In the Journals Plus

Diet intervention fails to reduce ‘ubiquitous’ BPA exposure for teens

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February 6, 2018

Lorna Harries
Lorna Harries

Adolescents who created real-world diets attempting to avoid exposure to bisphenol A, or BPA, for 7 days experienced no change in urinary BPA levels and reported difficulty in avoiding the endocrine-disrupting chemical, according to findings published in BMJ Open.

“Based on our evidence, it is extremely difficult to reduce one’s own exposure to BPA by actively trying to avoid known sources,” Lorna Harries, PhD, associate professor in molecular genetics at the College of Life and Environmental Sciences at the University of Exeter, United Kingdom, told Endocrine Today. “Our study indicates that the control over exposure to BPA currently does not lie with the consumer. At present, the ubiquitous nature of BPA in our environment and inadequacies in current labeling practices mean that it is very difficult to identify BPA-free foods.”

In a citizen science-based study, Harries and colleagues analyzed data from 94 adolescents aged 17 to 19 years recruited from six schools in Exeter, England. The students attended interactive workshops with researchers and collaborated to design real-world diets aimed at reducing consumption of BPA. Students designed all materials, including study protocols, food diaries, lifestyle questionnaires and patient-information sheets, and were asked to record daily diet details, including food and drink, and any associated packaging for 7 days. Students were asked not to alter diets before the intervention began. Urine samples were collected at baseline and after the intervention; BPA results were expressed as BPA-to-creatinine ratio. Researchers used repeated-measure analysis of variance models to assess the relationship between urinary BPA levels before and after the intervention.

Within the cohort, 86% of participants had at least trace amounts of urinary BPA.

Researchers did not observe any changes in urinary BPA levels between visits (P = .25), with results persisting after adjusting for creatinine levels (P = .2). There was no association between change in urinary BPA and BPA risk score (P = .55).

Most participants also reported feeling at least slightly restricted (91%) in their food choices when attempting to adhere to the diet, whereas 27% of participants reported feeling very restricted and 66% reported that they would find it hard or very hard to follow the diet long term.

In qualitative analysis, researchers identified four themes associated with difficulty in adhering to the intervention: widespread use of BPA-containing plastics, lack of clarity in labeling, perceived restrictions of the diet and the impact on shopping habits. The effect of “eating BPA-free” was the only identified positive theme, according to researchers.

“Participants were unable to achieve a reduction in their urinary BPA over the 7-day trial period, despite good compliance to supplied guidelines,” the researchers wrote. “Avoidance of BPA was not easily achieved on an individual level in our study population, with qualitative analysis indicating that participants experienced feelings of restriction and difficulties in sourcing BPA-free food due to inadequate labeling of foods and food packaging. This suggests that the intervention would be difficult to sustain in the longer term.”

“More research is needed into the potential health effects of these sorts of chemicals, and on safer replacements for them,” Harries said. – by Regina Schaffer

For more information:

Lorna Harries , PhD, can be reached at the College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK; email: l.w.harries@exeter.ac.uk.

Disclosures: The authors report no relevant financial disclosures.