“Equo ne credite, Teucri. Quidquid id est, timeo Danaos et dona ferentes (Don’t trust the horse, Trojans. Whatever it is, I fear the Greeks even bearing gifts).
― Virgil
The Aeneid (Book II, line 48)
One commonly encountered rebuttal to the increasing evidence that ultra-processed foods (UPFs) play a causative role in our current pandemic of chronic disability and disease is that we can make the same version of these UPFs at home, and they wouldn’t be ultra-processed (for further details of what constitutes an ultra-processed food, NOVA Classification Group Four, as referenced in this column, follow this link). Whilst this is true, as always, the devil is in the details – or, in this case, the devil’s food cake mix ingredient list. A from-scratch chocolate cake will include items like flour, chocolate, sugar, and eggs. It is unlikely to include industrial flavor enhancers and stabilizers, such as food additive emulsifiers.
Industrial food emulsifiers are used in the production of a wide variety of commercial food offerings. They often escape notice as they do not fall into the commonly “forbidden” food categories such as saturated fat or red meat. Additionally, they are often assumed to be innocuous, having undergone cytotoxic and genotoxic analysis prior to approval. These emulsifiers are used to achieve specific functional properties in manufactured comestibles, such as stabilizing emulsions, improving texture and mouth feel, improving dough handling and volume, enhancing aeration, allowing the reduction of fat, and preventing staling and enhancing shelf life. They can be found in a wide variety of foods, including salad dressings, mayonnaise, sauces, ice cream, frozen yogurts, margarine, processed cheese, baked goods like cookies, ready-to-eat meals, confectioneries, bread, cakes, pastries, croissants, and other layered dough products, sandwich bread, buns, rolls, whipped cream, mousse, some cake batters, low-fat spreads, some deli meats, chips, crackers, instant soups, bread mixes, dairy products, coffee creamers, and icings.
It’s worth noting that the approval process and safe consumption limit determinations for food additive emulsifiers do not include an examination of their potential effects on gut microbiota and their association with inflammation and metabolic perturbations, as recent experimental evidence has suggested. This week’s study spotlight examines an analysis from the French NutriNet-Santé study that explores the link between the consumption of food additive emulsifiers and the risk of type II diabetes.
- The study analyzed data from 104,139 adult participants of the French NutriNet-Santé study.
- The cohort was 79.2% female, with a mean age of 42.7 years and a mean follow-up duration of 6.8 years.
- The data was collected from 1 May 2009 through 26 April 2023.
- Dietary intake was assessed every six months utilizing three 24-hour dietary records collected non-consecutively over a two-week period, including two weekdays and one weekend.
The Take-Away:
- There was a significantly increased risk of type II diabetes with the consumption of the following food additives/emulsifiers:
- Carrageenans
- Tripotassium phosphate
- Acetyl tartaric acid esters of monoglycerides and diglycerides of fatty acids
- Sodium citrate
- Guar gum
- Gum arabic
- Xanthan gum
- The use of additives varies widely amongst different brands; for example, within this study, the same food item, a chocolate cookie, contained from 0 to 8 different additives depending on the manufacturer.
- In this European study, the most commonly used emulsifiers were lecithins which were found in 14% of the food products.
- The amount of ultra-processed food consumption in the study population was 17.3%, with an average total emulsifier intake of 4192 mg per day.
The Caveat:
The consumption of ultra-processed foods (UPFs) has been associated with an increased risk of chronic conditions like type II diabetes in over 75 recent prospective studies carried out worldwide.[1] Multiple European studies have linked ultra-processed food intake to an elevated risk of type II diabetes. This study is the first to quantitatively assess exposure to food additive emulsifiers used in the manufacture of UPFs in a large-scale cohort.
Not only are food emulsifiers ubiquitous in UPFs, where they enhance texture and allow for increased shelf life (and thus increase profitability), but they are also a key component of industrially manufactured foods that are often promoted as healthier choices, such as low-fat options and vegan/vegetarian alternatives like plant-based meats (PBMAs).
In the production of plant-based meats, emulsifiers play a crucial role in improving texture, stability, and mouthfeel. Commonly used emulsifiers involved in the construction of PBMAs that were examined in this study include mono- and diglycerides derived from glycerol and fatty acids, often sourced from vegetable oils, carrageenans, xanthan gum, and guar gum. Polysorbate 80 and carboxymethylcellulose are other emulsifiers used in manufacturing PBMAs that have been shown in other studies to negatively impact the gut microbiome.[2]
Experimental studies have shown that emulsifiers directly modulate the composition and function of the gut microbiome, creating an environment of chronic low-grade intestinal inflammation. This inflammation increases the risk and promotes the development of metabolic disorders like hypertension, obesity, and type II diabetes.
The amount of ultra-processed food intake in this particular European cohort, at less than 20%, was significantly less than the average US intake, which is estimated to be between 65-70%. However, because of the ubiquitous nature of food additives, 99.7% of the participants were exposed to at least one food additive emulsifier. An additional point of interest is that in contrast to what conventional wisdom might suggest, the main contributors to the exposure of industrial emulsifiers were ultra-processed fruits and vegetables, which contributed almost 20% (18.5%) of the total emulsifier intake.
Ultra-processed fruit and vegetable products often contain emulsifiers to enhance texture, extend shelf life, and maintain consistency. Some common types of UPF fruits and vegetables, often marketed as “healthy” alternatives, include fruit juices and smoothies (common emulsifiers: polysorbate 80, lecithin, mono- and diglycerides), vegetable-based spreads and dips (common emulsifiers: lecithin, xanthan gum, guar gum), canned or packaged soups and stews (common emulsifiers: mono- and diglycerides, soy lecithin, carrageenan), plant-based dairy alternatives (common emulsifiers: lecithin, carrageenan, guar gum, xanthan gum), frozen fruit and vegetable products (common emulsifiers: mono- and diglycerides, polysorbate 80), ready-to-eat meals (common emulsifiers: lecithin, xanthan gum, guar gum), and snack foods (common emulsifiers: soy lecithin, mono- and diglycerides).
Industrial emulsifiers are widespread across many categories of ultra-processed foods making their likelihood of unacknowledged consumption quite high. Approved emulsifiers have generally been deemed safe for human consumption following cytotoxic and genotoxic examinations, which have also been used to set their acceptable daily intakes (ADIs). In other words, their effects on the gut microbiome and upon us through gut microbiota-mediated effects have not been accounted for in their approval for use. For example, in the current study, despite no participant exceeding the 75mg per kilogram body weight ADI limit for total carrageenans, “a positive association with type 2 diabetes was observed for these extensively used additives.” For many other commonly used emulsifiers, no ADIs have even been established.
This study adds to a growing body of evidence that demonstrates “positive associations between various food additive emulsifiers and an increased risk of type 2 diabetes.” It is time we recognized that ultra-processed foods are a distinct category of comestibles with unique properties and unique risks; they are not simply more convenient forms of home-cooked foods. Because of the way they are constructed, commonly recommended “healthy” dietary approaches, such as focusing on a more plant-forward menu, must come with a caveat when considering offerings such as those derived from ultra-processed fruits and vegetables. Such caution should be applied to all UPFs, quidquid id est!
[1] (Srour, 2022)
[2] (Naimi, 2021)
Study:
Additional Resources:
Srour B, Kordahi MC, Bonazzi E, Deschasaux-Tanguy M, Touvier M, Chassaing B. Ultra-processed foods and human health: from epidemiological evidence to mechanistic insights. Lancet Gastroenterol Hepatol 2022; 7: 1128–40. https://doi.org/10.1016/S2468-1253(22)00169-8.
Srour B, Fezeu LK, Kesse-Guyot E, et al. Ultraprocessed food consumption and risk of type 2 diabetes among participants of the NutriNet-Santé prospective cohort. JAMA Intern Med 2020; 180: 283–91.
