Genetically modified food
Genetically modified foods (GM foods), also known as genetically engineered foods (GE foods), or bioengineered foods are foods produced from organisms that have had changes introduced into their DNA using various methods of genetic engineering. Genetic engineering techniques allow for the introduction of new traits as well as greater control over traits when compared to previous methods, such as selective breeding and mutation breeding.[1]
The discovery of DNA and the improvement of genetic technology in the 20th century played a crucial role in the development of transgenic technology.[2] In 1988, genetically modified microbial enzymes were first approved for use in food manufacture. Recombinant rennet was used in few countries in the 1990s.[3] Commercial sale of genetically modified foods began in 1994, when Calgene first marketed its unsuccessful Flavr Savr delayed-ripening tomato.[4][5] Most food modifications have primarily focused on cash crops in high demand by farmers such as soybean, maize/corn, canola, and cotton. Genetically modified crops have been engineered for resistance to pathogens and herbicides and for better nutrient profiles. The production of golden rice in 2000 marked a further improvement in the nutritional value of genetically modified food.[6] GM livestock have been developed, although, as of 2015, none were on the market.[7] As of 2015, the AquAdvantage salmon was the only animal approved for commercial production, sale and consumption by the FDA.[8][9] It is the first genetically modified animal to be approved for human consumption.
Genes encoded for desired features, for instance an improved nutrient level, pesticide and herbicide resistances, and the possession of therapeutic substances, are often extracted and transferred to the target organisms, providing them with superior survival and production capacity.[10][11][12][13][14][15][16] The improved utilization value usually gave consumers benefit in specific aspects.[10][11][15]
There is a scientific consensus[17][18][19][20][21] that currently available food derived from GM crops poses no greater risk to human health than conventional food,[22][23][24][25][26][27][28] but that each GM food needs to be tested on a case-by-case basis before introduction.[29][30][31] Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.[32][33][34][35] The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation,[36][37][38][39] which varied due to geographical, religious, social, and other factors.[10][40][41][42][43]
Derivative products[edit]
Lecithin[edit]
Lecithin is a naturally occurring lipid. It can be found in egg yolks and oil-producing plants. It is an emulsifier and thus is used in many foods. Corn, soy and safflower oil are sources of lecithin, though the majority of lecithin commercially available is derived from soy.[147][148][149] Sufficiently processed lecithin is often undetectable with standard testing practices.[150] According to the FDA, no evidence shows or suggests hazard to the public when lecithin is used at common levels. Lecithin added to foods amounts to only 2 to 10 percent of the 1 to 5 g of phosphoglycerides consumed daily on average.[147][148] Nonetheless, consumer concerns about GM food extend to such products.[151] This concern led to policy and regulatory changes in Europe in 2000, when Regulation (EC) 50/2000 was passed[152] which required labelling of food containing additives derived from GMOs, including lecithin. Because of the difficulty of detecting the origin of derivatives like lecithin with current testing practices, European regulations require those who wish to sell lecithin in Europe to employ a comprehensive system of Identity preservation (IP).[153][154]
Sugar[edit]
The US imports 10% of its sugar, while the remaining 90% is extracted from sugar beet and sugarcane. After deregulation in 2005, glyphosate-resistant sugar beet was extensively adopted in the United States. 95% of beet acres in the US were planted with glyphosate-resistant seed in 2011.[155] GM sugar beets are approved for cultivation in the US, Canada and Japan; the vast majority are grown in the US. GM beets are approved for import and consumption in Australia, Canada, Colombia, EU, Japan, Korea, Mexico, New Zealand, Philippines, the Russian Federation and Singapore.[156] Pulp from the refining process is used as animal feed. The sugar produced from GM sugar beets contains no DNA or protein – it is just sucrose that is chemically indistinguishable from sugar produced from non-GM sugar beets.[150][157] Independent analyses conducted by internationally recognized laboratories found that sugar from Roundup Ready sugar beets is identical to the sugar from comparably grown conventional (non-Roundup Ready) sugar beets.[158]
Vegetable oil[edit]
Most vegetable oil used in the US is produced from GM crops canola,[159] maize/corn,[160][161] cotton[162] and soybeans.[163] Vegetable oil is sold directly to consumers as cooking oil, shortening and margarine[164] and is used in prepared foods. There is a vanishingly small amount of protein or DNA from the original crop in vegetable oil.[150][165] Vegetable oil is made of triglycerides extracted from plants or seeds and then refined and may be further processed via hydrogenation to turn liquid oils into solids. The refining process removes all, or nearly all non-triglyceride ingredients.[166]
Other uses[edit]
Animal feed[edit]
Livestock and poultry are raised on animal feed, much of which is composed of the leftovers from processing crops, including GM crops. For example, approximately 43% of a canola seed is oil. What remains after oil extraction is a meal that becomes an ingredient in animal feed and contains canola protein.[167] Likewise, the bulk of the soybean crop is grown for oil and meal. The high-protein defatted and toasted soy meal becomes livestock feed and dog food. 98% of the US soybean crop goes for livestock feed.[168][169] In 2011, 49% of the US maize/corn harvest was used for livestock feed (including the percentage of waste from distillers grains).[170] "Despite methods that are becoming more and more sensitive, tests have not yet been able to establish a difference in the meat, milk, or eggs of animals depending on the type of feed they are fed. It is impossible to tell if an animal was fed GM soy just by looking at the resulting meat, dairy, or egg products. The only way to verify the presence of GMOs in animal feed is to analyze the origin of the feed itself."[171]
A 2012 literature review of studies evaluating the effect of GM feed on the health of animals did not find evidence that animals were adversely affected, although small biological differences were occasionally found. The studies included in the review ranged from 90 days to two years, with several of the longer studies considering reproductive and intergenerational effects.[172]
Enzymes produced by genetically modified microorganisms are also integrated into animal feed to enhance availability of nutrients and overall digestion. These enzymes may also provide benefit to the gut microbiome of an animal, as well as hydrolyse antinutritional factors present in the feed.[173]
Proteins[edit]
The foundation of genetic engineering is DNA, which directs the production of proteins. Proteins are also the common source of human allergens.[174] When new proteins are introduced they must be assessed for potential allergenicity.[175]
Rennet is a mixture of enzymes used to coagulate milk into cheese. Originally it was available only from the fourth stomach of calves, and was scarce and expensive, or was available from microbial sources, which often produced unpleasant tastes. Genetic engineering made it possible to extract rennet-producing genes from animal stomachs and insert them into bacteria, fungi or yeasts to make them produce chymosin, the key enzyme.[176][177] The modified microorganism is killed after fermentation. Chymosin is isolated from the fermentation broth, so that the Fermentation-Produced Chymosin (FPC) used by cheese producers has an amino acid sequence that is identical to bovine rennet.[178] The majority of the applied chymosin is retained in the whey. Trace quantities of chymosin may remain in cheese.[178]
FPC was the first artificially produced enzyme to be approved by the US Food and Drug Administration.[3][53] FPC products have been on the market since 1990 and as of 2015 had yet to be surpassed in commercial markets.[179] In 1999, about 60% of US hard cheese was made with FPC.[180] Its global market share approached 80%.[181] By 2008, approximately 80% to 90% of commercially made cheeses in the US and Britain were made using FPC.[178]
In some countries, recombinant (GM) bovine somatotropin (also called rBST, or bovine growth hormone or BGH) is approved for administration to increase milk production. rBST may be present in milk from rBST treated cows, but it is destroyed in the digestive system and even if directly injected into the human bloodstream, has no observable effect on humans.[182][183][184] The FDA, World Health Organization, American Medical Association, American Dietetic Association and the National Institutes of Health have independently stated that dairy products and meat from rBST-treated cows are safe for human consumption.[185] On 30 September 2010, the United States Court of Appeals, Sixth Circuit, analyzing submitted evidence, found a "compositional difference" between milk from rBGH-treated cows and milk from untreated cows.[186][187] The court stated that milk from rBGH-treated cows has: increased levels of the hormone Insulin-like growth factor 1 (IGF-1); higher fat content and lower protein content when produced at certain points in the cow's lactation cycle; and more somatic cell counts, which may "make the milk turn sour more quickly".[187]
