FOR a few brief years back in the 1960s, it looked as if there would be
enough food to feed everyone on Earth鈥攑roperly and regularly. This
optimism was born of the Green Revolution, the worldwide drive to introduce
high-yielding cereals and Western agricultural techniques to Asia and parts of
Africa and South America.
To some extent the optimism was justified. Between 1955 and 1985, world grain
production rose from 273 to 343 kilograms per person. India witnessed a
particularly spectacular gain: its total grain production trebled over that same
period, averting the huge famine that many had predicted would lay that country
to waste. But, like most revolutions, the Green Revolution had its detractors.
They pointed out that many people were still starving, and that the new crop
varieties were responsible for the soaring use of fertilisers and pesticides,
soil degradation, and for putting the economies of Third World countries at the
mercy of agrochemicals multinationals.
Now, however, there is increasing disquiet about another failing of the
revolution. In the early 1990s, nutritionists started noticing something
alarming and completely unexpected. Even in countries where the average food
intake had increased, incapacitating diseases associated with mineral and
vitamin deficiencies were still commonplace or, in some cases, actually
increasing. And according to a 1992 UN report on nutrition, some of these
deficiencies can be directly linked to the increased consumption of Green
Revolution crops.
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Vicious circle
The high-yield rice, wheat and maize varieties that the revolution spawned
are usually low in minerals and vitamins, and because they have displaced the
local fruits, vegetables and legumes that traditionally supplied these
essentials, the diet of many people in the developing world is now dangerously
low in iron, zinc, vitamin A and other micronutrients.
The paradox then is that even as the food supply in some countries has
increased, so has the number of people suffering incapacitating vitamin and
mineral deficiencies. This is threatening to lock parts of the Third World into
an endless cycle of ill-health, low productivity and underdevelopment.
The cycle works like this. Deficiencies in certain vitamins and minerals sap
people鈥檚 ability to resist infection and their capacity to do manual work. Those
two factors alone can wreck a country鈥檚 chances of progressing towards
sustainable economic growth and having a healthy, long-lived population. But
perhaps even more importantly deficiencies strike at one of the major forces
that drive progress鈥攊ntellectual resources. Improving primary school
education is one of the most efficient ways to fuel a country鈥檚 advancement, but
that opportunity can be wasted on children who are lacking certain key vitamins
and minerals because they may simply be incapable of learning.
鈥淚t鈥檚 a vicious circle,鈥� says plant physiologist Ross Welch of Cornell
University in Ithaca, New York. People who are continuously starved of
micronutrients never fulfil their intellectual or physical potential. 鈥淔or
development, we need to kick-start productivity,鈥� he says, 鈥渁nd to kick-start
productivity, we need to kick-start nutrition.鈥�
Welch is one of the authors of a paper on the crisis due to be released next
week by the International Food Policy Research Institute in Washington DC. In
the report, which the IFPRI hopes will help set the agenda for international
agricultural research for the next few decades, Welch and Robin Graham, a plant
scientist at the University of Adelaide in South Australia, argue that the only
thing that can help developing countries escape this impasse is a second
revolution.
This new revolution would avoid the traditional response to dietary
deficiencies鈥攖he expensive and piecemeal distribution of vitamin
injections, pills and other dietary supplements by aid organisations. Instead,
they argue, the crisis demands nothing short of an international effort to breed
new crop strains for the Third World which are both high-yield and rich in
vitamins and minerals.
Worsening worldwide
Take iron. The UN Food and Agriculture Organization in Rome estimates that
the amount of iron in people鈥檚 diets fell in most developing regions of the
world between 1970 and 1989, making iron deficiency the only nutritional problem
to have actually worsened worldwide. The most dramatic fall in iron intake
occurred in South and Southeast Asia, the very regions where the average
calorific intake has soared because of the Green Revolution. And as the amount
of iron falls, South and Southeast Asia, and other parts of the developing world
are experiencing a pandemic of anaemia. (The only exceptions are North Africa
and the Middle East, where the amounts of iron in the diet have increased and
the incidence of anaemia is down.) Worldwide, 40 per cent of non-pregnant women
and 50 per cent of pregnant women are anaemic, and at least 1.5 billion children
suffer from iron deficiency.
Iron is a component of haemoglobin, the blood鈥檚 oxygen-carrying molecule.
Severe anaemia is estimated to be responsible for up to 40 per cent of the half
a million deaths associated with childbirth each year, sometimes by triggering
heart failure by starving the heart muscle of oxygen during labour. And
anything that reduces the survival of pregnant women can have a massive impact
on a country鈥檚 productivity. The World Bank estimates that pregnancy-related
problems account for 18 per cent of healthy years of life lost in women aged
between 15 and 44, more than any other single cause. That loss cuts deep into a
country鈥檚 resources, because in the developing world women provide most of the
unpaid labour and one third of the wage labour.
As if that weren鈥檛 bad enough, iron deficiency may have an even greater
impact on a country鈥檚 intellectual resources. It causes debilitating tiredness
and poor concentration, and may even directly affect the development of the
nervous system. Either way, children who are iron-deficient cannot benefit fully
from their education. Ernesto Pollitt, an expert on human development, and
Ponpon Idjradinata of Padjadjaran University in Bandung, Indonesia at the
University of California at Davis found that iron-deficiency anaemia was
responsible for the poor mental and motor skills of a group of West Javanese
toddlers aged between 12 and 18 months old.
On the Bayley Scale, an internationally agreed standard for testing child
development, 50 anaemic West Javanese children scored an average of 88.5 and
88.8 respectively for their motor and mental skills, compared with 105.3 and
105.4 for 47 children who had normal levels of iron in their blood. After
receiving daily doses of 3 milligrams of iron per kilogram of the child鈥檚 weight
for four months, the scores of the previously anaemic children soared to 112 and
108.1 for motor and mental skills. In a similar study of more than a 100
children aged between 8 and 13 living in central Java, Politt鈥檚 team found that
when the anaemic children received iron supplements, their school test results
improved significantly compared with anaemic children who received placebo
pills. Just how iron affects motor and cognitive development in children is
still being investigated, but, says Pollitt, 鈥渨e know iron is abundant in
various areas of the brain, and that a number of neurotransmitters need iron [to
蹿耻苍肠迟颈辞苍闭鈥�.
And iron isn鈥檛 the only micronutrient essential for mental development that
is in short supply. According to the International Maize and Wheat Improvement
Centre in Mexico City, between 65 and 75 per cent of people living in the Middle
East and North Africa get most of their calories from bread made from low-zinc,
high-yield wheat. Zinc is needed in such minute quantities that severe
deficiency is extremely rare, but moderate deficiency, which is common in many
developing countries, triggers a wide range of disorders including loss of
appetite and depressed immune responses. In rats and mice, zinc is found in high
concentrations in the hippocampus, a part of the brain that is important for
learning and memory, and studies on humans suggest that we also need it for
optimal intellectual and physical functioning.
One such study was carried out by psychologist James Penland of the Grand
Forks Human Nutrition Research Center in North Dakota and his colleagues. They
found that, after receiving a 10-week course of 20 milligrams of zinc daily, a
group of Chinese children aged between six and nine, who had been zinc
deficient, performed significantly better in coordination and dexterity tests
than similar children who received a supplement that did not contain zinc.
Penland also found that a diet containing between 3 and 4 mg of zinc per
day鈥攚hich is well below the recommended daily intakes for that
nutrient鈥攁dversely affected the short-term memory and manual dexterity of
14 healthy American men. 鈥淭here鈥檚 a difference in having enough zinc to survive
from day to day and having the amount needed for optimal brain function,鈥� says
Penland. 鈥淔or those with long-term deficiency, that鈥檚 a great concern.鈥�
Scratching the surface
One of the other micronutrients in short supply is vitamin A. While the
numbers of people suffering from vitamin A deficiency appears not to have
increased, Green Revolution crops have done nothing to improve an already
desperate situation. Severe vitamin A deficiency blinds up to half a million
children each year.
But there is a far bigger problem which has been largely ignored until
recently: 227.5 million children and untold numbers of adults receive just
enough vitamin A to stave off blindness but not enough to maintain either their
immune systems, or the lining of their guts and respiratory tracts, which act as
a first line of defence against infection. Because these subclinical
deficiencies are so widespread, and because they greatly increase the likelihood
that people will become infected or die from, a variety of diseases ranging from
diarrhoea and measles to HIV, they potentially have an even greater impact than
blindness on a country鈥檚 productivity.
What makes finding solutions to the iron, zinc and vitamin A deficiencies so
urgent is the immense scale of the problem. Micronutrient deficiency is not
unknown in the West (in Britain, for example, there is a high prevalence of
anaemia in toddlers in inner-city areas). But in some developing countries the
majority of the population suffer this hidden starvation, which undermines their
productivity and any potential for development. The World Bank estimates that
iron, vitamin A and iodine deficiencies are responsible for slicing as much as 5
per cent from the GDP of the developing world, enough to wipe out any economic
growth in a low-income country.
What is more, according to IFPRI director-general Per Pinstrup-Andersen, the
traditional approach of providing vitamin and mineral pills and injections is
too expensive to implement on a scale large enough to do anything but scratch
the surface of the deficiency pandemics. Food fortification, often the approach
of choice in the West, is not practicable either, since it requires a
sophisticated food-processing industry and enforceable laws to ensure that what
should go into the food actually does. A third, more hopeful, option is to
re-introduce into Third World countries the once commonplace plant varieties
that are high in micronutrients, says Pinstrup-Andersen. But, he says, it will
take decades to develop strains that are high-yielding enough to make it worth
the farmers time to grow them, and require large-scale education programme to
get poor people to include the plants in their diet.
Plotting the escape
It was dilemmas such as these that inspired Welch and Graham to attack the
problem at its source. Cereals make up more than 90 per cent of people鈥檚 diets
in developing countries, so the two researchers reasoned that the best way to
treat the worldwide pandemics was simply to pack the micronutrients into grains
and beans as they grew. Graham had already identified a high-yield strain of
wheat that extracts zinc from even the poorest soil and concentrates it in its
seeds.
Meanwhile, researchers at the International Centre for Tropical Agriculture
in Cali, Colombia, have identified a strain of cassava, a crop that makes up a
large part of the diet of people in West Africa and parts of South and Central
America, that is high in betacarotene a precursor of vitamin A. Over the next
five years, Welch and Graham, working with researchers at international
agricultural centres in the Philippines, Mexico and Colombia, will scour seed
banks around the world for strains of maize, rice, wheat, beans and cassava that
are particularly high in iron, zinc and betacarotene.
Once they have found the richest strains, the researchers will grow them,
measure their yields, and where necessary crossbreed them to improve the yield.
In the final five years of the project, each micronutrient-enriched strain will
be grown under the conditions found in developing countries, and only those
strains that survive with their high-yield figures intact will be distributed to
farmers.
One aspect of plant genetics makes Welch and Graham particularly hopeful that
their enterprising project will reap dividends. Unlike breeding plants for high
yield, a trait to which hundreds of genes contribute, the ability to remove
micronutrients from the soil is often carried by only a few major genes. For
instance, a major gene is responsible for an enhanced ability to draw iron from
the soil in plants as disparate as soya bean, tomato, and maize. (The
researchers will not attempt to tackle iodine deficiency by breeding, because
that micronutrient is virtually absent from plants, and too little is known
about its potential for genetic enhancement.)
Moreover, the micronutrient content of plants need only be increased by a
modest amount to have a major impact on worldwide deficiencies. For instance,
says Howarth Bouis, an IFPRI economist, increasing the iron content of a staple
food such as rice from 15 to 50 parts per million would double the iron intake
of anyone who relied on that food, and could potentially wipe out iron
deficiency.
Micronutrient-rich plants have a better chance of reaching larger numbers of
people than vitamin and mineral supplements, and they are also far cheaper.
Bouis estimates that to produce commercially viable strains of crops that are
high in zinc, iron and betacarotene will take 10 years and cost no more than
$20 million鈥攚hich would only buy enough iron pills to treat about a
third of the anaemic pregnant women in India for a year. Because of their
exceptional ability to draw minerals from the soil, says Graham, the
鈥渕icronutrient-efficient鈥� strains will also be able to grow in
mineral-deficient soils for hundreds or even thousands of years with the
addition of little fertiliser.
Even so Welch and Graham admit that the project could still face major
hurdles. They are painfully aware, for instance, that plans in the early 1970s
to breed maize that was high in lysine, an amino acid essential for infant
growth, were derailed. To begin with the varieties which contained lysine in
abundance were the ones that had low yields. To make matters worse, the meal the
maize produced had a strange texture that made it unpleasant to eat. Eventually,
these problems were resolved, but not before the concept of breeding plants for
a particular nutrient content had been given a bad name.
Similar problems are less likely to hit breeding programmes designed to
create plants with a high mineral content because minerals make up only a minute
fraction of the seed and are therefore unlikely to affect the overall flavour
and texture. Plants that are high in betacarotene do, however, have a yellowish
tinge. One way round this would be to educate consumers to recognise yellow
grain as being better for them than the white. But a far better way, says Welch,
is to make sure the micronutrient-rich varieties have a higher yield, with even
less fertiliser, than the varieties farmers already have at their disposal. 鈥淚f
the varieties are high-yielding, they make more profits, and farmers will grow
them,鈥� says Welch.
鈥淚f we can double or treble the micronutrient content of these crops, we will
have a major impact,鈥� says Pinstrup-Andersen, 鈥淏ut it鈥檚 not going to happen
for 5 to 10 years.鈥� Meanwhile, he says, 鈥渨e must do everything we can with
supplements, and fortification, and education, but we must recognise that those
efforts will only reach a small proportion,鈥� of the two billion plus people
around the world who currently suffer from hidden hunger.