Hello everyone,
I am Francesca, writer of The PCOS Newsletter. I am a Nutritional Therapist with a love for science and research, which I put to use by reviewing studies and unpacking the complexity of this unique condition in a weekly article.
I’m here today because we so often discuss insulin resistance in relation to weight, metabolic health, and type 2 diabetes, but rarely in relation to our ovaries and reproductive system.
So when Beth offered me the opportunity to write a piece for her incredible publication Nest Wellness, I was so excited to share my view on the role that glucose control plays in the health of our reproductive health.
One of the most well known conditions that is impacted by insulin resistance is PCOS. PCOS, a condition I have had for 15 years, is a hormonal dysfunction affecting 1 in 10 women worldwide. If you don’t have it yourself, I am sure you have heard of a woman that does.
PCOS is characterised by irregular or absent ovulation, elevated levels of male hormones (androgens), and/or ovaries containing multiple small fluid-filled sacs called follicles. All in all, PCOS is characterised by failed ovulation. This can give rise to symptoms such as irregular periods, excess hair or loss of hair, acne, weight gain, and/or difficulty conceiving.
What causes PCOS is unknown. Epigenetic changes to the genes of a baby in the uterus of the mother due to high insulin and/or androgens is one of the leading hypotheses. What we do know is that insulin resistance and high levels of male hormones are the drivers of this condition.
Let’s briefly look into the role of insulin in PCOS
To make this explanation smooth, I want to review how we actually ovulate.
Ovulation Process:
FSH (follicle-stimulating hormone) and luteinizing hormone (LH) are released in pulses from our brain, communicating to our ovaries.
Under this communication, follicles in our ovaries get put forward to grow in the follicular phase of our cycle (usually cycle days 1-14).
As follicles grow, they secrete estrogen. Something that we might not realize is that estrogen is synthesized from cholesterol that gets transformed into testosterone, and then into estrogen.
This estrogen makes our endometrium grow.
As soon as there is enough estrogen in the system, a surge of LH makes one of the follicles burst and release an egg. Voila 🎉
In PCOS, things can go a bit awry, and ovulation stops:
LH:FSH Imbalance: Women with PCOS have high LH and low FSH, which prevents follicles from maturing properly. Without a dominant follicle, estrogen levels don't rise enough to trigger ovulation.
Excess insulin in the blood can directly act on the ovary, stimulating it to create too much testosterone that struggles to get converted to estrogen. In addition, excess insulin can further disrupt those pulses from our brain to the ovaries.
Excess Testosterone: High testosterone creates an androgenic environment in the ovaries, halting follicle growth and preventing the conversion of testosterone into estrogen.
No LH Surge: Without mature follicles and sufficient estrogen, the LH surge needed for ovulation never occurs, leading to anovulation (no egg release).
These immature follicles on the ovaries appear as little cysts, giving them the name of polycystic ovaries.
This is where having very good blood sugar balance really helps women with PCOS.
Essentially, less excess insulin in the blood will lead to less testosterone messing up with our reproductive system. The most important thing I work on with my PCOS clients is making sure that they eat in a way that is conducive to a healthy hormone balance.
Does excess insulin and poor blood sugar affect the reproductive system of all women?
Yes, it does.
Elevated insulin (hyperinsulinemia) can disrupt follicle development and ovulation, even in women without PCOS, by altering hormone signaling within the hypothalamic-pituitary-ovarian axis.
Some studies also show that insulin resistance and high insulin can negatively affect the endometrium (uterine lining), embryo implantation, and early pregnancy, increasing the risk of miscarriage and poor pregnancy outcomes.
Eating a diet that looks after your blood sugar levels will be beneficial for all aspect of your health.
When it comes to the right diet for PCOS, the research shows that a Mediterranean, lower-carbohydrate, and the DASH diet can be helpful in reducing insulin resistance.
As a Nutritionist, I don’t think there is ONE good diet for PCOS. However, I think what all of these diets have in common are the following principles:
Optimizing for nutrient-dense foods. I always ask myself: is this food going to nourish me? The less processed and packaged, the higher the chances that it’s higher in nutrients
Filling your plate with diverse vegetables and being playful about the ones you choose
Eating 1-2 max pieces of fruit per day
Consuming high in fibre foods (I have written a guide on fibre here)
Consuming fish 2-3 times a week or supplementing with Omega 3
Reducing sugars and simple carbohydrates
Increasing protein
Choosing healthy sources of fat
Beth has created a 7-day downloadable meal plan that uses these nutritional guidelines:
I hope you have enjoyed learning about this condition! Come join me and the beautiful community of women with PCOS on The PCOS Newsletter. I release articles every Sunday, including research overviews, nutritional content, fertility, and stories of women with PCOS.
If you know someone with PCOS, will you forward this post to them?
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Thank you for being here,
Link to publication
Nandi, A., Wang, X., Accili, D., & Wolgemuth, D. J. (2010). The effect of insulin signaling on female reproductive function independent of adiposity and hyperglycemia. Endocrinology, 151(4), 1863–1871. https://doi.org/10.1210/en.2009-0788
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Thank you, Fran for this wonderful, informative post about the PCOS and insulin resistance link. I so appreciate you filling in while I was traveling!🧡
Well done Fran :)