[ RadSafe ] Re: Calabrese reviews major NCI drug test database, shows hormesis, as normal biology

[Rad Sci Health]

> Friends,
> 
> Re the medical applications in the last paragraph, low-dose radiation immune
> function stimulation:  Was shown to prevent and treat cancer, and applied for
> infections and inflammatory conditions, from the 1910s to the late-40s and
> beyond. (It is still applied today for specific conditions.)
> 
> It was displaced by wonder drugs (serum drug profits in the 1930s, by FDA).
> This was reestablished after WWII by suppressing Manhattan Project data and
> research.  NCI was a major controller since the late-40s.
> 
> Regards, Jim Muckerheide
> ==================
> 
> Date: January 3, 2007
> 
> Measuring The Effects Of Very Low Doses: New Study Challenges How Regulators
> Determine Risk
> 
> Science Daily ‹ A new study of a large U.S. National Cancer Institute database
> provides the strongest evidence yet that a key portion of the traditional
> dose-response model used in drug testing and risk assessment for toxins is
> wrong when it comes to measuring the effects of very low doses, says Edward J.
> Calabrese, a scientist at the University of Massachusetts Amherst. The
> findings, based on a review of more than 56,000 tests in 13 strains of yeast
> using 2,200 drugs, are published in the journal Toxicological Sciences and
> offer strong backing for the theory of hormesis, Calabrese and his colleagues
> contend.
> 
> Calabrese says the size of the new study and the preponderance of evidence
> supporting hormesis, a dose-response phenomenon in which low doses have the
> opposite effect of high doses, is a breakthrough that should help scientists
> assess and predict risks from new drugs, toxicants and possibly carcinogens.
> Calabrese says, "This is a fundamental biological principle that has been
> missed."
> 
> Calabrese says that the field of toxicology got the dose response wrong in the
> 1930s and this mistake has infiltrated all regulations for low-dose exposures
> for toxic chemicals and drugs. These low-dose effects can be beneficial or
> harmful, something that the regulations miss because they are currently based
> on high-dose testing schemes that differ greatly from the conditions of human
> exposures.
> 
> In this latest study, which uses data from a large and highly standardized
> National Cancer Institute tumor-drug screening database, Calabrese says the
> evidence of hormesis is overwhelming. In the study, high doses of anticancer
> drugs frequently inhibit yeast growth, but at low doses they enhance growth,
> exactly what the hormesis model predicts.
> 
> Whether one accepts the hormesis theory is not the critical public policy
> issue, according to Calabrese. He says that the major issue is that the risk
> assessments models used by the federal Environmental Protection Agency and the
> Food and Drug Administration fail to accurately predict responses in the
> low-dose zone, that is, where people live most of their daily lives.
> 
> Calabrese also says challenging the existing dose-response model has profound
> public policy and health implications. "I believe the hormesis model is the
> fundamental dose-response and government testing and risk assessment
> procedures should reflect that," Calabrese says. For example, in environmental
> regulations, it has been assumed that most carcinogens possess real or
> theoretical risks at low levels, and therefore must be nearly completely
> removed from the environments to assure public safety. Some would contend that
> if hormesis is the correct model for very low levels, that cleanup standards
> may have to be significantly changed. Others, however, see the evidence as
> insufficient for such radical change and worry about other factors that can
> influence the effects of chemicals in low doses. The new study promises to add
> fuel to the debate, Calabrese says.
> 
> Calabrese also suggests that the findings may have important implications for
> the pharmaceutical industry and medical practices. He says that hormesis is
> likely to identify new life-saving drugs that were missed through traditional
> testing and to markedly improve the accuracy of patient dosing, which will not
> only improve health outcomes but also reduce adverse side effects.
> 
Note: This story has been adapted from a news release issued by University
Of Massachusetts Amherst.