French researchers have identified seven food additive emulsifiers found in ultra-processed foods – including some in previously regarded ‘healthy foods’, like plant-based milk – that they suggest could be associated with an increased risk of developing type 2 diabetes.
It’s been estimated that about 530m adults globally live with diabetes, with 98% of those diagnoses being type 2 diabetes, and while certain lifestyle choices can increase the risk of developing the condition, previous research also shows that moderate intake of ultra-processed foods, which generally contain large amounts of sugar, fat, salt and food additives, can heighten this risk.
Now, a study from the National Research Institute for Agriculture, Food and Environment (INRAE) and the National Institute of Health and Medical Research (INSERM) in France has found that consuming seven specific food additive emulsifiers found in ultra-processed foods may be associated with an increased risk of developing type 2 diabetes.
The study was published in The Lancet Diabetes & Endocrinology.
What are food additive emulsifiers?
Bernard Srour, PhD, junior professor at INRAE and co-lead author of the study, told Medical News Today emulsifiers are among the most commonly used additives in processed foods.
“They are often added to processed and packaged foods, and certain industrial cakes, biscuits and desserts, as well as ice creams, chocolate bars, breads, margarines and ready-made meals, to improve their appearance, taste and texture and lengthen shelf life, and to be able to mix aqueous substances with oil-based substances.”
The most unhealthy?
For this study, Srour and his team analysed medical data from more than 104 000 French citizens who participated in the NutriNet-Santé web-cohort study between 2009 and 2023.
Over 14 years, study participants provided at least two days of dietary records every six months. Foods consumed were matched against databases to identify the presence and amount of food additives.
After an average follow-up of seven years, the scientists identified seven food additive emulsifiers associated with an increased risk for type 2 diabetes.
These are:
1. tripotassium phosphate (E340) – 15% increased risk per increment of 500 milligrams (mg ) per day
2. guar gum (E412) – 11% increased risk per increment of 500 mg per day
3. xanthan gum (E415) – 8% increased risk per increment of 500 mg per day
4. mono- and diacetyltartaric acid esters of mono- and diglycerides of fatty acids (E472e) – 4% increased risk per increment of 100 mg per day
5. sodium citrate (E331) – 4% increased risk per increment of 500 mg per day
6. carrageenans (total carrageenans and E407) – 3% increased risk per increment of 100 mg per day
7. gum arabic (E414) – 3% increased risk per increment of 1 000 mg per day.
But the most unexpected finding was that these additives came up among ingredients in some foods and beverages that people often consider healthy.
“Some of the emulsifiers were present in some foods that are marketed as ‘healthy’, like plant-based light margarines, some types of bread, plant-based milks, flavoured yogurts, so even participants with more favourable dietary behaviours can be exposed to these substances,” Srour said.
How do emulsifiers increase risk?
Mathilde Touvier, PhD, research director at INSERM, co-ordinator of the NutriNet-Santé cohort, and co-lead author of this study, said the research team decided to study the potential impact of food additive emulsifiers on type 2 diabetes risk as a small number of experimental studies – in vitro, animal, and short-term randomised controlled trials – suggested adverse effects of some emulsifiers, like gut microbiota dysbiosis, inflammation, and metabolic perturbations.
“Two cohort studies from our group showed associations between exposure to various food additive emulsifiers and an increased risk of cardiovascular disease and cancer,” she said.
“No such investigation has yet, to the best of our knowledge, been conducted to assess the risk of type 2 diabetes. We decided to look into these associations in the NutriNet-Santé cohort, as we have detailed and repeated dietary data, including commercial brands of consumed foods, coupled with a long follow-up.”
In the future, Touvier said, the team would investigate the potential underlying mechanisms behind this association, as these are currently unclear.
“We will be looking at variations in certain blood markers and the gut microbiota linked to the consumption of these additives, to better understand the underlying mechanisms,” she said. “We will also look at the health impact of additive mixtures and their potential ‘cocktail effects’.”
Pouya Shafipour, MD, a family and obesity medicine physician at Providence Saint John’s Health Centre in Santa Monica, California, who was not involved in this research, said he was not surprised by the study’s findings.
“We know additives are a big contributing factor to obesity, so it’s not a surprise, as that increases fatty liver, and generally weight gain and insulin resistance. Hopefully the findings will encourage more government regulation and for patients to eat more real, wholesome foods.”
Shafipour said it was as easy as focusing on eating real whole foods.
“Even a lot of diet supplements, protein bars, protein shakes, anything that pretty much comes with a wrapper, something that’s dried, they have to add (…) different preservatives to be able to preserve and make it last longer.
“So the more natural sources we eat in terms of food and supplements, the better. Eating more fruits rather than fruit bars, fruit juices, (and) sodas. Instead of protein bars, more natural sources of protein like cheese, meats, or plant-based protein.”
Study details
Food additive emulsifiers and the risk of type 2 diabetes: analysis of data from the NutriNet-Santé prospective cohort study
Clara Salame, Guillaume Javaux, Mathilde Touvier et al.
Published in The Lancet Diabetes & Endocrinology in May 2024
Summary
Background
Experimental studies have suggested potential detrimental effects of emulsifiers on gut microbiota, inflammation, and metabolic perturbations. We aimed to investigate the associations between exposures to food additive emulsifiers and the risk of type 2 diabetes in a large prospective cohort of French adults.
Methods
We analysed data from 104 139 adults enrolled in the French NutriNet-Santé prospective cohort study from May 1, 2009, to April 26, 2023; 82 456 (79·2%) were female and the mean age was 42·7 years (SD 14·5). Dietary intakes were assessed with three 24 h dietary records collected over three non-consecutive days, every 6 months. Exposure to additive emulsifiers was evaluated through multiple food composition databases and ad-hoc laboratory assays. Associations between cumulative time-dependent exposures to food additive emulsifiers and the risk of type 2 diabetes were characterised with multivariable proportional hazards Cox models adjusted for known risk factors.
Findings
Of 104 139 participants, 1056 were diagnosed with type 2 diabetes during follow-up (mean follow-up duration 6·8 years [SD 3·7]). Intakes of the following emulsifiers were associated with an increased risk of type 2 diabetes: total carrageenans (hazard ratio [HR] 1·03 [95% CI 1·01–1·05] per increment of 100 mg per day, p<0·0001), carrageenans gum (E407; HR 1·03 [1·01–1·05] per increment of 100 mg per day, p<0·0001), tripotassium phosphate (E340; HR 1·15 [1·02–1·31] per increment of 500 mg per day, p=0·023), acetyl tartaric acid esters of monoglycerides and diglycerides of fatty acids (E472e; HR 1·04 [1·00–1·08] per increment of 100 mg per day, p=0·042), sodium citrate (E331; HR 1·04 [1·01–1·07] per increment of 500 mg per day, p=0·0080), guar gum (E412; HR 1·11 [1·06–1·17] per increment of 500 mg per day, p<0·0001), gum arabic (E414; HR 1·03 [1·01–1·05] per increment of 1000 mg per day, p=0·013), and xanthan gum (E415, HR 1·08 [1·02–1·14] per increment of 500 mg per day, p=0·013).
Interpretation
We found direct associations between the risk of type 2 diabetes and exposures to various food additive emulsifiers widely used in industrial foods, in a large prospective cohort of French adults. Further research is needed to prompt re-evaluation of regulations governing the use of additive emulsifiers in the food industry for better consumer protection.
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