National studies are mapping where food additives come from in the diets of children and adults

National studies are mapping where food additives come from in the diets of children and adults

By analyzing nationally representative dietary data, researchers show that food additives rarely occur alone, with children and adolescents most exposed to complex mixtures of additives, largely caused by highly processed foods.

A recent study in the journalScientific reportsexamined exposure to food additives and their mixtures in adults and children in France.

Widespread use of food additives in modern nutrition

Food additives are substances that, when added to foods, improve their appearance, shelf life, texture or taste. They are ubiquitous in the modern diet and appear in a range of foods, including expected items such as industrial biscuits, but also less expected items such as packaged bread and yoghurt. In France, foods with additives account for more than 50% of the market.

Emerging health concerns from additive mixtures

There is increasing evidence that chronic exposure to certain food additives can cause harmful effects, raising public health concerns, particularly for children. Additionally, experimental and human studies suggest that these substances may have synergistic effects when consumed in mixtures. However, these cumulative effects are typically not taken into account in current safety assessments, plausibly due to the lack of real exposure data and the fact that legal limits are largely derived from toxicological studies of individual additives.

Nationwide representative assessment of additive intake

In the present study, researchers examined exposure to food additives and their mixtures in French children and adults. This study was part of Esteban's cross-sectional study. Participants aged 3–74 years were recruited between 2014 and 2016. Sociodemographic and physical activity data were collected using questionnaires. Height and weight were measured and body mass index (BMI) was calculated. Dietary data were collected using three 24-hour dietary recalls or records.

Based on these dietary data, daily average food intake was calculated. Nutrient intake was determined using a comprehensive food composition database. The NOVA classification was used to identify highly processed foods (UPFs) and estimate their contribution to energy intake. Intake of additives was assessed by merging dietary intake information, including store brand information, with food composition databases and laboratory testing in food matrices.

For each additive, mean and mean intakes were calculated both in absolute numbers (g/day) and relative to body weight (mg/kg/day). The additives were classified according to the proportion of consumers. Food additive mixtures were identified using non-negative matrix factorization based on additives consumed by more than 5% of participants, with the resulting mixtures explaining most of the variability in additive exposure profiles. Their associations with lifestyle, diet and sociodemographic factors were assessed using regressions.

High additive load and UPF consumption

The study involved 2,177 adults aged 18-74 and 1,279 children aged 6-17. UPFs averaged 34.2% and 49.3% of daily energy intake in adults and children, respectively. A total of 125 and 122 food additives were found in the diet of at least one adult and one child, respectively. On average, the daily intake of food additives was 5.1 g/day in children and 4.4 g/day in adults, with body weight-adjusted exposure in children approximately twice as high as in adults.

71 food additives were consumed by more than 5% of children, compared to 60 in adults. Exceedances of the acceptable daily intake (ADI) were observed for rosemary extract (E392) in both children and adults and for sucralose (E955) in a small proportion of adults. Three food additive mixtures were identified for adults and four for children, together accounting for approximately three-quarters of the exposure variability in adults and more than four-fifths in children.

Adult exposure patterns in additive mixtures

In adults, Mixture 1 was characterized by acidity regulators, food colorings, and emulsifiers and thickeners commonly found in industrial cakes, cookies, salty and highly processed foods, savory snacks, and sweetened soft drinks. Adults exposed to Mixture 1 were more likely to be younger, male, more educated, and less likely to be blue-collar workers.

Mixture 2 contained a flavor enhancer, preservatives, food coloring and emulsifiers. Ready-to-eat meals, highly processed foods, fats and sauces, dairy products, savory snacks and dairy desserts were the most representative foods of this mix. Higher exposure to Mixture 2 was found in adults with higher BMI.

Mixture 3 featured emulsifiers, food colorings, acidity regulators, a glazing agent, and two sweeteners. Representative of this mix were baked goods and both sweetened and artificially sweetened beverages. Most adults exposed to Mixture 3 were 30-50 years old, smokers, men and workers.

Distinctive additive mixtures in children

In children, Mixture 1 contained acidity regulators, a texturizer, and emulsifiers and thickeners commonly found in cakes and cookies, highly processed foods, and savory snacks. Children most exposed to Mixture 1 were more likely to be between the ages of 6 and 10 and come from households with incomes between 1,900 and 3,100 euros.

Mixture 2 featured an acidity regulator, a preservative, a flavor enhancer and emulsifiers commonly found in fats and sauces, dairy desserts, highly processed foods and ready-to-eat dishes. Women aged 15 to 17 who have never smoked and those with a BMI > 97th percentile were most exposed to this mixture, with higher exposure also observed in certain parental occupational and educational groups.

Mixture 3 contained an emulsifier, an acidity regulator, a glazing agent, a sweetener, antioxidants and food colorings commonly found in sweetened soft drinks, confectionery, and cakes and cookies. Women aged 11 to 14 who have never smoked and whose parents had lower educational backgrounds were most exposed to this mixture.

Food Additive Blend 4 contained an emulsifier as well as sweeteners and sweeteners commonly found in baked goods and artificially sweetened beverages. Exposure to Mixture 4 was more likely in children whose caregiver parent had a middle-level job.

In general, food additive mixtures were inversely associated with protein, fiber, β-carotene, and vitamin C intakes. Nevertheless, positive associations were observed with energy intake, saturated fats and added sugars.

Public health implications for food additive mixtures

In summary, most additives characterizing mixtures were UPF markers, although some additives also appear in less processed food matrices. Consumption of food additive mixtures increased with age in children but decreased in adults, suggesting that young adults and adolescents are most exposed to the additives. Higher intakes of additive mixtures were associated with less favorable sociodemographic and health profiles, with some heterogeneity between mixtures and population subgroups.

Further studies are needed to investigate the health effects and possible antagonistic or synergistic interactions between additives, especially given that the Esteban data were collected almost a decade ago and dietary habits may have evolved since then, as well as new evidence from other French cohorts linking certain additive mixtures to cardiometabolic consequences such as type 2 diabetes.

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