IT IS hard to ignore the fact that we are facing a food crisis. As 快猫短视频 has reported, recent increases in the prices of staples such as rice, wheat and eggs could push 100 million people who have escaped from poverty back into it, and make life for the poor even more desperate. The cause seems simple: demand for grain and meat are rapidly rising, while production is failing to keep pace. What鈥檚 clearly required is another green revolution, one that can quickly boost crop yields to supply the world with the food it desperately needs.
That鈥檚 not the whole story, though. Almost as important as having food to eat is eating the right kind of food. A full stomach may ward off hunger, but it doesn鈥檛 necessarily stop people dying. People also need a diet that contains the right blend of micronutrients.
If that sounds like a minor issue, then chew on this: according to the , almost 1 billion people suffer from a condition called goitre, a swelling in the neck caused by an enlarged thyroid gland. This is because they do not get enough iodine in their diet. Iodine deficiency also causes measurable brain damage in almost 50 million people, and cretinism, a stunted growth condition, in another 16 million.
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An estimated 127 million pre-school children are affected by vitamin A deficiency, with up to half a million going blind each year, half of whom then die within 12 months. Anaemia caused by iron deficiency affects 2 billion people a year, killing 800,000. A lack of zinc is directly related to the severity and frequency of diarrhoea, a major problem in poor countries, while lack of folate, or vitamin B12, causes neural tube defects and spina bifida in newborns and cardiovascular disease and cancer in adults. The list goes on. Exact figures aren鈥檛 known, but informed estimates suggest that at least one-third of the world鈥檚 population don鈥檛 get the micronutrients they need, and millions die because of it every year.
This is the other food crisis 鈥� the one that doesn鈥檛 make the headlines. The reason micronutrient malnutrition is so widespread is because much of the world鈥檚 population increasingly relies on just a few staple foods, such as rice, maize, wheat and cassava, which cannot provide the range of nutrients required. In Africa, for example, popular varieties of cassava, maize and sweet potato contain almost no beta-carotene (a precursor of vitamin A).
In theory, the solution is simple 鈥� give people more foods to choose from. The reality is far more complex. The WHO seeks to tackle the problem in four ways: combating infectious diseases such as malaria, which can exacerbate conditions such as anaemia; increasing the production and supply of micronutrient-rich foods; handing out micronutrient supplements; and fortifying foods.
Combating infectious disease is a gargantuan issue in itself. Raising yields of crops that are naturally rich in micronutrients is almost impossible in many parts of the world, as local conditions do not allow most varieties to be grown in bulk. Supplements have an immediate impact, but they are relatively costly. For example, 500 million capsules of vitamin A are distributed globally each year, at a cost, after distribution and logistics are taken into account, of $1 a capsule (). Breeding a crop fortified with vitamin A that could be grown by local farmers might cost just 0.2 per cent of that. So engineering high-yield crops to contain higher levels of essential micronutrients offers our best hope of solving the problem long term.
In recent years, researchers have been working to fortify major crops in this way. Their successes include crops engineered to contain higher levels of carotenoids, vitamin E and folate. There is a problem, however.
Huge amounts of research have gone into genetically engineering crops to boost their nutrient content. But as plant geneticist and paediatrician Kendal Hirschi of the Baylor College of Medicine in Houston, Texas, argues in Trends in Plant Science this month, very little has been done to answer the question that matters: whether these foods actually give people more nutrients when eaten (). A classic example is golden rice, developed in 2000 to contain higher levels of beta-carotene. Eight years on and scientists are still pondering its nutritional benefit. Part of the problem is a lack of research to verify the nutritional content of such fortified foods, and part is that many plants themselves contain 鈥渁ntinutrients鈥�, chemicals that bind to nutrients preventing their uptake in the gut.
鈥淟ittle research has been done on whether fortified foods provide people with more nutrients鈥�
One small success came earlier this year when researchers from Dartmouth College in Hanover, New Hampshire, finally showed that carrots cultivated to contain more calcium do indeed deliver the mineral when eaten (, ). Most other fortified crops, however, have yet to be proven in this way, and more research is urgently needed.
Of course we need to find ways to boost productivity of crops. But let鈥檚 ensure that the food we grow is nutritious as well as a plentiful.