11-10-2011, 06:54 PM
My libido went down when I was still eating the flax seed. It takes an hour to chew 100 g of flax seed
I scooped up the old literature on flax increasing SHBG. This was a 12 week study on a diet consisting for 25 % of soy and flax:
http://journals.lww.com/menopausejournal..._on.5.aspx
"Marked increase in serum levels of SHBG was observed in the phytoestrogen-rich diet group (from 55.8 +/- 7.09 nmol/L to 71.2 +/- 6.56 nmol/L)."
That's huge. I assume 1 nmol/L binds 1 nmol/L of testosterone. Then the increase in SHBG after 12 weeks, 71.2 - 55.8 = 15.4 nmol/L could bind 15.4 nmol/L of testosterone.
"In the United States, male total testosterone levels below 300 ng/dL from a morning serum sample are generally considered low":
http://en.wikipedia.org/wiki/Testosterone
The molecular mass of testosterone is 288.42. Then 300 ng/dL is 300 ng/dL * 10 dL/L / 288.42 ng/nmol = 10.4 nmol/L. So the effect of 12 weeks of flax and soy on SHBG is enough to bind all of the testosterone a man has. Karen wrote that at her age, 500 is normal, 900 is way too high.
Moreover, in a male, only 0.7 % is free testosterone:
http://en.wikipedia.org/wiki/Testosterone/SHBG
I found another, unexpected conclusion in an even older publication: flax lengthens the luteal phase of the menstrual cycle. Only by 1 day, but still:
http://jcem.endojournals.org/content/77/5/1215.short
I wonder what that means for women who experience longer cycles on PM. Do all phyto-estrogens lengthen the cycle? Does estrogen lengthen the cycle?
I scooped up the old literature on flax increasing SHBG. This was a 12 week study on a diet consisting for 25 % of soy and flax:
http://journals.lww.com/menopausejournal..._on.5.aspx
"Marked increase in serum levels of SHBG was observed in the phytoestrogen-rich diet group (from 55.8 +/- 7.09 nmol/L to 71.2 +/- 6.56 nmol/L)."
That's huge. I assume 1 nmol/L binds 1 nmol/L of testosterone. Then the increase in SHBG after 12 weeks, 71.2 - 55.8 = 15.4 nmol/L could bind 15.4 nmol/L of testosterone.
"In the United States, male total testosterone levels below 300 ng/dL from a morning serum sample are generally considered low":
http://en.wikipedia.org/wiki/Testosterone
The molecular mass of testosterone is 288.42. Then 300 ng/dL is 300 ng/dL * 10 dL/L / 288.42 ng/nmol = 10.4 nmol/L. So the effect of 12 weeks of flax and soy on SHBG is enough to bind all of the testosterone a man has. Karen wrote that at her age, 500 is normal, 900 is way too high.
Moreover, in a male, only 0.7 % is free testosterone:
http://en.wikipedia.org/wiki/Testosterone/SHBG
I found another, unexpected conclusion in an even older publication: flax lengthens the luteal phase of the menstrual cycle. Only by 1 day, but still:
http://jcem.endojournals.org/content/77/5/1215.short
I wonder what that means for women who experience longer cycles on PM. Do all phyto-estrogens lengthen the cycle? Does estrogen lengthen the cycle?