TOPLINE:

A higher dietary exposure to food colouring additives — both natural and synthetic — was associated with a notably increased risk of developing type 2 diabetes (T2D).

METHODOLOGY:

• Researchers prospectively analysed data of 108,723 participants (mean age at baseline, 42.5 years; 79.2% women) from the French NutriNet-Santé cohort (2009-2023) to examine whether chronic exposure to natural or synthetic food colouring additives was associated with the risk of developing T2D.
• Dietary data were collected from repeated 24-hour dietary records including industrial food brands; eligible participants completed at least two records in the first 2 years.
• Cumulative exposure to food colouring additives was assessed by matching dietary records with composition databases; the dose of each additive was estimated based on lab assays or dose information from the European Food Safety Authority or the Codex General Standard for Food Additives.
• Exposure records were updated every 2 years, and participants were categorised into sex‑specific tertiles or into non-, low-, and high-consumer groups.
• T2D cases were ascertained using participant self-report and linkage to the national health insurance database and mortality registry; the median follow-up duration was 8.05 years.

TAKEAWAY:

• Overall, 1131 participants developed T2D.
• A higher intake of total food colouring additives was associated with a 38% increased risk of developing T2D among high vs non- or low consumers (P = .0002).
• The specific colouring additives that were positively associated with a higher risk for T2D included total caramel (European [E] codes E150, E150a, E150b, E150c, and E150d; hazard ratio [HR], 1.43), plain caramel (E150a; HR, 1.46), sulphite ammonia caramel (E150d; HR, 1.30), and beta-carotene (E160a; HR, 1.44; P < .05 for all).
• Additional significant associations were observed for total carotenes (E160, E160a, E160b, E160c, E161b, E160d, and E160e), carotenoids (E160), curcumin (E100), anthocyanins (E163), paprika-capsanthin-capsorubin (E160c), lutein (E161b), and cochineal-carminic acid-carmines (E120).

IN PRACTICE:

"Our findings revealed positive associations between widely consumed food colouring additives and type 2 diabetes incidence," the authors wrote.

"Further long-term epidemiological and experimental research is needed to understand underlying mechanisms. If confirmed, these results call for a reevaluation of regulations governing the use of food coloring additives by the food and beverage industry to better protect public health," they added. 

SOURCE:

The study was led by Sanam Shah of the Nutritional Epidemiology Research Team at Université Sorbonne Paris Nord and Université Paris Cité, Institut National de la Santé et de la Recherche Médicale (INSERM), Bobigny, France. It was published online on May 20, 2026, in Diabetes Care.

LIMITATIONS:

Unmeasured or residual confounding could not be completely ruled out. Some inaccuracies may have occurred in dietary assessment and the estimation of additive exposures. Exposure assessment was restricted to colouring additives permitted in the European Union, and several additives were not consumed by a sufficient number of participants to allow individual analysis.

DISCLOSURES:

The NutriNet-Santé study was supported by several public institutions, including Ministère de la Santé, Santé Publique France, INSERM, and Institut National de la Recherche pour l'agriculture. The project also received funding from the European Research Council under the European Union's research and innovation funding programme Horizon 2020, the French National Cancer Institute, the French Ministry of Health, the IdEx Université de Paris, and the 2021 Bettencourt-Schueller Foundation Research Prize. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.