The association between dietary acid load and endometriosis: a case-control study

Endometriosis is a chronic inflammatory disorder that affects 5-15% of women of reproductive age. It is characterized by severe symptoms, including dysmenorrhea and non-cyclic pelvic pain, which can substantially impair quality of life. Although diet is a major modifiable risk factor for many chronic diseases, its potential role in endometriosis has received limited attention. This study aimed to investigate the association between Dietary Acid Load (DAL) and the odds of endometriosis among Iranian women.

This hospital-based case-control study was conducted in Tehran, Iran, between February to September 2021. Participants included women diagnosed with endometriosis and healthy controls, all of whom were evaluated by a gynecologist who was blinded to the study object. Dietary intake was assessed using a validated 168-item food frequency questionnaire (FFQ). DAL was estimated using Two indices: Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP). Logistic regression models were used to investigate the association between DAL and odds of endometriosis.

A total of 105 women with endometriosis and 208 healthy controls were included in the study. The results showed that each one-unit increase in PRAL and NEAP was associated with an 8%, and 4% increase in the odds of endometriosis, respectively.

Higher DAL was associated with increased odd of endometriosis. These findings suggest that reducing the consumption of acid-producing foods may help lower the risk of endometriosis. Further prospective studies are warranted to confirm these findings and clarify the underlying mechanisms.