High intake of e-numbers found in food linked to risk of heart disease & stroke

A high intake of several ‘E-numbers’ which are widely used in many processed foods to improve texture and extend shelf-life, has been linked to the increased risk of cardiovascular disease (CVD), a new study suggests.

The research, published by The BMJ says that that these food additives are used ubiquitously in thousands of widely  consumed ultra-processed food products, and these findings have important public health implications.

According to The BMJ, emulsifiers are often added to processed and packaged foods such as pastries, cakes, ice cream, desserts, chocolate, bread, margarine and ready meals, to enhance their appearance, taste, texture and shelf life. They include celluloses, mono- and diglycerides of fatty acids, modified starches, lecithins, carrageenans  (derived from red seaweed; used to thicken foods), phosphates, gums and pectins.

But with all food additives, the safety of emulsifiers is regularly assessed based on the available scientific evidence, yet some recent research suggests that emulsifiers can disrupt gut bacteria and increase inflammation, leading to potentially increased susceptibility to cardiovascular problems.

Researchers in France set out to assess the associations between exposure to emulsifiers and risk of cardiovascular disease, including coronary heart disease and cerebrovascular disease - conditions affecting blood flow and blood vessels in the heart and brain.

Their findings were based on 95,442 French adults (average age 43 years; 79% women) with no history of heart disease who were taking part in the NutriNet-Santé cohort study between 2009 and 2021. During the first two years of follow-up, participants completed at least three (and up to 21) 24-hour online dietary records.

Each food and beverage item consumed was then matched at the brand level against three databases to identify the presence and the dose of any food additive. Laboratory tests were also performed to provide quantitative data.

Participants were also asked to report any major CVD event, such as a heart attack or stroke, which were validated by an expert committee after reviewing the participants’ medical records.

Deaths linked to CVD were also recorded using the French national death register, and several well known risk factors for heart disease including age, sex, weight (BMI), educational level, family history, smoking status, physical activity levels, and diet quality (e.g. sugar, salt, energy, alcohol intakes) were taken into account.

After an average follow-up of 7 years, higher intake of total celluloses (E460-E468), cellulose (E460) and carboxymethylcellulose (E466) were found to be positively associated with higher risks of CVD and specifically coronary heart disease.

However, Tracy Parker, heart health dietitian at the British Heart Foundation (BHF), said this type of study “can only show an association” between a high intake of certain emulsifiers and cardiovascular disease.

She added: “We need more research to properly understand the link between UPF and heart disease.

“While it would be hard to avoid UPF entirely in our diets, cutting down on food like cakes and biscuits and cooking more from scratch are already things we know can help improve our diets and, in doing so, lower our cardiovascular disease risk.

“It is also essential to create an environment that supports this, by implementing delayed policies that are already on the table to restrict the advertising and promotion of often highly processed foods which are high in fat, sugar and salt.”

Dr Gavin Stewart, senior lecturer in evidence synthesis at Newcastle University, said that while the “study demonstrates a potential effect” there is a need for “cautious interpretation”.

“The strength of evidence from a single observational study is inherently low because of uncertainty about confounders and causal relationships.

“Further studies and evidence synthesis are required to reduce this uncertainty.”

The BMJ stated that his is a single observational study, so can’t establish cause, and the researchers acknowledge some study limitations. For example, the high proportion of women, higher educational background, and overall more health conscious behaviours among the NutriNet-Santé study participants compared with the general French population, may limit the generalisability of the results.

However, the study sample was large and the researchers were able to adjust for a wide range of potentially influential factors, while using unique detailed brand-specific data on food additives. What’s more, the results were unchanged after further testing, suggesting that they are robust.

The researchers stressed that these results need replication in other large scale studies, but say they could “contribute to the re-evaluation of regulations around food additive usage in the food industry to protect consumers.”

“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,” they added.