Encrine disrupting chemicals, foremost substances eliciting effects similar to estrogen (dubbed xenoestrogens), are common in our environment. However, the extent to which they exist in foodstuffs and industrially processed foods is still poorly known. In this study, professor Raimo Pohjanvirta and his group examined three batches each of 15 popular processed foods, purchased from a local supermarket, for their estrogenic activity. “In addition, we included 3 x 5 ready-to-eat snacks acquired from a hamburger place for comparison. The assay system consisted of yeast cells transfected with a luciferase reporter gene that became activated by estrogen receptor-alpha-mediated signal transduction.” says Pohjanvirta.

Industrially processed chicken and beef burgers exhibited high estrogenic activity

In the majority of the samples analyzed, estrogenic activity was low. An exception to this rule were industrially processed chicken and beef burgers and, in particular, pepper salami, in which they consistently found quite high activities in all three batches. A fact common to these three food items was that they all contained soy protein as an ingredient. In the great majority of other samples, soy had not been used in their manufacture. Because soy has been shown to contain isoflavones with potential for estrogenic activity such as genistein, they further analyzed two soy sauces by their assay system; both proved highly positive.

An intriguing finding was that chicken, beef or cheese burgers bought from a hamburger restaurant were devoid of estrogenic activity, despite the fact that they were also informed to contain soy. The reason for the discrepancy may lie in a quantitative difference or, in the case of supermarket burgers, antioxidants might conceivably have potentiated the activity. Since the health impacts of soy are arguable, from the health risk point of view it would be advisable to avoid frequent exposure to it; this is especially true for children whose endocrine system can be more vulnerable to endocrine disrupters than that of adults. Finally, they also examined the wrapping materials of food products because there is a suspicion that certain estrogenic plasticizers such as phthalates and bisphenol-A might leach from the wrappings into food. However, all these samples were negative in their assay.

Further studies are warranted

Based on their results, they concluded that the majority of Finnish commercial food products do not contain xenoestrogens in concentrations that could be detrimental to health. The researchers remind, however, that their sample composition was fairly confined and therefore further studies are warranted regarding, for example, dietary supplements.

Link to the article

Iyekhoetin Matthew Omoruyi, Grit Kabiersch & Raimo Pohjanvirta , Food Additives & Contaminants: Part A (2013): Commercial processed food may have endocrine-disrupting potential: soy-based ingredients making the difference, Food Additives & Contaminants: Part A, DOI: 10.1080/19440049.2013.817025

Iyekhoetin Matthew Omoruyi  & Raimo Pohjanvirta, Department of Food and Environmental Hygiene (Food and Environmental Toxicology Unit), Faculty of Veterinary Medicine, University of Helsinki, F-00014 Helsinki, Finland
Grit Kabiersch, Division of Microbiology, Department of Food and Environmental Sciences, Faculty of Agriculture and Forestry, University of Helsinki, F-00014 Helsinki, Finland