Guest guest Posted September 15, 2004 Report Share Posted September 15, 2004 > 14 Sep 2004 12:46:22 -0000 > Non-GM Iron Rice a Solution? > press-release > > > The Institute of Science in Society Science Society > Sustainability http://www.i-sis.org.uk > > General Enquiries sam Website/Mailing > List > press-release ISIS Director > m.w.ho > ======================================================== > > > ISIS Press Release 14/09/04 > > Non-GM Iron Rice a Solution? > ********************* > > > Is genetic engineering necessary to develop rice > rich in > iron? Lim Li Ching reports on successes achieved > with > conventional breeding. > > > Sources http://www.i-sis.org.uk/full/NGMIRASFull.php > > for this article are posted on ISIS members' > website. > Details here http://www.i-sis.org.uk/membership.php. > > Iron deficieny > > Iron deficiency is the most common of all > nutritional > deficiencies. Approximately 3.7 billion people > suffer from > this condition, and it is most widespread in > children and > lactating mothers. Iron deficiency leads to anaemia; > > overall, 39% of pre-school children and 52% of > pregnant > women are anaemic, of whom more than 90% live in > developing > countries. > > Anaemia is bad for health and development. In > infants and > young children, it impairs growth, cognitive > development and > immunity; at school age it affects school > performance and > reduces activity levels; at adulthood it reduces > work > capacity and lowers resistance to fatigue. In > pregnant > women, it is linked with an increased risk of > maternal > mortality and illness, as well as an increased risk > of pre- > term delivery, retarded foetal growth, low birth > weight and > foetal death soon after birth. > > Iron tablets are a possible solution, but require a > continuous supply and can cause side effects. In the > long > term, ensuring adequate iron intake through food is > viewed > as the best option. For most populations, the best > sources > of iron are meat products, but these are relatively > expensive and little consumed by the poor. > > Conventionally bred 'biofortified' rice > > Rice, the staple diet of millions in the developing > world, > is a poor source of micronutrients. Where rice is > the > staple, about two billion people suffer from > iron-deficiency > anaemia. Efforts have thus focussed on > 'biofortifying' rice > to make it nutritionally better. Genetically > engineering > rice to increase its iron content has been one > course of > action (see " Rice in Asia: Too little iron, too much > > arsenic " , this series > http://www.i-sis.org.uk/RIATLITMA.php). > > But is genetic engineering needed to develop > iron-rich rice? > There are already successes reported in naturally > breeding > and selecting rice with high iron content, which > would not > carry the risks associated with genetic engineering. > > Plant breeders at the Philippines-based > International Rice > Research Institute (IRRI) have identified rice > varieties > that are naturally high in iron. They screened > nearly 7 000 > samples of rice germplasm stored in the IRRI gene > bank, for > high iron and zinc content. Of these, 1 138 samples > were > grown. They found that aromatic grains were usually > higher > in iron concentration and often also higher in zinc, > > compared to non-aromatic varieties. Data from > various > studies demonstrated that high iron and high zinc > traits > were generally expressed in all rice environments > tested. > > IRRI at the same time was trying to grow, by > conventional > breeding, new varieties that could thrive in poor > soils and > cold temperatures. " Quite by chance, it was > discovered that > one of the varieties designed to tolerate low > temperatures > had also inherited a richness in iron and zinc from > one of > its parents, " explains IRRI scientist Dr. Glenn > Gregorio. > > This aromatic variety is a cross between a > high-yielding > variety and a traditional variety from India, from > which > IRRI identified an improved line (IR68144-3B-2-2-3) > with > high iron concentration. The grain has 21 parts per > million > (mg/kg) of iron, about double the normal content in > rice, > and also about 34 parts per million of zinc. > > Research has shown that high zinc and iron densities > are > positively correlated. Zinc may enhance the body's > capacity > to absorb iron. It is essential for a healthy immune > system. > Zinc deficiency in children is also associated with > poor > growth, reduced motor and cognitive development, and > > increased infectious diseases. It is linked to > pregnancy and > childbirth complications, lower birth weight and > other > foetal effects lasting through childhood. Moreover, > high > zinc density is good for seedling vigour, improving > plant > yields. IR68144 is also reported to have a high > content of > Vitamin A. > > " Almost as a bonus, it had good flavour, texture, > and > cooking qualities. And, to please the farmers, it > was also > high-yielding. " This bodes well, for adding new > traits can > sometimes have a general negative effect on yield. > The rice > also has good tolerance to rice tungro virus and to > mineral- > deficient soils. All these factors are important for > > maintaining crop productivity and consumer > acceptance, > crucial to ensure that new varieties sustain > farmers' > incomes. > > Trials establish that iron is absorbed > > Does the increased iron content translate into > improved iron > status in the consumer? After 15 minutes of > polishing, > scientists found that IR68144 had approximately 80% > more > iron than a popular but low-iron commercial variety. > > Research conducted at Cornell University showed that > the > iron in IR68144 polished rice was absorbed by > laboratory > rats, and by human colon cells in culture. > > " Then we fed some other high-iron varieties > experimentally > to a family of two parents and four children living > near > IRRI's headquarters in the Philippine province of > Laguna, " > Dr. Gregorio said. " All but the father were mildly > anaemic. > After the family members ate the enriched rice for > two > months, however, their serum ferritin levels rose > dramatically, to the point where the lowest of them > was > double the level recommended for good health. " > > In 1999, a trial was carried out on 27 women in the > Philippines, who ate IR68144 exclusively over six > months. > The volunteers - sisters at a Roman Catholic convent > - had > their food measured, their activity monitored and > body > weight noted. Once a month, their blood was tested. > The > sisters were selected because they represent a sex > and age > segment of the population at high risk of iron > deficiency. > > Most of the sisters, aged between 20 and 30 years > old, were > mildly anaemic while on their normal diet of rice > purchased > from the market. 74% were anaemic (haemoglobin <120 > g/L) and > 48% were iron-deficient (serum ferritin <12 µg/L). > But, > after eating IR68144, the serum ferritin (an iron > storage > protein) levels in their blood increased - in many > instances > two or three times higher. In some cases, this was > sufficient to raise their iron levels from deficient > to > above average. > > A much larger and carefully structured clinical > trial, > involving 300 sisters from eight convents around > Manila > concluded in September 2003. In one of the largest > human > feeding trials of a staple food, each sister was > randomly > assigned to receive either regular (low-iron) rice > or the > high-iron variety. The sisters and the research team > were > not told what they were receiving during the trial. > The food > was cooked in a common kitchen and consumed in a > common > dining room, so the distribution and consumption of > different rice varieties could be carefully > monitored. > > The sisters' iron status, as shown by haemoglobin > and other > biochemical indicators, was measured before the > trial began, > halfway (4.5 months) and at the conclusion (9 > months). Women > remaining - or newly - iron-deficient at the end of > the > trial were given iron supplements to ensure this > deficiency > was corrected. The trial also examined the interplay > of > minerals and nutrients within the body to look at > their > interactions, and observed the sisters' cognitive > functions > and capacity to concentrate. > > Preliminary analysis of the data indicates positive > results. > There was modest improvement in blood iron levels, > showing > that iron in rice endosperm is absorbed by the body. > Among > the women who were iron-deficient but not yet > anaemic at the > start of the trial, total body iron reserves > improved > significantly. The women who consumed high-iron rice > took in > about 20% more iron per day than those who ate > regular rice, > and increased their body iron by 10%, while the > women > consuming control rice actually lost 6% of their > body iron. > The greatest increases in body iron were seen in the > women > who consumed the most iron from biofortified rice. > The > results of the study are being published. > > Future scenarios > > The next step would be to conduct trials on the > effect and > use of high-iron rice in a community setting and on > the > effect on children's iron status. A study is planned > in > Bangladesh in 2004-2005. If successful, IR68144 > seeds will > be given to agricultural research organizations in > various > countries for adaptability testing and to begin > crossbreeding for pest and disease resistance as > well as > hardiness for local conditions. > > IR68144 or its offspring could then be released to > farmers > in developing countries, for free, in two or three > years. > Meanwhile, IRRI's search continues, among the 26 000 > samples > of rice varieties it holds in trust for humankind. > Dr. > Gregorio is sure that a new variety could be bred > with even > higher iron content. IR68144 could be the first of > several > traditional rice varieties found to be nutritionally > richer > than previously thought. > > Already, recent reports indicate that Thailand's > Department > of Agriculture has identified two rice strains - > selected > from 45 strains of Thai rice - that can accumulate > iron. > Korkhor 23 has an iron content of 36.67 parts per > million > (ppm) when unpolished, reduced to 22.5ppm when > polished. > Unpolished Khao Hom Phitsanulok 1 rice has an iron > content > of 25ppm, compared with 22.5ppm in it polished > state. Rice > grown in different areas have different rates of > iron > accumulation. Research continues to find better > iron- > accumulating strains, and to determine the best > growing and > milling techniques to preserve iron in the rice. > However, > Dr. Laddawal Kannanut of the Rice Research Institute > was > quoted as saying that genetic engineering would be > used to > improve the strains' ability to accumulate iron. > > This is unnecessary, for as the IRRI research shows, > > conventional breeding can successfully develop > high-iron > rice that is both high yielding and disease > resistant. > Conventional breeding works because iron occurs > naturally in > rice grains and the high variability in the grain > iron > content allows selection of high-iron parents for > crossbreeding. Moreover, farmers will grow the > iron-dense > rice because its high-yielding characteristic makes > it > profitable to do so. And, trace minerals such as > iron are > undetected by the human eye and thus do not affect > consumer's preference. > > In future, it won't be just rice that is targeted > for > biofortification. Significant funding has been > committed to > develop biofortified crops. The IR68144 research is > now part > of a larger initiative by the Consultative Group on > International Agricultural Research (CGIAR) and its > research > centres worldwide, coordinated by the International > Food > Policy Research Institute (IPFRI). In October 2003, > the > Gates Foundation committed $25 million to this > initiative, > HarvestPlus, which aims to develop crops with > enhanced > nutrient status: not just with iron but also with > vitamin A > and zinc and in other key staple crops important to > the poor > (wheat, maize, beans, cassava, and sweet potato). > > The danger is that the efforts will focus on genetic > > engineering, at the expense of safer alternatives. > For > example, IRRI claims that for vitamin A enhancement, > genetic > engineering is needed, as vitamin A does not occur > naturally > in rice grains. In 1999, Swiss scientists > successfully > expressed vitamin A in transgenic rice grains - the > so- > called 'Golden Rice'. IRRI is now incorporating the > vitamin > A genes into high yielding varieties. > > Biofortifying food crops, even by means of > conventional > breeding, must not replace other interventions such > as > diversifying diets, conventional fortification and > supplementation. Efforts to enhance the iron content > of rice > must also be mindful of the interaction between iron > and > arsenic, a particular problem for the > arsenic-contaminated > paddy fields of Asia (see " Rice in Asia: Too little > iron, > too much arsenic " , this series > http://www.i-sis.org.uk/RIATLITMA.php). > In addition, in areas where iron intake is high, > iron > overload can become a real problem. > > The need for biofortification today is largely due > to the > mistakes of the past. For example Green Revolution > methods > have mined the soil of nutrients and monocultures > have > resulted in the loss of diverse traditional > varieties. > Alternative food sources rich in iron should be > promoted, as > should diverse cropping and sustainable agriculture. > This > could prove to be a much more sustainable strategy > in > addressing iron deficiency. > > > ======================================================== > > This article can be found on the I-SIS website at > http://www.i-sis.org.uk/NGMIRAS.php > > If you like this original article from the Institute > of > Science in Society, and would like to continue > receiving > articles of this calibre, please consider making a > donation > or purchase on our website > > http://www.i-sis.org.uk/donations. > > ISIS is an independent, not-for-profit organisation > dedicated to providing critical public information > on > cutting edge science, and to promoting social > accountability > and ecological sustainability in science. > > If you would prefer to receive future mailings as > HTML > please let us know. If you would like to be removed > from our > mailing list at > > http://www.i-sis.org.uk/mailinglist/.php > ======================================================== > > CONTACT DETAILS > > The Institute of Science in Society, PO Box 32097, > London > NW1 OXR > > telephone: [44 20 8643 0681] [44 20 7383 3376] > [44 20 > 7272 5636] > > General Enquiries sam Website/Mailing > List > press-release ISIS Director > m.w.ho > > MATERIAL IN THIS EMAIL MAY BE REPRODUCED IN ANY FORM > WITHOUT > PERMISSION, ON CONDITION THAT IT IS ACCREDITED > ACCORDINGLY > AND CONTAINS A LINK TO http://www.i-sis.org.uk/ > Quote Link to comment Share on other sites More sharing options...
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