Mice fed on a diet enriched with genetically engineered multivitamin corn show no sub‐acute toxic effects and no sub‐chronic toxicity

Abstract

SummaryMultivitamin corn is a novel genetically engineered variety that simultaneously produces high levels of b-carotene, ascorbate and folate, and therefore has the potential to address simultaneously multiple micronutrient deficiencies caused by the lack of vitamins A, B9 and C in developing country populations. As part of the development process for genetically engineered crops and following European Food Safety Authority (EFSA) recommendations, multivitamin corn must be tested in whole food ⁄ feed sub-chronic animal feeding studies to ensure there are no adverse effects, and potential allergens must be identified. We carried out a 28-day toxicity assessment in mice, which showed no short-term sub-acute evidence of dietrelated adverse health effects and no difference in clinical markers (food consumption, body weight, organ ⁄ tissue weight, haematological and biochemical blood parameters and histopathology) compared to mice fed on a control diet. A subsequent 90-day sub-chronic feeding study again showed no indications of toxicity compared to mice fed on control diets. Our data confirm that diets enriched with multivitamin corn have no adverse effects on mice, do not induce any clinical signs of toxicity and do not contain known allergens.

A question of balance: achieving appropriate nutrient levels in biofortified staple crops

“…No indications of toxicity were evident compared with animals fed on control diets. The study thus confirmed that diets enriched with 'multivitamin corn' did not have any adverse effects on mice, did not induce any clinical signs of toxicity and did not contain known allergens (61) .…”

A 90-day subchronic feeding study of genetically modified rice expressing Cry1Ab protein in Sprague–Dawley rats

“…However, it has been severely criticized by some scientists:it emphasizes chemical composition at the expense of biological, toxicological, and immunological tests; it is not clear what level of similarity can make the GM and non-GM food substantially equivalent (Bhattacharya et al 2013) or it does not define the point at which a food is no longer substantially equivalent (Picone et al 2011). Subchronic rodent toxicology studies have been conducted with whole grains and processed feed fractions obtained from numerous GM crops in accordance with guidelines of repeated dose 90-day oral toxicity study in rodents (Cao et al 2011;Yuan et al 2011;Arjó et al 2012;Liu et al 2012;Tang et al 2012).…”

High-carotenoid maize: development of plant biotechnology prototypes for human and animal health and nutrition

“…There were no significant differences in any of the production traits that were monitored during the trial (live weight, feed intake, average weight gain or feed conversion rate) agreeing with the 90-day exposure experiment in mice (Arjó et al, 2012). At 190 days, the pigs were slaughtered and samples of liver, subcutaneous fat and muscle (longissimus dorsi and gluteus medius) were collected to determine the fat content and composition.…”

“…Similarly, there were no significant differences between the diet groups in terms of clinical observations, hematological parameters, biochemical markers and absolute or relative changes in organ weight. In summary, Carolight® was found to be compositionally substantially equivalent to M37W and to satisfy current requirements to demonstrate the absence of sub-chronic toxicity (Arjó et al, 2012). No single animal model addresses all potential sources of toxicity (Gephart et al, 2001) but a positive outcome following a 90-day sub-chronic toxicity test provides strong supporting evidence for safety (Ricroch, 2013).…”

“…Carolight® was initially tested in the laboratory to confirm its substantial equivalence to the nearisogenic line M37W. Compositional analysis showed no nutritionally-relevant differences between Carolight® and M37W in terms of its major constituents, other than the intended modification of the carotenoid content (Arjó et al, 2012). This was followed by a 90-day sub-chronic toxicity study in mice, which was designed to address the consequences of repetitive exposure for a duration considered long enough to reveal the effects without confounding age-related effects (EFSA 2011a).…”