A study by researchers at the University of Exeter has found that bisphenol A (BPA) is difficult to avoid in everyday life. They reached this conclusion because BPA levels were the same in a group of teenagers after they made efforts to avoid dietary exposure as they were before the intervention[i].
BPA is used to make polycarbonate plastic, epoxy resins, and other materials. It is commonly used in food contact materials, such as plastic water bottles. Its health effects on humans are unclear, but concerns have been raised because it can behave in a similar way to the hormone, estrogen, and its use in food contact materials could be a source of exposure for humans. Some reviews conclude that BPA affects female reproduction and has the potential to affect male reproduction[ii].
The researchers of the new study aimed to investigate whether altering the diet could change the levels of BPA in the bodies of teenagers. Diet diaries and urine samples were provided by 94 students aged between 17 and 19 from the South West of the UK. The participants attempted to reduce their intake of dietary BPA by following guidelines for 7 days. Before the intervention, BPA was detected in the urine of 86 % of participants. The half-life of BPA in the body is around 6 hours, so measured levels should reflect exposure over the past several days. Overall, there was no difference in urinary BPA levels after the week of the experiment. However, some of those with the highest levels of BPA showed reductions in their amount of BPA. In addition, the participants reported that they would be unlikely to maintain the BPA-reduced diet long-term, due to the difficulty in identifying BPA-free foods. The researchers conclude that their study provides no evidence that is it possible to moderate dietary BPA exposure in a real-world setting.
Professor Galloway, the lead researcher, said:
‘We found that a diet designed to reduce exposure to BPA, including avoiding fruit and vegetables packaged in plastic containers, tinned food, and meals designed to be reheated in a microwave in packaging containing BPA, had little impact on BPA levels in the body’.[iii]
Professor Harries, another of the researchers, said:
‘In an ideal world we would have a choice over what we put into our bodies. At the present time, since it is difficult to identify which foods and packaging contain BPA, it is not possible to make that choice’.
[i] Galloway, T. S. et al. An engaged research study to assess the effect of a ‘real-world’ dietary intervention on urinary bisphenol A (BPA) levels in teenagers. BMJ Open 8, e018742 (2018). http://bmjopen.bmj.com/content/8/2/e018742
[ii] Peretz, J. et al. Bisphenol A and Reproductive Health: Update of Experimental and Human Evidence, 2007–2013. Environ Health Perspect 122, 775–786 (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123031/ (Accessed 23 January 2018)
[iii] Exposure to chemical found in plastics “hard to avoid” in everyday life. EurekAlert. 5 February 2018. https://www.eurekalert.org/pub_releases/2018-02/uoe-etc020518.php
[iv] Gender-bending chemicals found on plastic and linked to breast and prostate cancer are found in 86 % of teenagers’ bodies. Daily Mail. 6 February 2018. http://www.dailymail.co.uk/news/article-5351661/Chemicals-plastic-90-teenage-bodies.html (Accessed 6 February 2018)