Understanding PCOS and the role of nutrition

By Amber Charles-Alexis, MSPH, RDN

June 7, 2021

Polycystic ovary syndrome (PCOS) is the most common cause of infertility in women of childbearing age. This blog describes the impact of PCOS on women’s health and the role of nutrition in PCOS management.

What is PCOS | Symptoms | Diagnosis | Risk factors | Health impact | Nutrition | Takeaway

Picture: Canva, stock image

What is PCOS?

PCOS is a disorder of the female endocrine system – the network of glands responsible for producing the female reproductive hormones – estrogen and progesterone (1, 2).

Hormones are chemical messengers that control bodily functions, including metabolism, blood sugar, blood pressure and reproduction (3).

Women with PCOS produce higher levels of the male hormone, testosterone, and have lower levels of estrogen, the hormone responsible for female fertility (1, 4).

PCOS can affect up to 20% of women, depending on the criteria used for diagnosis (5).

Signs and symptoms of PCOS

The symptoms of PCOS are mainly due to the presence of excess testosterone – aka male androgens – a condition also called hyperandrogenism.

However, not all women with excess testosterone levels have PCOS, but they may share similar symptoms (5).

Common signs and symptoms of PCOS include (1, 5, 6, 7, 8):

  • Hirsutism or excessive body hair on the face, neck, back, chest and thighs

  • Acne occurs in 15-30% of women with PCOS

  • Increased abdominal fat/obesity

  • Weight gain or obesity

  • Irregular menstrual cycles or lack of a menstrual cycle

  • Insulin resistance and pre-diabetes

  • Chronic, low-grade inflammation and poor gut health

  • Hair loss (alopecia)

  • Non-alcoholic fatty liver disease (NAFLD)

How is it diagnosed?


PCOS is a diagnosis of exclusion.

This means that your medical team will determine if there are other underlying health conditions responsible for your symptoms before diagnosing PCOS (5, 7).

You can expect a combination of lab work (blood) and ultrasounds of your ovaries to confirm the presence of PCOS.

While there are several diagnostic frameworks for PCOS, the Rotterdam criteria is quite common and PCOS can be diagnosed if any 2 of the following are present (8):

  • Hyperandrogenism

  • Symptoms caused by hyperandrogenism, such as androgenic baldness, hirsutism

  • Menstruation and ovulation disorders

  • Enlarged (ovary volume > 10 cm3) or polycystic ovaries (at least 12 follicles) visible in an ultrasound image.

As you can see, you do not actually need cysts to be present on your ovaries to be diagnosed with PCOS.

Risk factors for PCOS

You are more likely to develop PCOS if you have (5):

  • A family history of PCOS

  • A history of weight gain

  • Epilepsy

  • Diabetes – type 1, type 2 or gestational

How does PCOS affect women’s health?

Excess testosterone is responsible for a myriad of negative health outcomes in women with PCOS.

The high levels of testosterone trigger inflammation which leads to the development of insulin resistance - a condition where your cells become less responsive to the action of insulin, the hormone that regulates blood sugar (1, 4, 8).

Approximately 50-70% of women with PCOS have insulin resistance (IR) (5).

Scientists believe that inflammation and IR play key roles in the development of metabolic syndrome and increases your risk for diabetes, high blood pressure, heart disease, high cholesterol, and some cancers, like breast and ovarian cancer (1, 2, 3, 4, 7, 8).

Furthermore, IR is also believed to cause increased visceral fat - the fat around the organs - and an expanding waistline.

Although there isn't a cure for PCOS, if left unmanaged it may lead to the development of many chronic, non-communicable diseases and a reduced quality of life.

Can I have PCOS if I am not overweight?

In short - yes.

As highlighted above, body weight is not a diagnostic criterion for PCOS (3, 8).

Furthermore, up to 75% of lean women with PCOS have insulin resistance (2).

This simply means that you can have a BMI within the normal range and still develop PCOS and its many side effects. However, women with higher body fat have more aggravate forms of PCOS and insulin resistance (2).

What is the role of nutrition in PCOS management?

While there isn't a specific diet for PCOS, nutrition and lifestyle changes are the first-line treatment for PCOS (2).

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