GMO is not only a broad but a controversial subject as well. Generally, the term is majorly used to refer to crop plants that have been genetically modified to be used for animal and human consumption (even though GMO technology has been used in pharmaceutical industry as well).
Genetic engineering allows selected individual genes to be transferred from one organism into another, even between non-related species in order to enhance desirable traits and improve nutritive value in some instances.
An example of a GMO is Bt. Corn. B.t. (Bacillus thuringiensis) is a naturally occurring bacterium that produces crystal proteins that are lethal to insect larvae. B.t. crystal protein genes have been transferred into corn, enabling the corn to produce its own pesticides against insects such as the European corn borer.
Safety concerns over the use of GMO technology
Potential human health impacts, including allergens, transfer of antibiotic resistance maker genes and other unknown effects e.g. congenital transfer of harmful genes to the unborn.
Potential environmental impacts, include unintended transfer of trans-genes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity.
Other controversial issues
a) Access and Intellectual Property
- Domination of world food production by a few companies
- Increasing dependence on industrialized nations by developing countries
- Bio piracy, or foreign exploitation of local natural resources
- Violation of natural organisms' intrinsic values
- Tampering with nature by mixing genes among species
- Objections to consuming animal genes in plants and vice versa
- Not mandatory in some countries
- Mixing GM crops with non-GM products confounds labeling attempts
- New advances may be skewed to interests of rich countries
GMO Risk Assessment
Criteria used to asses risk status of GM foods:
a) Allergenic Capacity
Check for the presence of genes usually associated with allergic reactions.
b) Gene transfer
Transfer of genes from GM foods into the body cells or bacteria in the GIT.
c) Gene out-crossing
Movement of genes from GM crops into other conventional crops or related species. Mixing of genes would raise food safety issues.
Vary from country to country; some countries have strong policies e.g. the U.S.A and European countries while others have more relaxed or no policies at all (especially third world countries).
Kenya for instance legislated a law (Kenya gazette supplement no. 17 of 2012 legal notice no. 40). This law makes it mandatory for millers to label all GM foods.
Perceived benefits of GMO
- Enhanced taste and quality
- Reduced maturation time
- Increased nutrients, yields, and stress tolerance
- Improved resistance to disease, pests, and herbicides
- New products and growing techniques
- Increased resistance, productivity, hardiness, and feed efficiency
- Better yields of meat, eggs, and milk
- Improved animal health and diagnostic methods
- Modifying cows to produce “human milk”
- "Friendly" bio herbicides and bio insecticides
- Conservation of soil, water, and energy
- Better natural waste management
- More efficient processing
- Increased food security for growing populations
- Vaccine producing bacteria e.g. insulin to help diabetics
- Edible vaccines in fruits
Disadvantages of GMO
a) Unintended harm to other organisms
It is impossible to design a B.t toxin that would only kill crop-damaging pests and remain harmless to all other species. Case study: toxicity of B.t corn pollen to monarch butterfly caterpillars.
b) Reduced effectiveness of pesticides
Insects will develop resistance against B.t and other crops designed to produce their own toxins.
c) Gene out-crossing
Detrimental when herbicide resistance genes are transferred to weeds, which would then become herbicide resistant as well. If out-crossing occurs in animals, it would result to situations like autoimmunity (where the immunity system acts against the cells/tissues of the organism).
d) Allergic reactions
The trans-genes may trigger allergic reactions in consumers. In Brazil, a proposal to incorporate a gene from Brazil nuts into soybeans was abandoned because of the fear of causing unexpected allergic reactions.
e) Unknown effects on human health
The trans-genes may cross the intestinal walls into the circulatory system. Once in the system it may cross the BBB especially in kids with underdeveloped BBB. Traces of toxic substances of GMO origin have been found in the blood of pregnant women and their foetuses.
f) Threat to soil ecosystems and aquatic life
B.T crops secrete toxins from their roots into the soil. Aquatic organisms may be endangered if they eat leaves from B.t and other GMO crops.
Way forward on this GMO subject
Embrace GM technology with considerable caution. Governments should adopt non-partisan policies when dealing with GM technology and dedicate more funds to scientific research in this field.