The Key Role of Omega-3 in PCOS Management

Omega-3s are part of lipids, a family of fatty compounds essential for the proper functioning of the body. Among lipids, we find steroids, phospholipids, carotenoids, triglycerides, and fatty acids, which play various structural, hormonal, or energetic roles.

Omega-3s are fatty acids, a category itself divided according to their chemical structure: saturated fatty acids (without double bonds), monounsaturated (one double bond), and polyunsaturated (several double bonds), the latter being recognized for their beneficial effects on health.

Omega-3s are polyunsaturated fatty acids, characterized by a first double bond placed on the third carbon atom of their chain. In comparison, this bond appears on the sixth atom for omega-6s and on the ninth for omega-9s.

There are three main forms of omega-3s: alpha-linolenic acid (ALA), essential because it is not synthesized by the body, and its derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA can be converted in the body into EPA and then into DHA through a series of complex reactions. However, this conversion is low (less than 2%) and varies between individuals.

Omega-3s are present in food at varying concentrations. Plant sources, such as walnuts or rapeseed and linseed oils, mainly provide ALA. However, fatty fish, such as salmon, mackerel, herring, sardines, or anchovies, directly provide EPA and DHA.

Our omega-3 intake is low. According to Anses, between 50 and 75% of women have insufficient DHA intake, and more than 75% for ALA and EPA. Supplementation may therefore be useful, given the fundamental role of these fatty acids for the proper functioning of the body.

Omega-3 fatty acids fulfill several essential functions in the body. First, on the energetic level, 1 gram provides 9 kcal, making it a highly concentrated energy source. They also play a major structural role by being part of cell membranes, whose fluidity they improve, thus promoting exchanges between cells.

Furthermore, omega-3s act on the functional level as precursors of anti-inflammatory mediators. Omega-3s are essential for proper brain and visual function: after adipose tissue, the brain is the organ richest in lipids. DHA, also called cervonic acid, constitutes 20% of the fatty acids in the brain and 60% of those present in visual cells.

Omega-3 fatty acids also play an important role in hormonal regulation, especially in women with PCOS.

Several scientific studies have demonstrated the beneficial effects of omega-3s on various hormonal markers. A decrease in LH levels, often too high in cases of PCOS, has been observed, which can promote more regular ovulation. In parallel, an improvement in the FSH/LH ratio seems to contribute to better menstrual cycle regulation.

Omega-3s also intervene in the reduction of circulating testosterone, a key factor in alleviating certain PCOS symptoms such as acne, hair loss, or hirsutism. They also promote an increase in SHBG, a transport protein that limits the action of free sex hormones.

The regulating effects of omega-3s on hormonal balance can have a favorable impact on fertility. By supporting better regulation of key hormones involved in ovulation, these essential fatty acids contribute to more regular menstrual cycles. This can be particularly beneficial in cases of PCOS, the main cause of infertility in young women, where hormonal imbalances often disrupt ovarian function.

Furthermore, omega-3s contribute to the regulation of metabolic disorders frequently associated with this syndrome, the latter participating in maintaining hormonal imbalances in a vicious circle.

Omega-3s improve lipid metabolism by lowering LDL levels, "bad" cholesterol, while increasing HDL, considered "good" cholesterol. They also limit lipogenesis, i.e., the formation of new fats from sugars, and reduce cholesterol absorption in the intestine.

Furthermore, omega-3s promote an elevation in plasma adiponectin concentrations, a hormone secreted by adipose tissue, essential for the regulation of lipid and glucose metabolism. Adiponectin levels are often lowered in overweight, obese, diabetic, or PCOS individuals, which reinforces the interest of omega-3s in this context.

Finally, omega-3s play an essential role in improving insulin sensitivity. On average, 50 to 70% of women with PCOS have insulin resistance, causing disturbances in glucose metabolism and increasing the risk of type 2 diabetes.

Clinical studies show that omega-3 intake leads to a significant reduction in fasting insulin concentrations and an improvement in the HOMA-IR index, a recognized marker of insulin resistance. By promoting more efficient glucose utilization by the body, omega-3s help restore a favorable metabolic balance, thus limiting complications related to PCOS. This action results in a decrease in waist circumference and body mass index (BMI). This nutritional approach thus constitutes a valuable complement in the overall management of the syndrome, with benefits on glucose metabolism and cardiovascular health.

This article is for informational purposes only and does not replace a consultation or advice from your doctor.

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• Anses opinion on the update of PNNS dietary guidelines for pregnant or breastfeeding women, 2019
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• Nadjarzadeh A. et al. Effect of Omega-3 supplementation on Visfatin, adiponectin, and anthropometric indices in women with polycystic ovarian syndrome. J Reprod Infertil 16, 212–220, 2015
• Melo V et al. Omega-3 supplementation in the treatment of polycystic ovary syndrome (PCOS) - a review of clinical trials and cohort. Endocr Regul. 2022 Feb 18;56(1):66-79
• Saini RK et al. Omega-3 Polyunsaturated Fatty Acids (PUFAs): Emerging Plant and Microbial Sources, Oxidative Stability, Bioavailability, and Health Benefits-A Review. Antioxidants (Basel). 2021 Oct 15;10(10):1627
• “PCOS and insulin: dangerous liaisons” Thursday, September 14, 2023. Part 1 PCOS: is it insulin’s fault? Dr. Geoffroy Robin