Question: Some say that ‘progesterone / progestins worsen bone loss’. everything I’ve read about progesterone says the opposite. In fact Dr John Lee wrote a book about it.
Answer: Most published stuff is rehash, opinion- not evidence.
Dont forget that Drs John Lee & Kathy Dalton never did or published a trial, merely their opinions. They wrote books and articles based purely on subjective experience- and didnt have Medline to give them evidence.. They probably benefitted millions of women by advocating at least some safe progesterone cream replacement that was undoubtedly a lot better than nothing. But all one can do from observations is formulate a theory, a hypothesis. Massive evidence is accumulating that all men and women with low progesterone should supplement with it to around a level of 1 -2 nmol/L for immune and neuroprotective -benefits; – but to no clear benefit against fractures when used alone.
No significant reported trials of progesterone or it’s synthetics that one can find, including from the top Osteoporosis reseach units in the world, show benefit of any progestin on its own on fracture risk – if anything the contrary– in postmenopausal women
At best, progesterone and androgenic progestins alone stop bone loss.
The only substances that safely and effectively reduce fractures and actually increase bone density and muscle longterm in simple safe lowcost combination – in both spine and hip – at all ages are the natural anabolics – calmag, boron, zinc, manganese, copper, selenium, vits (B6,9, 12,C, D & K), proline, glycine, creatine, lecithin, testosterone, estrogen and melatonin; and if deficient, iron (obvious in children and pregnancy); iodine and fluoride (regional deficiencies).
[It is unclear from published trials whether adding strontium, biphosphonates, SERM, calcitonin, parathyroid hormone , or human growth hormone in HGH-deficient elderly patients, further reduces fracture rates when added to appropriate essential supplements already listed above – this seems unlikely. and no Drug manufacturer is going to fund such a trial, which will likely only confirm the fruitlessness and risks of their exensive patent drugs] . .
Estrogen at best stops bone loss- and in the WHI, reduced fractures by just below a third . When combined with progestin, th anti-fracture benefit was slightly reduced.
What matters is that only vigorous vit D & appropriate testosterone actually restore lost bone and muscle mass / strength.
Bone density improvement on progesterone alone has been claimed, but there are no definitive studies in humans or animals to show this.
We do know that the synthetic progestins if anything reduce bone density EXCEPT perhaps the androgenic progestins -which progesterone is not. !
In the two arms of the giant Womens’ Health Initiative, in well-matched women, compared to placebo, premarin alone reduced all fractures by 29% (and hip fractures by 35%) whereas premarin + progestin reduced all by only 23% (and hip fractures by 33%) .
In the PEPI and the Lydeking-Olsen trials, progestins at least stopped fall in bone density- but only in the WHI did estrogen reduce fractures- and progestin did not help further.
So where are the trials showing that progesterone actually does reduce fractures? It will be great to see them.
However, in a landmark review that matches her study-of-the decade on the Perimenopause in 1998 (showing that that phase is in fact a time of estrogen excess) – Jerilyn Prior last month published with Seifert-Klauss another study-of-the-decade showing that progesterone itself is in fact a vital co-hormone in enhancing the bone-strengthening effect of estrogen provided they are given together continuously.
How much better against fractures is estrogen+progesterone than estrogen alone? There is still no objective data- but such a trial by Seifert-Klauss ea is in progress.
And given their increased cancer and cardiovascular risks, synthetic progestins ‘ theoretical bone benefits cannot be extrapolated to human progesterone.
But there is so much other evidence about the independent multisystem benefits of progesterone without estrogen – especially for its immune, anti-cancer and neuroprotective benefits- to make it obligatory for progesterone always to be prescribed with estrogen, irrespective of hysterectomy status.
Thus John Lee was wrong on progesterone alone against fractures, but correct for the combination of progesterone with estrogen giving better antifracture protection than estrogen alone. .