Lack of genotoxicity in vivo for food color additive Allura Red AC

Allura Red AC is a xenobiotic. Is it also a carcinogen?

Merriam-Webster and Oxford define a xenobiotic as any substance foreign to living systems. Allura Red AC (a.k.a., E129; FD&C Red No. 40), a synthetic food dye extensively used in manufacturing ultra-processed foods and therefore highly prevalent in our food supply, falls under this category. The surge in synthetic food dye consumption during the 70s and 80s was followed by an epidemic of metabolic diseases and the emergence of early-onset colorectal cancer in the 1990s. This temporal association raises significant concerns, particularly given the widespread inclusion of synthetic food dyes in ultra-processed products, notably those marketed toward children. Given its interactions with key contributors to colorectal carcinogenesis such as inflammatory mediators, the microbiome, and DNA damage, there is growing interest in understanding Allura Red AC's potential impact on colon health as a putative carcinogen. This review discusses the history of Allura Red AC, current research on its effects on the colon and rectum, potential mechanisms underlying its impact on colon health, and provides future considerations. Indeed, although no governing agencies classify Allura Red AC as a carcinogen, its interaction with key guardians of carcinogenesis makes it suspect and worthy of further molecular investigation. The goal of this review is to inspire research into the impact of synthetic food dyes on colon health.

Food Safety and Health Concerns of Synthetic Food Colors: An Update

The toxicity of food additives is widely studied and concerns many consumers worldwide. Synthetic food colors are often considered an unnecessary risk to consumer health. Since the European Food Safety Authority's (EFSA) re-evaluation between 2009 and 2014, the body of scientific literature on food colors has grown, and new evaluations are being published by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Therefore, this narrative review aims to review the toxicological data that have become available since 2014. The reviewed colors are Quinoline Yellow, Sunset Yellow, Azorubine, Amaranth, Ponceau 4R, Erythrosine, Allura Red, Patent Blue, Indigo Carmine, Brilliant Blue FCF, Green S, Brilliant Black, Brown HT, and Lithol Rubine BK. Tartrazine was not included in this paper; the overwhelming amount of recent data on Tartrazine toxicity requires more space than this review can provide. The issues regarding the toxicity of synthetic food colors and real population exposures are being regularly examined and reviewed by relevant authorities, such as the EFSA and JECFA. The current ADI limits set by the authorities are mostly in agreement, and they seem safe. However, the EFSA and JECFA assessments of some of the colors are more than a decade old, and new evidence will soon be required.

The synthetic food dye, Red 40, causes DNA damage, causes colonic inflammation, and impacts the microbiome in mice

The incidence of colorectal cancer (CRC) among young people has been on the rise for the past four decades and its underlying causes are only just starting to be uncovered. Recent studies suggest that consuming ultra-processed foods and pro-inflammatory diets may be contributing factors. The increase in the use of synthetic food colors in such foods over the past 40 years, including the common synthetic food dye Allura Red AC (Red 40), coincides with the rise of early-onset colorectal cancer (EOCRC). As these ultra-processed foods are particularly appealing to children, there is a growing concern about the impact of synthetic food dyes on the development of CRC. Our study aimed to investigate the effects of Red 40 on DNA damage, the microbiome, and colonic inflammation. Despite a lack of prior research, high levels of human exposure to pro-inflammatory foods containing Red 40 highlight the urgency of exploring this issue. Our results show that Red 40 damages DNA both in vitro and in vivo and that consumption of Red 40 in the presence of a high-fat diet for 10 months leads to dysbiosis and low-grade colonic inflammation in mice. This evidence supports the hypothesis that Red 40 is a dangerous compound that dysregulates key players involved in the development of EOCRC.

Food Intake and Colorectal Cancer

Colorectal cancer (CRC) accounts for considerable mortalities worldwide. Several modifiable risk factors, including a high intake of certain foods and beverages can cause CRC. This review summarized the latest findings on the intake of various foods, nutrients, ingredients, and beverages on CRC development, with the objective of classifying them as a risk or protective factor. High-risk food items include red meat, processed meat, eggs, high alcohol consumption, sugar-sweetened beverages, and chocolate candy. Food items that are protective include milk, cheese and other dairy products, fruits, vegetables (particularly cruciferous), whole grains, legumes (particularly soy beans), fish, tea (particularly green tea), coffee (particularly among Asians), chocolate, and moderate alcohol consumption (particularly wine). High-risk nutrients/ingredients include dietary fat from animal sources and industrial trans-fatty acids (semisolid/solid hydrogenated oils), synthetic food coloring, monosodium glutamate, titanium dioxide, and high-fructose corn sirup. Nutrients/ingredients that are protective include dietary fiber (particularly from cereals), fatty acids (medium-chain and odd-chain saturated fatty acids and highly unsaturated fatty acids, including omega-3 polyunsaturated fatty acids), calcium, polyphenols, curcumin, selenium, zinc, magnesium, and vitamins A, C, D, E, and B (particularly B6, B9, and B2). A combination of micronutrients and multi-vitamins also appears to be beneficial in reducing recurrent adenoma incidence.

Azo dyes in the food industry: Features, classification, toxicity, alternatives, and regulation

Azo dyes, including Tartrazine, Sunset Yellow, and Carmoisine, are added to foods to provide color, but they have no value with regard to nutrition, food preservation, or health benefits. Because of their availability, affordability, stability, and low cost, and because they provide intense coloration to the product without contributing unwanted flavors, the food industry often prefers to use synthetic azo dyes rather than natural colorants. Food dyes have been tested by regulatory agencies responsible for guaranteeing consumer safety. Nevertheless, the safety of these colorants remains controversial; they have been associated with adverse effects, particularly due to the reduction and cleavage of the azo bond. Here, we review the features, classification, regulation, toxicity, and alternatives to the use of azo dyes in food.

Risk assessment of azo dyes as food additives: Revision and discussion of data gaps toward their improvement

The food industry uses dyes mainly to overcome color loss during the processing and storage of products, with the azo dyes currently being the most employed. Studies on the safety of using these dyes in foods started in the 1950s and have indicated the potential for concern. This review discusses the risk assessment of food intake containing artificial azo dyes. There are case reports and, subsequently, double-blind placebo-controlled trials in some individuals who may experience adverse effects from the intake of azo dyes, but it is unclear whether these adverse effects are restricted to specific populations or more generalized. In view of this, different toxicological endpoints are evaluated to verify toxic effects in in vitro and in vivo models and to establish the no observed adverse effect level. Exposure estimation studies have shown that human exposure to azo dyes via oral intake is mainly below the acceptable daily intake established by advisory bodies. However, most countries do not have studies that estimate the oral intake of azo dyes. In this case, local food diversity and racial-ethnic specificities are not considered when stating the exposure estimate is below the acceptable daily intake for the human population and thus may not represent actual intake. Concerning the scenario established above, this review discusses the most critical gaps to be overcome to contribute to the direction of future studies and the development of more effective public policies concerning the safety of the intake of artificial azo dyes.

Safety and efficacy of a feed additive consisting of Allura Red AC for small non-food-producing mammals and ornamental birds (Versele-Laga)

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Allura Red AC for small non-food-producing mammals and ornamental birds when used as an additive that add or restore colour in feedingstuffs. The use of Allura Red AC up to the proposed conditions of use of 500 mg/kg complete feed is considered safe for guinea pig, chinchilla, degu, hamster, gerbil and chipmunk. The following maximum safe levels (mg/kg complete feed) apply to the following species: ferrets 99, rabbits 123, canaries, budgerigars, mynah and toucans 45, lovebirds 51, cockatiels 79, cockatoos 115, amazons 145, parrots 147, yellow breast macaw 150, blue-throated macaw 173 and hyacinth macaw 214. The maximum safe level of Allura Red AC for other small non-food-producing mammal is 99 mg/kg feed and for other ornamental birds is 45 mg/kg feed. Inhalation exposure of Allura Red is regarded as hazardous. In the absence of data, the Panel cannot conclude on the potential of Allura Red to be a skin/eye irritant or a skin sensitiser. The FEEDAP Panel cannot conclude on the efficacy of the additive.

Food colorants metabolized by commensal bacteria promote colitis in mice with dysregulated expression of interleukin-23

Both genetic predisposition and environmental factors appear to play a role in inflammatory bowel disease (IBD) development. Genetic studies in humans have linked the interleukin (IL)-23 signaling pathway with IBD, but the environmental factors contributing to disease have remained elusive. Here, we show that the azo dyes Red 40 and Yellow 6, the most abundant food colorants in the world, can trigger an IBD-like colitis in mice conditionally expressing IL-23, or in two additional animal models in which IL-23 expression was augmented. Increased IL-23 expression led to generation of activated CD4⁺ T cells that expressed interferon-γ and transferred disease to mice exposed to Red 40. Colitis induction was dependent on the commensal microbiota promoting the azo reduction of Red 40 and generation of a metabolite, 1-amino-2-naphthol-6-sulfonate sodium salt. Together these findings suggest that specific food colorants represent novel risk factors for development of colitis in mice with increased IL-23 signaling.

Early-onset colorectal cancer: initial clues and current views

Over the past several decades, the incidence of early-onset colorectal cancer (EOCRC; in patients <50 years old) has increased at an alarming rate. Although robust and scientifically rigorous epidemiological studies have sifted out environmental elements linked to EOCRC, our knowledge of the causes and mechanisms of this disease is far from complete. Here, we highlight potential risk factors and putative mechanisms that drive EOCRC and suggest likely areas for fruitful research. In addition, we identify inconsistencies in the evidence implicating a strong effect of increased adiposity and suggest that certain behaviours (such as diet and stress) might place nonobese and otherwise healthy people at risk of this disease. Key risk factors are reviewed, including the global westernization of diets (usually involving a high intake of red and processed meats, high-fructose corn syrup and unhealthy cooking methods), stress, antibiotics, synthetic food dyes, monosodium glutamate, titanium dioxide, and physical inactivity and/or sedentary behaviour. The gut microbiota is probably at the crossroads of these risk factors and EOCRC. The time course of the disease and the fact that relevant exposures probably occur in childhood raise important methodological issues that are also discussed.

All You Can Feed: Some Comments on Production of Mouse Diets Used in Biomedical Research with Special Emphasis on Non-Alcoholic Fatty Liver Disease Research

The laboratory mouse is the most common used mammalian research model in biomedical research. Usually these animals are maintained in germ-free, gnotobiotic, or specific-pathogen-free facilities. In these facilities, skilled staff takes care of the animals and scientists usually don’t pay much attention about the formulation and quality of diets the animals receive during normal breeding and keeping. However, mice have specific nutritional requirements that must be met to guarantee their potential to grow, reproduce and to respond to pathogens or diverse environmental stress situations evoked by handling and experimental interventions. Nowadays, mouse diets for research purposes are commercially manufactured in an industrial process, in which the safety of food products is addressed through the analysis and control of all biological and chemical materials used for the different diet formulations. Similar to human food, mouse diets must be prepared under good sanitary conditions and truthfully labeled to provide information of all ingredients. This is mandatory to guarantee reproducibility of animal studies. In this review, we summarize some information on mice research diets and general aspects of mouse nutrition including nutrient requirements of mice, leading manufacturers of diets, origin of nutrient compounds, and processing of feedstuffs for mice including dietary coloring, autoclaving and irradiation. Furthermore, we provide some critical views on the potential pitfalls that might result from faulty comparisons of grain-based diets with purified diets in the research data production resulting from confounding nutritional factors.

Effect of ultra-fine friction grinding on the physical and chemical properties of curcuma (Curcuma longa L.) suspensions

Curcuma longa is a rhizome used for the extraction of curcumin, a yellow colorant that only represents 3 wt% of the dried rhizome. To increase the possibility of using the entire rhizome as a food colorant, in the present investigation, the effect of ultra-fine friction grinding (supermasscolloider) to obtain turmeric suspensions was evaluated. To achieve this goal, two distances between the grinding stones or Gap were evaluated (G of -1 and -1.5), and the obtained suspensions were characterized by infrared spectroscopy and through the determination of curcumin content, color, particle size, sedimentation index, serum cloudiness, and microstructure. The results establish that a lower G contributes to an increase in the release of curcumin in the suspension up to 21%, which is related to a greater tendency for yellow coloration, observed in the increase of the ^* b coordinate of color (from 61.588 to 66.497). Additionally, it was found that a lower G generates smaller particle sizes, which is related to a lower turbidity. PRACTICAL APPLICATION: This research shows that ultra-fine friction grinding (UFFG) has great potential for the development of turmeric suspensions. The results have applications in the food industry sector, because UFFG could be used to produce different types of vegetable suspensions.

The nanotech potential of turmeric (Curcuma longa L.) in food technology: A review

New trends in food are emerging in response to consumer awareness of the relationship between food and health, which has triggered the need to generate new alternatives that meet the expectations of the market. Revolutionary fields such as nanotechnology have been used for the encapsulation of nutritional ingredients and have great potential for the management of food additives derived from fruits and plant species. Turmeric, a spice that has been used as a dyeing agent, is recognized for its properties in Ayurveda medicine. This article aims to provide an overview of the characteristics of turmeric as an ingredient for the food industry, including its properties as a coloring agent, antioxidant, and functional ingredient. This article also highlights the potential of nanotechnology to enhance these properties of turmeric and increase the possibilities for the application of its components, such as cellulose and starch, in the development of nanostructures for food development.

Sunset Yellow and Allura Red modulate Bcl2 and COX2 expression levels and confer oxidative stress-mediated renal and hepatic toxicity in male rats

Studies on the adverse health effects caused by azo dyes are insufficient and quite contradictory. This work aims to investigate the possible toxic effect of two types of widely used food additives, Sunset Yellow and Allura Red, by assessing the physiological, histopathological and ultrastructural changes in the liver and kidney. Also, we investigated the genotoxic effect of both dyes on white blood cells. Thirty adult male albino rats were divided into three groups of 10 animals each: control (received water), Sunset Yellow-treated (2.5 mg/kg body weight) and Allura Red-treated (seven mg/kg body weight). The doses were orally applied for 4 weeks. Our results indicated an increase in the biochemical markers of hepatic and renal function (Aspartate aminotransferase, alanine aminotransferase, urea, uric acid and creatinine) in animals administered with the azo dyes. We also observed a noticeable increase in MDA and a marked decrease in total antioxidant levels in azo dye-treated animals compared to controls. Conversely, both dyes adversely affected the liver and kidney of albino rats and altered their histological and fine structure, with downregulation of Bcl2 and upregulation of COX2 expression. Our comet assay results showed a significant elevation in the fold change of tail moment in response to application of Sunset Yellow but not Allura Red. Collectively, we show that Sunset Yellow and Allura Red cause histopathological and physiological aberrations in the liver and kidney of male Wistar albino rats. Moreover, Sunset Yellow but not Allura Red induces a potential genotoxic effect.

Safety assessment of sodium acetate, sodium diacetate and potassium sorbate food additives

Cytotoxicity and genotoxicity of sodium acetate (SA), sodium diacetate (SDA), and potassium sorbate (PS) was tested on Human Umbilical Vein Endothelial Cells (HUVEC). Cytotoxicity was investigated by MTT assay and flow cytometry analysis, while genotoxicity was evaluated using DNA fragmentation and DAPI staining assays. The growth of treated HUVECs with various concentrations of SA, SDA and PS decreased in a dose-and time-dependent manner. The IC50 of 487.71, 485.82 and 659.96 µM after 24 h and IC50 of 232.05, 190.19 and 123.95 µM after 48 h of treatment were attained for SA, SDA and PS, respectively. Flow cytometry analysis showed that early and late apoptosis percentage in treated cells was not considerable. Also neither considerable DNA fragmentation nor DNA smear was observed using DAPI staining and DNA ladder assays. Overall, it can be concluded that the aforementioned food additives can be used as safe additives at low concentration in food industry.