Endometriosis is a chronic condition in which tissue similar to the uterine lining grows outside the uterus. This triggers inflammation, severe pelvic pain, fatigue, and gastrointestinal troubles that can last for years. For many of the more than 190 million women worldwide living with endometriosis, the monthly pain of menstruation is just the beginning.

Among its most maddening symptoms is what many women call “endo belly” — a persistent bloating that can mimic the discomfort of irritable bowel syndrome or even the appearance of pregnancy.

A new study shows that many women are experimenting with dietary changes and reporting good results. The biggest culprits seemed to be alcohol, gluten, dairy, and caffeine. Sugar and processed foods were not far behind.

Diet and endometriosis

Endometriosis is a complex disease that affects an estimated one in ten women of reproductive age. Even though it’s so common, it remains notoriously difficult to diagnose and treat. Much of the problem emerges because symptoms often overlap with other conditions, leading to confusion and diagnostic delays that can span years. Moreover, current treatments — primarily hormone-suppressing drugs or surgery — are not effective for all patients and often come with significant side effects.

This leaves millions of women frustrated and looking for alternatives. Oftentimes, these women end up trying different diets to see if it affects their condition. So, this is the largest study to date investigating these diets’ effects.

For Francesca Hearn-Yeates, the study’s lead author, the idea began where most good science starts: listening to patients. Many patients reported looking for alternatives. Social media abounds with tips and advice about cutting out gluten or dairy on social media, but there hadn’t been a large-scale attempt to understand just how common these strategies were and how well they worked.

Together with a patient advocacy group, Endo Warriors West Lothian, the research team launched a global online survey. In just under three months, over 2,850 people responded, with 2,388 participants reporting a confirmed medical diagnosis of endometriosis. Their average age was 35, though responses came from individuals as young as 16 and as old as 71. An overwhelming majority — 97% — reported experiencing chronic pelvic pain, and more than 91% suffered from frequent bloating.

The results of the surveys were convincing.

More than 83% of respondents had tried at least one dietary change to relieve symptoms, and nearly 59% had tried supplements. Among those who altered their diets, two-thirds said their pain improved. Those who used supplements reported a 43% success rate.

Rather than subscribing to complicated eating regimes, most people in the study made specific eliminations. Alcohol was the most frequently avoided item and it seems to be a good bet. Out of the 1,252 respondents who reduced or eliminated it, 53% reported pain relief. Gluten and dairy followed closely, each cited by over 1,100 respondents with a nearly 45% improvement rate. Caffeine reduction also proved popular and effective.

What women are cutting out for endometriosis

Essentially, most patients are engaging in intuitive, trial-and-error approaches to food, often based on anecdotal evidence from others online. This patchwork experimentation may not sound scientific, but it reflects a sound idea: that the gut and immune system are deeply entwined with reproductive inflammation.

“Women are in need of anything that can help with the pain of endometriosis. This condition is so under-researched and there is so much to discover, but there is growing evidence that gut bacteria could play a part in symptoms, and that explains why many women have experimented with changing their diets, and why we have found that this appears to work for many,” says Hearn-Yeates to The Guardian.

Among supplements, magnesium emerged as the most widely used — and among the more effective. Of 812 respondents who took it, 32% reported pain relief. Magnesium is known to play a role in muscle relaxation and may ease uterine cramping.

Other popular supplements included multivitamins, probiotics, vitamin D, and omega-3 fatty acids. Herbal remedies like turmeric, peppermint, and ginger also featured in the responses, though with varying success rates. For example, only 13.7% of those who took turmeric found it helped.

A cautious analysis

So where are people getting their ideas? The study found that both social media and healthcare professionals played a role in prompting dietary changes. But patients often turned to peer support forums and Instagram influencers when doctors had no clear answers.

This can be a double-edged sword.

Social media is full of questionable (and sometimes, outright dangerous) advice. Furthermore, the survey has significant limitations.

The participants were self-selecting, mostly from Europe, and primarily white (88%). The survey was only available in English, and didn’t account for how long a diet or supplement had been tried, or whether improvements lasted.

But this is an important starting point.

For researchers, the next step is to understand how different foods might influence the underlying biology of endometriosis. Could gluten or dairy, for instance, worsen inflammation in some women but not others due to genetic or microbial differences? Are there biomarkers that could help predict who will benefit from a specific intervention? What interventions offer sustainable benefits? Those are the questions to look at next.

The study was published in JAMA.