Impact of dietary patterns on pain and quality of life in ovarian and deep endometriosis: observational study for nutritional interventions

Abstract

Background

Endometriosis impairs multiple dimensions of women’s lives. Ovarian endometrioma and deep endometriosis present distinct clinical profiles. The dietary pattern has shown controversial data both for pain control and in the effect on women’s vitality and physical health. This study aimed to evaluate the relationship between dietary patterns and quality-of-life outcomes and pain perception in women with endometrioma and deep endometriosis.

Methods

This cross-sectional observational study included 40 Spanish-women grouped as controls, with endometrioma, or deep endometriosis. Dietary intake was assessed using a food frequency questionnaire, and was estimated macronutrient and food group intake, as well as adherence to DASH-diet, Mediterranean adherence, and healthy eating index. They were measured bodily pain, vitality, general health, and quality of life dimensions specific to endometriosis.

Results

Dietary supplement use was higher in women with deep endometriosis (70%) compared to controls (13.3%, P = 0.015). Women with endometrioma consumed more dietary fat, monounsaturated fatty acids, and cholesterol than controls and, their adherence to the Mediterranean diet (control = 29.1 ± 5.0; endometrioma = 24.1 ± 7.2) and healthy eating index (control = 57.3 ± 3.9; endometrioma = 49.6 ± 8.0) were significantly lower. Dairy intake was lower in endometriosis groups compared to controls, while meat, snack, and fat consumption was higher in the endometrioma group. Furthermore, fat intake negatively impacted physical and reproductive health in endometriosis, while adherence to healthy dietary patterns was associated with improved life-outcomes.

Conclusions

Dietary patterns impact the health of women with ovarian and deep endometriosis, especially regarding pain and quality of life. Women with endometrioma have poor dietary habits, which affect sexual function and vitality. Targeted dietary interventions, particularly focusing on healthy fats, may improve pain symptoms and overall well-being.

Graphical abstract

Schematic representation of the relationship between dietary patterns and quality-of-life outcomes in women with endometriosis. Women with endometrioma showed higher consumption of fats and meats and lower adherence to healthy eating patterns compared with controls and those with deep endometriosis. Increased fat intake was negatively associated with body pain control and menstrual and sexual function, while adherence to a healthy dietary pattern was positively associated with vitality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-025-04148-6.

Background

Endometriosis is a challenging and often misunderstood condition that affects not only women´s reproductive system but also impacts all spheres of their life. It occurs when uterine related tissue lining grows outside the uterus, forming painful lesions. For those living with endometriosis, chronic pain can be a constant companion, often accompanied by symptoms like fertility struggles, fatigue and digestive problems. Ovarian endometrioma can be found in 50% of women treated for infertility [1]. In this condition, the quality of life may be affected, however the reproductive sphere can be preserved under close clinical monitoring [2]. The rate of deep endometriosis among all patients affected by endometriosis is estimated at 20%, resulting in an overall prevalence of 2 to 10% of women of reproductive age [3]. This is the most debilitating endometriosis condition [4]. Most treatments for endometriosis involve surgery or medications to suppress ovarian steroid hormones, but these options do not work for everyone [5]. For this reason, many people turn to lifestyle changes, including diet, to alleviate symptoms and improve their quality of life. Unfortunately, the data is lacking to confirm which lifestyle strategy is the most effective [6].

The largest survey ever conducted on diet and endometriosis found 45% who stopped eating gluten and 45% who cut out dairy reported an improvement in pain. Additionally, when women cut down on caffeine, 43% report reduction in their pain, while 53% of women who cut back on alcohol reported the same [7]. Women adhering to a healthy diet (refers to high intake of fruits, vegetables, whole grains, legumes, nuts, and healthy fats, and limited consumption of processed foods, added sugars, and saturated fats) reported less pain and better quality of life. In women with endometriosis over 6-months of follow-up, participants on healthy diet reported less bloating, and better emotional well-being, social support, and sexual functions [8]. Similarly, a Mediterranean diet intervention enhanced health-related quality of life [9], but particularly pain context was not explored. However, individual and contextual differences remain a challenge. For example, it has been found that women who had high weekly consume of red meat have a 56% to develop endometriosis [10]. In contrast, studies in Iranian women did not demonstrate such an association [11]. It could be due to the type of meat consumed and its processing [12]. Dairy products have also been debated in relation to endometriosis. While reducing its consumption could prevent endometriosis, a stratified analysis by nutritional category only showed that high butter consumption increases the endometriosis risk [13]. Nonetheless, the relationship between diet and pain or other areas such as reproductive function or vitality remains to be explored. Furthermore, fatty acids seem to influence the risk for endometriosis [14], where high intake of omega-3 polyunsaturated fatty acids decreases its risk, but high intake of trans-unsaturated fat seems to favor by inflammatory processes, being associated with menstrual pain [15]. Because inflammation plays a key role in endometriosis, monitoring of quantitative and qualitative fat intake might be recommended for disease treatment.

Most of the studies have explored the dietary pattern in women with endometriosis, without specifying the type of endometriosis may have on the patient’s quality of life and pain. Therefore, the aim of this study was to explore the effect of nutritional patterns have on pain perception, vitality, physical component, and reproductive function in women with ovarian and deep endometriosis. This analysis sought to distinguish between women with ovarian endometrioma and deep endometriosis due to the distinctive characteristics of the condition.

Methods

Study design and setting of the study

In this observational and cross-sectional study was recruited women in the specialized follow-up endometriosis unit of gynecology service from Hospital Universitario La Paz (HULP, Madrid, Spain). The inclusion criterion were women without menopause between 25 and 55 years, with non-diagnosed of cancer, emotional disorders, hypertension, or obesity. In addition, the exclusion criterion was drug abuse. Endometriosis was initially suspected during routine gynecological examinations and women with symptoms consistent with the condition were referred to a specialized endometriosis appointment. At the hospital, the diagnosis was confirmed through gynecological examination and transvaginal ultrasound. The women with advanced endometriosis were clustered in two groups according to their diagnoses: endometrioma and deep endometriosis. Deep endometriosis was defined as endometrial-like tissue infiltration extending >5 mm beneath the peritoneal surface, involving structures such as uterosacral ligaments, rectovaginal septum, bowel, bladder or ureters [16]. All women in endometrioma group had ovarian cyst, between 1 and 2 cysts of roughly more than 40 mm, being bilateral in the 63.6%. All cases were treated with progestogens and 54.5% were also surgically treated. Women with deep endometriosis had ovarian or bowel resection surgery. Woman had 1 to 8 years of endometriosis progression, being women with deep endometriosis who had been diagnosed the longest.

Women in the control group were recruited during routine gynecological follow-up visits. None had a diagnosis of advanced endometriosis, as confirmed by gynecological examination, nor had they undergone previous surgery. Additionally, none presented symptoms suggestive of endometriosis, such as dysmenorrhea, dyspareunia, or infertility.

The recruitment period lasted from March 2023 to October 2024. Finally, a total of 40 women signed the informed consent form and were included in the study (control = 16; endometrioma = 12; deep endometriosis = 12). As this was an exploratory study, no sample size calculation techniques were used.

The women were answered sociodemographic questions including, age, nationality, educational level, monthly income, smoking habits, special diet use (e.g., gluten-free or vegetarian) and use of dietary supplements information. In addition, the food frequency questionnaire and health dimensions were collected. The women were scheduled to take an 8 ml blood sample by venipuncture. This sample was used to determine hematological (erythrocytes, hematocrit, platelets and leukocytes) and biochemical (hemoglobin, glucose, bilirubin, creatinine, albumin, lipid, coagulation and hepatic profiles) parameters for clinical medicine laboratory of HULP and to test their systemically health at the time of the study. Furthermore, from medical records was extracted the weight of the women.

This design has the approval of the Research Ethical Committee of HULP (PI-5435; approved on 02 December 2022) and follows the Strengthening of the Reporting of Observational Studies in Nutritional Epidemiology extension (STROBE-Nut guidelines; [17]). Informed consent to participate was obtained from all women in the study.

Nutritional and dietary pattern

Dietary intake was one-time assessed using the Spanish version of the Food Frequency Questionnaire (FFQ; [18–20]), a validated tool designed to estimate habitual food consumption over a specific period [21, 22]. FFQ is easy to administer, making it ideal for assessing long-term dietary intake [23]. FFQ estimate food groups and nutrient intakes and classify women by dietary patterns. FFQ is the most widely used tool in epidemiological nutrition for studying relationships between dietary intake and health outcomes [24]. FFQ included 137 food items with specified portion sizes and offer 9 frequency response options (never or less than once, 1–3 times a month, 1 time per week, 2–4 times per week, 5–6 times per week, 1 time per day, 2–3 times per day, 4–5 times per day, and more than 6 times a day). To standardize portion sizes of the different food items referred to in the questionnaire, participants were shown the ENALIA photographic atlas (developed by the Spanish Agency for Food Safety and Nutrition; https://www.aesan.gob.es/). A nutritionist assisted with questionnaire completion as well as in the use of the ENALIA photographic atlas.

The data collected was processed and analyzed using the FETA (Food Frequency Questionnaire European Transformation Algorithm) [25]. FETA is an open source, cross-platform tool that processes dietary data from the FFQ used by the European Prospective Investigation into Cancer and Nutrition Norfolk (EPIC-Norfolk) and automatically generates a spreadsheet containing energy, nutrient and food group intakes (https://www.mrc-epid.cam.ac.uk/ffq-epic-tool-for-analysis-feta/), standardizing the dietary intake estimations by accounting for portion sizes, nutrient composition, and frequency of consumption. The EPIC FFQ has been validated for use in Spanish adults [26, 27]. For the proposal of this study was extracted total energy (kcal), water intake (l/day); carbohydrates (g/day and %kcal), proteins (g/day and %kcal), fats (g/day and %kcal); fiber non-starch polysaccharides (NSP, g/day); starch (g/day); saturated fatty acids (SFAs, g/day); monounsaturated fatty acids (MUFAs, g/day); polyunsaturated fatty acids (PUFAs, g/day); cholesterol (mg/day); total sugar (g/day); and alcohol (g/day). In addition, the ratio MUFA: PUFA and SFA: PUFA were calculated. In addition, FETA allows to estimate the nutritional group of consumption in g/day of vegetables, fruits, cereals, grains and legumes, nuts and seeds, potatoes, eggs and derivatives, fish and derivatives, dairy products, soups and broths, meats and derivatives, fats and oils, and snacks.

The Dietary Approaches to Stop Hypertension (DASH; [28]) index was calculated based on the consumption of key food groups associated with the DASH diet, including scores for intakes of fruits, vegetables, grains, dairy, nuts, legumes, sodium, red and processed meats, and sugar-sweetened beverages. Each component was scored on a standardized scale, ranging between 8 and 40 with higher scores indicating greater adherence to the DASH dietary pattern.

The adherence to the Mediterranean Diet (MEDI Index; [29]) was assessed using a scoring system based on the consumption of traditional Mediterranean food groups, including fruits, vegetables, grains, legumes, nuts, fish, and olive oil, the score is reduced with the consumption of red and processed meats and alcohol intake. Total scores ranged from 0 to 55, with higher values indicating greater adherence to the Mediterranean dietary pattern.

The Healthy Eating Index (HEI-2020) was used to evaluate diet quality based on adherence to the Dietary Guidelines for Americans 2020 [30], but also HEI was used in Spanish population [31]. This index is adjusted by energy and includes dietary components such as total fruit and vegetables, grains and refined grains, dairy, protein, seafood, SFAs, fatty acid ratios, sodium, and added sugars. HEI total score range of 0 to 100, where higher scores reflect better diet quality.

Health dimensions

Short Form-36 health survey (SF-36)

This is an instrument to assess overall quality of life grouped into 8 factors [32]. SF-36 was previously used in women with endometriosis [33]. For the proposal of this study was one-time evaluated: bodily pain assesses its interference with daily activities; general health; and vitality, balance between energy and fatigue. SF-36 also allows calculation of the physical component. Scores for each dimension are transformed into a scale from 0 to 100, where higher values indicate better health.

Pain Catastrophizing Scale (PCS)

This instrument assesses the catastrophe pain [34] that can influence in coping with chronic pain. PCS was associated with endometriosis, showing higher levels of disability [35]. The scale consists of 13 items rated on a Likert scale from 0 to 4, with a total score ranging from 0 to 52. Higher scores indicate greater pain.

Stellenbosch Endometriosis Quality of Life (SEQOL)

SEQOL assess the quality of life in women with endometriosis [36]. The version comprises 35 items ranging on a Likert scale from 1 to 5, where higher values indicate greater life functionality. For the propose of this study was one-time evaluated sexual and relationship function, reproductive function, and menstrual characteristics. SEQOL has demonstrated reliability of 0.92 [37].

Statistical analysis

The analysis was performed by R software version 4.4.1 (R Core Team 2022, Vienna, Austria; https://www.R-project.org/) with the RStudio interface (version 2023.06.0 + 421 for Windows; Boston, MA, USA). The packages used were rio, dplyr, compareGroups, tidyverse, ggplot2, ggpubr, patchwork, corrplot, dietaryindex [38], effectsize and pwr.

The distribution of the variables was checked using the Kolmogorov-Smirnov test. The data was summarized by sample size (n) and relative frequency in categorical variables and mean and standard deviation in quantitative variables. The table of proportion was assessed by Fisher´s exact test and one-way analysis of variance (ANOVA) in quantitative variables. The post-hoc test was Tukey´s Honestly significant differences (HSD). The correlations between nutritional patterns and health dimensions were tested by Spearman’s Rho coefficient. Additionally, considering control group as the reference, linear regression model was constructed separately by each nutritional variable on each health dimensions, adjusted for age, weight and dietary supplementation. The standardized beta coefficient of the factor and the standard error were extracted from the models. No missing data imputation techniques were used in this study. The P-value (P) < 0.05 was considered statistically significant in all analyses. In addition, statistical power (1–β) and effect size were calculated for the significant comparisons. Effect size was reported as Cohen’s d index (absolute value) and interpreted according to conventional benchmarks (medium ≥ 0.5 or large ≥ 0.8).

Results

Social context and blood parameters

The women age was 36.6 ± 7.69 years old, being Spanish 91.4% and with university degrees 85.7% of them; 62.9% were in couples and 97.2% were active working, the 50.0% with a monthly income level similar to the Spanish average (https://www.ine.es). Women with deep endometriosis had undergone bowel resection (41.7%, n = 5) and shaving techniques (41.7%, n = 5). The remaining cases were not operated. In the case of women with endometrioma, there were cases without surgery (50%, n = 6) and underwent ovarian cystectomy surgery (50%, n = 6). Although without significant differences, women with deep endometriosis were older than controls (Table 1). In the entire cohort, the smoking habit was 25.0% and 22.2% were on a diet. The most common dietary responses in the control group were lactose- and gluten-free and veganism; in endometrioma group were anti-inflammatory diets; and in deep endometriosis group were low-fat, free of processed foods, gluten and sugar-free, free of fried foods, and dairy products. No differences between groups were detected in these variables. The use of diet supplementation was significantly higher in deep endometriosis group than control group but did not show differences with endometrioma group (Table 1). Mainly, these supplements were multivitamins, magnesium, and calcium. Dailly it was taken 1.1 ± 0.4 pill as dietary supplement.

Table 1.

Contextual and hematological variables in women with endometrioma and deep endometriosis

	Control (n = 15)	Endometrioma (n = 11)	Deep endometriosis (n = 11)	P
Age (years)	34.2 ± 6.92	36.9 ± 7.53	39.7 ± 8.49	0.216
Weight (kg)	57.2 ± 4.47	68.7 ± 12.6	71.5 ± 17.3	0.057
Smoker	13.3% (2)	45.5% (5)	20.0% (2)	0.180
Following a diet	13.3% (2)	18.2% (2)	40.0% (4)	0.270
Diet supplementation	13.3% (2)a	27.3% (2)ab	70.0% (7)b	0.015
Erythrocytes (×106/µl)	4.58 ± 0.45	4.71 ± 0.27	4.74 ± 0.38	0.512
Hemoglobin (g/dl)	13.8 ± 1.30	14.2 ± 0.74	14.2 ± 0.91	0.471
Hematocrit (%)	42.7 ± 3.54	44.0 ± 2.03	43.9 ± 2.78	0.465
Platelets (×103/µl)	238 ± 42.5	253 ± 47.2	261 ± 57.2	0.475
Leukocytes (×103/µl)	6.01 ± 1.39a	7.55 ± 2.85ab	7.96 ± 1.77b	0.047

Data shows mean ± standard deviation in the quantitative variables and relative frequency and sample size (n) in the categorical variables. The P-value (P) was extracted from one-way ANOVA test in the quantitative variables and Fisher´s exact test in the categorical variables. The groups with different letters indicate P < 0.05 by Tukey HSD test.

Hematological parameters did not show significant differences between groups, except for leukocyte levels, which were significantly higher in women with deep endometriosis than controls, with no differences with women with endometrioma (Table 1), suggesting inflammatory-related disease. In addition, women with endometrioma had a lower AST: ALT ratio than women with deep endometriosis, with no differences compared to control. The remaining blood biochemical parameters showed no significant differences between groups (Supplementary material table S1).

Nutritional and dietary pattern in women with ovarian and deep endometriosis

Carbohydrate and protein intake did not differ significantly between women (Fig. 1A-B). However, fat intake was significantly higher in the endometrioma group than control group (P = 0.032; 1-β = 0.58; d=|0.87|), with no differences compared to the women with deep endometriosis (Fig. 1C). Control did not show significant differences compared to deep endometriosis.

Fig. 1.

Macronutrients and energy proportions intakes in women with endometrioma and deep endometriosis. Data shows mean ± standard deviation. The P-value (P) was extracted from Tukey HSD post-hoc test. The dashed lines indicate the healthy proportion of energy intake allocated by each macronutrient

Although there were no significant differences between groups, the proportion of energy from carbohydrates was slightly lower in women with endometriosis than controls (Fig. 1D). The proportion of protein was similar in all groups (Fig. 1E). However, the proportion of energy from fat was significantly higher in women with endometrioma compared to controls (P = 0.004; 1-β = 0.79; d=|1.11|), with no differences compared to women with deep endometriosis (Fig. 1F). In this case, deep endometriosis had a higher trend proportion of energy from fat than control.

MUFA (P = 0.041; 1-β = 0.62; d=|0.92|) and cholesterol (P = 0.029; 1-β = 0.68; d=|0.98|) intakes were significantly higher in women with endometrioma than control (Table 2). SFA intake was nearly significantly higher in women with endometrioma compared with control and women with deep endometriosis. Furthermore, alcohol consumption was nearly significantly higher in control women compared with women with endometrioma. The remaining dietary components did not show significant differences between groups.

Table 2.

Micronutrient intakes and dietary groups in women with endometrioma and deep endometriosis

	Control (n = 15)	Endometrioma (n = 12)	Deep endometriosis (n = 11)	Control vs. endometrioma (P)	Endometrioma vs. Deep endometriosis (P)	Control vs. Deep endometriosis (P)
Micronutrients
Water intake (ml/day)	450 ± 253	600 ± 505	492 ± 311	0.548	0.775	0.956
Energy (kcal/day)	1422 ± 423	1807 ± 661	1413 ± 599	0.189	0.236	0.999
Fiber NSP (g/day)	13.7 ± 9.19	13.7 ± 6.15	15.1 ± 9.41	0.999	0.916	0.912
Starch (g/day)	65.2 ± 22.9	84.5 ± 54.6	79.9 ± 41.6	0.443	0.963	0.648
SFAs (g/day)	18.3 ± 5.37	25.5 ± 10.5	17.6 ± 9.34	0.086	0.088	0.977
MUFAs (g/day)	22.3 ± 11.0	34.8 ± 15.8	26.0 ± 10.8	0.041	0.251	0.762
PUFAs (g/day)	10.0 ± 5.59	13.1 ± 6.20	10.1 ± 3.98	0.310	0.403	0.999
MUFA: PUFA (a.u.)	2.36 ± 0.51	2.79 ± 0.62	2.59 ± 0.35	0.095	0.652	0.514
SFA: PUFA (a.u.)	2.06 ± 0.69	2.27 ± 1.34	1.78 ± 0.57	0.828	0.439	0.740
Cholesterol (mg/day)	209 ± 67.9	300 ± 112	229 ± 78.7	0.029	0.153	0.846
Total sugar (g/day)	90.1 ± 37.5	97.5 ± 29.8	70.7 ± 42.1	0.859	0.215	0.406
Alcohol (g/day)	4.05 ± 3.76	2.11 ± 3.39	2.33 ± 2.48	0.098	0.988	0.425
Nutritional groups
Vegetables (g)	234 ± 201	208 ± 132	245 ± 189	0.926	0.878	0.987
Fruits (g)	318 ± 356	202 ± 143	366 ± 415	0.628	0.470	0.930
Cereals, grains & legumes (g)	136 ± 68.8	170 ± 109	163 ± 79.7	0.587	0.984	0.729
Nuts & seeds (g)	15.2 ± 24.7	22.3 ± 26.5	6.90 ± 7.36	0.694	0.253	0.634
Potatoes (g)	32.6 ± 30.2	54.2 ± 41.3	70.0 ± 48.1	0.341	0.618	0.064
Eggs & derivatives (g)	15.9 ± 11.6	18.7 ± 13.1	17.8 ± 11.3	0.823	0.983	0.924
Fish & derivatives (g)	49.3 ± 40.7	45.2 ± 36.0	50.6 ± 32.6	0.957	0.939	0.996
Dairy products (g)	491 ± 173	338 ± 155	214 ± 109	0.036	0.044	< 0.001
Soups & broths (g)	50.5 ± 39.9	70.4 ± 55.4	56.1 ± 63.9	0.592	0.800	0.963
Meat & derivatives (g)	85.1 ± 45.5	167 ± 110	114 ± 58.3	0.022	0.246	0.613
Fats & oils (g)	3.50 ± 4.41	7.63 ± 7.95	6.64 ± 5.01	0.054	0.920	0.023
Snacks (g)	15.6 ± 8.14	43.0 ± 45.3	21.8 ± 14.1	0.036	0.180	0.845

Data shows mean ± standard deviation. The P-value (P) was extracted from Tukey´s HSD post-hoc test. Sample size (n); non-starch polysaccharides (NSP); saturated fatty acids (SFAs); monounsaturated fatty acids (MUFAs); polyunsaturated fatty acids (PUFAs); arbitrary units (a.u.).

Regarding the nutritional groups, women with ovarian and deep endometriosis consumed significantly fewer dairy products than controls (Table 2), even when their endometriosis was deep. Furthermore, women with endometrioma consumed more meat products (P = 0.022; 1-β = 0.67; d=|0.97|) and snacks (P = 0.036; 1-β = 0.55; d=|0.84|) than control. Fats and oils consumption was higher in women with endometrioma and in women with deep endometriosis compared to control.

Regarding dietary indices, the DASH index did not show significant differences between groups (Fig. 2A). However, women with endometrioma scored significantly lower on Mediterranean diet (P = 0.032; 1-β = 0.66; d=|0.96|) (Fig. 2B) and the Healthy eating index (P = 0.005; 1-β = 0.94; d=|1.42|) (Fig. 2C) compared to control. Women with deep endometriosis did not have significantly different scores than control women.

Fig. 2.

Dietary indexes in women with endometrioma and deep endometriosis. Data shows mean ± standard deviation. The P-value (P) was extracted from Tukey HSD post-hoc test

Health dimensions and dietary pattern in women with endometriosis

Women with endometrioma had significantly lower vitality (P = 0.050), menstrual characteristics (pain, bleeding, and cycle-related disturbances during menstruation; P = 0.049), reproductive (concerns and difficulties related to fertility and childbearing; P = 0.007) and sexual functions than controls (impact of endometriosis on sexual activity, intimacy, and partner relationships; P = 0.008). All health dimensions were significantly lower in women with deep endometriosis compared to control. Exceptionally, the pain sensitivity was higher in women with endometrioma and deep endometriosis compared to control (Fig. 3). Among women with endometrioma and deep endometriosis, no significant differences were shown.

Fig. 3.

Radar health dimensions in women with endometrioma and deep endometriosis. The chart shows the mean scores for each dimension by group of women

In control group, intake of fats and MUFAs, meat and derived products, and snacks correlated negatively with reproductive function, general health, and physical component, while the healthy eating index correlated positively with sexual and reproductive functions, menstrual characteristics, general health, and physical component. Women with endometrioma showed significantly negative correlations between fats, MUFAs, cholesterol, meat derived products, snacks, and adherence to Mediterranean and healthy diet with sexual function, menstrual characteristics, body pain, general health, vitality, and physical component. Furthermore, vitality and pain sensitivity had positive correlations with dairy, meat products and cholesterol intake. Women with deep endometriosis had negative correlations between fats, MUFAs, cholesterol, and meat consumption with reproductive function and vitality. Furthermore, following a healthy diet was positively correlated with vitality. In this group, dairy products and the Mediterranean diet were ambivalent; while it positively correlated with pain sensitivity, it was negatively correlated with reproductive function (Supplementary material figure S1). These variables were brought into the models to adjust the association between dietary components and women’s health dimensions.

Association of diet and control of health

The models were adjusted for age, weight, and dietary supplement intake, with the control women as the reference. For women with endometrioma, these models showed that fats intake decreased sexual function and body pain score, indicating worsening interference between life domains due to pain. Furthermore, MUFAs consumption decreased physical component and vitality. Increased healthy diet scores improved menstrual characteristics and sexual function (Fig. 4A). In women with deep endometriosis, diet was associated with vitality. Consumption of fats and meat by-products decreased vitality, while a healthy diet increased it (Fig. 4B).

Fig. 4.

Association between health dimensions and dietary variables in women with endometrioma and deep endometriosis. Data shows beta coefficients ± standard error extracted from linear models adjusted by women age, weight and supplements intakes considering the control group as a reference. Red line indicating P<0.05

Discussion

This study explored the influence of nutritional patterns on pain, physical health, and reproductive function in women with ovarian and deep endometriosis, distinguishing ovarian endometrioma from deep endometriosis. According to our data, women with endometrioma had low healthy diet quality, with high fat, MUFAs and meat intakes. In addition, high fat intake decreased bodily pain control, sexual function, vitality, and physical performance. In women with deep endometriosis, vitality was also diminished by high meat consumption. Following a healthy diet was positively associated with vitality, sexual health, and better menstrual characteristics.

Western diet has been characterized by a high consumption of omega-6 long-chain PUFAs, generating a dietary ratio of 16:1 omega-6:omega-3 [39]. This ratio could generate a pro-inflammatory environment that perpetuates pathogenesis of inflammatory conditions. Currently, there are not explicit recommendations regarding the total intake of PUFA for women with endometriosis [14]. Additionally, specific diets, such as gluten-free, could be beneficial [40]. 96.9% of women with endometriosis often have problems controlling pelvic pain, and 91.2% dealt frequent abdominal bloating. Dietary control is often a lifesaver for these women, as 83.8% have tried a diet to manage these symptoms, using supplements in the 58.8% [40]. In fact, according to our data, 27.3% of women with endometrioma use dietary supplements, rising to 70% of women with deep endometriosis. The control of dietary pattern improved the perception of pain in about 50% of women with endometriosis [40]. Among the most significant dietary patterns suggested was to reduce alcohol, gluten, dairy products and caffeine intake. Our data confirms this trend where women with ovarian and deep endometriosis follow sugar-, gluten- and lactose-free diets. However, although they stated that they followed a diet free of fried foods, fats, and processed foods, our detailed analysis did not reveal the same, since they had a higher consumption of fats and meat, including processed. Therefore, it is worth consulting a dietitian to individual nutritional plan to cover the needs of each woman suffering from endometriosis.

The controversy is clear since eliminating foods with high levels of fermentable carbohydrates (FODMAP diet) or adherence to the Mediterranean diet did not have a high impact on quality of life, particularly pain perception [41–44]. In this context, although we do not detect an association with pain perception, women who adhered to healthy dietary habits improved their vitality and sexual function. According to our data, while women with deep endometriosis behaved like control group, women with endometrioma had the lowest Mediterranean diet adherences, with no differences in fruit and vegetable consumption. Another study in Polish women with endometriosis with diet rich in fish, legumes, and nuts, proposed that fruit and vegetable consumption were insufficient [45]. These results highlight the need to improve nutritional knowledge among women with endometriosis. Additionally, it is important to note that there was no single solution that effectively worked for everyone, emphasizing the need for personalized strategies.

1Proinflammatory processes are the cornerstone of endometriosis. Table S2 shows examples of pro- and anti-inflammatory foods relevant to endometriosis. Specific dietary fatty acids increase the levels of proinflammatory markers, which are high in women with endometriosis [46]. Furthermore, the leukotrienes and prostaglandins are based on their omega-3/omega-6 PUFA precursors [47, 48]. Although elevated levels of leukotriene B4 and prostaglandin E2 have been associated with pelvic pain in endometriosis [47], our data could not find an association between PUFA intake and life domains. Additionally, women with endometriosis may have a high risk of hypercholesterolemia [49], being postulated that the selection of dietary fat quality was inadequate. According to our data, although cholesterol was not associated with life outcomes, it found that dietary cholesterol intake was elevated in women with endometrioma.

SFAs are found primarily in butter, lard, red meat, cheese, palm oil, and coconut oil. Palmitic acid is one of the main SFAs present in these foods [50]. SFAs have been associated with adverse effects on health [51], and dietary guidelines recommend limiting its intake. A meta-analysis indicates a relationship between SFA intake and the risk of endometriosis [52]. However, a prospective study only reported an association with palmitic acid and not with all SFAs [15]. In addition, a case-control study found that the intake of SFAs in women with endometriosis was similar to women without endometriosis [53]. The controversy continues as a study found inverse associations between SFAs consumption and endometriosis risk [54]. Thus, the relationship between SFAs and endometriosis is doubtful; but women with endometriosis should be recommended a diet low in SFAs, limiting palmitic acid. According to our data, women with endometrioma had higher intake of SFAs than control and women with deep endometriosis, which may indicate that dietary strategies should focus on women whose endometriosis is less disabling.

MUFAs are primarily derived from olive oil, nuts, and whole milk products, being oleic acid the most common [55]. There are no guidelines for MUFA intake [56] but decrease the proinflammatory environment [57–59]. Meta-analysis and prospective studies did not find association between MUFA intake and endometriosis risk [15, 52], but other studies found an inverse association [54, 60]. Although without strong recommendations, increasing the consumption of foods rich in MUFAs could be supported by the fact that women with endometriosis consume less of these nutrients than women without this inflammatory disease [61]. However, our data does not support this trend. Women with endometrioma consumed more MUFAs than control and this MUFA intake improved pain control. Despite their high MUFA intake, vitality and physical activity were lower than women without endometriosis. This could be due to the high consumption of pork in Spain, as well as its derivatives. Pork is rich in oleic acid, unlike other animals such as cattle, which convert dietary fat into palmitic acid [62]. These associations highlight the need for epidemiological studies in women with endometriosis where dietary intervention and disease control would be the primary endpoints.

Finally, emerging evidence suggests that the intake of meat and dairy products may influence the development and symptomatology of deep endometriosis, with implications for pain, vitality, and quality of life. A prospective study suggested a potential link between red meat consumption and pain symptoms in endometriosis [10]. According to our data, the consumption of meat may be associated with a reduction in vitality. Furthermore, a systematic review and dose-response metanalysis reported that higher total dairy consumption was associated with a decreased risk of endometriosis [13]. In this context, we were unable to demonstrate any association between dairy products and the life spheres of these women. However, other authors did not detect that reduced dairy products had a protective effect when examining specific dairy products individually [52]. While these findings underscore the potential role of dietary modifications in managing deep endometriosis and enhancing patient well-being, further research is warranted to elucidate the mechanisms underlying these associations and to develop evidence-based dietary recommendations for individuals with endometriosis.​.

Dietary interventions with clinical implications

Rising evidence highlights the importance of dietary fat composition in the management of endometriosis. Dietary interventions rich in anti-inflammatory and antioxidant components -such as omega-3 fatty acids, polyphenols, fiber, and vitamins- may help modulate systemic inflammation, reduce pain, and improve gastrointestinal function. In women with inflammatory bowel disease and endometriosis overlapping symptoms has been highlighted the potential benefit of nutritional strategies targeting common inflammatory mechanisms to complement medical and surgical treatments [63]. Furthermore, although no definitive association has been established between fat intake and endometriosis incidence, the type and quality of dietary fatty acids appear to play a significant role in modulating disease risk and progression. Specifically, diets high in SFAs have been shown to exacerbate inflammatory processes, upregulating proinflammatory cytokines. This is of particular concern in endometriosis, an estrogen-dependent inflammatory condition, as excessive intake of palmitic acid has been associated with increased endogenous estrogen production, which may further amplify inflammatory pathways and contribute to disease severity [15]. Conversely, MUFAs and omega-3 PUFAs exert anti-inflammatory effects and may reduce the risk or symptom burden of endometriosis, reinforcing the mechanistic role of lipid metabolism in disease pathology [64].

In terms of quality of life, a cross-sectional study in Dutch women with endometriosis revealed that adherence to an “endometriosis diet”—exclusions of red meat, caffeine, and sugar—was significantly associated with improvements in multiple life-domains. Importantly, participants who adhered strictly to the dietary recommendations reported better outcomes compared to those with lower adherence, suggesting the potential benefit of structured dietary guidance as an adjunct to conventional treatment [65]. Collectively, these findings advocate for the integration of personalized dietary counseling into the multidisciplinary management of endometriosis, with a focus on reducing pro-inflammatory dietary components and enhancing the intake of anti-inflammatory fatty acids.

Limitations and futures directions

Several limitations must be acknowledged. First, the sample size was relatively small, which may limit the generalizability of the findings. However, the methodological strategies of the analysis (know the distribution of variance and adjust the models by covariates) ensure robustness in the interpretation. Second, the cross-sectional design precludes any inference of causality between dietary patterns and health outcomes. Therefore, the need for longitudinal intervention studies in endometriosis is reinforced. Third, although the use of validated questionnaires, such as FFQ, continues to be one of the most widely used dietary assessment strategies in epidemiological nutritional-observational studies [24, 66], dietary intake was assessed using self-reported questionnaires, which may not fully describe fluctuations related to menstrual phases or pain episodes. In addition, it would be useful to describe the proportion of specific fatty acids in each case as well as the ratio of omega-6:omega-3 PUFAs in the diet. Furthermore, we cannot exclude that some women with deep endometriosis also presented endometrioma. Nevertheless, once deep endometriosis is established, the severity of symptoms renders the endometrioma less disabling.

Regarding future perspectives, randomized controlled trials evaluating the effects of anti-inflammatory or Mediterranean-style diets on clinical outcomes such as pain intensity, fertility parameters, and quality of life would provide stronger evidence for dietary recommendations. Furthermore, integrating biomarkers of inflammation, oxidative stress, and gut permeability may elucidate the mechanistic pathways linking diet and disease expression. Additionally, exploring potential confounders factors such as physical activity, stress levels, and microbiota may also influence both diet and health perceptions. Future studies should consider the surgical technique in patients with endometriosis. Segmental or discoid resections and shaving showed an improvement in overall quality of life, but data are controversial regarding postoperative symptoms [67]. Additionally, it has been demonstrated that patients with deep endometriosis may present similar symptomatology to those treated with low resection, even before surgery, and that these symptoms persist after surgery, regardless of the surgical technique [68]. These findings highlight the need to consider both symptomatic benefits and functional and sexual adverse effects when planning the surgical approach to deep endometriosis. Finally, surveying personalized nutrition approaches based on endometriosis phenotype and metabolic profiles could enhance dietary management and improve patient-centered care in this population.

Conclusions

Dietary patterns have a significant influence on the health outcomes of women with ovarian and deep endometriosis, particularly in terms of pain management and quality of life, emphasizing the need for personalized nutritional recommendations. Women with endometrioma exhibit suboptimal dietary habits, with high intake of fats, cholesterol, and processed foods, which negatively impacts sexual function, vitality, and general health, indicating the necessity for dietary interventions to improve these outcomes. Targeted dietary interventions, particularly focused on monounsaturated fatty acids, may alleviate bodily pain in women with endometrioma, suggesting potential therapeutic benefits of modifying fat intake. Adherence to a healthy diet, characterized by balanced nutrition, is positively correlated with improved menstrual characteristics and enhanced vitality in women with endometriosis, highlighting the role of dietary habits in supporting overall well-being. These conclusions provide actionable insights for clinicians, nutritionists and researchers to explore dietary interventions as part of a holistic approach to managing endometriosis.

Authors’ contributions

E.S. contributed to the conceptualization, investigation, and supervision of the study, provided resources, validated the results, and participated in reviewing and editing the manuscript. A.L. contributed to conceptualization, investigation, supervision and provided resources. B.D.F. contributed to methodological design and formal analysis. R.A.d.C. was responsible for data curation and data visualization, as well as the original drafting of the manuscript. A.B. participated in the validation of the study and contributed to reviewing and editing the manuscript. D.R.-C. was involved in conceptualization, investigation, data curation, formal analysis, and software development, as well as the original drafting of the manuscript, visualization of the data, and methodological design. All authors read and approved of the final manuscript.

Funding

The authors declare that financial support was received for the research and publication of this article. This study was supported by Dr. Luis Álvarez grant 2021 of IdiPAZ (Madrid, Spain; Ref. PI-5435) in its first modality for emerging groups and associated clinicians, and “Mona Lisa Smile” European Project 2022 (Ref. 2022-1-IT01KA220-VET-000087262).

Data availability

Datasets are available from the corresponding author on reasonable requests. Requests to access the datasets should be directed to [David.ramiro@uam.es](mailto: David.ramiro@uam.es).

Declarations

Ethics approval and consent to participate

Informed consent to participate was obtained from all women in the study. This design has the approval of the Research Ethical Committee of Hospital Universitario La Paz, Madrid, Spain (PI-5435; approved on 02 December 2022). The study complied with the Declaration of Helsinki: Ethical Principles for Medical Research Involving Human Subjects.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.