Think YOUR Job Sucks? Meet the Sprague-Dawley Rat

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If your goal is to achieve a lofty station in life, it would be unwise to start as a Sprague-Dawley rat. Not only are they bred to test whether chemicals and foods might give people cancer, but they don't even do it well. In short, it's not great to be one of them, and here's why.

Edgar

When you are born a lab rat, your life has very little upside. There are pretty much two options in your future. They are called "control" and "treated," and neither of them ends up very well.

But, maybe if you do your job right, you'll leave the planet just a little better than when you entered it.

Pity the Sprague-Dawley Rat (SD rat). It is the low rat on the totem pole. By comparison, its wild compatriots are leading a life that would be the envy of the miniature poodle finalists in the Westminster Kennel Club Dog Show.

And it's an albino, which is common in lab-bred rodents, so forget that trip to the Caymans.

One of its jobs is to get cancer when exposed to carcinogens, but the poor thing can't even get that right. The breed generates tumors spontaneously 45 percent of the time. So, how are you supposed to tell whether this or that is giving the rats cancer or they are doing it by themselves?

For example, if you want to know whether a chemical or drug may pose a risk of breast cancer in women, and you test it in female SD rats, you will find out precious little. Although the numbers vary, female SD rats spontaneously developed breast tumors between 22 and 67 percent of the time, depending on the breed variety and the colony in which they were raised.

Not to be outdone, male SD rats were estimated to give false positive readings as high as two-thirds of the time when evaluated for testicular cancer.

How good are all those nasty endocrine disruptor claims that are made based on rat experiments? The answer is: well, you tell me. Most rat cancers studies are designed to last three months. But, of SD rats that survived a full two years, 81 percent were found to have tumors of the endocrine system. And this was a control group. They were fed none of the tired old group of chemicals that groups like EGW and NRDC have been falsely braying about forever.

Here's the thing. When the control group has a high response rate, by definition, the difference between control and treated groups of bacteria, rodents, people, whatever, is small, and it takes a whole lot of test subjects to come up with a legitimate answer. Otherwise the chances are that what you are seeing is real are, uh, pure chance.

Which can interfere, for example, with a study that was designed to prove if a certain food might be harmful. Like genetically modified corn.

This is why the Seralini SD rat-GM corn study was ridiculed by multiple scientists as soon as it came out. Even Marion Nestle, professor in the Department of Nutrition, Food Studies and Public Health at New York University, and professional skeptic, said Even though I strongly support labeling, I m skeptical of this study... It s weirdly complicated and unclear on key issues: what the controls were fed, relative rates of tumors, why no dose relationship, what the mechanism might be. I can t think of a biological reason why GMO corn should do this.

There are too many scientists who expressed similar (or worse) opinions about the Seralini study to even fit them here. Now you know why.

I smell a rat.