Endometriosis: our research shows changing your diet may reduce pain symptoms

Endometriosis affects nearly 200 million people worldwide. This chronic condition is characterised by tissue resembling the lining of the womb growing outside of the uterus.

This common condition has devastating impacts on patients’ wellbeing. It causes chronic pain (particularly during their periods), infertility and symptoms similar to irritable bowel syndrome, including bloating, constipation, diarrhoea and pain during bowel movements.

While there are ways of managing endometriosis, these treatments can be invasive and often don’t work for everyone. This is why many patients seek out their own ways of managing their symptoms.

A frequent question we get from patients is, “Can you recommend a diet that will help me manage my pain and gut symptoms?” While ample advice exists online, there’s little information from clinical studies to adequately answer whether or not diet can have an effect on endometriosis symptoms.

So, we conducted an international online survey, inviting people with endometriosis to share their experiences of how diet has affected their endometriosis pain symptoms.

Diet and pain

Before publishing the survey online, we collaborated with a local Scottish endometriosis patient support group to come up with appropriate questions.

The final survey included multiple-choice and free-text questions about the participant’s demographics, their pain, their use of diet in managing symptoms and their sources of dietary advice. It was promoted online through social media and patient support groups. The survey received 2,599 responses from 51 countries. The age of participants ranged from 16-71.

Most respondents reported experiencing pelvic pain (97%) and frequent abdominal bloating (91%). This highlighted how common these symptoms are in people with endometriosis.

Participants were also asked to rate the average level of their abdominal and pelvic pain over the past month, on a scale from zero to ten. The responses highlighted a wide range of pain experiences, though the majority of respondents either rated their average pain a four (can mostly be ignored but with difficulty) or a seven (makes it difficult to concentrate, interferes with sleep and takes effort to function as normal).

The majority (83%) of respondents also reported making dietary changes to control symptoms. Around 67% noted this had a positive effect on pain.

The survey listed 20 different diets (plus “other”), allowing participants to select all the diets they’d tried and explain which had affected their pain symptoms. Some of the most popular diets patients had tried included: reducing alcohol intake, going gluten-free, going dairy-free, drinking less caffeine and reducing intake of processed foods and sugar.

Around half of participants reported improvements in their pain after adopting at least one of these diets. For the most popular diets, a reduction in pain was reported by 53% who reduced alcohol consumption, 45% who went gluten-free and dairy-free and 43% who reduced caffeine intake.

Reducing inflammation

This survey, which was the largest of its kind to date, was only conducted in English. This might have limited participation. Additionally, the observed changes were all self-reported, meaning we cannot confirm that the dietary modifications directly caused the changes in pain.

Still, our findings show diet may be an important tool in managing the pain caused by endometriosis. Importantly, no specific diet benefits everyone, so it may take some trial and error to figure out what works best. It’s also worth noting that diet changes appeared to be less beneficial for those with the most severe symptoms.

Research into why people with endometriosis experience pain has identified excess inflammation as a key factor. Inflammation is the body’s mechanism for fighting off an infection or recovering from an injury. In people with endometriosis, it’s thought that the inflammatory response is overstimulated – triggering sensitisation of nerves and amplifying the perception of pain.

Certain foods may also promote inflammation in the body. For instance, it’s thought that gluten and dairy could promote inflammation due to the way they interact with the cells lining the gut and the by-products they produce when broken down by the gut microbes. These by-products have the potential to move around the body and cause more widespread inflammation. Alcohol is also known to be pro-inflammatory.

Reducing intake of certain foods may therefore help reduce overall inflammation levels in people with endometriosis. This may explain why the participants in our study, and others, reported seeing improvements in their symptoms as a result of cutting out inflammatory foods.

Moving forward, we need properly controlled clinical studies that monitor food intake, real-time recording of pain and IBS-like symptoms, and precise measurement of inflammation in the body, in order to understand the reasons why diet may help people with endometriosis.

This is something our research team is already working on. We’re launching a large-scale study with more than 1,000 people who have endometriosis. Each participant will donate stool and blood samples, record food intake details and report on the use of pain medications, supplements, prebiotics, probiotics and dietary modifications. The long-term goal with this project is to support a more holistic and personalized approach to caring for people with endometriosis.

Philippa Saunders has received funding from The Medical Research Council. She is a Fellow of the Academy of Medical Sciences and sits on the Scientific Advisory Group of the Royal College of Obstetrics and Gynaecology.

Andrew Horne reports receiving grants from the National Institute for Health and Care Research, Chief Scientist Office, Wellbeing of Women, Roche Diagnostics, and European Union, receiving consultancy and lecture fees from Theramex, Roche Diagnostics and Gedeon Richter, and having patents issued for a UK patent application No. 2217921.2 and international patent application No. PCT/GB2023/053076 outside the submitted work. He is President-elect of the World Endometriosis Society and Trustee to Endometriosis UK. He is Specialty Advisor to the Scottish Government's Chief Medical Officer for Obstetrics and Gynaecology.

Francesca Hearn-Yeates does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.