[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[SANET-MG] reply to the codex questionnaire question 2 and references



Reply to Questionnaire Codex Guideline for the Conduct of Food Safety Assessment of Foods Derived from Recombinant-DNA Plants
Professor Joe Cummins
Dr. Mae-Wan Ho
For Independent Science Panel
question 2 and references
Question #2: In order to assist with the identification of additional safety and nutritional considerations that the assessment of recombinant-DNA plants modified for nutritional or health benefit may warrant, please consider the elements listed below and for each of them provide comments on the need, added value and relevance of addressing such items given the intent of the modification introduced in such recombinant-DNA plants.

a) Estimation of potential exposure distribution patterns - how to go about determining potential exposure distribution patterns in both target and non-target populations of a country and evaluate the safety of such exposure in vulnerable groups. Techniques are available using population dietary intake data that permit modelling of usual intakes through simulated inclusion of the modified food in exchange for foods reported to be used the dietary survey. In this regard, lessons can be learned from modeling of potential intakes resulting from vitamin and mineral addition to foods; Answer: Modeling is appropriate but there is no substitute for controlled trials and investigations, first in animals, and then in consenting, informed humans. It is essential that the GM foods be clearly labelled in the marketplace to provide a means of identifying the GM foods in epidemiological studies as part of post-release monitoring and risk management.

b) Bioavailability - when bioavailability testing would be advisable and some considerations of the techniques available for determining bioavailability of various types of substances; Answer: Bioavailability should be incorporated into regulatory reviews of all of the modified plants purporting to enhance nutrition or health. Bioavailability can be studied using radioactively labeled tracers of the compounds or elements being studied. Gut cell cultures have been employed in such studios; approaches to studying bioavailability of nutrients have been reviewed [23].

c) Upper limits of safe intake - the need to determine upper limits of safe intake for the nutrient or bioactive substance, if they are not already defined, and how to assess the level of exposure according to population sub-group of the substance or substances in question against those upper limits; Answer: Upper limits of elements such as iron are essential because iron overload in males leads to a condition called hemochromatosis, resulting in liver dysfunction and cancer. Vitamin A toxicity is linked to birth defects and toxic side effects in adults. Genetic modification to provide for deficiency in some geographic areas may therefore create toxic side effects in areas where the diet for the nutrients is adequate. The supplemented crops must be clearly identified and efforts taken to prevent their use without informed consent. Upper limits for novel supplements such as human milk protein in maize or pig lactalbumin in maize clearly require full testing. Full tests for immunogenicity and toxicity must be carried out on all novel proteins, as stated above. Safe upper limits of ingestion should be established using pure nutrients or enzymes and the final foodstuffs, first in animals then in human volunteers.

d) Stability - what is involved in stability testing, and why that is a component of risk assessment; Answer: Stability of primary nutrients such as vitamins and minerals are well established, however the stability of novel proteins such as the enzymes introduced into the modified crop should be undertaken because the novel products may create unexpected toxic by-products. The behavior of these products during food processing and storage must be studied, and altered products should be subject to toxicity testing.

e) Risk/benefit consideration - what consideration should be given to the benefit intended to be provided by the modified food in drawing conclusions from the risk assessment. Benefits may accrue to certain target groups while at the same time, health risks may be a concern for others, but also there may be benefits at lower intakes and adverse effects at higher intakes. Additionally, how strong the evidence is for the benefits compared to potential adverse effects may need to be assessed in these circumstances; Answer: The precautionary principle must prevail in every case. Consideration must be given as to whether the benefit really exists, and whether cheaper, safer alternatives exist, given the known risks of genetic modification.

f) Animal feeding studies - when should animal feeding studies be considered and what types of studies might be useful depending on the question; Answer: Animal studies should be undertaken with every modified crop or in crosses between modified crops and crops bearing genes for nutrients or health products that have been enhanced using conventional breeding or marker assisted breeding. It has become common practice to used crude measures of size to evaluate the outcome of feeding experiments. That is not acceptable. Full tissue and organ necropsy is required in every case to detect cell damage and to identify pre-cancerous lesions. In addition, immunogenic and toxicity tests must also be carried out.

g) Study Design - the design and conduct of studies to obtain reliable, repeatable data on composition of the modified food with respect to the intended and potential unintended changes, at the appropriate stages of crop and food production. In particular, whereas in evaluating unintended effects comparative data in the raw product is usually quite acceptable, where an intended change has been introduced, there will need to be data on the variation in tissue concentration relevant to the parts of the plant that will be used for food production and data to show that the content of the substance remains stable with time, processing and storage. The impact of factors known to affect crop composition from year to year and by geographical location, soil type and fertility, etc. may need special attention in the case of intended changes. Answer: Common stress factors in crops such as water deprivation or water logging, nitrogen deprivation or over use and temperature stress all contribute markedly to nutritional value and health related products. We understand that Codex has pointed to the need for evaluation of stress in the approval of GM crops. Codex should work to formalize the most significant stressors and to insure that those significant stressors are evaluated correctly in the approval of GM crops slated for the global market. It is certainly clear that GM crops approved under optimum environmental conditions cannot presume to be substantially equivalent to GM crops produced under conditions of extreme stress.

h) Any other considerations? Please specify.
Answer: Two major flaws are present in the regulation of GM crops in North America. The first of these is secretive field tests of GM crops prior to their commercialization. Bystanders and residents near the test areas are provided little or no information as to the nature of the crops being tested. These individuals are exposed to pollen, plant debris from broken and decayed plant material in dust and from transgenic products in surface and ground water. The other major flaw is that the GM food products are not labelled in the marketplace and those suffering ill effects from consuming the novel materials have no way of knowing what has injured them. Proper epidemiology of human exposures is impossible without labelling. GM nutrition and health products must be labelled and details on field tests must be revealed to the public in full.

*The Independent Science Panel, launched 10 May 2003 at a public conference in London, UK, consists of dozens of prominent scientists from 11 countries spanning the disciplines of agroecology, agronomy, biomathematics, botany, chemical medicine, ecology, epidemiology, histopathology, microbial ecology, molecular genetics, nutritional biochemistry, physiology, toxicology and virology (http://www.indsp.org/ISPMembers.php)

References
1. Prescott VE, Campbell PM, Moore A, Mattes J, Rothenberg ME, Foster PS, Higgins TJ and Hogan SP. Transgenic expression of bean alpha-amylase inhibitor in peas results in altered structure and immunogenicity. J Agric Food Chem. 2005 Nov 16, 53(23):9023-9030. 2. Ho MW. Transgenic pea that made mice ill. ISIS/ISP report, 27 November 2005. 3. Cummins J. Beware Monsanto’s Vistive soybeans. ISIS Press Release 2004 http://www.i-sis.org.uk/BMVS.php; also Science in Society 2005, 25, 5. http://www.i-sis.org.uk/isisnews.php 4. Siritunga,D,Arias-Garzon,D,White,W. and Sayre,T. Over-expression of hydroxynitrile lyase in transgenic cassava roots accelerates cyanogenesis and food detoxification. Plant Biotechnology Journal 2004, 2, 37-43. 5. Lamphear B, Barker D, Brooks C, Delaney D, Lane J, Beifuss K, Love R, Thompson K, Mayor J, Clough R, Harkey R, Poage N, Drees C, Horn M, Streatfield S, Nikolov Z, Woodard S, Hood E, Jilka J and Howard J. Expression of the sweet protein brazzein in maize for production of a new commercial sweetener. Plant Biotechnology Journal 2005, 3, 103–114. 6. Yang SH, Moran DL, Jia HW, Bicar EH, Lee M and Scott MP. Expression of a synthetic porcine alpha-lactalbumin gene in the kernels of transgenic maize. Transgenic Res. 2002, 11(1), 11-20. 7. Arakawa T, Chong DK, Slattery CW and Langridge WH. Improvements in human health through production of human milk proteins in transgenic food plants. Adv Exp Med Biol. 1999, 464, 149-59. 8. Harker M, Holmberg N, Clayton J, Gibbard C, Wallace A, Rawlins S, Hellyer S, Lanot A and Safford R. Enhancement of seed phytosterol levels by expression of an N-terminal truncated Hevea brasiliensis (rubber tree) 3-hydroxy-3-methylglutaryl-CoA reductase. Plant Biotechnology Journal 2003, 1, 113–121. 9. Ursin VM. Modification of plant lipids for human health: development of functional land-based omega-3 fatty acids. J Nutr. 2003,133(12), 4271-4. 10. Qi B, Fraser T, Mugford S, Dobson G, Sayanova O, Butler J, Napier JA, Stobart AK and Lazarus CM. Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants. Nat Biotechnol. 2004, 22(6):739-45. 11. Galili G and Hofgen R. Metabolic engineering of amino acids and storage proteins in plants. Metab Eng. 2002, 4(1), 3-11. 12. KimW and Krishnan HB. Expression of an 11 kDa methionine-rich delta-zein in transgenic soybean results in the formation of two types of novel protein bodies in transitional cells situated between the vascular tissue and storage parenchyma cells. Plant Biotechnology Journal 2004, 2 199–210, 13. Lucas D. Monsanto Petition for non-regulated status for lysine maize LY38 Monsanto Petition #04-CR-114U 2004 http://www.aphis.usda.gov/brs/aphisdocs/04_22901p.pdf 14. Giovinazzo G, D'Amico L, Paradiso A, Bollini R, Sparvoli F and DeGara L. Antioxidant metabolite profiles in tomato fruit constitutively expressing the grapevine stilbene synthase gene. Plant Biotechnology 2005, 3, 57-69. 15. Dormann P. Corn with enhanced antioxidant potential. Nature Biotechnology 2003, 21,1015-16. 16. Datta K, Baisakh N, Oliva N, Torrizo L, Abrigo E, Tan J, Rai M, Rehana S, Al-Babili S, Beyer P, Potrykus I and Datta S. Bioengineered 'golden' indica rice cultivars with β-carotene metabolism in the endosperm with hygromycin and mannose selection systems Plant Biotechnology 2003, 1,81-90. 17. Weyens G, Ritsema T, Van Dun K, Meyer D, Lommel M, Lathouwers J, Rosquin I, Denys P, Tossens A, Nijs M, Turk S, Gerrits N, Bink S, Walraven B, Lefèbvre M and Smeekens S. Production of tailor-made fructans in sugar beet by expression of onion fructosyltransferase genes Plant Biotechnology Journal 2004, 2, 321-327. 18. Lonnerdal B. Genetically modified plants to improve trace element nutrition. J. Nutr. 2003, 133,1490S-1493S.
19. Rea P. Ion genomics. Nature Biotechnology 2003, 21,1149-50.
20. Goto F, Yoshihara T, Shigemoto N, Toki S and Takaiwa F. Iron fortification of rice seed by the soybean ferritin gene. Nat Biotechnol. 1999, 17(3), 282-6. 21. Hacisalihoglu G and Kochian L. How do some plants tolerate low levels of soil zinc? Mechanisms of zinc efficiency in crop plants. New Phytologist 2003, 159, 341-50. 22. Rumeau D, Bécuwe-Linka N, Beyly A, Carrier P, Cuiné S, Genty B, Medgyesy P, Horvath E and Peltier G. Increased zinc content in transplastomic tobacco plants expressing a polyhistidine-tagged Rubisco large subunit. Plant Biotechnology Journal 2004 2, 389-99. 23. Wood RJ and Tamura T. Methodological issues in assessing bioavailability of nutrients and other bioactive substances in dietary supplements: summary of workshop discussion. J Nutr. 2001, 131(4 Suppl),1396S-8S.

********************************************************
To unsubscribe from SANET-MG:
1- Visit http://lists.sare.org/archives/sanet-mg.html to unsubscribe or;
2- Send a message to <listserv@sare.org> from the address subscribed to the list. Type "unsubscribe sanet-mg" in the body of the message.

Visit the SANET-MG archives at: http://lists.sare.org/archives/sanet-mg.html.
Questions? Visit http://www.sare.org/about/sanetFAQ.htm.
For more information on grants and other resources available through the SARE program, please visit http://www.sare.org.