Associations between food additive emulsifiers and cancer risk

In a recent study published in PLoS Medicine, researchers assessed associations between food emulsifier intake and cancer risk among NutriNet-Santé study participants.

Background

Emulsifiers, common in industrially processed foods, have been linked to chronic inflammation and an increased risk of cancer. These additives help stabilize lipid-containing food preparations, which account for a considerable amount of dietary energy consumption.

Recent research shows that unfavorable consequences, such as changes in the gut microbiota and increased inflammation, may raise the risk of gut diseases and chronic diseases such as extraintestinal malignancies. Large-scale epidemiological studies are required to determine the long-term influence on human health.

About the study

In the present population-based prospective cohort study, researchers investigated whether consuming food additive emulsifiers increases cancer risk.

The French NutriNet-Santé study involved 92,000 adult participants without prevalent cancer at recruitment, aged 45 years, and 79% female. They completed five questionnaires querying their dietary intake, health, anthropometric data, physical activity, sociodemographic data, and lifestyle data.

The team followed the participants for seven years and estimated food additive emulsifier intakes for those with three or more 24-hour dietary records over two weeks during their initial two years of follow-up. They excluded individuals underreporting total calorie intake (17%, n=21,423).

The researchers matched the food items consumed in specific dietary records against three databases to determine food additive presence: Observatoire de la qualité de l’alimentation (OQALI), Mintel Global New Products Database (GNPD), and Open Food Facts. They estimated the number of additives consumed based on ad hoc assays, generic food groups, and doses, following the European Food Safety Authority (EFSA) and Codex General Standard for Food Additives (GSFA) guidelines.

Among food additive substances quantified from participant dietary records, the team identified 60 as emulsifying salts or emulsifiers and summed their intakes to determine the total food emulsifier exposure. They totaled individual emulsifier substances with those having identical chemical bonds into eight groups: lactylates, phosphates, polyglycerol ester molecules of fatty acids (FAs, monoglycerides, and diglycerides), carrageenans, celluloses, alginates, and modified starches.

The researchers asked participants to report health occurrences on an online interface, verified by expert physicians after evaluating participant medical records and gathering additional data from hospitals and their treating doctors when required. They used the International Classification of Diseases, Clinical Modification Codes (ICD-CM, 10th revision) to classify cancers.

The team conducted a study on primary cancer cases diagnosed two years after enrollment through 5 October 2021, using multivariable Cox regression modeling to determine the hazard ratios (HRs) for the association between food emulsifiers and cancer risk. They adjusted the model for factors such as age, sex, BMI, height, physical activity, smoking status, educational level, dietary records, family history of cancer, energy intake without alcohol, daily alcohol intake, lipids, sugars, sodium, fiber, consumption levels of fruits and vegetables, red and processed meats, and dairy products.

Results

The mean age of the study participants was 45 years. They provided six dietary records; on average, 99.8% of the study participants consumed one or more food emulsifiers. Compared to individuals with low emulsifiers, those with high intake were younger and showed a lower likelihood of smoking, lower alcohol intake, higher body mass index, educational attainment, physical exercise levels, dietary calorie intake, and ultra-processed food proportion in their diets.

The team reported 2,604 new-onset cancer cases over two years of follow-up, including 90 lymphomas, 110 squamous cell carcinomas, 124 lung cancers, 162 melanomas, 207 colorectal, 322 prostate cancers, and 750 breast cancers. Increased monoglyceride and diglyceride fatty acid intake (especially E471) was related to higher cancer risk (hazard ratio, 1.2 for high versus low category), breast malignancy (HR, 1.2), and prostate tumors (HR, 1.5).

Additionally, the team observed associations with the risk of breast cancer for increased total carrageenan intake (HR, 1.3) and E407 carrageenan consumption (HR, 1.3). They found no significant link between emulsifier intake and colorectal cancer incidence, and although they identified some links with other food emulsifiers, none were robust in the sensitivity analyses.

The most common breast cancers were of the estrogen-positive (ER+, 85%) and progesterone-positive (PR+, 75%) types, while triple-negative breast cancers denoted 10% of all breast cancer cases. At diagnosis, 69.6% of breast cancers were local, 28.9% were advanced, and the remaining were metastatic. Regarding prostate cancers, 42%, 45%, and 13% were low-risk, intermediate-risk, and high-risk, respectively, as assessed using Gleason scores.

Conclusion

Overall, the study findings showed exposure to seven food emulsifiers was associated with an increased risk of cancer in French individuals. The findings may lead to changes in food industry laws on emulsifier use.

The researchers also discovered links between greater consumption of carrageenans and fatty acid monoglycerides and diglycerides and overall prostate and breast cancer risk. To ensure consumer safety, public health officials advocate restricting cosmetic additive intake. Further research is required to replicate these findings in different populations.