- Bans on GMO corn, glyphosate in Mexico would shrink food supplies, industry saysThe Mexican government's push to wean itself off a massive dependence on genetically modified corn imports would upend the country's food supply, including its big livestock sector, industry officials warn.Reuters3 days ago
- Mexico bans GMO corn: 2024 deadline includes elimination of glyphosate herbicideMexico’s government has issued a decree to phase out the use of both glyphosate and genetically modified corn for human consumption by 2024.AGRINEWS2 hours ago
- Should GMO food be globally banned?GirlsAskGuys4 days ago
- Mexico to Decide if GMO Corn Ban Will Apply to Animal FeedBloomberg1 week ago
- A CRISPR picture emerges on European Union GMO directivePhys.org2 weeks ago
Most currently available GMO foods are plants, such as fruit and vegetables. All foods from genetically engineered plants on sale in the United States are regulated by the Food and Drug...
- Amanda Barrell
In the decades since the first genetically modified foods reached the market, no adverse health effects among consumers have been found. By Jane E. Brody With an Eye on Hunger, Scientists See...
Jul 02, 2020 · In the United States, foods grown using GMO techniques include corn, soybean, canola, sugar beet, alfalfa, cotton, potatoes, papaya, summer squash, and a few varieties of apples. Although current...
Many GMO crops are used to make ingredients that Americans eat such as cornstarch, corn syrup, corn oil, soybean oil, canola oil, or granulated sugar. A few fresh fruits and vegetables are...
- Clinical significance
Arguably the most realistic solution for matching increased global demand for crops is to boost the crop yields on currently cultivated land. Currently, the rate of increase in crop-yield is less than 1.7% whereas the annual increase in yield needs to be 2.4% to meet the demands of population growth, improved nutritional standards and decreasing arability (see below) . This is a daunting task, which seems only achievable by means of optimization of crop genetics coupled with quantitative improvements in management of the agricultural system.
FAO predicted that the finite amount of arable land available for food production per person will decrease from the current 0.242 ha to 0.18 ha by 2050 . This problem confounds those of population growth and malnutrition. Yet our ability to bring additional acreage under cultivation seems limited. The alternative is greater yield per acre, which in turn must come from greater agriculture inputs, such as fertilizer, water, pest and weed control and/or genetic improvement . This scenario is compounded by several complicating factors: (1) the increased demand for biofuel and feedstock production; (2) accelerated urbanization; (3) land desertification, salinization, and degradation; (4) altered land use from staple foods to pasture, driven by socioeconomic considerations; (5) climate change; (6) water resource limitation.
Conventional breeding relies on sexual crossing of one parental line with another parental line, in hopes of expressing some desired property (e.g. disease resistance) . To select for the desired trait and to dilute irrelevant or undesired traits, breeders choose the best progeny and back-cross it to one of its parents (plant or animal). The process usually takes several years (depending on generational time, e.g. 1015 years for wheat) before actual expression of the desired trait that can be assessed, and further expanded by conventional breeding to commercially useful numbers. Besides the inherently long generation times, the following facts limit the development of conventional breeding: Prerequisite to breeding strategies is the existence of genetic variation that is, existence of an available gene-pool manifesting the desired traits, and sexual compatibility of organisms with those traits. In fact, nowadays genetic variety has dwindled (probably as a result of past efforts at optimization), thus we operate in a restricted space for improvement. Modern methodologies can increase this space by utilizing chemicals or radiation to introduce new mutational variation. However, these are blunt instruments that result in improved traits only by random chance and sparse luck. Indeed, the non-selectivity of these methods probably extend the breeding timeline .
Taking these facts into account, the emergence of biological technologies and the development of GM foods promise to reduce dramatically production timelines to new strains, and to provide us with optional strategies to achieve sustainable global food security.
The use of Agrobacterium tumefaciens opened a new era for inserting exogenous genes into plant cells. The soil bacterium A. tumefaciens infects plants, forming a gall at the crown. The bacteria actually alter the genome of the plant, not only causing proliferation of the plant cells, but also enabling the plant to produce modified amino acids as a specialized food source for themselves. The bacteria possess a tumor-inducing plasmid (Ti-plasmid), which enable them to accomplish gene-insertion; researchers hijack the plasmid by inserting designer gene's into the T-DNA (transfer DNA) section of the Ti-plasmid. In 2012, the CRISPR-Cas9 system was developed. It constitutes a revolutionary genome editing tool, and provides another method to alter genes in various type of cells , . This technique dramatically increases the efficiency of genetic engineering, making the work with plants much easier .
From 2006 to 2012, the global increase in farm income from GM food had reached $116 billion, almost triple that of previous 10 years , . According to the estimation from James and Brookes, about 42% of the economic gain was from the increased yield due to advanced genetics and resistance to pests and weeds. The decreased costs of production (e.g. from reduced pesticide and herbicide usage) contributed the remaining 58%.
Enhanced nutritional value in transgenic products has been obtained by manipulating their composition of carbohydrates. Let us consider further the example of Amflora. The bulk of polysaccharides in the potato-bulb is formed by two types of starch: amylose and amylopectin. Amylose is useful only as food starch, while amylopectin is widely used in the production of non-food starch, paper, and in textile processing. The synthesis of starch requires various enzymes, which include a granule-bound starch synthase (GSBB), the primary function of which involves the production of amylose. In the absence of GSBB, amylopectin is produced exclusively. Exploiting this knowledge has led to methods to modify the composition of potato starch. The transgenic process involves the introduction into potato bulbs of an additional copy of the GSBB-coding gene. Counter intuitively, the extra gene in fact suppressed expression of GSBB, by a process know as co-suppression, a.k.a. gene silencing. The resultant Amflora potato is with decreased amylose, but rich in amylopectin .
Three major health risks potentially associated with GM foods are: toxicity, allergenicity and genetic hazards. These arise from three potential sources, the inserted gene and their expressed proteins per se, secondary or pleiotropic effects of the products of gene expression, and the possible disruption of natural genes in the manipulated organism .
Starlink maize provides an example of a food hazard caused directly by the expression of the inserted gene , , , , . The modified plant was engineered with genetic information from Bacillus thuringinesis in order to endow the plant with resistance to certain insects. The inserted gene encodes a protein, called Cry9c, with pesticidal properties, but with an unintended, strong allergenicity. Several cases have been reported of allergic reaction in consumers after consuming the Starlink maize.
Modification on the expression level of natural components of the manipulated organism can also exacerbate allergy. One example is the production of soybeans enriched in the amino acid methionine. The enhanced synthesis of this amino acid is the result of a gene isolated from Brazil nuts. As a consequence, some consumers allergenically sensitized to these nuts have allergic reactions to the transgenic soybean.
Secondary and pleiotropic effects are much less straightforward to recognize than direct effects of the gene or its products. The modified gene may encode an enzyme involved in otherwise natural metabolic pathways of the modified organisms. Such changes might alter the levels of other metabolites, including toxic ones, at some metabolic distance from actual metabolic perturbation. Connecting the causative dots presupposes an intimate understanding of the biochemical and regulatory pathways which may be beyond current comprehension.
- Chen Zhang, Robert Wohlhueter, Han Zhang
Jan 11, 2021 · My co-founders and I were featured in Food Evolution, a “pro-science” documentary that shed light on the truth about GMOs and was narrated by Neil deGrasse Tyson, whom the New York Times ...
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Jun 04, 2019 · Genetically modified food: A guide to overcoming skepticism. The researchers followed up by conducting a five-week longitudinal study with 231 undergraduates in the US to test, first, if a lack of ...
Feb 26, 2018 · Consumers are deeply suspicious of GMO foods--products made from genetically modified agricultural crops. They are told that growing such crops may have adverse health effects. They are warned that...
- Omri Ben-Shahar