GM Foods: Understanding the science and the Ghanaian Society (3)

The World Health Organisation (WHO) has stated that no effects on human health have been shown as a result of consumption of GM foods across the world.

Perhaps the greatest concern over the release of transgenic plants into the environment is the potential for new sources of toxins or allergens in the food supply. A number of studies carried out on the health implication of the consumption and application of GM foods failed to establish differences between GM and non-GM foods. However, some studies have found that allergenic properties associated with some genes have been produced in GM foods, demonstrating that an allergenic factor from one plant species can be transferred into another by genetic engineering. 

However, it has long been known that allergenic properties of related plant species tend to be similar; suggesting that sources of genes for plant improvement may be guided by knowledge of related species to ameliorate the possibility of creating a new allergenic plant type. 

Nonetheless, a great deal of concern has been expressed by the public over the presence of transgenic plant materials in food products. The finding of any transgenic plant material not approved for human consumption in food products will definitely cause a great public outcry, a situation currently observed in Ghana.

Are there some legal risks involved in the introduction of GMOs?

Many possible legal issues surround GMOs and have already started to affect society on personal, national and worldwide levels. Recently, it has been established that pollen dispersal distances can be several kilometres. Thus the earlier small-scale studies carried out to predict pollen movement underestimated the possible distances. 

Hence, the risk of contamination of non-transgenic crops with transgenic pollen can be very great. It is apparent from recent legal rulings in other countries that growers of transgenic crops such as maize who do not report genetic contamination to the company owning the patent on a gene may be sued for patent infringement even if they gain no economic benefit from the unwanted gene flow into their fields. 

Uncontrolled gene flow via pollen or seeds raises many legal issues. It is possible that growers may lose the right to save the seeds from their own landraces or varieties that they have developed, possibly after many years of selection, if those populations are contaminated with patented genes. 

Should growers be obliged to adjust their crop rotation, herbicide schedules, and field layout in order to protect their crops from contamination from neighboring transgenics? 

Should growers of non-transgenic crops bear the cost of dealing with gene flow that is unwanted and arguably forced upon them? 

Will companies or nearby growers reimburse non-GM growers if gene flow forces the non-transgenic grower to use a more costly herbicide or less efficient crop rotation plan? 

Contamination of fields with engineered genes may prevent products from being marketed as “GMO free” or “organic.” Who will reimburse losses of growers targeting these premium-price markets? If a consumer or company claims to be injured by the use, production, or transportation of GM crops, can growers be held liable?

It is possible that the widespread use of transgenic crop varieties will lead to the loss of markets for farmers producing the transgenic products, regardless of the legality of those crops. For example, widespread public disapproval of transgenic crops in Europe essentially removes the European market as an outlet for transgenic crops grown in the United States or elsewhere, even though no legal bans might have been in place in such countries. 

In this situation, a farmer attempting to grow non-transgenic crops may lose access to a market if his or her crop were to become contaminated with transgenic pollen. 

These and many other issues clearly constitute a set of new risks that consumers, growers and companies continue to face. 

Are there some environmental risks posed by the introduction of GMOs?

Considerable discussions have ensued concerning the impact transgenic crops may have on surrounding plant and animal populations. 

Perhaps the two most widely discussed cases to date are those of possible contamination of wild populations of maize in Mexico with transgenic pollen, and the possible killing of monarch butterfly larvae by maize pollen expressing Bt toxin incidentally deposited on milkweed plants. 

Earlier report indicated that Bt maize pollen could cause significant death of monarch butterfly larvae feeding on milkweed plants in and around transgenic maize fields. However, this conclusion was challenged and led to a spate of investigations and reports which indicated that the impact of Bt maize on the monarch butterfly was negligible. 

Nonetheless, the potential for the kind of impact reported in this case cannot be ignored and should be investigated for any new transgenic crops prior to their approval and release.

Another potential environmental risk of GM crops is the loss of native or wild-type varieties through hybridisation with the cultivated GM crops when introduced into the natural habitats or ecological zones harbouring the wild plants.

The unexpected

There may be unexpected benefits to growing transgenic crop plants. The Green Revolution was made possible largely by the introduction of a very few genes. 

Even though Green Revolution varieties greatly increased crop yields in much of the developing word, these varieties also required intensive fertiliser and pesticide inputs. In the 1980s, many environmentalists began to oppose the use of high amounts of inputs because of environmental pollution. 

However, those environmentalists overlooked a major environmental benefit of the Green Revolution, a tremendous worldwide drop in deforestation. In fact, without high-yield agriculture, either millions would have starved or increases in food output would have been realised through drastic expansion of acres under cultivation - losses of pristine land a hundred times greater than all losses to urban and suburban expansion. 

It has been estimated that in India alone, natural wilderness equal to 10 times the size of Ghana would have been lost to cultivation if not for the Green Revolution. One or a few transgenes of the future may have similar, unexpected benefits.

Are there health risks associated with GM Foods?

The writer is a Senior Lecturer, Dept of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology (KNUST)

PMB Kumasi, Ghana

 Tel: +233-245-131806

Email: [email protected]; [email protected] 

www.knust.edu.gh