Nutrition/Obesity
Consumption of soy and other high protein foods and odds of adenomyosis: a case-control study Ling Guan* Ling Guan Kristen Upson Holly Harris
Adenomyosis, characterized by endometrial glands and stroma within the myometrium, can confer life-altering pelvic pain. The historic reliance on hysterectomy for diagnosis has limited the epidemiologic study of adenomyosis, including the investigation of dietary factors on disease risk. Using a novel case-control study design employing two control groups, we evaluated the association between soy and other high protein foods and adenomyosis. Among female enrollees aged 18-59 of a large, integrated healthcare system in western Washington State, we identified incident, pathology-confirmed adenomyosis cases diagnosed in 2001-2006 (n=386). Cases were compared to randomly-sampled age-matched enrollees with an intact uterus (“population controls”, n=323) and hysterectomy controls (n=233). Participants completed an in-person interview and a food frequency questionnaire that included dietary intake of soy and high protein foods (red meat, poultry, eggs, dairy, and seafood) over the prior year. Adjusted odds ratios (ORs) and 95% CIs for the association between dietary factors and adenomyosis risk were estimated using logistic regression, comparing cases to each control group in separate analyses. In analyses using population controls, each serving per day of soy was associated with 66% lower odds of adenomyosis (OR=0.34, 95% CI: 0.08-1.50). Conversely, red meat intake (≥1 vs. <1 servings per day) was associated with a 2.25 higher odds of adenomyosis (95% CI: 1.05-4.83). No association was observed with egg, poultry, seafood, or dairy intake. We observed similar results in analyses using hysterectomy controls, except for the attenuated association with red meat intake (OR=1.21, 95% CI: 0.50-2.93). Our data suggest an altered odds of adenomyosis with soy and red meat intake. Given that estrogen and inflammation are central to adenomyosis pathogenesis, the observed associations with soy (a phytoestrogen) and red meat (linked with inflammation) warrant further investigation.