A systematic review of the effectiveness of dietary interventions to treat endometriosis in the journal Reproductive Sciences has found a potential benefit of the Mediterranean diet and antioxidant supplementation on endometriosis-associated pain.
The review also concluded that certain patients with endometriosis suffering from gastrointestinal symptoms might benefit from diets that exclude or reduce specific substances such as gluten-free, low-nickel and low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) foods.
Senior author Konstantinos Nirgianakis, MD, a consultant in ob/gyn at the University Hospital of Bern in Switzerland, was inspired to undertake the review because of the need of his patients in the endometriosis unit to receive a treatment other than hormones or surgery.
The authors noted that the therapeutic potential of dietary interventions is currently unclear and there are no guidelines to help physicians.
“The available evidence from a systematic review on the dietary possibilities to treat endometriosis-associated pain can be now presented to interested patients,” Nirgianakis told Contemporary OB/GYN®.
MEDLINE and COCHRANE were searched electronically. Of the nine human studies included, two were randomized controlled trials, two were controlled studies, four were uncontrolled before-after studies and one was a qualitative study.
Study follow-up periods ranged from 4 weeks to 12 months. Four studies were from Italy, and 1 each from Austria, Sweden, Australia, Mexico, and Iran.
All the studies assessed a different dietary intervention, which the authors classified into 1 of 3 groups: complete diet modification, supplementation with selected dietary components, and exclusion of selected dietary components.
“Most of the studies found that diet had a positive effect on endometriosis,” Nirgianakis said. “However, all studies are characterized by moderate and/or high-risk bias, thus limiting the validity of the results.”
The Mediterranean diet reduced endometriosis-associated pain in a randomized controlled trial (RCT). Among the 68 women who adhered to a nutrition plan of fresh vegetables, fruit, white meat, fish rich in fat, soy products, wholemeal products, and foods rich in magnesium and cold-pressed oils, “there was a significant relief of general pain, dysmenorrhea, dyspareunia and dyschezia, as well as an improvement in the general condition of endometriosis,” Nirgianakis said.
Three studies investigated the role of an antioxidant supplementation like specific vitamins, fish oils, and mineral salts. “A significant reduction of symptoms was observed in 2 of these studies, 1 of which was a randomized controlled trial,” Nirgianakis said.
Three studies evaluated diets excluding or reducing specific substances. “Two of the studies enrolled only patients with endometriosis and gastrointestinal symptoms, while the third study included patients with endometriosis in general,” Nirgianakis said. All 3 studies showed an improvement of symptoms in at least 70% of patients adhering to the diet.
“Overall, it was a surprise to me the lack of adequate studies on such an important topic as dietary interventions for endometriosis,” Nirgianakis said.
The authors advocate an evidence-based clinical approach for physicians to use during consultations with their patients. However, further well-designed RCTs are needed to accurately determine the short- and long-term effectiveness and safety of different dietary interventions for endometriosis.
Nirgianakis reports no relevant financial disclosures.