As every woman knows, progesterone is the second steroid hormone of a normal menstrual cycle. (For the one man who doesn’t know, oestrogen is the first steroid hormone of that normal menstrual cycle.) As menstrual bleeding ends, ovaries secrete more and more oestrogen until the peak at ovulation when an ovary releases an egg for its journey towards the uterus and just possibly a meeting with a sperm cell.
At that time of ovulation, the ovaries produce a surge of progesterone, reaching levels much higher than prior to ovulation. After ovulation, progesterone levels stay relatively high for a while, waiting for the egg (egg cell to be technically correct) to meet and merge with a sperm cell.
But if that doesn’t happen, progesterone levels decline along with oestrogen levels, and the next menstrual bleeding begins.
(Serious hormone scholars will point out that progesterone is also made by adrenal glands, too, specifically the adrenal cortex which also produces cortisol, DHEA, aldosterone, and dozens of related natural steroid hormones. However, these other natural steroids are not an intrinsic part of the menstrual cycle.)
Although testosterone is usually thought of as a ‘male hormone’, it’s actually the third steroid hormone of a normal menstrual cycle, as ovaries secrete all three: oestrogen, progesterone and testosterone. Although testosterone is certainly not the only hormone driving libido for women, it is the major libido-driver for many.
So it just makes sense that in most normal menstrual cycles, testosterone starts to rise after menstrual bleeding stops, and reaches its highest levels (surprise!) before and at the time of ovulation. This small testosterone peak often means the newly released egg will have a better chance of meeting and greeting a sperm. After ovulation, testosterone declines again, and if it dips more than usual, the relatively low testosterone can also contribute to oestrogen dominance.
As menopause approaches, progesterone levels decline, usually well before oestrogen levels do. This can lead to an imbalance (‘imbalance’ relative to the oestrogen/progesterone ratio in a woman’s 20s and earlier 30s) that’s sometimes termed ‘oestrogen dominance’. Oestrogen dominance can be associated with a variety of symptoms. See the box below for some of the most common ones.
Flaxseed the hormone helper
All the way back in 1993, researchers reported that ground flaxseed powder can favourably affect all three natural steroid hormones – oestrogen, progesterone, testosterone – of the menstrual cycle.1 Now I know that information would cause some to say, ‘Back in 1993? Isn’t that research out of date?’ But as a Nutrition & Healing reader you know that if eating ground flaxseed powder had effects on human ovarian hormones in 1993, eating ground flaxseed powder will always have those effects whether it’s 2013 A.D. or 2013 B.C.
In stark contrast, the effects of patent medicines tend to be greatest during the 17-year duration of the patent, and frequently suffer a dramatic decline after that, only to be replaced by yet another patent medicine! But I digress…
Researchers recruited 18 women having normal menstrual cycles, using a balanced, randomised, crossover design. (For the technically non-inclined, this design eliminates ‘researcher bias’.)
Each woman ate her usual diet (omnivorous, relatively low fibre) for three complete menstrual cycles and continued that very same diet with flaxseed powder for another three complete menstrual cycles. Hormone levels of the second and third menstrual cycles with usual diet but no added ground flaxseed powder were compared with hormone levels of the second and third menstrual cycles with the same usual diet, but with added ground flaxseed powder.
During the ‘luteal phase’ (for the technically non-inclined, the days of the menstrual cycle starting with ovulation and ending at the start of menstrual bleeding) the progesterone/oestradiol ratios were significantly higher during the cycles when the 18 women were adding ground flaxseed powder to their usual diets. The ‘luteal phase’ was also a day longer during the cycles when ground flaxseed powder was consumed.Wishing you the best of health,
Dr. Jonathan V. Wright
Nutrition & Healing
Volume 6, Issue 12 – December 2012
Full references and citations for this article are available in the downloadable PDF version of the monthly Nutrition and Healing issue in which this article appears.