Consuming a recommended healthy diet was not found to protect individuals from exposure to endocrine-disrupting chemicals, according to the results of a study published in Environmental Research.
Data from the National Health and Nutrition Examination Survey (NHANES) conducted in 2013-2014 and 2015-2016 were used in this analysis. Twenty four-hour dietary recall data were evaluated for quality using the 2015 Healthy Eating Index (HEI), the relative Mediterranean diet score (rMED), and Dietary Approaches to Stop Hypertension (DASH) tools and assessed against endocrine-disrupting chemical content in urine.
The proportion of individuals with detectible levels of 26 selected nonpersistent endocrine-disrupting chemicals in their urine ranged from 49.8% (cyclohexane-1,2-dicarboxylic acid-monocarboxy isooctyl ester) to 100% (2-hydroxynaphthalene). Most of the endocrine-disrupting chemicals (n=18) were detected among more than 90% of urine samples.
Compared with people who did not consume fast food, those who had consumed food from restaurants without waiter/waitress service, sports venues, pizzerias, or street vendors within the prior 24 hours had lower excretion of bisphenol S (P =.01) and increased Ʃ-di-iso-butyl phthalate (P =.005).
Among those who consumed a Mediterranean diet, a 2.7% greater concentration of urinary nitrate was noted for every 1-point increase in rMED score. In addition, 6.8% more perchlorate and 5.3% more nitrate were reported for every 10-point increase in HEI.
No associations were significantly related with the DASH diet after adjustment.
Mediation analysis found evidence that perchlorate was a mediator between HEI and total thyroxine level among all adults, accounting for 57.5% of the effect (P =.03). Among all women, nitrate was a mediator between rMED and total triiodothyronine level, accounting for 51.2% of the effect (P =.01). Perchlorate mediated rMED and total thyroxine level among women aged 20 to 44 years, accounting for 50.9% of the effect (P =.04).
A limitation of this study is the potential inclusion of missing or incorrect information, as dietary intake was based on 24-hour recall.
This study found that following recommended healthy diet guidelines did not protect individuals from exposure to endocrine-disrupting chemicals. Cumulative exposure to these chemicals may inhibit thyroid hormone production and contribute to adverse health outcomes. The study authors advise that these findings underscore the importance of safety monitoring of chemicals used in food production and processing.
Melough MM, Maffini MV, Otten JJ, Sathyanarayana S. Diet quality and exposure to endocrine-disrupting chemicals among US adults.Environ Res. 2022;211:113049. doi:10.1016/j.envres.2022.113049