SOS Endometriosis: between forbidden foods and proper nutrition

Initial note: This article was previously published and updated according to scientific and informative criteria. It is for informational purposes only and does not replace medical advice: for diagnoses or therapies, consult your doctor.

IN BRIEF

• Endometriosis is an inflammatory and hormone-dependent disease that can affect pain, fertility, and quality of life.
• Evidence suggests that types of fats and dietary patterns rich in plant-based foods and omega-3 may be associated with lower risk or milder symptoms; data remain predominantly observational.
• Reducing ultra-processed foods and trans-fats and prioritizing oily fish, fruits, vegetables, and extra virgin olive oil is biologically plausible, but no "curative" diets validated in large RCTs exist for endometriosis.
• Some antioxidant supplements (e.g., combinations of vitamins C+E) and anti-inflammatory interventions show promising results on pain in clinical studies, but more solid data are needed for generalized recommendations.
• Every dietary choice should be personalized and evaluated with a doctor or specialized nutritionist.

Abstract: what does science say?

Endometriosis is a chronic condition characterized by the presence of endometrial tissue outside the uterus, with a strong inflammatory component and estrogen sensitivity. Large-scale observational studies have identified associations between high consumption of red meat, trans-fats, and the risk of endometriosis diagnosis, while a higher intake of omega-3 fatty acids and fruits and vegetables has been correlated with reduced risk or less severe symptoms. Small trials and meta-analyses suggest that antioxidant and omega-3 supplementation can reduce menstrual or pelvic pain in some individuals, but there is no definitive evidence of an effect on disease progression or fertility. The overall evidence is heterogeneous: most comes from observational studies, reviews, and a few RCTs, so practical recommendations must remain cautious and individualized.

What is endometriosis and why can diet play a role?

Endometriosis is a gynecological disease characterized by the presence of endometrium-like tissue outside the uterine cavity; it causes local and systemic inflammation, chronic pain, and can affect fertility. Immune alterations, oxidative stress, and estrogen modulation are relevant biological mechanisms. Since diet and metabolism influence inflammation, sex hormone metabolism, and gut microbiota composition, the biological hypothesis is that dietary components can modify the risk of onset or the intensity of symptoms: for example, some dietary fats modulate the production of eicosanoids (prostaglandins) and cytokines, while fiber and plant compounds can alter estrogen reabsorption. However, the exact relationship between individual foods, dietary patterns, and biological phenomena remains complex and mediated by dose, form of consumption (e.g., fresh fish vs. farmed salmon), metabolic context (e.g., BMI), and individual variability [1][2][3].

What observational studies and reviews show

Numerous observational studies (case-control and cohorts) have explored associations between diet and endometriosis risk. In the largest prospective American cohort, high consumption of red meat was associated with an increased risk of laparoscopic diagnosis; similarly, combined studies have shown a lower probability with higher intake of omega-3 fatty acids and a higher risk with high levels of trans-fats [1][2][3]. More recent systematic reviews and umbrella reviews synthesize consistent results in reporting benefits associated with a dietary pattern rich in vegetables, fiber, and omega-3 rich fish, and potential risks linked to high consumption of red meat and ultra-processed foods [4][6][10]. These relationships are primarily associations: they do not prove causality and can be influenced by confounders (lifestyle, access to care, contraceptive use, body composition).

Role of microbiota and inflammatory pathways

Emerging research suggests that alterations in the gut and genital microbiota may contribute to the inflammatory microenvironment that promotes the persistence of endometriotic lesions. Systematic studies show evidence of dysbiosis in patients with endometriosis, but the picture remains evolving and cause-effect relationships are not yet clear. The microbiota can influence estrogen homeostasis and immune response, offering a plausible biological link between diet, microbiota, and disease [5][12].

Foods and dietary patterns: what is worth considering

Evidence suggests that there is no single "miracle food" or curative diet, but some elements recur in scientific works as potentially useful or harmful. Dietary patterns rich in fruits, vegetables, whole grains, legumes, extra virgin olive oil, and oily fish — i.e., patterns similar to the Mediterranean diet — are associated with lower systemic inflammation and, in limited observations and interventional studies, with improved pain and quality of life [6][9].

Foods to prioritize (biological plausibility)

Foods rich in omega-3 (sardines, mackerel, anchovies), sources of antioxidants (fruits, vegetables, nuts), and monounsaturated fats (extra virgin olive oil, avocado) have plausible mechanisms to reduce inflammation and modulate the production of pro-inflammatory eicosanoids. For example, high omega-3 intake has been associated with a lower risk of diagnosis in observational studies, and several meta-analyses on dysmenorrhea show pain reduction with n-3 supplementation [1][7].

Foods to limit (and why)

Processed and unprocessed red meats, trans-fats, and ultra-processed foods have been associated with a higher risk in several observational studies; biological plausibility includes increased oxidative stress, pro-inflammatory lipid intake, and, sometimes, exposure to environmental contaminants present in some animal products. High consumption of simple sugars and sugary drinks can also support a pro-inflammatory metabolic state [2][3].

Role of supplements: what trials say

Small clinical studies and meta-analyses have evaluated the effect of anti-inflammatory and antioxidant supplements (omega-3, vitamins C and E, N-acetylcysteine, and others) on endometriosis-related pain. Meta-analyses and systematic reviews report that combinations of antioxidant vitamins can reduce pain intensity in some clinical contexts, and that omega-3 supplementation can improve dysmenorrhea in general. However, trials are often small, with different formulations and outcomes, so the evidence is not yet definitive and not always generalizable [7][8][11].

Note on N-acetylcysteine and other nutraceuticals

Cohort studies and some non-randomized evidence suggest that N-acetylcysteine (NAC) and other antioxidant compounds may reduce endometrioma size or improve symptoms in some patients; however, large, replicated, long-term RCTs confirming efficacy and safety on a larger scale are lacking. Therefore, supplements should not be proposed as an alternative to medical or surgical therapy but can be considered as support under medical supervision [11][15].

Fertility and quality of life: practical evidence

Endometriosis can be associated with conception difficulties and impact daily life due to chronic pain. Studies that have explored whether diet modifies fertility in women with endometriosis are limited and results are inconclusive; some reviews observe indirect improvements in quality of life with dietary interventions and with reduction of painful symptoms, but the direct effect on spontaneous pregnancy or reproductive outcomes remains poorly documented [6][9]. It is therefore prudent to consider nutrition as part of a multidisciplinary approach to improve general well-being, not as an exclusive treatment for fertility.

What it means in practice

For people with endometriosis, evidence supports a dietary approach aimed at reducing systemic inflammation and improving overall nutritional status: increasing consumption of fruits, vegetables, whole grains, legumes, nuts, and oily fish; prioritizing extra virgin olive oil as the main fat source; limiting red meats and ultra-processed products and reducing simple sugars and trans-fats. These indications, consistent with public health recommendations, also have potential benefits beyond endometriosis (heart, metabolism). Supplements with positive data (e.g., combinations of antioxidant vitamins or omega-3) can be evaluated on a case-by-case basis with the doctor, taking into account dose, interactions, and clinical status [6][7][8].

KEY POINTS TO REMEMBER

• Evidence suggests associations between types of dietary fats and risk/symptoms: favorable omega-3, unfavorable trans-fats [1][4].
• Dietary patterns rich in vegetables and fish (Mediterranean style) show plausible benefit on inflammation and pain [6].
• Clinical studies on antioxidant and omega-3 supplements show promising results for pain, but larger and standardized RCTs are needed [7][8].
• There is no evidence that a specific diet "cures" endometriosis; nutritional intervention is a complement to the multidisciplinary medical pathway.

Limitations of the evidence

The literature is predominantly composed of observational studies, reviews, and meta-analyses that synthesize heterogeneous studies; this entails interpretation limitations. Observational studies can identify associations but not prove causality: confounders (e.g., BMI, physical activity, medication use) and selection bias can alter results. The few available RCTs often have small sizes, short durations, and variable endpoints. Furthermore, the effect of a food depends on dose, frequency, form of consumption, and individual context (e.g., reproductive age, ongoing therapy). Therefore, caution is needed in interpretation and the need for randomized studies, with standardized biological measures and adequate follow-up [4][6][16].

Editorial conclusion

The nutritional approach to endometriosis is a rapidly evolving field: the biological plausibility that anti-inflammatory and antioxidant foods can alleviate symptoms is supported by observational studies and some trials. However, clinical recommendations must remain cautious and individualized. For people with endometriosis, it is sensible to adopt a balanced dietary pattern, aimed at reducing systemic inflammation and maintaining an adequate body weight, integrating any supplements only under medical supervision. Nutrition can improve symptoms and quality of life, but it does not replace established medical or surgical therapies when necessary.

Editorial note

This update was prepared with criteria of transparency and scientific dissemination, citing systematic reviews, cohort studies, and trials when available. The information provided is for informational purposes and does not constitute personalized therapeutic guidance.

SCIENTIFIC RESEARCH

1. Missmer SA, et al. A prospective study of dietary fat consumption and endometriosis risk. Hum Reprod. 2010;25(6):1528–1535. https://doi.org/10.1093/humrep/deq044
2. Harris HR, et al. A prospective cohort study of meat and fish consumption and endometriosis risk. Am J Obstet Gynecol. 2018;219(2):178.e1–178.e10. https://doi.org/10.1016/j.ajog.2018.05.034
3. Parazzini F, et al. Selected food intake and risk of endometriosis. Hum Reprod. 2004;19(8):1755–1759. https://doi.org/10.1093/humrep/deh395
4. Hansen SØ, Knudsen UB. Endometriosis, dysmenorrhoea and diet—what is the evidence? Eur J Obstet Gynecol Reprod Biol. 2013;169:162–171. https://doi.org/10.1016/j.ejogrb.2013.03.028
5. Leonardi M, et al. Endometriosis and the microbiome: a systematic review. BJOG. 2020;127:239–249. https://doi.org/10.1111/1471-0528.15916
6. Nirgianakis K, et al. Effectiveness of dietary interventions in the treatment of endometriosis: a systematic review. Reprod Sci. 2021;29:26–42. https://doi.org/10.1007/s43032-020-00418-w
7. Systematic review/meta-analysis: The impact of omega-3 on primary dysmenorrhea. Eur J Clin Pharmacol. 2021; DOI: https://doi.org/10.1007/s00228-021-03263-1
8. Zheng Y, et al. Antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans: a systematic review and meta-analysis. Reprod Biol Endocrinol. 2023;21:79. https://doi.org/10.1186/s12958-023-01126-1
9. Porpora MG, et al. Observational studies on N-acetylcysteine and endometriosis (cohort data and case series) [see review evidence]. (See reviews included in the literature cited above.)
10. Umbrella review: Diet and Endometriosis: An Umbrella Review. Foods. [2025]. https://doi.org/10.3390/foods14122087

Note: some cited reviews and meta-analyses synthesize multiple original studies; for further details, please refer to the DOIs indicated above. Where complete data are missing, references to the most recent reviews summarizing the available literature have been included.