Ketogenic diet may improve hormonal imbalances associated with PCOS

In the first-ever meta-analysis and systematic review of clinical trials on the association, ketogenic diets followed for 45 days to 24 weeks demonstrated improvements in serum sex hormone binding globulin (SHBG), serum free testosterone, and luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio.

The researchers reported a possible association between the ketogenic diet and improvement in the levels of reproductive hormones in women with PCOS via a meta-analysis of the usable and available studies. They, however, note several limitations of the accessible literature, reducing the transferability and acceptability of these results to the general PCOS population.

They add, "These findings have important clinical implications, particularly for dieticians, gynaecologists, and endocrinologists, who should carefully plan and customize individual diet recommendations for women with PCOS."

Polycystic ovary syndrome is a complex multisystem disorder having a similar pathogenesis as other chronic diseases with genetic-environmental interaction. In women, PCOS remains the most common endocrine disorder. Recently, the ketogenic diet has made a comeback as a part of dietary and lifestyle modifications in PCOS patients. Previous studies have suggested its beneficial effects in reversing hormonal balance in PCOS patients but the evidence has been patchy and derived from small populations under varying conditions.

To address this, Karniza Khalid, Ministry of Health Malaysia, Kuala Lumpur, Malaysia, and colleagues aimed to pool evidence from clinical trials to study the effects of ketogenic diet on reproductive hormones (LH/FSH ratio, serum progesterone, free testosterone) and observe evidence of weight change.

For this purpose, the researchers searched online databases for clinical trials evaluating the effects of a ketogenic diet in established PCOS women consistent with the Rotterdam classification. They included single- or double-arm studies that included an outcome of interest. To screen potential articles and a designated investigator extracted data on study characteristics, two investigators worked independently to screen potential articles and evaluated the outcomes.

The authors reported the following findings:

• Following ≥45 days of intervention with a ketogenic diet among women with PCOS, significant improvement was observed in reproductive hormone levels, with reduced LH/FSH ratio (d −0.851), reduced serum free testosterone (d −0.223), and an increase in serum sex hormone binding globulin (SHBG) (d 9.086).
• Significant weight loss was unanimously observed in all included studies (d −11.56).

"Short-term ketogenic diet potentially improved hormonal imbalances commonly associated with PCOS," the researchers wrote.

"The results are interesting and useful to formulate a hypothesis but they must be interpreted with caution due to the small number of subjects investigated," they concluded. 

Reference:

Khalid, K., Apparow, S., Mushaddik, I. L., Anuar, A., Rizvi, S. A., & Habib, A. (2023). Effects of Ketogenic Diet on Reproductive Hormones in Women With Polycystic Ovary Syndrome. Journal of the Endocrine Society, 7(10). https://doi.org/10.1210/jendso/bvad112