UPDATED BY FRANZISKA SPRITZLER, RD, CDE
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age and the leading cause of infertility. In this article, we discuss PCOS and the growing body of research supporting ketogenic diets as an effective option to treat this condition and improve overall metabolic health.
What is PCOS?
PCOS is a complex syndrome and autoimmune condition caused by a hormonal imbalance between luteinizing hormone (LH) and follicle-stimulating hormone (FSH). When LH production increases above normal ranges, the body starts producing androgens, like testosterone, which can lead to irregular menses and infertility. Other signs and symptoms of PCOS include ovarian cysts, excessive body hair, acne, weight gain, and an increased risk of chronic metabolic diseases like type 2 diabetes and heart disease. Currently, PCOS is estimated to impact approximately 15 percent of women of reproductive age worldwide.
What Causes PCOS?
While the exact cause of PCOS is unknown, researchers believe it’s a combination of genetic predisposition and numerous lifestyle factors. Insulin resistance is typically seen in women with PCOS, which comes as no surprise since hyperinsulinemia (having high insulin levels) has been shown to increase LH production.
Treatment Options for PCOS
In recent years, researchers have started to explore dietary and lifestyle interventions for treating PCOS. While it is hard to determine if the insulin resistance that is so commonly seen in PCOS is a result or cause of the condition, the fact that insulin resistance is present offers up a therapeutic target: improving insulin sensitivity.
New research suggests that improving insulin sensitivity—and weight loss—are likely the most effective means to treat PCOS. In fact, losing weight can significantly improve hormonal imbalances, increase fertility and reduce miscarriage rates. Furthermore, increasing insulin sensitivity can reduce excess androgen hormone production, normalizing the balance between LH and FSH.
Since improving insulin resistance and body weight seem to play such big factors, the ketogenic diet offers a very promising dietary intervention for PCOS.
Impact of the Ketogenic Diet on PCOS
The ketogenic diet is most notably known for its impact on weight loss, epilepsy, type 2 diabetes, neurological disorders, and certain types of cancer. However, due to emerging research and anecdotal evidence, keto is now being considered for many additional conditions, such as PCOS.
Besides the fact that eliminating excess glucose from the diet will significantly improve health parameters, ketogenic diets have been proven to be remarkably effective for reducing insulin concentrations and improving insulin sensitivity.
While research is limited, it is promising and growing:
- A 2005 pilot trial in six obese women diagnosed with PCOS found that limiting carbohydrate intake to 20 grams or less per day for 24 weeks resulted in significant reductions in weight, testosterone, LH/FSH ratio, and fasting insulin levels. In addition, two of the women became pregnant during the study despite previous fertility complications.
- A 2020 trial in overweight women with PCOS found that following a ketogenic diet for 12 weeks resulted in significant reductions in body weight, visceral fat, glucose, insulin, and triglycerides, in addition to improving reproductive hormone imbalances.
- In a 2021 randomized trial, 18 women with PCOS, obesity, and liver dysfunction who followed a ketogenic diet for 12 weeks experienced significant improvements in liver function, menstrual cycle regularity, blood glucose, body weight, and fatty liver symptoms compared to conventional pharmacological treatment.
- A 2023 review of six trials, including the three above, found that ketogenic diet interventions lasting at least 45 days in women with PCOS significantly improved reproductive hormone levels, reducing LH/FSH ratio and serum free testosterone. Significant weight loss was also consistently observed across all studies.
- In a 2023 retrospective study of 12 overweight women with PCOS who had previously failed to become pregnant with in vitro fertilization (IVF), eating a ketogenic diet led to significant weight loss, insulin sensitivity, and improvement in metabolic health markers. Moreover, two-thirds of the women became pregnant and successfully gave birth following their second round of IVF after switching to a ketogenic diet.
Over the past several years, several practitioners have begun prescribing the ketogenic diet as a treatment for PCOS, and many anecdotal success stories have been reported.
The Final Word
To date, pharmacological treatment options for PCOS have been ineffective. Insulin resistance, a driver of PCOS, offers a therapeutic target that can be addressed through various lifestyle improvements, including the ketogenic diet.
We hope that the promising research on ketogenic diets for PCOS will encourage the academic community to continue exploring these interventions to help the many women living with this condition.
