Common Food Additives Singled Out for Cardiovascular Risk

Food additive emulsifiers were individually associated with modest increases in cardiovascular disease (CVD) in a large French epidemiological cohort, researchers found.

Various types of emulsifiers — widely used to keep oils and water mixed together and prolong the shelf-life of processed foods — were positively associated with higher risks of CVD and coronary heart disease in the prospective NutriNet-Santé study, reported Bernard Srour, PharmD, PhD, MPH, of Université Sorbonne Paris Nord and Université Paris Cité, and colleagues in The BMJ.

After correction for multiple testing, carboxymethylcellulose remained associated with an increased risk of CVD (HR 1.03, 95% CI 1.01-1.05) and coronary heart disease (HR 1.04, 95% CI 1.02-1.06) over more than 7 years of follow-up, as did citric acid ester of monoglycerides and diglycerides of fatty acids (CVD: HR 1.04, 95% CI 1.02-1.07; coronary heart disease: HR 1.06, 95% CI 1.03-1.09).

Lactic ester of monoglycerides and diglycerides of fatty acids were also linked with an increased risk of CVD (HR 1.06, 95% CI 1.02-1.10).

“Owing to the observational nature of our study, we were unable to confirm that emulsifiers are causally related to CVD risk. However, we have as much as possible isolated the role of emulsifiers by adjusting for the proportion of ultra-processed foods in the diet, as well as for several dietary features that might causally impact CVD risk, including intakes of sugar, sodium, saturated fatty acids, energy, fiber, and artificial sweeteners,” Srour and team wrote.

While processed foods as a whole have already been linked to higher risks of obesity, CVD, cancer, and mortality, the effects of specific food additives had not been so clear.

The authors analyzed the role of emulsifiers, which are some of the most consumed food additives and count among them modified starches, lecithins, xanthan gum, and pectins. It is estimated that over half of industrially processed foods and beverages around the world contain at least one emulsifier, they noted.

“We now know from studies in animals and in the laboratory that some emulsifiers can change our microbiome, and cause inflammation in the gut; however, there is very little research undertaken in humans,” commented Kevin Whelan, PhD, a nutritional scientist of King’s College London.

“The evidence is not yet strong enough to advise that everybody avoids eating emulsifiers,” Whelan said in a statement.

“To identify a cause and effect, we need to do clinical trials. Before that, it is important people think about eating a healthier diet that includes lots of fruits and vegetables, [and] cooking from scratch is a good way to do this if you are able to. More exercise and avoiding smoking is also crucial,” he added.

Srour and colleagues nevertheless suggested that their findings linking emulsifiers and CVD support new food laws to protect consumers.

“Despite the moderate magnitude of the associations, these findings may have important public health implications given that these food additives are used ubiquitously in thousands of widely consumed ultra-processed food products,” they wrote. “Meanwhile, several public health authorities recommend limiting the consumption of ultra-processed foods as a way of limiting exposure to non-essential controversial food additives.”

This prospective cohort study was based on the French NutriNet-Santé cohort with data spanning from 2009 to 2021. The authors included over 95,000 adults without baseline CVD (mean age 43.1 years, 79% women) who provided at least three 24-hour food diaries in the first 2 years of participation.

From these records, the authors collected data on specific commercial brands of industrial food consumed, and estimated each person’s exposure to each individual food additive.

The most consumed emulsifiers were total modified starches (33.5%), sodium bicarbonate (26.9%), and pectins (6.4%). Food additive emulsifiers were most frequently found in processed fruit and vegetables, cakes and cookies, and dairy products.

Follow-up of study participants lasted a median 7.4 years, during which participants self-declared any major health events and sent supporting medical records.

Major limitations of the study included the disproportionate number of women and highly educated people in the French cohort, putting into question the findings’ generalizability to the larger population.

In addition, emulsifier consumption may have been underestimated due to the study’s inability to capture the presence of these agents in non-labeled foods (e.g., bakery pastries) and in naturally occurring settings (e.g., lecithins in eggs), Srour and team acknowledged.

“Future short-term human intervention studies, long-term epidemiological studies, and preclinical experiments will bring additional arguments to strengthen the plausibility of causal associations,” they noted.