Contaminants in our food: What are the health effects?

We inhale chemicals from the environment, take them up through our skin or eat them with our lunch. In the course of our life, we come into contact with at least 10,000 to 100,000 different pollutants and foreign substances, explains Benedikt Warth from the Department of Food Chemistry and Toxicology. In a large-scale ERC project addressing the exposome, the scientist from the University of Vienna investigates how contaminants in our food affect our health.

From exposure to exposome

The term "exposome", is derived from the term "exposure" and refers to all environmental factors that have an effect on our health: chemicals in the air, water and food as well as the substances that our body produces in response to various influences. The term was coined by the renowned cancer researcher Chris Wild (most recently at the International Agency for Research on Cancer in Lyon). He discovered the link between certain fungal toxins (mycotoxins) and liver cancer, and has shaped the emerging discipline of exposome research.

Since then, the exposome has become a hot topic in international research. "We now know that the genetic disposition is often not sufficient to explain the causes of, for example, cancer and neurodegenerative diseases. The probability of contracting a disease in the course of our lives is by two thirds determined by environmental factors, such as nutrition and lifestyle, but also by the associated exposure to chemicals," says Warth about the growing interest in the exposome.

"Quantum leaps" in mass spectrometry

The recent technological advancements have certainly contributed to the rise of exposome research. "Our methods now allow us for the first time to measure even the tiniest traces of chemicals. When contaminants are taken up through food or water, we can detect their traces in biological samples, such as urine, saliva or blood." The machines that achieve this feat are called mass spectrometres, and they are running at full throttle at the Faculty of Chemistry. These instruments at the University of Vienna are among the best of their kind and can detect the smallest traces of many chemicals in parallel.

Coming to grips with breast cancer development

The sophisticated high-tech equipment supports Warth and his team in their current research project, which is funded by the European Research Council and aims to identify potential chemical triggers of breast cancer. The researchers are analysing blood and urine samples from women participating in a long-term study conducted in Italy. Some of the women developed breast cancer in the course of the study, while others did not. Based on the samples, Benedikt Warth and his team aim to uncover whether and which chemical risk factors are involved in cancer development, in particular hormone-disrupting substances.

While we understand the toxicology of most pollutants as individual substances, we do not know how they interact with the many other substances we encounter daily, both intentionally and unintentionally. "Our research into the exposome allows us to identify the previously unknown effects that can occur when different xenobiotics are combined and interact with each other," says Warth.

Pollution in the womb

The placenta usually functions as a protective barrier against bacteria, viruses and foreign substances from food or medication. In a study into zearalenone, a natural mycotoxin that is found in cereals or bread and has an oestrogen-like effect, the Warth lab showed that this placental barrier does not protect the foetus against all pollutants. "Our experiment provided the first evidence that the environmental hormone can travel across the placental barrier. Unborn children may thus be exposed to various xenobiotics already in the mother’s womb." 

A new longitudinal study, conducted in collaboration with US colleagues also supports this hypothesis. It showed that major mycotoxins, including zearalenone, can be detected in the urine and blood serum of pregnant women. The study emphasises the need for regular monitoring of mycotoxins in groups who may be at risk, such as pregnant women and unborn children.

In cooperation with the Medical University of Vienna – a collaboration partner in the Exposome Austria network headed by Benedikt Warth – the food chemist strives to push ahead with this study and initiate a large-scale human biomonitoring project in Austria. His vision: Women provide biological samples already during pregnancy. In addition, blood or urine samples are taken from the new-born regularly in the first years of life. "A survey of exposure and effect across generations would provide completely new possibilities for investigating the effects of xenobiotics and pollutants on the development of the unborn child," explains Warth.

From "repair" medicine to personalised prevention

The results of the study should be taken into account in health and environmental policies and in future risk assessments of chemicals. "With our research, we aim to understand which factors are actually problematic and thus contribute to reducing their impact. This would be a major step towards prevention," says the scientist about his overarching vision.

"In healthcare, we currently focus primarily on treating sick people instead of doing everything we can to enable healthy ageing for as long as possible. Therefore, we want to expand our capacities to ensure that comprehensive preventative monitoring programmes, for example during pregnancy, will soon become a reality in Austria." (hm)