Genetically modified plants and its impact on the human health

    Genetically modified plants have attracted a wide range of attention from the media in the past and still continue to do so even today. Despite all the media coverage concerning the GM Plants and their impacts on the human health, very few people know what GM plants are and what contribution biotechnology has to offer on the full range of applications of the plants and their products. Since the introduction of the first GM plant, there has been the emergence of two main areas of interest namely; the risk of the GM plants to the environment and the risk on human health. Despite the fact that there have been campaigns to sensitize the general public on what GM plants are, most of the information that is published are quite unreliable and does not state the real facts and scientific evidence of the GM plants.

    This article will, therefore, examine the manner in which GM plants directly impacts the human health. This is regarding nutrition and advancement of the recombinant medicine production. This form of discovery is exciting in ensuring that the people’s health is advanced through vaccine production, monoclonal antibodies.   

GM plants food applications

    Globally, there is a total of 850 million that are undernourished and a surviving on a small ration of calories per day. This translates to approximately 1.3 million people living below the poverty line of spending $1/day. Most of these people are often rural smallholder farmers that occupy rural regions in developing countries who rely almost entirely on agriculture for upkeep. GM plant technologies are one of the approaches that have been developed to take care of these problems by increasing the yield and the nutritional content of the plants.

Nutritional content

    In developing countries where people often depend on one food as their staple source of energy, the nutritional content is one of the major areas of focus for biotechnological advancement to alleviate some of the issues associated with plant engineering. This is to ensure that the GM plants can express more products to prevent the problem of malnutrition. An excellent discovery example of the GM plants is “The Golden Rice Project”.

    Vitamin A deficiency is a problem that is of global health concern and is estimated to account for over two million deaths in children, especially in developing countries. Additionally, it is this deficiency that is the main reason for blindness among surviving children. Human beings can synthesize Vitamin A from its precursor called β –carotene commonly found in many plants and not cereals. The strategic discovery of the Golden Rice project was based on the targeted introduction of correct steps of metabolism in the endosperm of rice that would permit synthesis of β-carotene. Ye et al. (2000) engineered rice thus giving rise to rice with moderate levels of β-carotene thus paving the way for increased yields of vitamin A. This is estimated that 70 g of dry GM rice produces 50 % of the RDA of Vitamin A for a child aged between 1-3 years.  This serves as a brilliant example of a health solution offered through plant biotechnology.

Increasing food production

    The yield of crops across the globe is often affected by a wide range of factors that includes pathogens, parasites as well as insects. There are two brilliant examples of discoveries of commercial GM plants that are resistant to insects by expressing Bacillus thuringiensis (Bt) gene and GM papaya that is resistant to viruses. The primary cause of plant loss across the globe is abiotic stress, salinity, drought and unfavorable temperatures. Despite the fact that a wide range of abiotic stress tolerant GM plants has been produced, the research is still at the laboratory level. A good example of this is the GM maize that expresses a protein that plays a central role in oxidative signal cascade responsible for tolerating extreme conditions of cold, heat and salinity.

Are GM plants safe for human consumption?

    There is evidence that demonstrates that GM plants are not safe for human consumption because of the potential toxins present in them. In 1999, a study showed that GM potatoes expressing a gene coding lectin Galanthus nivalis agglutinin were significantly affected in the sense that they caused damage to the gut mucosa. 

    The question that most people ask is whether there is any priori reason to believe that GM plants are harmful to humans upon consumption. Many of the reasons often point at the presence of foreign DNA sequence in the food. However, this does not have any intrinsic impact on the human health. What is of most concern is the possibility that protein produced by the GM plant may be toxic and is absorbed into the human system. Potential Allergenicity of the GM plant on consumption poses a great challenge to people’s health such as soft-fleshed fruits, soy among other foods. This is because there is a possibility of protein-protein interaction between the allergenic gene introduced into the plant and the allergenic protein already existing in the plant thus giving rise to novel allergens or altering the expression of proteins by the plant, thus contributing to the toxicity of the plant. Two examples of this include.

    A project that was geared towards the production of GM peas through the addition of protein derived from beans. This protein conferred resistance to weevils and in addition to this, the consumption of GM peas led to lung allergies among mice. Another project is that of GM soybeans that involved the expression of Brazil nut protein that caused allergies when consumed by humans.

Non-food discovery of GM plants

    The use of GM plants has been a great platform for the production of pharmaceutical products. For instance, GM plants have been used to produce multimeric antibodies. These antibodies have been shown to play a central role in the treatment of topical, mucosal infections. Currently, there is the production of Hepatitis B vaccine using GM yeast.

    Based on the findings discussed in this article, it is evident that GM plants play a central role in contributing positively to the human health through nutrition and drug production. However, the major challenge is the exorbitant cost of the product that makes it less affordable by the poor in developing countries. Additionally, the production of GM plants requires a wide space to increase production to meet the growing demand for the products across the globe.

The safety of genetically modified plants produced through use of biotechnology

    The safety of genetically modified plants has been at the forefront of many scientific debates trying to ascertain the safety of the plants and its produce to human and animal health upon consumption. This is where the Society of Toxicology comes into play to ensure that they offer maximum protection and enhancement of the human, animal as well as environmental health. This is achieved through the sound application of biotechnological processes in production. Typically, in this context, biotechnology refers to the processes that involve the transfer of transgenes from organisms to plants hence food production. This may also apply to the expression of individual existing genes s modified permanently by employing genetic engineering techniques. Therefore, it is important for you to realize that it is not the method of modification of plants that is the concern of human and environmental safety but rather the product.

    In this article, the question we will try to answer is whether the product of the transgene is capable of presenting a risk to both the consumers and the handlers of genetically modified plants. This means that the potential toxicity of the transgene plant product has to be considered by case-by-case design. This means that taking into consideration the possibility that the transgene produces toxins that are known such as protein allergens.

Toxin production

    The level of toxins that are produced by the genetically modified plants and the threat it possesses to the producers and the consumers is often the focus of interest of toxicologist. This is through the use of standard toxicological approaches such as the evaluation of Bt (Bacillus thuringiensis) endotoxins as described by US EPA in 2001. The safety of these plants is therefore determined by their digestibility and absence of intrinsic activity in the mammalian systems. In this case, therefore, in-depth comprehension of the mechanism of action of the Bt toxin and the selective pressure that takes place in their biochemical systems increases the surety of safety assessments. However, each transgenic novel product of plants has to be considered individually. This is based on the levels of exposure, potency in causing toxic effects among other safety paradigms.

Allergen production

    Allergenicity is one of the major safety concerns of consuming foods derived from transgenic plants. In as much as we are raising eyebrows on the safety of GM plants and their products, consumption of conventional foods is not equally safe. This is because the occurrence of allergies has been reported with conventional foods. However, some of the issues that have to be addressed with a high level of stringency are the potential Allergenicity associated with genetically modified plants/crops. Some of these issues include;

    Do the products of the novel gene inserted into plants elicit allergic reactions in humans or animals that are already sensitized to the same protein? Does the transgenic approach employ induce alteration of the level of expression of the proteins that exist in the host crop?  Do the products derived from genetically engineered plants used for food have the ability to induce de novo sensitization among humans or animals that are susceptible?

    Characterization of the potentially allergenic proteins produced by the GM plants produced through biotechnological technique is based on three factors;

    Structural similarity, serological and sequence homology; the principal aim of this is to determine whether and to what level does the protein produced by the genetically modified foods have similarity to other known proteins that have the potential of causing allergies among humans and animals. This is through the determination of the overall structure of the protein of interest and its similarity to allergens that are known. The use of the protein database offers the possibility of determining the similarity of the novel protein of interest with those of allergens that are known on their sequence alignments homology. This could also be compared to discrete motifs and domains in the protein where there is complete sequence similarity with that which is present in known allergens, therefore, indicating possibility of shared protein epitopes. The third approach is the use of serological techniques to determine whether there are specific IgE antibodies present in the serum of sensitized humans or animals capable of recognizing the protein of interest.

    Proteolytic stability: According to research, there is evidence of a correlation between protein resistance to proteolytic digestion and their potential to cause allergic reactions. The theory, in this case, is that relative resistance plays a role in inducing allergic responses on condition that the protein of interest possesses allergenic characteristics. In this case, the approach that is effective is characterizing the susceptibility of the protein of interest to its digestibility by pepsins and other gastric stimulated proteins. However, it is important to note that this approach alone may not be sufficient for the identification of cross-reactive proteins that have the potential of eliciting allergic responses in foods.

    Use of animal models: animal models are the other biotechnological approach that may be used to assess the safety of products derived from GM plants. Currently, there is the absence of adequate animals that can be used as model organisms to simulate the same environment as humans thus facilitating their use in identification of protein allergens. However, there is ongoing research geared towards the development of techniques that are suitable for characterization of allergic responses in rodents and other species that mimic human physiological surrounding.

    The safety of the GM plant and plant products has been lots of concern across the globe. However, it is important to appreciate the fact that despite the safety concerns, it is also playing a significant role in charting the path towards food security. However, a major limitation is predicted to occur in future if the transgenic technology gives rise to more substantial and complexity in the products derived from GM plants. This means that there is a need for improving the methods that are used in plant profiling of their proteins as well as studying their gene expression. This is especially important in detecting any changes that occur unexpectedly in the GM plants to determine their substantial equivalence. Therefore, continuity in the evolution of toxicological methods, as well as regulatory strategies, are necessary to be put in place to ensure that safety of GM plants and products comes first as far as human, animal and environmental factors are concerned.