Health impacts of exposure to synthetic chemicals in food

Abstract

Humans are widely exposed to synthetic chemicals, especially via food. The types of chemical contaminants in food (including food contact chemicals) are diverse, and many of these are known to be hazardous, with mounting evidence that some contribute to noncommunicable diseases. The increasing consumption of ultra-processed foods, which contain synthetic chemicals, also contributes to adverse health. If the chemical contamination of foods were better characterized, then this issue would likely receive more attention as an important opportunity for disease prevention. In this Review, we discuss types and sources of synthetic food contaminants, focusing on food contact chemicals and their presence in ultra-processed foods. We outline future research needs and highlight possible responses at different food system levels. A sustainable transition of the food system must address the health impacts of synthetic chemicals in food; we discuss existing solutions that do justice to the complexity of the issue while avoiding regrettable substitutions and rebound effects.

Fig. 1 |. Sources and types of synthetic chemicals in foodstuffs.

Food and beverages can be contaminated during different stages of the value chain and with different types of synthetic chemicals. Most attention is paid toward pesticides, while direct food additives and FCCs have received considerably less awareness, even though they are likely to contribute to the adverse health outcomes associated with the consumption of contaminated foods. The reason for this may relate to the intended use of food additives and food contact materials, such as tubing and storage containers used during food transport, conveyor belts and machinery used during food processing, packaging, tableware and kitchenware.

Fig. 2 |. Migration of FCCs into foodstuffs.

Migration is influenced by different factors, including temperature, storage time and chemical properties of the foodstuff. The term FCCs describes all types of chemicals present in food contact materials, including NIASs, such as impurities, reaction by-products and degradation products. All migrating FCCs are relevant for human exposure as they are likely to be ingested with food and beverages. Sources are packaging but also (industrial) processing equipment, tableware and kitchenware and storage containers. Some FCCs may also have uses other than in food contact materials, leading to increased exposure from all sources.

Fig. 3 |. Proportion of daily energy intake from UPF across countries and health impacts of UPFs and FCCs with convincing evidence.

Globally, there is a large disparity in the percentage of daily energy intake from UPFs. Several health outcomes have been studied, including respiratory health, gastrointestinal health, metabolic health and cancers, based on data from multiple population-based studies worldwide, including >9.8 million people in total. The density of evidence is the highest for cardiometabolic diseases, obesity, common mental disorders and premature death. Several FCCs are not fully specific to UPFs but have been detected in larger quantities in the urine of consumers of larger amounts of UPFs^,. For the FCCs BPA, DEHP, phthalates as group and PFOA, causative health outcomes are shown (data sources: refs. 88,89,96,113,114,131,195).

Fig. 4 |. Functions of food packaging.

Food-packaging functions have evolved over time, from the basic, first functions (mid-19th century; top left), to more advanced requirements and functions emerging with a more industrialized food system (early to mid-20th century; middle), to today’s modern, globalized, lean production and overconsumption-inducing food system (late 20th century to today; bottom right).