Certain food additive mixtures may be associated with an increased risk of type 2 diabetes

Widely used by the agri-food industry, food additives are mainly found in the ultra-processed products sold in our supermarkets. The scientific literature now provides information on the potential harmful effects of consuming several of these substances, which have been associated with the development of metabolic disorders, chronic inflammation and gut microbiome imbalance. Recent studies from the NutriNet-Santé cohort have also revealed an association between the consumption of some of these additives and an increased risk of type 2 diabetes, cancer and cardiovascular diseases.

Although these studies provide insights into the individual effect of each of these substances, no study had yet looked at the possible impact of their combined consumption. And this is despite ultra-processed foods often containing mixtures of food additives, each with its specific properties (preservatives, flavour enhancers, colourants, texture agents, etc.).

To measure the consequences of exposure to these mixtures, a research team led by Mathilde Touvier, Inserm research director and study coordinator, analysed the health data of 108 643 adults in the NutriNet-Santé cohort over an average follow-up period of 7.7 years.

The participants completed at least two days (up to 15 days) of online dietary records of all food and drink consumed and their brands.

In order to obtain a reliable estimate of the exposure to additives and to focus on those with a potentially significant health impact, only those additives consumed by at least 5% of the cohort were included in mixture modelling. The presence or absence of each additive in each food was determined by cross-referencing several databases, taking into account the date of consumption (to incorporate any reformulations over time), as well as some laboratory assays of quantitative levels of additives in the food.

Five main mixtures of additives were identified, representing groups of substances frequently ingested together (due to their joint presence in industrially processed products or resulting from the co-ingestion of foods often consumed together).

The results show two of these mixtures to be associated with a higher incidence of type 2 diabetes, regardless of the nutritional quality of the diet (intake of sugar, calories, fibre, saturated fat, etc.) and sociodemographic and lifestyle factors. No associations were found for the other three mixtures.

The first mixture incriminated was primarily composed of several emulsifiers (modified starches, pectin, guar gum, carrageenans, polyphosphates, xanthan gum), a preservative (potassium sorbate) and a colouring agent (curcumin). These additives are typically found in a variety of ultra-processed foods, such as stocks, milky desserts, fats and sauces.

The other mixture implicated was primarily composed of additives found in artificially-sweetened drinks and sodas. It contained acidifiers and acidity regulators (citric acid, sodium citrates, phosphoric acid, malic acid), colouring agents (sulphite ammonia caramel, anthocyanins, paprika extract), sweeteners (acesulfame-K, aspartame, sucralose), emulsifiers (gum arabic, pectin, guar gum) and a coating agent (carnauba wax).

In this study, interactions between the additives of these mixtures were detected suggesting that some could interact with each other, either by enhancing their effects (synergy) or by attenuating them (antagonism).