Crop bio-fortification can combat ‘hidden hunger’

Increasing nutritional value of edible parts of plants can have widespread benefits.

FAISALABAD:

Cereals – especially rice, wheat, and maize – provide nutrition to the populations of many developing countries. Most of the population in such countr0ies depends on a low-protein and low-mineral diet comprising these staple foods.

Meanwhile, according to an estimate, over 60% of the world’s people are iron deficient, over 30% are deficient in zinc, 30% are deficient in iodine, and about 15% lack sufficient selenium in their systems.

Insufficient consumption of these important micronutrients has resulted in many health and physical disorders. For instance, zinc deficiency results in impairments to physical growth, the immune system and learning ability, combined with an increased risk of infections, damage to a person’s DNA and development of cancer. Pakistan is among countries whose populations are at a 75% risk of zinc deficiency.

Similarly, iodine deficiency gives rise to goitre and cretinism, which results in retardation in physiological development and other health problems. Iodine deficiency in many parts of the world has been compensated to some extent by the introduction of salt fortified with iodine.

Iron is needed to form haemoglobin, and anaemia is a common disease in underdeveloped or developing countries of South East Asia – including Pakistan – where humans do not consume enough of it. The absorption of iron is very low in the body – normally 5-10% of ingested iron is actually absorbed – so it requires substantial intake.

Although selenium deficiency is rarer as compared to these other elements, people dependent on food grown on selenium-deficient soil can suffer from it, as seen in New Zealand and some other parts of the world. It has been proven that supplementary selenium can be helpful against some diseases like diabetes, tuberculosis and even cancer. No authentic data is available regarding selenium deficiency in Pakistan; however, the risk remains because selenium deficiency in soil has been identified in some regions of India.

As developing economies remain unable to arrange sufficient food for the poorer parts of their population, it seems improbable that they will be able to provide them with supplementary doses of these important micronutrients. Lower literacy rates are also a huge constraint on convincing governments to spend on the ‘hidden hunger’ in human beings for these nutrients.

Bio-fortification of staple food is an appealing solution to this problem. It is a low-cost, easy solution to the emerging crisis. Food fortification refers to incorporating micronutrients during the processing of food, but bio-fortification refers to strategies to increase the nutritional value of the edible parts of plants. It is attained through conventional selective breeding, genetic engineering and agronomic measurements.

Bio-fortification differs from ordinary food fortification because it focuses on making plant foods more nutritious during their growing period, rather than addition of nutrients to foods when they are being processed. It is a step forward in providing essential nutrients to rural and poor populations, which seldom have access to commercially fortified foods.

Development of ‘golden rice’ is a great step towards bio-fortification of food crops. Golden rice has been produced through genetic engineering to biosynthesise beta-carotene – a precursor of pro-vitamin A – in the edible parts of rice. About 250 million people in Africa depend on the root starch of the cassava plant. The BioCassava Plus programme has employed modern biotechnology to improve the health of Africans through the development of genetically-engineered cassava with increased concentrations of zinc, iron, protein, and vitamin A.

Both macro and micronutrient fertiliser application can increase their accumulation in edible plant parts. For certain essential micronutrient elements such as zinc, iodine, and selenium, increasing soil-available supply to food crops results in a significant increase in their concentrations in edible plant parts/products. Increasing the supply of zinc and selenium to wheat improves their bioavailability in wheat grain. Zinc fertilisation has also been shown to increase zinc content in other crops such as navy beans, rice etc. Iodine, supplied in irrigation water, can greatly increase levels of iodine in edible portions of food crops – alleviating the risk of the debilitating cretinism disease, as well other related disorders to populations dependent on low-iodine soils.

Therefore, along with conventional breeding and transgenic approaches, fertiliser with micronutrients can be used as an effective and quick agricultural tool to improve the nutrition and health of people in developing economies like Pakistan. However, we need to work on bio-fortification of our local crop genotypes/varieties. Research efforts are in progress; however, a comprehensive approach, including agronomic, breeding and transgenic approaches to produce high quality staple food, is required to eliminate nutrient deficiency for the sustainable health of the Pakistani people.

Hafeezur Rehman is a Lecturer at the Department of Crop Physiology, University of Agriculture, Faisalabad (UAF). Dr Abdul Wakeel is an Assistant Professor at the Institute of Soil and Environmental Sciences, UAF.

Published in The Express Tribune, October 15^th, 2012.