Controverisal Issues

1. New allergens could be inadvertently created

- known allergens could be transferred from traditional foods into GM foods. For instance, during laboratory testing, a gene from the Brazil nut was introduced into soybeans. It was found that people with allergies to Brazil nuts could also be allergic to soybeans that had been genetically modified in this way. No allergic effects have been found with currently approved GM foods.

2. Antibiotic resistance may develop

- bioengineers sometimes insert a ‘marker’ gene to help them identify whether a new gene has been successfully introduced to the host DNA. One such marker gene is for resistance to particular antibiotics. If genes coded for such resistance enter the food chain and are taken up by human gut microflora, the effectiveness of antibiotics could be reduced and human infectious disease risk increased. Research has shown that the risk is very low; however, there is general agreement that use of these markers should be phased out.

3. Cross-breeding

- other risks include the potential for cross-breeding between GM crops and surrounding vegetation, including weeds. This could result in weeds that are resistant to herbicides and would thus require a greater use of herbicides, which could lead to soil and water contamination. The environmental safety aspects of GM crops vary considerably according to local conditions.

4. Pesticide resistant insects

- the genetic modification of some crops to permanently produce the natural biopesticide Bacillus thuringiensis (Bt) toxin could encourage the evolution of Bt-resistant insects, rendering the spray ineffective. Wherever pesticides are used, insect resistance can occur and good agricultural practice includes strategies to minimise this.

5. Biodiversity

- growing GM crops on a large scale may also have implications for biodiversity, the balance of wildlife and the environment. This is why environmental agencies closely monitor their use.

6. Cross-contamination

- plants bioengineered to produce pharmaceuticals (medicines etc) may contaminate food crops. Provisions have been introduced in the USA requiring substantial buffer zones, use of separate equipment and a rule that land used for such crops lie fallow for the next year.

Ethical concerns

Concerns about genetic modification include:

• The possible monopolisation of the world food market by large multinational companies that control the distribution of GM seeds.
  
• Using genes from animals in plant foods may pose ethical, philosophical or religious problems. For example, eating traces of genetic material from pork could be a problem for certain religious groups.
  
• Animal welfare could be adversely affected. For example, cows given more potent GM growth hormones could suffer from health problems related to growth or metabolism.
  
• New GM organisms could be patented so that life could become commercial property through patenting.

GM labelling and the law

Since December 2002, the law in Australia states that food labels must show if food has been genetically modified or contains genetically modified ingredients, or whether GM additives or processing aids remain in the final food.

Special labels are not required for:

• ‘Highly refined’ foods where the altered DNA or protein is no longer in the food (for example, oil from modified corn).
  
• GM food additives or processing aids - unless the new DNA remains in the food to which it is added.
  
• GM flavours where less than 0.1 per cent is present in the food.
  
• Food, food ingredients or processing aids where GM ingredients are ‘unintentionally’ present in less than 1.0 per cent.
  
• Food that is prepared at the point of sale (so takeaway and restaurant food will not have to be labelled).

Labels may be required where:

• Genetic modification has altered the food so that its composition or nutritional value is ‘outside the normal range’ of similar non-GM goods; for example, if GM technology is used to add vitamins.
  
• Naturally occurring toxins are ‘significantly different’ to similar non-GM foods.
  
• The food produced using GM technology contains a ‘new factor’, which can cause allergic reactions in some people.
  
• Genetic modification raises ‘significant ethical, cultural and religious concerns’ regarding the origin of the genetic material used.

GM food on the shelves

There are around 20 GM foods, additives, flavourings, growth hormone (bovine somatotropin) and enzymes (like rennet, used to make cheese) currently approved in Europe. In the USA, there are more than 40 approved GM foods.

The main sources of GM foods in Australia include:

• Imported soya from the United States. This is one of the main sources of GM ingredients in food sold in Australia since 1996. The soya has been genetically modified to be resistant to a herbicide. It can be found in a wide range of foods, such as chocolates, potato chips, margarine, mayonnaise, biscuits and bread. Cottonseed oil made from GM cotton (resistant to a pesticide) is also used in Australia. It is used for frying by the food industry, and in mayonnaise and salad dressings.
  
• Imported GM corn is mainly used as cattle feed at present and has not been approved for farming in Australia. However, GM corn may have entered the Australian market through imported foods like breakfast cereal, bread, corn chips and gravy mixes; if so, it is now required to be labelled.
  
• Other GM foods available overseas that may be ingredients in foods imported to Australia include potatoes, canola oil, sugar beet, yeast, cauliflower and coffee.

Reference: "Genetically Modified Foods." Better Health Channel. Nov. 2006. Deakin University- Faculty of Health and Behavioural Sciences. 27 June 2008 .

Toxins found in Flour and Starch products

Toxins found in Flour and Starch Products:

Fusarium
Distributed in soils and plants worldwide, Fusarium can invade corn and barley and produce toxins at lower temperatures than many fungi. Fusarium has affected water-damaged carpets, and can cause infections in immunocompromised individuals. Frequently involved in eye, skin and nail infections, and is reported to be allergenic.

Reference: http://www.gcmpinc.com/commonmolds.htm

Fungal Poisons and Toxins

Fungal toxins broadly fall into two groupings, the mycotoxins, produced by hyphae of common
molds, and mushroom toxins or poisons, produced in the fleshy fruiting bodies of some fungi.
(But for our package, i focus more on the mycotoxins as compared to the mushroom toxins)

Mycotoxins:

Mycotoxins are mainly produced by fungi growing in contaminated foods; the
compounds most commonly develop during storage and remain within the food after
processing and cooking
If eaten by humans or livestock, these toxins can have profound chronic and acute
effects; mycotoxins are also highly carcinogenic
An example is a group of toxins called aflatoxins produced by the fungus Aspergillus
flavus.

Foods contaminated with this fungus have killed fowl and other animals, and
humans have also died from eating contaminated corn (e.g., in 1974 in India).

It is also possible that high rates of liver cancer among some groups of people in
Asia and Africa are associated with consumption of aflatoxin-contaminated foods.

More than 200 mycotoxins have been identified from 150 species of fungi; conditions
that lead to food spoilage, such as warm temperatures, are important environmental
triggers in some species for the production of toxins.


Ergot of rye and ergotism:

Ergot is a toxin caused by Claviceps purpurea. The disease causes ergotism in livestock if hays or grains are infected. Ergot occurs every year on cereals and grasses, and is more prevalent in rye and triticale. The most common sign of ergot is the dark purple to black sclerotia found replacing the grain in the heads of cereals and grasses just prior to harvest. The ergot disease occurs abundantly during wet seasons. The wet weather and wet soils favor germination of the ergot bodies.

Ergot is a disease of rye, which infects the flowers and produces hard mycelial masses (ergots) in place of the grains.
The ergots contain numerous alkaloids, and if they are ground along with healthy grain
the resulting flour and baked breads can cause a condition known as ergotism; historical
records of epidemics indicate that the symptoms followed two different patterns.

Chronic poisoning caused gangrenous ergotism:
Cold prickling or burning sensations in the fingers and toes that gradually spread to the
entire limb.
Swelling of the limbs and burning pains alternating with icy coldness
Numbness of the limbs followed by the affected parts turning black with a dry
gangrene that gradually spread upward and necessitated amputation of the limb
Pregnant women frequently miscarried.

Acute poisoning caused convulsive ergotism:
Itching, prickling under the skin, numbness, muscle cramps or spasms
Quickly followed by hallucinations and convulsions.
Severe brain damage and fatality.
Today we know that the symptoms can be attributed to the abundant alkaloids within
the fungal ergots.
Some of the alkaloids affect smooth muscles and cause vasoconstriction leading to
muscle pain, spasms, miscarriages, and gangrene.
Other alkaloids affect the central nervous system resulting in convulsions,
hallucinations, brain damage, and death.

Reference: http://www.sbs.utexas.edu/mbierner/BIO305E/Lectures,%20etc/Fungi%20V.pdf

Toxins- Aflatoxins

Toxin: AFLATOXINS

Aflatoxins are toxic metabolites produced by certain fungi in/on foods and feeds . They are probably the best known and most intensively researched mycotoxins in the world. Aflatoxins have been associated with various diseases , such as aflatoxicosis, in livestock , domestic animals and humans throughout the world . The occurence of aflatoxins is influenced by certain environmental factors ; hence the extent of contamination will vary with geographic location , agricultural and agronomic practices, and the susceptibility of commodities to fungal invasion during preharvest , storage, and/or processing periods . Aflatoxins have received greater attention than any other mycotoxins because of their demonstrated potent carcinogenic effect in susceptible laboratory animals and their acute toxicological effects in humans . As it is realized that absolute safety is never achieved , many countries have attempted to limit exposure to aflatoxins by imposing regulatory limits on commodities intended for use as food and feed .

Occurence

In Raw Agricultural Products :
Aflatoxins often occur in crops in the field prior to harvest . Postharvest contamination can occur if crop drying is delayed and during storage of the crop if water is allowed to exceed critical values for the mold growth . Insect or rodent infestations facilitate mold invasion of some stored commodities.Aflatoxins are detected occasionally in milk, cheese, corn, peanuts, cottonseed, nuts, almonds, figs, spices, and a variety of other foods and feeds . Milk, eggs, and meat products are sometimes contaminated because of the animal consumption of aflatoxin-contaminated feed . However, the commodities with the highest risk of aflatoxin contamination are corn, peanuts, and cottonseed.

In Processed Foods :
Corn is probably the commodity of greatest worldwide concern , because it is grown in climates that are likely to have perennial contamination with aflatoxins and corn is the staple food of many countries . However, procedures used in the processing of corn help to reduce contamination of the resulting food product . This is because although aflatoxins are stable to moderately stable in most food processes , they are unstable in processes such as those used in making tortillas that employ alkaline conditions or oxidizing steps . Aflatoxin-contaminated corn and cottonseed meal in dairy rations have resulted in aflatoxin M1 contaminated milk and milk products , including non-fat dry milk , cheese , and yogurt .

Recent Methods of Analysis for Aflatoxins in Foods and Feeds

Sampling and Sample Preparation:

Sampling and sample preparation remain a considerable source of error in the analytical identification of aflatoxins. Thus, systematic approaches to sampling, sample preparation, and analysis are absolutely necessary to determine aflatoxins at the parts-per-billion level. In this regard, specific plans have been developed and tested rigorously for some commodities such as corn, peanuts, and tree nuts; sampling plans for some other commodities have been modeled after them. A common feature of all sampling plans is that the entire primary sample must be ground and mixed so that the analytical test portion has the same concentration of toxin as the original sample.

Solid-Phase Extraction:

All analytical procedures include three steps: extraction, purification, and determination. The most significant recent improvement in the purification step is the use of solid-phase extraction.Test extracts are cleaned up before instrumental analysis(thin layer or liquid chromatography) to remove coextracted materials that often interfere with the determination of target analytes.

Thin-Layer Chromatography:

Thin layer chromatography (TLC), also known as flat bed chromatography or planar chromatography is one of the most widely used separation techniques in aflatoxin analysis. Since 1990, it has been considered the AOAC official method and the method of choice to identify and quantitate aflatoxins at levels as low as 1 ng/g. The TLC method is also used to verify findings by newer, more rapid techniques.

Liquid Chromatography:

Liquid chromatography (LC) is similar to TLC in many respects, including analyte application, stationary phase, and mobile phase. Liguid chromatography and TLC complement each other. For an analyst to use TLC for preliminary work to optimize LC separation conditions is not unusual. Liquid chromatography methods for the determination of aflatoxins in foods include normal-phase LC (NPLC), reversed-phase LC (RPLC) with pre- or before-column derivatization (BCD), RPLC followed by postcolumn derivatization (PCD), and RPLC with electrochemical detection.

Immunochemical Methods:

Thin layer chromatography and LC methods for determining aflatoxins in food are laborious and time consuming. Often, these techniques require knowledge and experience of chromatographic techniques to solve sepatation and and interference problems. Through advances in biotechnology, highly specific antibody-based tests are now commercially available that can identify and measure aflatoxins in food in less than 10 minutes. These tests are based on the affinities of the monoclonal or polyclonal antibodies for aflatoxins. The three types of immunochemical methods are radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), and immunoaffinity column assay (ICA).

These are mostly chemical methods of detection but still provide an insight into the immunochemical methods such as ELISA and RIA which can used to detect aflatoxins in foods, such as flour and starch products produced by the company.

Confirmation of Identities of the Aflatoxins:

Although analytical methods might consist of different extraction, clean-up, and quantitation steps, the results of the analyses by such methods should be similar when the methods are applied properly. Since the reliability of the quantitative data is not in question, the problem still to be solved is the confirmation of identity of the aflatoxins. The confirmation techniques used involve either chemical derivatization or mass spectrometry (MS).

Monitoring Techniques for Assessing Human Exposure to Aflatoxins

In the last few years, new technologies have been developed that more accurately monitor individual exposures to aflatoxins. Particular attention has been paid to the analysis of aflatoxin DNA adducts and albumin adducts as surrogates for genotoxicity in people. Autrup et al.(1983) pioneered the use of synchronous fluorescence spectroscopy for the measurement of aflatoxin DNA adducts in urine. Urine samples collected after exposure to alfatoxins were found to contain 2,3-dihydroxy-2-(N7-guanyl)-3-hydroxyaflatoxin B1, trivially known as AFB-Gual. Wild et al.(1986) used highly sensitive immunoassays to quantitate aflatoxins in human body fluids. An enzyme linked immunosorbent assay (ELISA) was used to quantitate aflatoxin B1 over the range of 0.01 ng /ml to 10 ng/ml, and was validated in human urine samples. Using this method, aflatoxin-DNA adduct excretion into urine was found to be positively correlated with dietary intake, and the major aflatoxin B1-DNA adduct excreted in urine was shown to be an appropriate dosimeter for monitoring aflatoxin dietary exposure.

References: http://www.abc.cornell.edu/plants/toxicagents/aflatoxin/aflatoxin.html

GMFOOD!

What are genetically-modified foods?

The term GM foods or GMOs (genetically-modified organisms) is most commonly used to refer to crop plants created for human or animal consumption using the latest molecular biology techniques. These plants have been modified in the laboratory to enhance desired traits such as increased resistance to herbicides or improved nutritional content. The enhancement of desired traits has traditionally been undertaken through breeding, but conventional plant breeding methods can be very time consuming and are often not very accurate.

Genetic engineering, on the other hand, can create plants with the exact desired trait very rapidly and with great accuracy. For example, plant geneticists can isolate a gene responsible for drought tolerance and insert that gene into a different plant. The new genetically-modified plant will gain drought tolerance as well. Not only can genes be transferred from one plant to another, but genes from non-plant organisms also can be used.

The best known example of this is the use of B.t. genes in corn and other crops. B.t., or 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.


What are some of the advantages of GM foods?

• Pest resistance- Crop losses from insect pests can be staggering, resulting in devastating financial loss for farmers and starvation in developing countries. Farmers typically use many tons of chemical pesticides annually. Consumers do not wish to eat food that has been treated with pesticides because of potential health hazards, and run-off of agricultural wastes from excessive use of pesticides and fertilizers can poison the water supply and cause harm to the environment. Growing GM foods such as B.t. corn can help eliminate the application of chemical pesticides and reduce the cost of bringing a crop to market.
  

• Herbicide tolerance- For some crops, it is not cost-effective to remove weeds by physical means such as tilling, so farmers will often spray large quantities of different herbicides (weed-killer) to destroy weeds, a time-consuming and expensive process, that requires care so that the herbicide doesn't harm the crop plant or the environment. Crop plants genetically-engineered to be resistant to one very powerful herbicide could help prevent environmental damage by reducing the amount of herbicides needed. For example, Monsanto has created a strain of soybeans genetically modified to be not affected by their herbicide product Roundup. A farmer grows these soybeans which then only require one application of weed-killer instead of multiple applications, reducing production cost and limiting the dangers of agricultural waste run-off.
  

• Disease resistance- There are many viruses, fungi and bacteria that cause plant diseases. Plant biologists are working to create plants with genetically-engineered resistance to these diseases.
  

• Cold tolerance- Unexpected frost can destroy sensitive seedlings. An antifreeze gene from cold water fish has been introduced into plants such as tobacco and potato. With this antifreeze gene, these plants are able to tolerate cold temperatures that normally would kill unmodified seedlings. (Note: I have not been able to find any journal articles or patents that involve fish antifreeze proteins in strawberries, although I have seen such reports in newspapers. I can only conclude that nothing on this application has yet been published or patented.)
  

• Drought tolerance/salinity tolerance- As the world population grows and more land is utilized for housing instead of food production, farmers will need to grow crops in locations previously unsuited for plant cultivation. Creating plants that can withstand long periods of drought or high salt content in soil and groundwater will help people to grow crops in formerly inhospitable places.
  

• Nutrition- Malnutrition is common in third world countries where impoverished peoples rely on a single crop such as rice for the main staple of their diet. However, rice does not contain adequate amounts of all necessary nutrients to prevent malnutrition. If rice could be genetically engineered to contain additional vitamins and minerals, nutrient deficiencies could be alleviated. For example, blindness due to vitamin A deficiency is a common problem in third world countries. Researchers at the Swiss Federal Institute of Technology Institute for Plant Sciences have created a strain of "golden" rice containing an unusually high content of beta-carotene (vitamin A). Since this rice was funded by the Rockefeller Foundation, a non-profit organization, the Institute hopes to offer the golden rice seed free to any third world country that requests it. Plans were underway to develop a golden rice that also has increased iron content. However, the grant that funded the creation of these two rice strains was not renewed, perhaps because of the vigorous anti-GM food protesting in Europe, and so this nutritionally-enhanced rice may not come to market at all.

• Pharmaceuticals- Medicines and vaccines often are costly to produce and sometimes require special storage conditions not readily available in third world countries. Researchers are working to develop edible vaccines in tomatoes and potatoes. These vaccines will be much easier to ship, store and administer than traditional injectable vaccines.

• Phytoremediation- Not all GM plants are grown as crops. Soil and groundwater pollution continues to be a problem in all parts of the world. Plants such as poplar trees have been genetically engineered to clean up heavy metal pollution from contaminated soil.

What are some of the criticisms against GM foods?

Environmental hazards

• Unintended harm to other organisms- Last year a laboratory study was published in Nature showing that pollen from B.t. corn caused high mortality rates in monarch butterfly caterpillars. Monarch caterpillars consume milkweed plants, not corn, but the fear is that if pollen from B.t. corn is blown by the wind onto milkweed plants in neighboring fields, the caterpillars could eat the pollen and perish. Although the Nature study was not conducted under natural field conditions, the results seemed to support this viewpoint. Unfortunately, B.t. toxins kill many species of insect larvae indiscriminately; it is not possible to design a B.t. toxin that would only kill crop-damaging pests and remain harmless to all other insects. This study is being reexamined by the USDA, the U.S. Environmental Protection Agency (EPA) and other non-government research groups, and preliminary data from new studies suggests that the original study may have been flawed. This topic is the subject of acrimonious debate, and both sides of the argument are defending their data vigorously. Currently, there is no agreement about the results of these studies, and the potential risk of harm to non-target organisms will need to be evaluated further.
  

• Reduced effectiveness of pesticides- Just as some populations of mosquitoes developed resistance to the now-banned pesticide DDT, many people are concerned that insects will become resistant to B.t. or other crops that have been genetically-modified to produce their own pesticides.
  

• Gene transfer to non-target species- Another concern is that crop plants engineered for herbicide tolerance and weeds will cross-breed, resulting in the transfer of the herbicide resistance genes from the crops into the weeds. These "superweeds" would then be herbicide tolerant as well. Other introduced genes may cross over into non-modified crops planted next to GM crops. There are several possible solutions to the three problems mentioned above. Genes are exchanged between plants via pollen. Two ways to ensure that non-target species will not receive introduced genes from GM plants are to create GM plants that are male sterile (do not produce pollen) or to modify the GM plant so that the pollen does not contain the introduced gene. Cross-pollination would not occur, and if harmless insects such as monarch caterpillars were to eat pollen from GM plants, the caterpillars would survive. Another possible solution is to create buffer zones around fields of GM crops. For example, non-GM corn would be planted to surround a field of B.t. GM corn, and the non-GM corn would not be harvested. Beneficial or harmless insects would have a refuge in the non-GM corn, and insect pests could be allowed to destroy the non-GM corn and would not develop resistance to B.t. pesticides. Gene transfer to weeds and other crops would not occur because the wind-blown pollen would not travel beyond the buffer zone.

Human health risks

• Allergenicity- Many children in the US and Europe have developed life-threatening allergies to peanuts and other foods. There is a possibility that introducing a gene into a plant may create a new allergen or cause an allergic reaction in susceptible individuals. A proposal to incorporate a gene from Brazil nuts into soybeans was abandoned because of the fear of causing unexpected allergic reactions. Extensive testing of GM foods may be required to avoid the possibility of harm to consumers with food allergies. Labeling of GM foods and food products will acquire new importance, which I shall discuss later.
  

• Unknown effects on human health- There is a growing concern that introducing foreign genes into food plants may have an unexpected and negative impact on human health. A recent article published in Lancet examined the effects of GM potatoes on the digestive tract in rats. This study claimed that there were appreciable differences in the intestines of rats fed GM potatoes and rats fed unmodified potatoes. Moreover, the gene introduced into the potatoes was a snowdrop flower lectin, a substance known to be toxic to mammals. The scientists who created this variety of potato chose to use the lectin gene simply to test the methodology, and these potatoes were never intended for human or animal consumption.
  On the whole, with the exception of possible allergenicity, scientists believe that GM foods do not present a risk to human health.
  

Economic concerns

• Bringing a GM food to market is a lengthy and costly process, and of course agri-biotech companies wish to ensure a profitable return on their investment. Many new plant genetic engineering technologies and GM plants have been patented, and patent infringement is a big concern of agribusiness. Yet consumer advocates are worried that patenting these new plant varieties will raise the price of seeds so high that small farmers and third world countries will not be able to afford seeds for GM crops, thus widening the gap between the wealthy and the poor. It is hoped that in a humanitarian gesture, more companies and non-profits will follow the lead of the Rockefeller Foundation and offer their products at reduced cost to impoverished nations.
  

Reference: http://www.csa.com/discoveryguides/gmfood/overview.php