How to potentially reverse PCOS with low carb
Polycystic ovary syndrome (PCOS) is a common disorder that affects 4-20% of women of childbearing age worldwide, and its incidence appears to be increasing over time.1 Beyond menstrual problems and other physical signs and symptoms, it’s a leading cause of infertility.2
Fortunately, there’s a potentially effective lifestyle treatment available: a low-carb diet.
Signs and symptoms
Here are the most common signs and symptoms associated with PCOS:
- Menstrual irregularities like irregular, skipped or heavy periods.
- Inability to get pregnant.
- Excess facial and body hair, showing up in a male pattern (including the upper lip, chin, and chest).3
Causes and treatment
The underlying causes of PCOS are complex and have been debated for decades. However, it is clear that the vast majority of women with PCOS have what is known as functional ovarian hyperandrogenism. This means that the ovaries are extraordinarily sensitive to signals that lead them to overproduce androgens (hormones like testosterone with “male” effects).4
An additional 50% of women with PCOS have insulin resistance, which aggravates the hyperandrogenism through the effect of insulin on the ovaries. Insulin resistance also stimulates the storage of fat, which can lead to obesity, which in turn can further exacerbate insulin resistance and PCOS symptoms.5
This, of course, also increases the risk of developing type 2 diabetes. Given that low-carbohydrate diets have been proven very effective for treating insulin resistance, obesity, and type 2 diabetes, it makes sense that they would also be useful for treating PCOS.6
In fact, any lifestyle intervention that results in weight loss or pharmacologic intervention that enhances insulin sensitivity may improve the features of PCOS.7
But, given that low-carb diets directly address insulin resistance — beyond any effect on weight — we believe that they are a particularly effective tool in the toolkit for PCOS. There is now a growing body of research that supports this contention:
- In 2005, researchers followed 11 women with PCOS as they followed a keto diet for six months. The five women who completed the study lost weight and improved some of their hormonal markers. What’s more, two of the women became pregnant during the study, despite previous infertility problems.8
- A 2013 study found that even a very modest reduction in carbohydrates (41% of calories) can lead to significant improvements in hormones and other metabolic risk factors, even in the absence of weight loss.9
- A 2017 systematic review of clinical trials found that low-carb diets tend to “reduce circulating insulin levels, improve hormonal imbalance and resume ovulation to improve pregnancy rates.“10 A 2019 meta-analysis of randomized trials showed similar findings, concluding “proper control of carbohydrate intake provides beneficial effects on some aspects of PCOS and may represent one of the important interventions improving the clinical symptoms of affected patients.”11
- In a 2020 study, 14 women with PCOS followed a ketogenic Mediterranean diet for 12 weeks. By the end of the study, they achieved lower blood glucose and insulin levels, improvements in reproductive hormone levels and function, reduction of heart disease risk factors, and an average weight loss of 20 pounds (9.4 kg).12
- A 2021 study of women with PCOS, obesity, and fatty liver randomized the participants to a ketogenic diet or conventional pharmacologic therapy. Those who received the ketogenic diet demonstrated better decreases in blood sugar and weight, and greater improvement in fatty liver.13
- Finally, a 2021 systematic review of RCTs concluded that dietary interventions improve PCOS symptoms, and low-carb is likely superior for fertility and restoring normal menstruation.14
Reversing PCOS and getting pregnant
There are several stories of women reversing their PCOS symptoms and in some cases suddenly getting pregnant after going low carb.15 It can sometimes feel like a miracle. Of course, it’s not that kind of miracle, but it’s still pretty impressive.
This is simple biology. Cutting back on carbs can help with weight loss, lower insulin levels, and reverse insulin resistance, which may help to balance the hormonal system. This can enable ovulation and a normal menstrual cycle, in addition to improving or eliminating other symptoms.16
While the stories of these women can be inspirational, it’s important to remember that a collection of anecdotes does not equate with scientific evidence:
Here’s a longer post on the topic:
Trying to conceive? Try the better baby diet of beef, butter & bacon
GuideIt’s possible that cutting carbs prior to conception might improve a woman’s chances of becoming pregnant.
Some health care professionals have also found that carb restriction can be incredibly effective for helping people with PCOS reverse their disease and get pregnant.17 This includes a group of Australian dietitians that we previously wrote about.
Dr. Fox found that compared to only using drugs, adding a low-carb diet for PCOS patients increased their chance of pregnancy from 45% to over 90%!18
Dr. Michael Fox can be contacted at the Jacksonville Center for Reproductive Medicine.
More about PCOS and keto
Top 8 reasons to adopt a low-carb diet for PCOS
GuideAlmost all the symptoms of a common female condition called PCOS respond very well to a low-carb or ketogenic diet. Here are the top 8 reasons why.
More benefits of low carb
Why should you consider eating fewer carbs? There are many potential benefits, at all ages (although there’s hardly ever a reason for healthy kids to do a strict low-carb diet).
Here are some of the main benefits, and how to adapt a low-carb diet for your specific needs, to maximize the positive effects on your health.
The four most common benefits
More common benefits
Possible, less certain benefits
How to potentially reverse PCOS with low carb - the evidence
The guide contains scientific references. You can find these in the notes throughout the text, and click the links to read the peer-reviewed scientific papers. When appropriate we include a grading of the strength of the evidence, with a link to our policy on this. Our evidence-based guides are updated at least once per year to reflect and reference the latest science on the topic.
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The following study demonstrated an increased incidence of PCOS between 2007 and 2017:
American Diabetes Association Diabetes Spectrum 2015: The role of polycystic ovary syndrome in reproductive and metabolic health: overview and approaches for treatment [overview article; ungraded] ↩
The likely reason is both an excess of male hormones and increased sensitivity to these hormones. These hormonal disturbances may also result in a deepening of the voice and male-pattern baldness.
Journal of Diabetes and Its Complications 2015: Effects of a high-protein/low carbohydrate versus a standard hypocaloric diet on adipocytokine levels and insulin resistance in obese patients along 9 months [randomized trial; moderate evidence]
Nutrition Journal 2010: Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women [randomized trial; moderate evidence]
Frontiers in Endocrinology 2019: Long-term effects of a novel continuous remote care intervention including nutritional ketosis for the management of type 2 diabetes: a 2-year non-randomized clinical trial [non-randomized study; weak evidence] ↩
These two publications are both from the same study:
Nutrients 2017: The effect of low carbohydrate diets on fertility hormones and outcomes in overweight and obese women: a systematic review [systematic review of randomized and non-randomized trials; moderate evidence] ↩
Journal of Obstetrics and Gynaecology Research 2021: Ketogenic diet in women with polycystic ovary syndrome and liver dysfunction who are obese: A randomized, open-label, parallel-group, controlled pilot trial [moderate evidence] ↩