Does a hig h-fat diet during pregnancy increase breast cancer risk — in humans?
Hilakivi-Clarke et al. tried to answer this question by feeding pregnant laboratory rats a high-fat diet. They reported that, indeed, rats fed a high-fat diet did have more b reast cancer than pregnant rats fed a low-fat diet.
Hilakivi-Clarke et al. then stated that
If further studies find that the results from animal model studies are applicable to humans, some human breast cancers may be preventa ble by dietary manipulation during pregnancy.
But reading this study more carefully reveals that it probably wasn't the high fat diet causing the observed cancers. Rather, the researchers themselves induced the breast cancers.
< P>Hilakivi-Clarke fed the rats 7,12-dimethylbenzn[a]anthracene (DBMA) to induce breast cancer. (DBMA is a carcinogen that is known to cause breast cancer in rats. But it is not known to be cause breast cancer in humans.)They induced the can cers because they wanted to be sure that at least some of the rats got breast cancer, regardless of whether the cancer was caused by dietary fat.
So these researchers took rats that are very susceptible to cancer by virtue of their birth (the Spra gue-Dawley type), fed them a chemical that is known to cause breast cancer in rats, and then concluded that "some human breast cancers may be preventable by dietary manipulation during pregnancy"?
I thought I smelled a rat in this study!
Here's the solution.
