New Study Finds Pregnancy Diet Guidelines Reduce Harmful Chemical Exposure, but Can't Eliminate It

Pregnant people who more closely followed the U.S. Dietary Guidelines had measurably lower levels of certain harmful chemicals in their urine compared to those with poorer dietary quality, but the same dietary choices had little protective effect against another set of chemicals that enter the body through routes other than food, according to a new study published July 9, 2026 in the American Journal of Clinical Nutrition.

The study, led by epidemiologists Diana Pacyga and Jessie Buckley at the UNC Gillings School of Global Public Health and funded through the NIH's ECHO Cohort, analyzed data from nearly 1,500 pregnant participants. The findings add meaningful but bounded evidence to one of maternal health's most persistent questions: can what you eat during pregnancy protect you from the chemicals all around you?