No governmental agencies require either long-term studies of the active ingredient (such as glyphosate or G) in herbicides used on genetically-modified (GM) crops. Neither do they regulate short term studies of the entire ingredients of such products as Roundup (R, which contains G and other chemicals). The products are not studied as they are sold with the agents (adjuvants) which increase the effectiveness of G. The few studies done by the herbicide producing companies are on rats for only three months.
In these studies, though it appears that consuming GM foods cause no harm, there are studies done for longer periods of time and different interpretations of outcomes. The researchers question the safety of consuming such foods. In such studies, evidence for kidney and liver damage suggest the appearance of early toxicity. This could be due to pesticide residues on and in food.
It is known that R residues at 1/1000th of the maximum residue levels (MRL) allowed by regulatory agencies can cause endocrine abnormalities and toxicity in human cells. Also, feeding studies of GM soy feed for several months in rats produced the same damage in the liver and pancreas as was produced by direct exposure of liver cells to R. No industry studies have been done of animals for 2 years after exposure of the animals to R.
G, the active ingredient of R, can only penetrate plants with the aid of adjuvants, chemicals which, with G, comprise the product as sold. The adjuvants make it easier for G to enter cells and cause endocrine disruption in human cells. Adjuvants are found in groundwater and could be the cause of kidney and liver toxicity. Adjuvants have been found in the rivers in England, and have been found to disturb wildlife sexual reproduction.
To address the above deficiencies, the authors performed a 2.year chronic feeding toxicity study using NK603 GM corn (maize) as used in Monsanto studies. Those company studies were for only 90 days and abnormalities seen in liver and kidneys were considered not ‘biologically significant’. The same types of rats as used by Monsanto were used in the 2-year studies. Studies were done of GM maize alone, GM maize with R, and R alone at low environmental levels.
The results were that mild abnormalities seen in Monsanto’s 3-month studies escalated to severe organ damage, with increased rates of cancer over the 2-year course of the repeat study, even at the lowest doses. “Surprisingly, there was also a clear trend in increased tumor incidence, especially mammary tumors in female animals, in a number of the treatment groups.” The tumors seen were believed to be the result of endocrine disruption. This study emphasizes the shortcomings of the 90-day studies.
CONCLUSION: This study of toxicity of Roundup and glyphosate in diets of rats over 2 years emphasizes the inadequacy of Monsanto’s 90-day studies. What was only mild liver and kidney dysfunction at 90 days rapidly developed into severe damage. Increased tumors were seen, especially in female rats.
Future studies of toxicity of pesticides and adjuvants should be done for at least 2 years. The abnormalities were seen after feeding genetically-modified maize with or without Roundup, and with Roundup treatments alone. The importance of this cannot be ignored in the most widely used herbicide worldwide.
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PMID: 27752412.
Summary #566.