Evidence-based Evaluation of Safety of Genetically Modified Food ——An Report on Adverse Events of Carcinogenesis

Article type
Authors
Shen C1, Yin X2, Jiao B3, Li J1, Jia P4, Zhang X1, Ren J2, Cheng X2, Li X1, Robinson N5, Fei Y1, Liu J1
1Center for Evidence-Based Chinese Medicine, School of Chinese Medicine, Beijing University of Chinese Medicine
2School of Chinese Materia Medica, Beijing University of Chinese Medicine
3School of Chinese Medicine, Beijing University of Chinese Medicine
4School of Life Sciences, Beijing University of Chinese Medicine
5School of Health and Social Care, London South Bank University
Abstract
Objective: To assess the incidence of adverse effects/events of genetically modified (GM) food consumption by an evidence-based evaluation of safety of GM food.

Methods: Seven databases were searched from January, 1st, 1983 till October, 8th, 2019. in vivo animal studies and human studies in multiple languages were included. Participants of both animals and humans were included, with no prespecified limitations such as age, population, species/race or health status. However, the studies were excluded if they focused the effects of GM food on secondary or multilevel consumers in the food chain where GM food was only consumed by primary consumers. Interventions/exposures of the genetically modified animal/plant/microorganism food included referred to GM foods, GM food ingredients and GM feed, regardless of their dosage, duration, or whether the food was prepared or has been approved for marketing. The whole study focuses on the incidence of adverse effects/events of GM food consumption and it is still ongoing and data synthesis on adverse events has not been completed yet. This abstract focuses on adverse events on carcinogenesis.
Researchers independently review the retrieved articles by titles and abstracts and the full text to identify the studies meeting eligibility criteria and independently extracted data from the included studies according to a predesignated extraction table. The discrepancies were resolved through consensus and if necessary, arbitrated by another researcher. Statistical analyses were carried out using Microsoft Excel 2010 and SPSS 20.0.

Results: Of the 9328 citations, 173 articles with 22 kinds of GM food were included after 432 full-text reading. However, no human clinical study met the inclusion criteria.
Finally, only two mouse/rat feeding studies have been reported to trigger cancer/tumor. Seralini GE 2012, which has been retracted but republished, did a long-term toxicity study on a Roundup-tolerant GM maize (from 11% in the diet), cultivated with or without Roundup, and Roundup alone for 2 years in rats. It found that females in the treatment groups almost always developed large mammary tumors more often than and before controls. As for males, 4 times more large palpable tumors than controls were presented which emerged up to 600 days earlier. Velimirov A 2008 revealed a life term study where mice in the three groups were fed with transgenic maize NK603xMON810 (from 33.0% in the diet), control isoline diet and GM free Austrian corn reference diet respectively. The survival rate was not significantly different while cancer (leucosis) was the common cause of death.

Conclusion: A majority of studies failed to detect adverse events of carcinogenesis while animal studies occupy the lowest hierarchy of evidence. Further clinical study such as cohort study are still warranted.