What causes PCOS ? Some new ideas on an ancient disease and modern women

Sometimes I am asked – is PCOS caused by eating too much sugar, unhealthy fat and our sedentary lifestyle?  Interestingly, the disease of PCOS does not appear to increase in areas of the world where obesity is more prevalent.  This indicates that this disease is not caused primarily by obesity.  There are many ancient medical records describing women with PCOS conditions (including prolonged menstrual cycles, infertility, acne, abdominal fat, and hirsutism). A recent article in Fertility and Sterility proposes that PCOS is actually an ancient genetic condition that has persisted over thousands of years in women.  But why would PCOS persist in our gene pool when it leads to infertility or decreased reproduction in women?

Ancient Hunter-Gatherer communities and women with PCOS

There are several reasons why PCOS variants may have persisted in women over thousands of years. In ancient hunter gatherer communities those who had metabolisms which conserved energy and stored fat had definite survival benefits. Women with PCOS do carry these metabolic advantages.  They tend to be metabolic energy conservers – something which is of great advantage in times of low food supply.  Because women with PCOS generally had fewer children due to reduced fertility rates, they often had the survival advantage of caring for only one young child at a time and had greater resources for themselves and their families. Childbirth related complications were a common cause of death, so women with pcos were also at a survival advantage due to decreased maternal mortality. In ancient cultures, there was less food supply, more physical activity and therefore less obesity, so women with PCOS generally had  a lower BMI (Body Mass Index) compared to modern women.  At times when food was in short supply, women with PCOS would tend to have more normal BMIs (leading to more normal levels of fertility). At these same times, women without PCOS would have lower BMIs and may have been more prone to have subfertility themselves.

Generally, fertility is lower amongst women with PCOS at all BMI levels. In times when BMIs are on average lower in the population, women with PCOS will have more normal reproductive rates.  . This illustrates the importance of achieving a healthy BMI for women with PCOS and that the condition actually is one of subfertility rather than infertility.

Please view the following table to see the relationship of BMI to fertility in women with and without PCOS variants:

Figure 1: Hypothetical BMI-fecundity relationship in PCOS. © 2010 American Society for Reproductive Medicine

Another point to consider  is that PCOS genes are also carried through males, who also carry these metabolic survival advantages and do not experience subfertility.  PCOS genetic variants include greater lean muscle mass and bone density and these males could pass on these beneficial genes to their offspring.  This explains how this genetic type could persist through thousands of years even though it is related to subfertility.

How This Translates to Modern Women

In general, BMI levels tend to be increased with the modern western diet and lifestyle, so the effects on reproduction of PCOS are amplified compared to those in ancient times.   Women with this condition must pay extra attention to achieving a healthy BMI.   Although having a high BMI does not cause PCOS, it will definitely cause lower fertility levels. For those women who have a high level of insulin resistance (which is aggravated by the western diet), extra attention must be paid to working with insulin balance in the body.  This can be done very effectively with the right diet and supplements.

Integrative Medicine Assessments

PCOS variants should be screened for in all women seeking fertility treatment who have a long cycle, acne, hirsutism, or abdominal fat accumulation (even in slimmer women). Many traditional assessments can miss mild cases of this condition or “leanings” towards the condition.  Restoring pituitary and metabolic function in these women can effectively restore fertility and often heavy medical intervention is not required.

  • Glucose to insulin ration and oral glucose tolerance testing
  • HBA1C
  • Day 3 LH to FSH ratio
  • Full early AM androgen panel – (androstenedione, free testosterone, DHEA-S, 17-OH Progesterone)
  • AM cortisol or diurnal cortisol
  • Transvaginal pelvic ultrasound to check for cystic ovaries

In a women who has an elevated LH to FSH ratio we can assume much of the PCOS is related to hypothalamic pituitary dysfunctions. With a normal LH to FSH ratio other metabolic disorders are often more prevalent and contributing factors should be identified. Androgen balance is of great importance, and elevated levels should be identified. It is also important to note that PCOS variants can be closely mimicked or aggravated by adrenal conditions so assessment of the adrenal function including diurnal cortisol, and DHEA-S testing is very important. It is also important to rule out other causes for lack of/delayed ovulation such as elevated prolactin levels or clinical/subclinical thyroid disease.

PCOS Treatment

PCOS Treatment very much depends on the individual characteristics of each woman’s condition. There are many different PCOS variants as this is a syndrome involving reduced frequency of ovulation and is not a discrete disease with one cause.  A patient does not have to have all of the diagnostic criteria of PCOS to have her fertility affected by a milder variant of this disease.  Each patient will require different treatment based on her lab values, metabolic characteristics, body type, severity of disease and level of inflammation.

Hunter-Gatherer Diets and PCOS

Returning the patient to a healthy bmi is much more important for fertility than in women without PCOS.   Thus, healthy diets with attention to glycemic index are of great effectiveness. I always counsel patients with PCOS extensively on nutrition and diet as this is an area of special need for them even if they are a “lean” type.  A hunter-gatherer diet is often the best type of diet for pcos. This diet is high in healthy proteins such as lean meats, seafood, fruits and berries, vegetables, and nuts and low in grains.  Most especially of course, the diet should be low in sugar since hunter gatherer cultures had very low sugar intake overall.

A simple one day hunter-gatherer diet for PCOS variants:

  • Breakfast:  Omelette made with onions and spinach.
  • Snack:  Ambrosia (pear, avocado and 1/2 unripe banana – blend in blender until smooth and creamy)  *Did you know unripe bananas have a glycemic index of 50 whereas a ripe banana has a glycemic index of 82
  • Lunch:  Tilapia fillet drizzled with olive oil, with brocolli or salad (dressing of fresh lemon, olive oil and fresh herbs)
  • Snack:  sliced baby cucumber with fresh lemon squeezed on top.  3 tbsp almonds and 1 cup of fresh blueberries
  • Dinner: Grilled chicken breast with pesto and baby bok choy

This diet would be varied with respect to quantity and calories for differing weight loss or maintenance requirements.


I use supplement therapy as a mainstay along with diet in the treatment of PCOS and have found the combination works wonderfully to restore cycle regularity.  Supplements are aimed at restoring normal hypothalamic-pituitary function, increasing antioxidant status, improving insulin resistance, and minimizing excess androgen levels if required.  Supplement protocols will vary widely with different “types”  and lab results found in different pcos variants.


  1. Carmina E, Guastella E, Longo RA, Rini GB, Lobo RA. Correlates of increased lean muscle mass in women with polycystic ovary syndrome. Eur J Endocrinol 2009;161:583–9.
  2. Di Carlo C, Shoham Z, MacDougall J, Patel A, Hall ML, Jacobs HS. Polycystic ovaries as a relative protective factor for bone mineral loss in young women with amenorrhea. Fertil Steril 1992;57: 314–9.
  3. Good C, Tulchinsky M, Mauger D, Demers LM, Legro RS. Bone mineral density and body composition in lean women with polycystic ovary syndrome. Fertil Steril 1999;72:21–5.
  4. Ricardo Azziz, Daniel A. Dumesic, Mark O. Goodarzi. Polycystic ovary syndrome: an ancient disorder? Fertility and Sterility – 27 October 2010
  5. To WW, Wong MW. A comparison of bone mineral density in oligomenorrhoeic adolescents with polycystic ovaries and normal ovaries. Gynecol Endocrinol 2005;20:237–42.

5 thoughts on “What causes PCOS ? Some new ideas on an ancient disease and modern women”

  1. I have had PCOS for 18 yrs now.And I have had one miscarriage .And after the miscarriage I find out that I had PCOS and didn’t know what it was.And I also have diabetes and having minor issues with my heart.my husband also has problems and that is the reason we can’t have children.And were both over weight and there isn’t really a good dr to take care of all these problems .Really don’t understand all of this.Any advise would be great.I’m also taking insulin and metformin for my diabetes.I have fibroid on my uterus and A cyst on my left ovary.

    1. Hi Debra

      I’m so sorry to hear about your miscarriage. There are many supplements that can help with PCOS. Overall, if you are overweight, my best suggestion would be to reach a health weight. In particular, your waist circumference should be less than 35 inches if you are normal sized frame, or less than 33 inches if you are smaller framed. Exercise is also very beneficial for women with PCOS! As I cannot give medical information out here, please feel free to contact our clinic if you’d like to learn more about our programs for PCOS.

      warmest wishes,

      Dr. Fiona

  2. Thank you for this article. I am 35 and was diagnosed with PCOS when I was in my late 20s, but most likely have had PCOS all of my life as my menstrual cycle has never been normal, along with other criteria. A few years ago the weight started packing on (quit smoking, got a desk job), and more recently I had a bout of viral meningitis. Once my post meningitis headaches started to lessen, I realized that my weight was not where I wanted it to be , I had hit the 250 Mark. I went to a new doctor, who suggested we start by talking with an obgyn. She was very nice,knew a bit about PCOS and we talked about nutrition as therapy as well as exercise. Basically simple Carbs, for me and my body, are bad! I’ve been trying the Hunter gatherer type diet, low grains, whole foods, low glycemic foods, low sugar, and smaller portions at night. I am proud to say that even though I’ve only dropped 10 lbs, I have lost a few inches and I’m not dealing with swollen legs at the end of the day. Boy do I miss pasta though! Your article just hammers the point home. PCOS isn’t just something you pick up like the flu. For me, it’s something that I have personally battled my whole life. I’ve never been able to conceive, but there still is hope as a year ago my once sporadic if they ever happened at all periods have regulated on their own. My hair loss has slowed (or I should say my rapid hair regrowth has slowed), my acne only comes around with my period and is not constant, and my emotionss are more stable. I also take a supplement, and exercise is something I battle. But all in all, thank you for this article and your others. There is hope for those with PCOS.

  3. Absolutely fascinating articles on this website. They are refreshing takes on PCOS. It’s fascinating because we always try to understand why this is happening to our bodies. We always ask ourselves “Why us?” With a why, we can rationalise and make better decisions.
    Without a why, we can still make better decisions, but the logic is lost and anxiety persists as we continue to search for answers.
    I am a very logical, rational person, and the mood swings and altered perception of anxiety and depression and food cravings are exactly not who I am.
    So, thanks for bringing rationale to the table. It puts everything into perspective and helps me make better choices for myself. I’ll certainly pass this website link to other cysters and I’ll continue to read the invaluable information.
    Thank you.

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