Benefits of a Plant Based Diet For PCOS?

Polycystic Ovarian Syndrome (PCOS) is a common endocrine disorder affecting 5%-10% of women of reproductive age. Common symptoms of this condition include; infertility, insulin resistance, irregular periods, hair loss, acne and hirsutism.


Currently, there is no recommended diet for this population of women. Many women with PCOS have succeeded on a vegan plant based diet, while others have managed their PCOS on a Ketogenic diet.

Studies show that changes in lifestyle, such as nutrition, exercise, weight, psychological stress, environmental exposure can help PCOS and improve many of its symptoms.



A highly likely cause of PCOS is sugar. A diet high in sugar and refined carbohydrates increases insulin levels and leads to fat storage, which drives infertility.


In recent years the consumption has increased dramatically.

The Western diet is comprised of unhealthy amounts of sugar. Sugar is hiding in many food products we often never expect or believe they are 'healthy' and this adds to the over consumption of sugar.


Insulin is a hormone made in the pancreas and it has many roles in the body. However, one critical role is to keep blood sugar levels under control.

Cells in the body will burn glucose for fuel, but it will also store some for later use.


Eating a diet high in carbohydrates, especially simple sugars, such as white bread and white rice, increases your blood sugar levels and in turn spikes your insulin. If your blood sugar is constantly elevated and you have too much glucose in your bloodstream it is difficult you body to start burning fat as fuel as it keeps going to carbs as they require immediate action.


The more insulin you secrete, the more likely it is the cells in your body will become resistant to insulin. Which means the cells in your body have difficulty absorbing glucose in the bloodstream. In turn, it will take a lot of insulin to the job it is meant to do, which is to keep blood sugar levels stable. As a result of all of this insulin, your body is storing calories as fat instead of fuel.


Insulin not only causes you to store fat, it also causes inflammation and oxidative stress in the body, resulting in many health risks, such  as; high blood pressure, diabetes, infertility, high cholesterol, an increased risk of cancer, thickening of the blood, low HDL, high triglycerides, poor sex drive, depression and Alzheimer’s.


Carbohydrates are not Bad


It is often believed that following a plant based diet which is made up of mostly carbohydrates is not the best option for someone who is insulin resistant, or who are at risk of Type 2 Diabetes. Just as you distinguish between types of protein and fat, you do the same for carbohydrates. Not all carbohydrates are bad and should be avoided. Several studies have found that carbohydrates from whole grains and cereal fibers reduce the risk of developing diabetes while refined, low-fiber carbohydrates can increase the risk of diabetes.


Studies have found that following a whole-foods plant based diet improves insulin resistance even when there is no weight loss, and/or with statistical adjustment for body weight.


A study examed the effects of both a high carbohydrates diet and a high protein diet, in which fat intake was constant at 30%, for eight weeks in patients with type 2 diabetes. The results showed that while there were no differences in weight loss, the high carbohydrate group increased insulin sensitivity, fasting plasma glucose and hemoglobin A1c. No significant changes to these parameters were observed in the high protein group.


Advanced glycation endproducts


Research indicates that foods such as meat are high in oxidant compounds known as advanced glycation endproducts (AGEs) and the amount increases especially when grilled, broiled, roasted, seared, or fried). However, plant-based foods such as fruits, vegetables, legumes, and whole grains are low in AGEs.

Advanced glycation endproducts have been linked to the cause of type 2 diabetes, whereas a diet low in these compounds has been found to improve insulin resistance in people with type 2 diabetes.


High in Fiber

Plant-based diets are high in fiber, antioxidants, and magnesium, all of which have been shown to promote insulin sensitivity.

It is suggested that antioxidants such as polyphenols may inhibit glucose absorption, stimulate insulin secretion, reduce hepatic glucose output, and enhance glucose uptake.


Fiber, only found in plant foods, helps to manage blood glucose levels after a meal. Furthermore, short chain fatty acids are produced when friendly gut bacteria ferment fiber in your colon, which helps to improve the glucose response, insulin signaling, and insulin sensitivity.


Furthermore, fiber provides fewer calories per gram of food,  as a result, promotes satiety. It has been associated with weight loss, which is may be because of the increase in satiation and fullness, allowing individuals to eat less
throughout the day. Moreover, the reduction in weight also reduced insulin resistance.


Fiber has also be associated with decreased evidence of inflammation, which may also help with insulin resistance.


Hormone Free


Animal products contain hormones and many other toxins which can cause health problems.

The hormones that are found in meat does not help women who suffer from PCOS. Women with PCOS already have a hormone imbalance and therefore a benefit of a plant based diet is that you avoid this risk.



Infertility is a common symtpom of PCOS. High insulin levels are shown to cause the ovary to produce too much testosterone in turn causing problems with fertility.

It is suggested that consuming more vegetable protein than animal protein can help improve fertility.

A study conducted by Chavarro et al. found that women who consumed 5% of total energy intake as vegetable protein rather than as animal protein was associated with a more than 50% lower risk of ovulatory infertility (P = 0.007).


The Nurse's Health Study (NHS II) found that a high carbohydrate diet is linked to ovulatory infertility. Results show women who consumed high levels of carbs had a 78% greater risk of ovulatory infertility. Also, the study showed vegetable protein consumption was associated with a 43% lower risk.


Women in the highest glycemic-load category were 92 percent more likely to have had ovulatory infertility than women in the lowest category.

Therefore, it is not about how many carbs you eat, it is about the type of carbs you eat that effect fertility.


On the other hand however, plant based food crops are sprayed with herbicides and pesticides and studies have found pesticides have and effect on female and male fertility.

The female reproductive system is dependent on a healthy hormone balance and pesticides are known endocrine disruptor.

Research has shown glyphosate blocks the enzyme aromatase, which is meant to aid in the androgen to estrogen conversion, in turn causing an excess of androgen.




A further common symptom of PCOS is acne, this is a result of the elevated levels of androgens, both testosterone and DHT. For many years dermatologist the denying the connection between diet and acne. However, in recent years, studies have been continuing to show the link between a diet high in dairy and a high glycemic load.


I have previously written a post about why you should avoid dairy and PCOS, as well as its links to acne.


While a plant based diet is high in carbohydrates, the carbohydrates that are consumed are low glycemic, such as legumes, vegetables, fruits, whole grains. A plant based diet excludes dairy products and highly refined foods like bleached flour, refined sugar, and oil.

A 10-week randomised controlled trial found that a low glycemic load diet resulted in improvement of acne, they also found a reduction in skin inflammation and in the size of sebaceous glands.

In another, which lasted 12-weeks found that a low glycemic load diet resulted in improvement of acne, with an improvement in insulin sensitivity, a reduction in testosterone bioavailability, and a decrease in adrenal androgens.




McMacken, M, and Shah, S. (2017). A plant-based diet for the prevention and treatment of type 2 diabetes. Journal of Geriatric Cardiology. 14(5): 342–354. Available from:


Uribarri J, Woodruff S, Goodman S, Cai W, Chen X, Pyzik R, Yong A, Striker GE, Vlassara H. (2010). Advanced glycation end products in foods and a practical guide to their reduction in the diet. Journal of the American Dietetic Association. 110(6):911-16. Available from:

Kim Y, Keogh JB, Clifton PM. (2016). Polyphenols and Glycemic Control. Nutrients. Available from:


Canfora EE, Jocken JW, Blaak EE. (2015). Short-chain fatty acids in control of body weight and insulin sensitivity. 11(10):577-91. Available from:













If you liked this post, why not give it a share...

Like what you've read so far?

Don't miss a post. Sign up to PCOS and Nutrition's email updates and get the latest PCOS and nutrition news, recipes, products and product reviews direct to your inbox. Plus you will receive PCOS and Nutrition's "Ten Top Nutrition Tips for Living a Healthy and Balanced Lifestyle". All free.

We respect your privacy. We will NEVER sell, rent or share your email address. That's more than a policy, it's our personal guarantee!