Citing some particular instances the ICMR study entitled Regulatory Regime for Genetically Modified Foods : The Way Ahead, said the case of GM potatoes experiencing Galanthus nivalis lectin gene for insecticidal properties is an example of the potential of GM foods to cause toxicity. In a group of rats fed with GM potato damage to immune system and stunted growth was observed and the experiment had generated considerable controversy.
In case of the GM rice, soyabean and rapeseed the study said currently developed plants with improved nutritive value include GM rice with enriched vitamin A and GM soyabean and rapeseed with modified fatty acid. The impact of such intended modification in nutrient level in a crop plants can affect nutritional status of the individual. There is also the potential for unexpected alteration in nutrient as it was observed in the case of GM rice (accumulation of xanthophylls, increase in prolamines). Such changes can affect nutrient profiles resulting in nutritional imbalances in the consumer.
The ICMR study has been circulated among concerned ministries and departments of the government.
The study noted that 73 per cent of the GM crops in the world are developed for herbicide tolerance while 18 per cent are developed for resistance to insects and 8 per cent developed contain both the traits. Only 0.1 per cent of GM crops are for yield improvement and vitamin enrichment. The study cautioned that GM crops for herbicide and pest resistance could have a potential for development of resistance in target organism. This has been particularly observed in crops developed for insect resistance like cotton. This has resulted in the use of a refugia while cultivating Bt crops. Similarly in the case of herbicide resistance crops like soyabean, a potential for development of superweeds due to spread of herbicide resistance from GM crops to weeds exists, the study said.
In context, the study suggested that more than herbicide resistance, India needs crops resistant to drought, temperature and soil stress and crops for nutritional enrichment, increased productivity and pest resistance. It also said that GM varieties which will eliminate the problem of naturally occuring toxins like the unusual toxic amino acids in Lathyrus satvus are important.
The study also said although the cultivation of GM crops have been claimed to be profitable to farmers, the impact varies by year, location, crop etc. It cautioned that as modern biotechnology is being increasingly subjected to intetellectual property protection and is being generally developed by private sector companies, this could lead to reduced competition, monopoly of profits and expoiltation of small farmers. GM crop production may harm small farmers in the developing countries as imported GM commodities will undercut local production. Modern agriculture biotechnology could lead to increased inequality of income and wealth because large farmers may capture most of the benefits.
The study expressed several other concerns relating to genetic pollution and pollen movement, health safety, allergenicity and potential for gene transfer but in the same breath it said it is significant to point out that there has been no report of any adverse health effect of GM foods and there are no peer reviewed publications on the health effects of GM foods in humans.
Citing an example of pollen transfer, the study said the transgenic material from a GM maize cultivated by a farmer can be transferred without the farmers knowledge to a non-GM maize cultivated in the neighbouring field. Such kind of pollen transfer varies with different environmental conditions.
Expressing concerns over health safety, the study said the use of recombinant DNA technology in the production of GM foods involves transfer of genes from different species into food producing organism. Such a transfer is facilitated along with various regulatory elements obtained from bacterial or viral sources that are required to empower to produce the trait in the host organism. The safety of these components of the genetic construct is not clearly known as they have the potential to induce toxicity, transfer to gut flora or produce unintended effects leading to changes that are relevant from toxicological/nutritional perspective. Specific safety issues associated with GM foods include direct or indirect consequences of new gene product or altered levels of existing gene product due to GM, possibility of gene transfer from ingested GM food and potential adverse effect like allergenicity and toxic effects.
It said that crops modified for insect resistance have been shown to have the potential for allergic response like Sartlink corn. The allergenicity potential of GM food has often been difficult to establish with existing methods as the transgenes transferred are frequently from sources not eaten before, many have unknown allergenicity or there may be a potential for genetic modification process to result in increase of an allergen already present in the food, the study said.
The study also expressed concern over the possibility of transfer of GM DNA from plant to gut microflora of humans and animals. Of importance have been the antibiotic resistant genes that are frequently used as selection markers in the genetic modification process. Such genes have the potential to adversely affect the therapeutic efficacy of orally administered antibiotics, it said.