Genetically Modified Organisms
Genetically modified organisms (GMOs) are the main subject of controversy throughout the world. Some of the controversies revolve around what constitutes a GMO.
(WHO) The World Health Organization represents them as organisms “in which the genetic material (DNA) has been altered in a manner that does not happen naturally via mating and/or recombination.”
This definition implies that GMOs are transgenic—containing one or more genes from unrelated organisms.
A broader definition of Genetically modified organisms includes organisms whose own genes have been edited—modified, inactivated, or removed—or contain genes from other strains of the same species or genes synthesized in a laboratory.
With the new gene-editing technology CRISPR, this will constitute the largest class of genetically modified (GM) foods.
The broadest definition defines GMOs as any plant, animal, or microorganism produced through genetic manipulation.
This could apply to essentially all organisms raised for food because humans have been modifying genomes (the genetic material of organisms) through selection, crossbreeding, and hybridization within and between species ever since plants and animals were first domesticated many thousands of years ago.
However, molecular biological technologies create GMOs much faster, more precisely, and less randomly than traditional methods.
Scientists and others who understand how these new organisms are created generally tend to support GMOs. In contrast, consumers are concerned with what is in their food and how it is produced, and the environmental effects of Genetically modified organisms.
GMO proponents argue that genetic modifications must improve and increase the food supply for a growing global population and that diminished and deteriorating agricultural land. A changing climate necessitates faster-growing, more nutritious crops able to withstand higher temperatures, droughts, and floods.
Crops can be genetically altered to improve hardiness, yield, and food quality and decrease the need for environmentally damaging pesticides and fertilizers.
Theoretically, GMOs could
- grow faster and stronger
- require less water
- tolerate rising salt concentrations and/or submersion in floodwaters
- thrive at higher temperatures
- resist frost
- resist disease, insects, weeds, and other pathogens
- be more nutritious
- contain needed micronutrients such as vitamins
- taste better
- appear more appetizing
- have longer shelf-lives
- be of less cost and less labor-intensive to produce
- be used as vaccines or medicines
“Golden rice” was one of the first commercial Genetically modified organisms engineered to improve nutrition. It contains genes from corn and bacteria for producing beta-carotene, which the human body uses to make vitamin A.
Vitamin A deficiency causes up to 500,000 cases of childhood blindness every year and contributes to 2 million deaths annually in low-income countries.
Since rice is a dietary staple in much of the world, golden rice can prevent blindness and save lives.
However, consumer fear of Genetically modified organisms has kept golden rice out of regions most affected by vitamin A deficiency.
The major focus of commercial GMO development—especially on Monsanto-Bayer—has been crops that express herbicide-resistance genes.
This resistance enables farmers to apply far greater amounts of toxic weed-controlling herbicides—purchased from Monsanto—that contaminate neighboring non-GMO and organic crops and encourage the rise of herbicide-resistant weeds.
GMOs also are being developed to fight disease. Mosquitoes that spread diseases such as malaria and the Zika virus have been engineered to spread infertility or fatal genes.
In some cases, a gene drive technique is used to spread these genes through a population rapidly.
Local trials of these GMOs are ongoing, although the environmental effects of wiping out an entire mosquito species are unknown.
Humans have been genetically altering organisms for millennia via plant hybridization and selection, and animal breeding.
Tree grafting appears to have enabled even distantly related plant species to swap genes and genomes.
Mutation breeding—inducing mutations with radiation or chemicals—has been used since the 1930s, resulting in more than 3,200 commercial varieties of more than 210 plant species.
The first Genetically modified organisms food, the FlavrSavr tomato, was introduced in the US market in 1994.
It ripened more slowly and remained on the vine longer than conventional tomatoes and so was available later in the year.
However, it proved economically nonviable and was withdrawn after three years.
Tomato paste from GMO tomatoes was introduced in the United Kingdom in 1996 but was withdrawn owing to poor sales because of consumer concerns about its safety.
Despite these early failures, global acreage planted in Genetically modified organisms seeds has been increasing steadily since 1996—the year Monsanto introduced Roundup Ready soybeans.
Glyphosate, the potent herbicide (and probable carcinogen) in Roundup, killed essentially every plant except the GMO soybeans, allowing the spraying of Roundup throughout the growing season.
Soon, almost all US soybeans, corn, and cotton had been engineered to resist glyphosate or other pesticides.
Global glyphosate use increased from 16 million lb (7 million kg) to more than 280 million lb (127 million kg).
Millions of these pounds drift onto nearby fields, destroying millions of dollars worth of non-GMO and organic crops.
Furthermore, within four years, newly evolved glyphosate-resistant superweeds were significantly reducing crop yields.
In 2005, scientists discovered a bacterial gene that conferred resistance to the old herbicide dicamba.
Dicamba-resistant seeds were soon one of Monsanto’s most successful products ever, accounting for one-quarter of all US soybeans.
Drifting dicamba sparked yet another—sometimes violent—herbicide war among farmers.
In addition, President Donald Trump’s administration reversed the bans of the Barack Obama administration on certain pesticides and on farming GMO crops in national wildlife refuges.
GMOs entered a second revolution in the second decade of the twenty-first century by developing easy, fast, inexpensive, and efficient CRISPR gene editing.
Previously, transgenic Genetically modified organisms were created by inserting foreign genes into plant genomes, with little or no control over where in the genome the foreign gene is inserted.
In contrast, CRISPR can remove or edit specific genes within a plant or precisely introduce new genes at positions within the genome where they are active and do not interfere with other genes.
Soon US grocery stores were carrying “White Russet” bruise-resistant GMO potatoes and non-browning GMO “Arctic” apples.
In 2019, Burger King, the second-largest US fast-food chain, introduced a meatless Impossible Burger, containing a “meaty”-tasting heme (iron-containing compound) made from GMO yeast and soybean roots.
As of 2019, biotechnology companies were using CRISPR to develop new products such as
- high-yield row crops (soybeans and corn) with disease, stress, and herbicide resistance
- higher-yield canola and soybeans with higher oil contents
- a high-yield tomato that can be shipped long distances and tastes fresh off the vine
- a new type of berry formed by domesticating ground cherries using some of the genes that, over thousands of years of plant breeding, transformed tomatoes into a profitable mass-produced fruit
- fruits and vegetables with improved taste and other characteristics for increasing their attractiveness as healthy snack foods
- disease-resistant bananas at a time when America’s favorite fruit was facing extinction
- waxy corn for producing a starchy adhesive
- decaffeinated coffee
In 2019, the first GMO animal was finally cleared to be raised and sold for food in the United States.
This farmed Atlantic salmon, often referred to as “frankenfish,” grows twice as fast as typical farmed salmon on less food, thanks to a growth-promoting gene from a Chinook salmon and a gene promoter an ocean pout.
The global prevalence of GMOs varies greatly, depending on local regulations, markets, and public opinion.
Many US food and clothing comes from GMOs since the vast majority of commodity crops—corn, soybeans, sugar beets, and cotton—are grown from GMO seeds. Almost all Canadian-grown canola has been genetically engineered to resist herbicides.
As a result, an estimated 70% of US processed foods contain at least one GMO ingredient—including any food made with soy products or vegetable oil or fats from soy, corn, cottonseed, or canola—although processing usually removes most of the modified genes and the proteins they produce.
Thus, nonorganic products such as flour, pasta, bread, crackers, infant formulas, ice cream, cereals, chips, salad dressings, candy, tofu, tamari and soy sauce, sugars, peanut butter, white vinegar, and corn syrup include Genetically modified organisms ingredients.
In addition, many food additives, enzymes, flavorings, and processing agents are obtained from GMOs, including aspartame and rennet for making hard cheeses. US meat, eggs, and dairy products come from animals fed GM alfalfa.
Dairy cows often are treated with the GM recombinant bovine growth hormone (rbGH). Bees utilize GM pollen to produce honey and bee pollen.
Even GMO-free foods may have been contaminated with GMO seeds or pollinated with pollen from GMOs. GMO produce includes summer squash, zucchini, papaya, and sweet corn.
Some US processors will not buy certain GMO crops because the European Union (EU) and other export markets will not import them, and some US restaurant chains refuse to serve GMO foods.
PUBLIC HEALTH ROLE AND RESPONSE
Although most scientists claim that GMO foods are as safe as their conventional counterparts, opponents argue that they present potential health risks, such as allergic reactions to introduced proteins or other immune system effects.
In the 1990s, a Brazil nut allergen was accidentally transferred to GMO soybeans, although the soybeans were never commercialized.
There has been no evidence of any allergic reactions to GMOs grown in the United States.
Studies have shown differences between animals fed GMO and non-GMO feed, but these studies have not been considered “biologically relevant.”
It also has been argued that there is sometimes little difference between GMO foods and foods endorsed as organic by the US Department of Agriculture (USDA), which cannot contain GMO ingredients.
For example, the Bt gene added to corn to confer insect resistance and possibly reduce the amount of applied insecticide comes from the same bacterium that organic farmers use as a natural insecticide.
In contrast, opponents claim that the companies that make and sell GMOs have almost complete control over their human and environmental health and safety.
They argue that small genetic changes can have major effects on plant characteristics and that GMOs are not always adequately tested.
Furthermore, herbicide-resistant Genetically modified organisms crops encourage the increased application of pesticides that can harm humans and the environment.
These GMO plants also may become less resistant to some pests or more susceptible to others.
GMOs may be partly responsible for the collapse of honeybee colonies or the decline of Monarch butterflies since heavier applications of glyphosate kill the milkweed that the butterflies depend on.
Critics also worry that GMO agricultural dominance carries the risk of losing plant genetic diversity and other environmental consequences, including the unknown consequences of their escape into the environment.
For example, GMO salmon could escape into the wild, contaminate native salmon gene pools, and even cause extinctions.
Furthermore, GMO salmon may be much more allergenic than regular salmon, and any human effects from their foreign growth hormone are unknown.
Efforts and solutions
In 2016, the US National Academies of Sciences, Engineering, and Medicine reported their two-year study of the risks and benefits of GMO foods.
They concluded that GMOs appear to be as safe as conventionally bred food and pose no larger risk to the environment. However, genetic engineering has not as yet significantly increased crop yields.
Genetically modified organisms feed does not appear to harm animals. The study also argued that GMOs should be regulated based on the organism’s characteristics rather than on the technology used to create it.
They suggested that regulators use genome sequencing (the process of determining DNA makeup) and analyze proteins and small molecules in new GMOs to determine whether they differ from conventional varieties in ways that could affect health or the environment.
Likewise, WHO and the American Medical Association have concluded that there is no evidence of health hazards from GMO foods.
LEGAL AND REGULATORY ISSUES
Three US government agencies regulate and monitor GMOs: the USDA, the Food and Drug Administration (FDA), and the Environmental Protection Agency (EPA), with the USDA’s
Animal and Plant Health Inspection Service (APHIS) determining their regulatory status.
US Genetically modified organismsregulations were developed in the 1980s when foreign genes were introduced into plants using bacterial or viral vectors (agents that transmit disease) that could be considered “plant pests.”
In 2016, APHIS declared that several new gene-edited foods would not be reviewed or regulated since they did not include foreign genetic material from “plant pests.”
A browning-resistant mushroom with just a few base-pair changes in the DNA of one gene became the first CRISPR-edited food.
Amidst the first decade of the twenty-first century, the FDA had decided that genetic modifications to food animals should be classified as veterinary drugs when they contain transgenes from other species because this alters the “structure or function” of the animal.
This ruling temporarily dried up research money for the creation of GMO food animals. For FDA approval, regulated GMO animal foods must be proved to be as safe and nutritious as their non-GMO equivalents.
The EPA regulates GMO plants containing pesticide-related genes.
As of 2019, legislation and regulations affecting the production, importation, and labeling of GMOs were in flux worldwide.
Governments debated whether CRISPR gene-edited products were GMOs and if or how they should be regulated.
In 2018, the USDA decided that most CRISPR-edited organisms would be regulated as foods obtained by traditional breeding methods. However, the FDA appears to consider CRISPR gene editing the same as older GMO technologies in animals.
In the United States, the controversy has been more focused on if and how GMOs should be labeled.
For years, American consumers have demanded to know whether they are eating GMOs. Farmers and the food industry have vigorously opposed GMO labeling because consumers would not buy Genetically modified organisms foods.
Indeed, many foods began carrying “GMO-free” labels to appeal to consumers. In 2016, President Obama signed a mandatory GMO-labeling law.
Because of loopholes and exemptions in the law and its preemption of state labeling laws, anti-GMO groups refer to it as the “Deny Americans the Right to Know (DARK) Act.”
The law excluded highly processed GMOs such as sugar beets and soy oil from the labeling requirement. CRISPR gene-edited foods also will probably not require labeling.
Critics claim that the new rules are based on agriculture interests rather than environmental concerns such as the increased use of toxic pesticides.
The FDA, which opposed mandatory labeling, objected to non-GMO since most GMO foods do not contain or consist of entire organisms.
The FDA also distinguishes between “genetically modified” and neered” because almost all food plants and animals have been genetically modified for centuries by hybridization or breeding.
The USDA finally decided that Genetically modified organisms would bear the label bioengineered, rather than the term GMO, which most consumers are familiar with.
These new labeling rules do not correspond to those used in other countries. The Non-GMO Project certifies non-GMO foods using guidelines similar to those used in the EU.
Both the WHO and the Food and Agricultural Organization of the United Nations have declared that identifying and evaluating unintended effects of GMO foods and animal feed are of utmost importance.
Genetically modified organisms have disrupted international trade because many countries refuse to grow or import them, and at least 64 countries require GMO labeling.
The EU has banned glyphosate and requires that all GMO foods undergo a strict premarket approval process.
All food and animal feed having more than 0.9% of a GMO ingredient must be appropriately labeled.
Non-packaged Genetically modified organisms foods require a nearby sign identifying them as genetically modified.
The European Court of Justice has classified gene-edited CRISPR crops as GMOs that require extensive risk evaluation before they can be planted or sold.
The Court argued that gene editing, as genetic material is transferred between organisms to form transgenes, changes the organism’s genetic material in ways that do not occur in nature.
Individual EU member countries also make their own decisions.
For example, Germany does not allow the planting of GM corn, and Spain is the only EU country that allows the cultivation of GM maize.
Japan imports GMOs, but there is little consumer interest, and most Japanese farmers do not grow Genetically modified organismscrops.
However, the country decided that gene-edited foods without foreign DNA do not require safety evaluations since they are similar to traditionally bred foods.
GMOs appear to be here to stay and may become essential for preventing future famines.
Starting from 2019, the Bill and Melinda Gates Foundation was funding an “end world hunger” campaign to promote the evidence-based use of GMOs in developing countries.
Education may help resolve the conflicts between scientists and the public. Some public opposition seems to stem from a shortage of understanding of how GMOs are created and tested, especially the differences between gene-edited organisms and transgenic organisms containing foreign DNA.
For example, all new food plants, regardless of whether they were created by traditional breeding or modern genetic technologies, pose risks to humans and the environment.
Of particular importance is distinguishing the environmental harm caused by the heavy application of toxic and/or carcinogenic pesticides to GMO crops from minor genetic changes that make foods cheaper, healthier, and more appetizing
The immediate future for GMOs will depend on global regulations and agreements. However, the growing population and changing climate will require new crop varieties to feed the world population.
An avalanche of new Genetically modified organisms—animals as well as plants—is expected shortly. Some of these developments may improve animal welfare.
For example, researchers have introduced a gene from beef cows lacking horns into dairy cows to eliminate the need for painful dehorning.
CRISPR may be used to produce all-male beef cows and all-female dairy cows, preventing the wasteful destruction of animals of the wrong sex.
CRISPR also has been used to create pigs and chickens with immunity to flu viruses, potentially preventing animal and human pandemics.
Genetically modified organisms crops can lessen the use of pesticides and nitrogen fertilizers that poison rivers and oceans.
Pesticides also are dangerous for farmworkers and may leave potentially harmful residues on foods.
In 2015, Chinese scientists used CRISPR to delete all three copies of a single wheat gene, resulting in a strain that was completely resistant to powdery mildew, one of the most widespread blights.
Nitrogen fertilizer production is a significant source of carbon dioxide emissions, which contribute to global warming.
Reductions in the use of agricultural chemicals also may lower the cost of food production and consumer prices.
In the future, animal and animal feed may be genetically modified to reduce methane emissions from livestock, another major contributor to global warming.
GMO foods may stay fresh longer, enabling better distribution to food-limited populations and limiting food waste.
Some Genetically modified organisms foods may benefit human health: for example, bruise-resistant potatoes may produce less carcinogenic acrylamide in response to high heat.
Healthier gene-edited soybean oil is high in oleic oil with less saturated fat.
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