Safety Issues For GM Foods

Allergenicity - The allergenicity potential of the new protein expressed on the transgene inserted into the plant is a major food safety concern. Most traits introduced into GM crops result from the expression of one or more protein that may possess allergenic properties. Crops modified for insect resistance have been shown to have the potential for allergic responses. 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. If the GM food contains genes, which are known to have a relation to allergenicity, a series of special chemical and immunological tests are required to identify the proteins, which cause the allergenic reaction. These in vitro tests have to be confirmed by in vivo tests. In any case, the new food should be labelled to inform the consumer that traces of an allergenic protein could be included.

Antibiotic Resistance - Potential for Gene transfer: Concern has been expressed on the possibility of transfer of GM DNA from the 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.

Nutritional composition - Genetic modification of plants may result in alteration in nutritional composition which in turn may affect the nutritional status of the consumer or population groups. 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 crop plants can affect nutritional status of the individual. There is also the potential for unexpected alteration in nutrients 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.

Levels of antinutrients in GM Food
An antinutrient is a substance that interferes the uptake of nutrients. Antinutrients found in conventional foods include trypsin inhibitors and phytic acid. High levels of trypsin inhibitors are often found in raw cereals and legumes, especially soybean. Trypsin is an enzyme produced in the gut and digests proteins. Trypsin inhibitors interfere with the action of trypsin, affecting the digestion of proteins in the gut and subsequent absorption of nutrients, resulting in malnutrition. They are easily inactivated by heat and so may not be of concern as long as foods containing them are heat treated. Phytic acid is naturally present in plants such as soybeans and canola. It reduces the uptake of phosphorous, calcium, magnesium and zinc from food. However, phytic acid also appears to protect against some forms of cancer, so this beneficial effect needs to be weighed against the antinutritional effect.

Toxicity Potential - Various toxicants are known to be inherently present in different plants. Genetic engineering has the potential to alter such constituents or produce newer toxicants. Crops developed for pest resistance and herbicide resistance are particularly focussed for toxicity concern. 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 systems and stunted growth was observed and the experiment had generated considerable controversy.

The Stability of Inserted Gene -

Other Unintended Effects -