Ongoing exposure to the synthetic chemicals used to process, package and store foods may be harming our health, warns an international team of environmental scientists in a provocative commentary published today in the Journal of Epidemiology and Community Health.
The researchers point out that these chemicals — which can be found in a variety of packaging materials, including the coating in cans, the laminate on beverage cartons, and the caps and closures on glass jars — are not inert, but seep (migrate is the technical term) into the food we eat, exposing us to low levels of them throughout our lives.
Although many of these chemicals are regulated (under the category of “indirect food additives” in the United States) and have been declared safe at low levels, no one really knows their long-term effects on human health, according to the commentary’s authors.
Of particular concern, they add, is the lack of knowledge about the effects that repeated low-level exposure to these chemicals has on children’s developing brains and bodies.
Reasons for concern
The authors of the commentary, which include one American scientist, Pete Myers, the CEO of the nonprofit group Environmental Health Sciences, cite several reasons why we should be concerned about this issue.
To begin with, some of the chemicals are known toxicants.
“In the USA, several types of asbestos are authorized as indirect food additives for use in rubber,” Myers and his colleagues explain. “Formaldehyde, another known carcinogen, is widely present at low levels in plastic bottles made of polyethylene terephthalate; formaldehyde also migrates from melamine formaldehyde tableware.”
“Considering how widely beverages are consumed from polyethylene terephthalate soda bottles, this may amount to a significant, yet unrecognized, exposure of the population,” they add.
In addition, known hormone-disrupting chemicals, such as bisphenol A, tributyltin, triclosan and several kinds of phthlates, are used in the processing and packaging of food.
“Whereas the science for some of these substances is being debated and policy makers struggle to satisfy the needs of stakeholders, consumers remain exposed to these chemicals daily, mostly unknowingly,” Myers and his colleagues write.
(In 2012, the World Health Organization and the United Nations Environment Programme declared hormone-disrupting industrial chemicals “a global health threat.”)
A third concern of the researchers is the sheer number of chemicals used in the processing and packaging of food. More than 4,000 are known to be intentionally used for these purposes, but there is an unknown number of other “non-intentionally added substances” — chemical by-products, impurities and breakdown compounds — that also end up leaching into the processed foods we eat.
A challenge to scientists
Establishing a direct causal link between lifelong exposure to these chemicals and human disease is challenging, the authors of the commentary admit. To begin with, almost everybody has been exposed to the chemicals, which means there are no unexposed populations to use for comparative purposes in studies. In addition, exposure to the chemicals varies widely across population groups and among individuals.
Still, Myers and his colleagues call for more research, especially into possible links between ongoing, low-level exposure to hormone-disrupting chemicals and chronic medical conditions, such as cancer, diabetes, obesity, and neurological disorders.
“Since most foods are packaged, and the entire population is likely to be exposed, it is of utmost importance that gaps in knowledge are reliably and rapidly filled,” they stress.
The Journal of Epidemiology and Community Health is the official journal of the Society of Social Medicine, and is published by BMJ. Unfortunately, this commentary is behind a paywall, but you’ll find an abstract on the journal’s website.