early warnings, and accountable governments know they have to respond to emergencies. The recent crushing of the independent media in Zimbabwe is one reason why the WFP expects trouble this year.
In other places, the battle against hunger is steadily being won. Better nutrition is making people cleverer and more energetic, which will help them grow more prosperous. And when they eventually join the ranks of the well off, they can start fretting about growing too fat.