A prospective cohort study of meat and fish consumption and endometriosis risk.
Level 3 - non-randomized controlled study
Prospective cohort study with long-term follow-up
PubMed 29870739 · doi:10.1016/j.ajog.2018.05.034
What was done
Researchers analyzed prospective cohort data from 81,908 premenopausal participants in the Nurses' Health Study II followed from 1991 through 2013 (1,019,294 person-years of follow-up). Diet was assessed every 4 years using food frequency questionnaires. Cox proportional hazards models were used to calculate rate ratios (RR) and 95% confidence intervals (CI) for incident laparoscopically confirmed endometriosis across intake categories of red meat, poultry, fish, seafood, and eggs.
What was found
During follow-up, 3,800 incident cases of laparoscopically confirmed endometriosis were reported. Women consuming >2 servings/day of red meat had a 56% higher risk of endometriosis (95% CI, 1.22-1.99; P trend < .0001) compared with ≤1 serving/week. Nonprocessed red meat intake had the strongest association (RR 1.57, 95% CI 1.35-1.83 for ≥2 servings/day vs ≤1 serving/week; P trend < .0001), particularly among women without reported infertility (P interaction = .0004). Processed red meat intake of ≥5 servings/week versus <1 serving/month was also associated with increased risk (RR 1.20, 95% CI 1.06-1.37; P trend = .02). Intakes of poultry, fish, shellfish, and eggs showed no significant association with endometriosis risk.
Why it matters
This large prospective study indicates that red meat consumption, particularly nonprocessed red meat, is a modifiable dietary risk factor for endometriosis, especially among women presenting primarily with pain symptoms rather than infertility.
Limits
Dietary intake was self-reported via food frequency questionnaires every 4 years, introducing potential measurement error. The cohort consisted exclusively of US female nurses, limiting generalizability to broader populations. Outcome ascertainment was restricted to laparoscopically confirmed cases, potentially missing undiagnosed or non-surgically evaluated cases. Observational design cannot entirely rule out residual confounding.
Cited by
- partial Higher dietary red meat intake is associated with poorer embryo development, worse IVF outcomes, and higher staging of endometriosis at surgery.