The French study on GMOs showing rats with huge tumors when fed a strict GM corn diet........It didnt take me long to find many problems with this study. It was basically a reproduction study done on a specific type of rat that is extremely susceptible to mammary tumors when fed a strict corn diet. This study was done way back in the 70s. And this French dude basically did a copycat study with GM corn......I still have 5 full PDFs to read through but I am already convinced this is junk science. Here is a portion of a letter sent to the publisher-Dear Dr. Hayes, I have serious concerns related to a recent online publication in one of the Elsevier Journals, Food and Chemical Toxicology: Séralini et al. Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize. Food Chem. Toxicol. (2012). This paper has some relevant flaws from the experimental design, through the statistical analysis and the way the data is presented. In addition, it lacks of some crucial information for the proper understanding and full assessment of the work. First the choice of the rat breed, Sprague–Dawley, the duration and the uncontrolled feeding used in the study. These animals were maintained for 24 months and fed ad-lib. This specific breed of rats is well known to be prone to develop cancer with age and especially when there is no dietary restriction. For example, Prejean et al. (1973) noted a spontaneous tumour incidence of 45% in 360 Sprague–Dawley rats (179 males and 181 females) in an 18-month series of carcinogenesis experiments. The percentage of female rats with tumours was almost double that of males. Durbin et al. (1966) reported a mean incidence of 71%, the peak incidence in normally aging rats were age-related with abrupt increases in the rate of development of mammary tumour, one occurring at about the 500th and the other at about the 660th day of life, with the median age at 671 ± 41 days. Harlan, the company that marketed the animals, describes the high incidence of 76% of mammary gland tumours (predominantly fibroademonas) in females on Life-span and Spontaneous Disease of Sprague-Dawley. Keenan et al. (1995) describes spontaneous tumours in up to 87% of females and up to 71% of males fed ad lib. Dietary restriction significantly reduced the incidence of tumours. Uncontrolled ad libitum feeding significantly contributes to a high variability and poor reproducibility of a study limiting its usefulness in risk assessment (in Keenan et al. (1999)). The number of rats in Séralini et al. (2012) developing tumours fall within the history of reported spontaneous tumour rate in this breed of rat. Séralini et al. even mention that control animals survived on average less than 24 months but it is not explained about their death in sufficient detail.
Posted on: Sun, 24 Nov 2013 06:06:15 +0000