Thanks for sharing Dr. Voskuhl's perspectives--on estriol being "the neuroprotective plug" and
Concerning progestin vs. progesterone, Dr. Voskuhl's response to me was "no evidence that a progesterone is more neuroprotective. Go with what the gyn wants you to use to protect your uterus from "unopposed" estrogens".
As a layperson, I respectfully disagree with Dr. Voskuhl's perspective on the evidence concerning progestin vs. progesterone and neuroprotection. And, I think there are researchers who would disagree with her as well. Perhaps the difference is in what one considers "evidence" as you suggest, but I definitely think there's research beyond "anecdotal" statements.
Certainly I think we'd all love to have a lot more research/evidence than seems to exist, but there is some pre-clinical and clinical research
on the topic. Here's a sample: Progesterone-Induced Neuroprotection
Here, we review the data from various laboratories including our own that support the protective role of progesterone and describe the multiplicity of mechanisms by which progesterone elicits these protective effects.
Finally, we contrast the neurobiology of progesterone with that of the clinically used progestin, medroxyprogesterone acetate (MPA), and suggest that the "natural" progesterone may be the better choice when considering which progestin to use for future therapeutic/ palliative purposes in CNS-related disorders.
I think MS is a CNS-related disorder. Progestins and neuroprotection: are all progestins created equal?
And though additional research is certainly needed to explore the neurobiology of progesterone and its related progestins more completely, we provide evidence that, at least with respect to the brain, not all progestins are created equal.Reduced metabolites mediate neuroprotective effects of progesterone in the adult rat hippocampus. The synthetic progestin medroxyprogesterone acetate (Provera) is not neuroprotective
The ovarian hormone progesterone is neuroprotective in different experimental models of neurodegeneration.Medroxyprogesterone acetate exacerbates glutamate excitotoxicity
In conclusion, our findings indicate that progesterone is neuroprotective against kainic acid excitotoxicity in vivo while the synthetic progestin MPA is not and suggest that progesterone metabolism to its reduced derivatives DHP and THP is necessary for the neuroprotective effect of the hormone.
We previously demonstrated that progesterone functions as a neuroprotective agent whereas medroxyprogesterone acetate (MPA; Provera) does not.
Moreover, MPA antagonized the neuroprotective and neurotrophic outcomes induced by 17beta-estradiol (E2).
Results of these analyses indicated that both crystalline MPA and a pharmaceutical formulation (Depo-Provera) lacked neuroprotective efficacy, indicating that the effects were not dependent upon MPA formulation.
Likewise, MPA in the prevention and treatment paradigms were equally ineffective at promoting neuronal survival, indicating that timing of MPA administration was not a factor.
Further, the detrimental effects of MPA were not due to the presence of the acetate group, as medroxyprogesterone was as ineffective as MPA in promoting neuronal survival.
Moreover, MPA pretreatment exacerbated neuron death induced by glutamate excitotoxicity as indicated by a 40% increase in neuron death
Collectively these results predict that the progestin formulation of hormone therapy will affect the vulnerability of the central nervous system to degenerative insults.
And, last but not least, slides 11 and 12 in the following link highlight some of the neuroprotective properties of progesterone, not MPA. Progesterone has had at least two successful clinical trials in traumatic brain injury. I'm not aware that MPA has had any.
Hormonal Therapy of MS
by Patricia K. Coyle, Professor and Acting Chair of Neurology, Director, MS Comprehensive Care Center
, SUNY at Stony Brook, New York
Now, I totally agree with you that it is important to take both to maintain balance as well. I'm all for people having their hormone levels tested and "balanced" accordingly. Since what you're taking is working for you, you've got every reason to stick with it. Undoubtedly the "evidence" is slim on the topic of progestins vs. progesterone and neuroprotection, but there is research.
DIM--There's an interesting note on DHEA on slide 13 in that link that I think reinforces your statement. But I'm with you, who knows?
Take care both