LONDON (AlertNet) - Most families across the world will have felt the pinch from the rising cost of food in the past few years. But in poorer nations the health risks, particularly for young children, are far more severe.
In developing countries people spend a larger proportion of their income on food than in wealthy countries – as much as 80 percent in some cases. So when prices head higher, they cut down on non-staple foods like meat, fish, fruit and vegetables, which contain more minerals and vitamins than cereals and grains but are more expensive.
"When food prices go up, people become poorer, and they can't afford to buy as diverse a basket of food as before," says Lawrence Kent, an agricultural development officer with the U.S.-based Bill & Melinda Gates Foundation. "And it's when you cut out nutritious foods that people are more susceptible to deficiencies."
With international food prices having touched a record high in February, there is concern that a growing number of poor families are not consuming enough micronutrients – including iron, zinc and vitamin A – to stay healthy and enable their children to develop properly.
Micronutrient malnutrition – often called "hidden hunger" – can cause stunted growth, anaemia, complications in childbirth, blindness and greater susceptibility to infections like diarrhoea and measles.
For example, between 250,000 and 500,000 vitamin A-deficient children become blind every year, half of whom die within a year of losing their sight, according to the World Health Organisation (WHO). Vitamin A deficiency hits young children and pregnant women the hardest, especially in Africa and southeast Asia.
Experts say finding sustainable ways to improve the nutritional status of low-income families is more urgent than ever. In many developing countries, local food prices are heading back up towards their 2008 peaks, and are expected to remain under pressure in the coming decades as climate change threatens crops with more droughts and floods and the world's population expands.
One promising solution, which is starting to gain ground in Africa and Asia, is the breeding of crop varieties enriched with higher levels of minerals and vitamins – a process known as biofortification.
ORANGE SWEET POTATO
HarvestPlus, an international programme that is breeding nutrients into staple food crops to reduce hidden hunger, released its first varieties of vitamin A-rich orange sweet potato in Uganda and Mozambique from 2007-2009. It says 65-75 percent of target households adopted the conventionally bred sweet potatoes, leading to increases in vitamin A intake of two thirds or more among children and women.
In Uganda, four varieties of orange sweet potato – two with naturally high levels of vitamin A and two new biofortified types – were introduced in three districts, covering around 10,000 households.
While Ugandans already grow white sweet potatoes, the challenge was to get them to try the orange version, which is generally sweeter and softer, says Anna-Marie Ball, the HarvestPlus country manager in Uganda. But persuading farmers, many of them women, to start growing the crop and feeding it to their families wasn't as difficult as she'd been warned.
Children like the bright colour and the sweet taste. And a health ministry programme that hands out vitamin A capsules alongside twice-yearly immunisations had helped raise nutritional awareness among mums.
"We could explain that the orange sweet potatoes contain vitamin A, and with a scoop a day, children can maintain their (vitamin) stocks and immunity to disease," says Ball. "This clicked with people."
For Jennifer Amoding, a farmer in Bukedea District and a widowed mother of 13 children, the orange sweet potato offered a way not just to provide better food for the four grandchildren she lives with, but also to generate additional income. Cultivating it enabled her to pay for medical treatment, buy sugar, soda and soap, and even start building a new home.
"I have always had a dream of sleeping in a tin-roofed house. So when we were told that we could sell (orange sweet potato) vines and roots, I was convinced that this is the opportunity for me to realise my dream," she told HarvestPlus.
Project managers acknowledge, however, that introducing new biofortified crop varieties to rural subsistence farmers isn't plain sailing. It requires efforts to disseminate information about growing techniques and health benefits through farmers' support networks and aid groups working with communities on the ground.
In East Africa, women have been amenable to messages about strengthening their children's health, but men are tougher nuts to crack because they prefer the white sweet potato, experts say.
Margaret Benjamin, a programme officer with Helen Keller International in Tanzania where the organisation has introduced vitamin A-rich orange sweet potato to 30 farmers' groups since 2009, worries that as long as families see it as a food for children, they won't grow it in large quantities.
When checking how much was being consumed, the health charity found mothers were simply boiling the sweet potatoes and leaving them for their children to eat while they were out. So to make them more attractive to the rest of the family, they trained women to cook and serve them with a peanut sauce or bananas.
Some groups also concocted recipes with beans, meat and fish, and a few even began making them into biscuits, crisps and juices to sell.
Still, Benjamin says most farmers have taken a fairly cautious approach, planting the orange sweet potato alongside traditional crops. The challenge is to build interest in producing a surplus that can be traded in local markets, spreading the nutritional benefits more widely.
Scientists working to biofortify staple food crops agree it's not an intervention that can be rolled out overnight, not least because breeding new plant varieties can take up to 10 years.
In a paper published in March, Howarth Bouis, the director of Washington-based HarvestPlus, which works with over 200 agricultural and nutrition scientists, wrote with colleagues it will take a decade before a first wave of biofortified crops is widely adopted in several developing countries.
It is only once this happens, and the crops are shown to produce significant reductions in iron, zinc and vitamin A deficiencies, that biofortification will be endorsed as an effective strategy for reducing micronutrient malnutrition, alongside vitamin and mineral supplementation, food fortification and nutrition education, they added.
HarvestPlus plans to release yellow cassava enriched with vitamin A in Nigeria this year, followed in 2012 by high-iron beans in Rwanda, orange maize in Zambia and high-iron millet in India. High-zinc rice is scheduled for Bangladesh in 2013, and high-zinc wheat for India in 2014.
Bouis says that while biofortified crops can have a positive impact on individual households in the first year, it's likely to take five to eight years in any country for them to bring about a recognisable improvement in public health.
But he is optimistic the idea will catch on: "In the long term, we could see maybe 80 to 90 percent of food staples eaten in Africa and Asia biofortified, and we would be reaching billions (of people)," he told AlertNet.
Jere Haas, a professor of nutrition at New York's Cornell University, believes crop biofortification offers a cheaper and more reliable way to keep people healthy than handing out pills.
"Working through the agricultural system is more sustainable than, for example, (vitamin and mineral) supplements, which have an expensive delivery system, and people have to keep coming back. Instead, you can give smaller doses (through food) every day," he explains.
In a study Haas worked on in the Philippines, involving some 300 nuns in convents around Manila, those who were given high-iron rice to eat over a nine-month period saw their body iron rise by 20 percent – enough to make a difference to their health. And of 600 Mexican boarding school children who participated in a similar experiment last year, those fed high-iron beans also experienced a significant increase in their body iron levels, according to Haas.
"This is an investment for the long term," he says. "Over the years, we can shift the whole distribution (of people meeting their nutritional requirements) to close to 100 percent."
Still, crop biofortification can’t solve health problems in developing countries on its own, he cautions, and needs to be implemented in conjunction with other interventions such as diversified diets, better sanitation and immunisation.
The trick in enticing farmers to opt for the biofortified crops is to ensure the new varieties also incorporate other attractive traits, experts say. They must be high-yielding, resistant to diseases, and able to tolerate climate extremes like droughts and floods so that they are adapted to the effects of global warming.
For example, in India, climate change means biofortified millet is likely to become more favoured than rice in some areas, according to HarvestPlus' Bouis.
If done right, biofortification could help farmers, especially in Africa, to cope with the additional stresses climate change is predicted to bring.
"Poverty is associated with very poor diets, and with climate change, you will have increased levels of poverty, which strengthens the need for biofortification," says Kent of the Gates Foundation.
In April, the foundation awarded a further $10.3 million to the International Rice Research Institute (IRRI) for the development of Golden Rice varieties containing beta carotene, which the body converts to vitamin A, for the Philippines and Bangladesh. It also gave $8.3 million to the Donald Danforth Plant Science Centre to support an ongoing project aimed at increasing the nutritional value of cassava for Kenya and Nigeria.
Both of those programmes are using a range of crop-breeding techniques, including genetic modification. A transgenic approach is necessary to create Golden Rice, for example, because existing varieties of rice contain negligible amounts of beta carotene, according to the Gates Foundation.
"Yes, there will be some controversy, but it will be incumbent on governments to generate bio-safety data, and make decisions (on what to approve)," says Kent. "Then it will be up to the farmers."
Governments are increasingly enthusiastic about the potential of biofortification, he adds, boosting hopes they will invest in it as a cost-effective way to improve people's nutritional status.
In Uganda, meanwhile, HarvestPlus has requested funding from the U.S. government to expand the orange sweet potato programme to new districts in the north and southwest, potentially reaching more than 225,000 families over the next five years.
Ideally, Ball would like to see "just about every farming household" growing biofortified orange sweet potato in their fields, with urban dwellers also able to buy it in shops and markets knowing it's a good source of vitamin A.
"When people are poor and are given the chance to make a healthy choice, they will," she says.
AlertNet also has a factbox on the health impacts of hidden hunger.