“Our study clearly shows that the GM transformation process results in profound compositional differences in NK603, demonstrating that this GMO corn is not 'substantially equivalent' to its non-GMO counterpart. 

The marked increase in putrescine and especially cadaverine is a concern, since these substances are potentially toxic, being reported as enhancers of the effects of histamine, thus heightening allergic reactions, and both have been implicated in the formation of carcinogenic nitrosamines with nitrite in meat products. Our results call for a more thorough evaluation of the safety of NK603 corn consumption on a long-term basis.”    Dr. Antoniou stated.

1. The establishment of compositional ‘substantial equivalence’ is a key starting point requested by regulatory agencies for assessing the safety of a GMO crop and food. If analysis for nutrients and known toxins shows that the composition of a GMO crop is found to be in a similar range to that present in a corresponding, genetically similar non-GMO variety (often the non-GMO parent), then it is deemed to be ‘substantially equivalent’ and to require little, if any, further safety testing, especially in the USA. 
2. Genetically modified (GM) corn NK603, engineered to survive being sprayed with glyphosate based weedkillers such as Roundup, was assessed as ‘substantially equivalent’ to its non-GM parent corn variety, based on a nutrient composition analysis of both crops. It was subsequently granted market approval.
3. However, the nutrient compositional analysis is relatively crude and may miss subtle yet important differences between the GMO and non-GMO food, which could have health consequences for the consumer. For example, the compositional analysis includes measurement of total protein content, yet this is less important than the profile of different types of proteins. In other words, the message is in the detail, yet this detail is currently lacking in regulatory analysis investigating the substantial equivalence of a product.
4. This gap in compositional information for the Roundup-tolerant NK603 corn was addressed in this study by analysing this GMO with the nearest non-GMO corn variety as a control. The two crops were grown under similar conditions, in the same location and season, spaced at a sufficient distance to avoid cross-contamination. One field of NK603 was sprayed once with Roundup, whilst another field of NK603 was not treated with Roundup. Samples were produced in two cultivation cycles over two growing seasons. Thus all precautions were taken to minimise environmental factors that could influence the composition of the crops. The result is a comparative analysis that specifically highlights the effect of the genetic modification (GM) transformation process.
5. Rats fed this GMO corn over 2 years presented signs of a higher incidence of liver and kidney damage (Séralini et al., Environmental Sciences Europe, 26:14) compared with controls.

1. A total of 117 proteins and 91 small molecule biochemicals (metabolites) were found to be statistically significantly altered in NK603 corn by the GM transformation process.
2. The GM transformation process was the major contributor to variation in the protein and metabolite profiles, rather than environmental factors such as the spraying of the Roundup weedkiller or the growing season.
3. Alteration in the protein profile revealed by the proteomics analysis was reflective of an imbalance in energy utilisation and oxidative stress (damage to cells and tissues by reactive oxygen).
4. Small molecule biochemical profile differences revealed by metabolomics mostly consisted of an increase in a class of compounds known as polyamines; the levels of potentially toxic putrescine and especially cadaverine were markedly increased in the GM NK603 corn.

1. GM NK603 corn and its corresponding non-GMO corn variety are not substantially equivalent.
2. The GM transformation process caused alterations in both protein and metabolite composition profiles in NK603 corn.
3. The non-substantial equivalence of NK603 corn with the corresponding non-GMO corn, and the increases in potential toxic compounds (polyamines; putrescine, cadaverine) in NK603 corn, indicate that a more thorough investigation of the safety of consuming products derived from this GMO food is warranted.