For years, various environmental and academic groups have been desperately trying to explain how it can be that high doses of chemicals (a common target: bisphenol-A, BPA), referred to as endocrine disruptors, have little or no adverse effects in rodents, but low doses can pose risks?
Rather than give up, they have persisted to the point where they made up an entirely new (and well beyond irrational) hypothesis, based on faulty (to say the least) science. Rather, they should have raised the white flag and conceded, Well, we really screwed this up, guys. Let s move on.
No such luck. Instead, they somehow decided that a better explanation was a bit of craziness called the low dose effect a splendid piece of science sleight-of-hand, which, if twisted properly can be made to look somewhat like a rational explanation. But you have to really do some twisting.
Fortunately, the FDA is having none of this nonsense. Their new study found that bisphenol A the poster child of chemical scares does not affect the health of rats fed low doses. Or high doses (unless they are very high, and even then, just barely).
ACSH s Dr. Josh Bloom wonders. Once the dust settles, I would not be surprised to see this idiocy continue. Perhaps they will find that the low dose effect is valid, but only on Pluto. And can the medium dose effect be that far off?
He adds, After 20-plus years of pharmaceutical research where dose-related toxicity was one of the most common problems we encountered while trying to discover new drugs, neither I, nor any of my colleague have ever seen a single instance where this effect has been observed. In fact, during preliminary toxicology experiments, there is always a dose at which no effect is observed. There is something called NOEL (no observable effect level), which is the highest dose or exposure level of a any given chemical that produces no noticeable toxic effect on animals. Below that nothing.
And ACSH has been on this for a long time. See our publication on The Low-dose Effect.
The FDA s conclusion is quite clear. Commenting on a peer-reviewed study, which was published in the journal Toxicological Sciences, a spokesperson said:The study reported no effects of BPA at any dose, except at the very highest levels, and is consistent with the FDA s current position that BPA is safe at the very low amounts that occur in some foods.
And also: Our interpretation of the results of the present study is that BPA in the 'low dose' region from 2.5 to 2,700 μg/kg bw/day did not produce effects in the evaluated endpoints that differ from normal background biological variation."
Perhaps this silliness will now go away. But don t count on it.