With the effects of BT toxins now coming under close scrutiny, thanks are due to GM Watch for reminding us of three papers which appeared in 1999 and 2000 which show how the Cry1Ac protein has a toxic effect on mice. As the article points out, if "natural" BT proteins are harmful (contrary to the protestations of the GM industry, which keeps on trying to convince us that toxic chemicals, designed to kill things, are actually harmless!) then the BT toxins actually found in GM plants, with their promoters, will be a great deal more dangerous. But they are never tested, since tests are conducted (supposedly on cost grounds) on surrogate proteins instead. Time for this farcical pseudo-science to stop...... and time for the regulators like EFSA to insist on genuine safety tests conducted with the BT plants themselves.
Wednesday, 11 May 2011 22:17
NOTE: GM lobbyists are claiming it doesn't matter if the Bt toxin is turning up in people's blood because the Bt toxin is natural, known to be harmless to humans, and has been safely used for decades in agriculture in the form of natural insecticidal sprays, including in organic farming. In addition, they say, Bt crops have been tested and approved as safe.
But the Bt toxin produced in GM crops is not the same as the natural Bt toxin. The process of genetic engineering changes it (as is admitted even by the pro-GM website GMO Safety). And testing is not actually performed on the Bt toxin extracted from GM plants, which would be the scientific way, as it is claimed that it is too expensive to isolate. Instead, testing is done on Bt toxin isolated from E. coli bacteria (as is the norm for GM risk assessments). The protein would be different from that present in the actual GM crop.
GM Bt toxins are engineered into plants with promoters designed to keep the Bt toxin protein expressing in every cell of the plant. The Bt is ingested by animals and people who consume crop plants like Bt maize. The natural Bt used in agricultural sprays, by contrast, degrades rapidly in daylight and does not end up being eaten by people, so it is unlikely to ever end up in consumers' bodies.
This is fortunate because even natural Bt can cause harm when ingested. While the GM lobbying website, GMO Safety, claims, "the Bt protein is harmless to mammals and humans", in fact, studies show that natural Bt toxin has ill effects on laboratory animals, producing a potent immune response and enhancing the immune response to other substances:
*Vázquez RI, Moreno-Fierros L, Neri-Bazan L, De La Riva GA, Lopez- Revilla R. Bacillus thuringiensis Cry1Ac protoxin is a potent systemic and mucosal adjuvant. Scand J Immunol. Jun 1999;49(6):578-584.
*Vázquez-Padrón RI, Moreno-Fierros L, Neri-Bazan L, de la Riva GA, Lopez-Revilla R. Intragastric and intraperitoneal administration of Cry1Ac protoxin from Bacillus thuringiensis induces systemic and mucosal antibody responses in mice. Life Sci. 1999;64(21):1897-1912.
*Vázquez-Padrón RI, Moreno-Fierros L, Neri-Bazan L, Martinez-Gil AF, de-la-Riva GA, Lopez-Revilla R. Characterization of the mucosal and systemic immune response induced by Cry1Ac protein from Bacillus thuringiensis HD 73 in mice. Braz J Med Biol Res. Feb 2000;33(2): 147-155.
As for the Bt toxin found in GM plants, even Monsanto's own studies show that it's not safe. A re-analysis of Monsanto's own data on its GM Bt maize MON863 (approved for use in Europe since 2005) by Prof G-E Seralini found liver and kidney toxicity in rats fed with the maize. Seralini concluded, "with the present data it cannot be concluded that GM corn MON863 is a safe product".