Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder affecting women of reproductive age, characterized by reproductive, metabolic, and hormonal disorders. The worldwide prevalence of PCOS is 6-10% and tends to increase with economic development. It is a complex condition involving reproductive, metabolic, and psychological challenges, making diagnosis and management difficult.
PCOS is diagnosed when at least two of the following are present: hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. Despite significant research efforts, the exact cause of PCOS remains unclear, although genetics, environmental influences, and lifestyle factors are believed to play key roles. The condition accounts for 50-70% of cases of anovulatory infertility in women of childbearing age, impacting not only women's health but also having a generalized effect on many aspects of life.
Given its multifactorial nature, PCOS management requires a multidisciplinary approach. Lifestyle and dietary interventions are central to treatment, as they directly influence metabolic and endocrine pathways. Specific dietary patterns, such as low-glycemic index (GI), Mediterranean, and ketogenic diets, have shown promise in improving insulin sensitivity and hormonal balance in PCOS.
The Role of Diet in PCOS Management
According to the American Society for Reproductive Medicine (ASRM) 2018 Guidelines, the first-line treatment of PCOS is lifestyle adjustment, including diet control and exercise, with weight control being especially important for PCOS patients. Recently, dietary interventions have been reported to ameliorate clinical symptoms of PCOS, including menstrual disorders, abnormal hormonal indicators, and ovulation.
Dietary interventions significantly attenuated fasting blood glucose (FBG), fasting blood insulin (FBI), and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The dietary intervention significantly reduced body mass index (BMI), body weight (BW), and waist circumference (WC). Weight loss of as little as 5 to 10% can attenuate androgenemia, menstrual irregularities and infertility cardiometabolic risk in women with PCOS.
Read also: Paleo Granola Recipes
Understanding Low-Carbohydrate Diets (LCD)
A low-carbohydrate diet (LCD) refers to a dietary structure that helps to manage or prevent disease by limiting the consumption of carbohydrates and correspondingly increasing the intake of proteins and/or lipids. Low-carbohydrate diet has been demonstrated to effectively decrease body weight and facilitate the treatment of infertility in obese PCOS patients.
Meta-Analysis of LCD Effects on PCOS
To assess the effect of a low carbohydrate diet (LCD) on women with polycystic ovary syndrome (PCOS), data from randomized controlled trials (RCTs) were obtained to perform a meta-analysis of the effects of LCD in PCOS patients. The primary outcomes included the changes in BMI, homeostatic model assessment for insulin resistance (HOMA-IR), and blood lipids, including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), follicle-stimulating hormone (FSH), luteotropic hormone (LH), total testosterone (T), and sex hormone-binding globulin (SHBG).
Eight RCTs involving 327 patients were included. In comparison with the control group, the LCD decreased BMI, HOMA-IR, TC, and LDL-C. Stratified analyses indicated that LCD lasting longer than 4 weeks had a stronger effect on increasing FSH levels, increasing SHBG levels, and decreasing T levels, and the low-fat and low-CHO LCD (fat <35% and CHO <45%) had a more significant effect on the levels of FSH and SHBG than the high-fat and low-CHO LCD (fat >35% and CHO <45%).
Based on the current evidence, LCD, particularly long-term LCD and low-fat/low-CHO LCD, may be recommended for the reduction of BMI, treatment of PCOS with insulin resistance, prevention of high LDL-C, increasing the levels of FSH and SHBG, and decreasing the level of T level. Together, the analyzed data indicate that 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.
Search Strategy for Meta-Analysis
The search for relevant publications included the Cochrane Library, PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), China Biomedical Abstracts Database (SinoMed), China Academic Journals Network Publishing Library (CNKI), Wanfang Database, and unpublished grey literature. The search covered the time from the publication of the oldest articles in the respective library to December 2018. The search was performed according to the PICO format [6] and used the following components (see Table 1): participants (P), intervention (I), control (C), outcome (O), and study design (S). The MeSH terms such as “polycystic ovary syndrome” and “low carbohydrate diet” were employed. The search algorithm was constantly adjusted and improved by trial and error approach, taking into account the retrieval requirements specific for each database.
Read also: Paleo Diet Delivered: What You Need to Know
Exclusion Criteria for Meta-Analysis
Exclusion criteria were as follows: (1) combination of the LCD with other drugs, such as metformin; (2) data duplicated in conference papers and journal articles or in Chinese and English literature. The higher-quality source was selected in these instances; (3) in case of the came content being published in two articles, only one was selected; (4) the publication was an abstract, and a full-text version was not available after contacting the author; (5) the patients were clomiphene citrate-resistant, or infertility was due to causes other than PCOS; and (6) the study was a review.
Data Extraction and Analysis
Two of the authors (XZ and YZ) conducted the literature search. The differences encountered were resolved by consensus or discussion with the corresponding authors (YG and ZL). The extracted data comprised the name of the first author, year and country of publication, diagnostic criteria, population, sample size, age, study design, duration of the study, intake ratio of the three major nutrients, type of intervention, and endocrine and metabolic indicators, such as body mass index (BMI), HOMA-IR, TC, LDL-C, HDL-C, testosterone (T), sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
The Cochrane Collaboration Risk of Bias tool was used to assess the risk of bias of the included RCTs. The assessment was based on the information related to the following domains: random sequence generation, allocation concealment, blinding of participants and outcome assessment, incomplete outcome data, selective outcome reporting, and other bias. For each study, the risk of bias was assessed as low, unclear, and high. Any disagreements during the selection process were addressed by discussion until a consensus was reached.
The data presented in the selected papers were analyzed using the Review Manager (Version 5.3). Weighted mean difference (WMD) or standardized mean difference (SMD), 95% confidence interval (CI), and odds ratio (OR) or relative risk (RR) were used to define the magnitude and statistical significance of the effect. Before the meta-analysis was performed, the heterogeneity between the results of each included study was tested by chi-square test. In the absence of statistical heterogeneity (P > 0.1, I2 < 50%), the fixed effect model was used for analysis, while in its presence (P < 0.1, I2 > 50%), the random effects model was applied.
Findings from the Meta-Analysis
- BMI: Meta-analysis demonstrated that the difference in the BMI between the two groups was statistically significant.
- HOMA-IR: Meta-analysis indicated a statistically significant difference between patients on LCD and control diet.
- FSH: Meta-analysis indicated a statistically significant difference between patients on LCD (regardless of the diet type and duration) and control diet. The stratified analysis documented that LCD intervention longer than 4 weeks had increased the level of FSH more than intervention lasting 4 weeks or less
- LH: Meta-analysis showed that the difference between the PCOS patients subjected to LCD and control PCOS patients was not statistically significant. In stratified analyses, the effect of LCD intervention longer than 4 weeks on LH levels did not differ significantly from that of shorter LCD interventions
- SHBG: Meta-analysis showed a significant difference between PCOS patients treated with LCD intervention and control PCOS patients. In stratified analysis, LCD intervention longer than 4 weeks had a higher effect on SHBG levels than intervention lasting 4 weeks or less
- Testosterone: This meta-analysis did not detect significant difference between the LCD and control groups. In stratified analysis, LCD intervention longer than 4 weeks had a higher impact on T levels than intervention lasting 4 or less weeks
- Blood Lipids: Meta-analysis demonstrated that the difference between the experimental and control groups was statistically significant. By meta-analysis, the difference between the LCD-treated patients and the control group was not statistically significant
The Paleo Diet: An Alternative Approach
The contemporary Paleo diet consists mainly of fish, grass-fed pasture-raised meats, eggs, vegetables, fruit, seafood, nuts and seeds, and excludes grains, legumes, starchy vegetables, refined sugar, refined vegetable oils, and dairy products. Proponents claim that genetically our bodies are virtually the same as they were at the end of the Paleolithic era and we haven’t evolved to be able to digest grains and beans properly.
Read also: Paleo Mayonnaise Recipe
The primary treatment of PCOS is to manage insulin resistance, either through medication or diet and lifestyle changes or both. Some health practitioners recommend a low carb diet for PCOS, and the Paleo diet can be low carb. While low carb diets may help initially with the symptoms of PCOS, they can lead to long-term problems.
The Paleo diet emphasizes real, whole foods and as a way to cut back on all the processed, packaged food that surrounds us. If you’re going to try Paleo for PCOS, general weight loss or lifestyle changes, make sure to include plenty of healthy carbohydrates like starchy root vegetables and fruit. Also, don’t overdo the nuts and meat.
Potential Benefits of Paleo for PCOS
- Reduced Inflammation: The Paleo diet emphasizes the consumption of anti-inflammatory foods such as fruits, vegetables, and omega-3 fatty acids, while limiting inflammatory foods like processed foods, refined sugars, and unhealthy fats.
- Improved Insulin Sensitivity: By eliminating refined carbohydrates and focusing on whole, unprocessed foods, the Paleo diet may help improve insulin sensitivity, a key factor in managing PCOS.
- Weight Management: The Paleo diet's emphasis on lean proteins, healthy fats, and non-starchy vegetables may promote weight loss and improve body composition, which can be beneficial for women with PCOS.
Considerations for a Paleo Diet
- Carbohydrate Intake: It is important to include plenty of healthy carbohydrates like starchy root vegetables and fruit.
- Nutrient Balance: Ensure a balanced intake of nutrients by including a variety of foods from the approved Paleo list.
- Professional Guidance: Consult with a healthcare professional or registered dietitian before making significant dietary changes, especially if you have PCOS or other underlying health conditions.
Macronutrient and Micronutrient Balance
Macronutrient composition is another essential element. High-protein and low-carbohydrate diets improve satiety, preserve muscle mass, and reduce insulin resistance and hyperandrogenism. Research suggests that reduced carbohydrate intake, specifically complex carbohydrates, is more effective for blood sugar levels and metabolic outcomes in women with PCOS. Dietary fat quality also has a significant influence, with unsaturated fats, particularly omega-3 fatty acids, exhibiting anti-inflammatory and insulin-sensitizing effects. Conversely, an overabundance of saturated fat has been associated with amplified androgen levels and metabolic disorders in PCOS.
Micronutrient deficiencies prevail in cases of Polycystic Ovary Syndrome among women and might be the cause of the progression of the disease. Essential nutrients, including vitamin D, niacin, and magnesium, are some examples of such nutrients that have been investigated for their affirmative healing effects. Vitamin D deficiency is more common in women with PCOS and is related to insulin resistance, ovulatory dysfunction, and infertility. Supplementation with vitamin D has been shown to improve insulin sensitivity, menstrual regularity, and fertility outcomes. Myo-inositol and D-chiro-inositol supplementation were shown to have a beneficial effect by helping women with PCOS to become ovulatory, also to balance hormones, and restore metabolic health in PCOS (polycystic ovary syndrome) patients. Regarding improved insulin sensitivity and inflammation reduction, magnesium, an essential micronutrient, has been shown to be an important part of nutritional therapy in PCOS.
Herbal Medicine as a Supplementary Approach
Beyond conventional dietary interventions, herbal medicine has assumed the role of a promising supplementary approach for PCOS. Some different types of herbs, such as cinnamon, curcumin, sage, and fennel, have been the subject of extensive research regarding their potential to improve metabolic health and fertility.
Being a widely used spice, cinnamon has been found that it can lower sugar levels by improving the efficiency of insulin and glucose intake. The meta-analysis of clinical trials has determined that the cinnamon supplements blood glucose, whether fasting insulin and other insulin resistance markers in women with PCOS, showed improvement. Due to the anti-inflammatory and antioxidant characteristics of the active part of turmeric, called curcumin, they may be helpful in the improvement of PCOS. Clinical research has shown that taking the curcumin supplement can improve insulin sensitivity and also lower the androgen levels of women with PCOS. Sage, which has been traditionally used in Iranian medicine, was found to restore insulin sensitivity and reduce BMI in PCOS patients. Moreover, fennel is a phytoestrogen and has been studied to recognize its potential to regulate menstrual cycles and improve metabolic health in women with PCOS.
Preferences for Diet and Lifestyle Programs
Diet and lifestyle programs improve health, but women’s preferences for these programs have not been formally explored. A study examined diet and lifestyle program preferences among women with PCOS. At least half of the respondents expressed strong interest in programs addressing energy level, anxiety, depression, weight, diabetes prevention, menstrual period regulation, and hirsutism. Similarly, at least half reported willingness to modify their sleep, stress, and physical activity; and slightly less than half reported willingness to adopt a very low-carbohydrate, paleo, or low-glycemic index diet. Younger age was associated with interest in help with acne and fertility; higher body mass index was associated with wanting help with weight loss, energy, and anxiety; and greater stress eating was associated with wanting help with depression, anxiety, and menstrual period regulation.
Results suggest that the majority of women prefer programs targeting numerous outcomes, including increasing energy, reducing anxiety and depression, losing weight, lowering diabetes risk, regulating menstruation, and reducing hirsutism. A clear majority were interested in a topical coverage of sleep, stress reduction, and physical activity. There were lower rates of interest in various diets. For example, the younger the women were, the more interested they were in typical concerns of younger women, including reducing acne and increasing fertility. Further, the higher a woman’s BMI, the more she preferred a program to help with weight loss, improved energy, and reduced anxiety.