All the Colors of the Rainbow: Synthetic Dyes in US Packaged Foods and Beverages in 2020.

BACKGROUND

Research over the past 40 or more years has raised questions around the safety of synthetic food dyes approved for use in foods and beverages in the United States, especially in relation to impacts on neurobehavior in some children. Understanding the prevalence of synthetic dyes in US foods and beverages, especially those marketed to children, can help inform policy makers interested in taking legislative or regulatory action.

OBJECTIVE

The objective of this study was to examine the use of synthetic dyes in US foods and beverages (overall and by category) sold by the top 25 US manufacturers in 2020 and to examine differences in the total sugar, sodium, and saturated fat content of products between those with and without synthetic dyes. The proportions of products in the top 5 categories marketed to children that contained synthetic dyes were compared with all remaining products.

DESIGN

This study was a cross-sectional analysis using ingredient data for all products from the top 25 manufacturers in the United States. Data were sourced from Label Insight (a NielsenIQ company) in 2021 (final sample, n = 39 763).

MAIN OUTCOME MEASURES

The number and proportion of products containing synthetic dyes were calculated. Products in the top 5 categories marketed to children were compared with all other product categories.

STATISTICAL ANALYSES

Mean levels of total sugar, sodium, and saturated fat for each category and company were calculated, and differences in nutrients between products with and without synthetic food dyes were examined using Student t test. P < .001 was considered significant.

RESULTS

Synthetic dyes were present in 19% of products, representing more than $46 billion in consumer purchases in 2020. The most common synthetic dye was Food, Drug and Cosmetic Red No. 40 (14% of products). The number of synthetic dyes per product ranged from 0 to 7, with 19% of foods containing 1 or more synthetic dyes. Twenty-eight percent of products in the top 5 categories marketed to children contained synthetic dyes compared with 11% in the remaining categories. Mean total sugar in products containing synthetic dyes was 141% higher (33.3 g/100 g) compared with products without synthetic dyes (13.8 g/100 g; P < .001). Products containing synthetic dyes had lower levels of sodium and saturated fat.

CONCLUSIONS

Foods and beverages containing synthetic dyes are widely prevalent in the US food supply, particularly in sweet foods and beverages, which are commonly marketed to children.