Looking at the ingredient labels on foods lining supermarket shelves, it’s common to see names such as “potassium sorbate,” “citric acid,” and “L-ascorbic acid (vitamin C).” These substances are food additives used to prevent spoilage and preserve quality, and they are widely incorporated into industrially produced processed foods. According to Open Food Facts, the world’s largest open food database, more than 20 percent of the processed foods and beverages in its database contain at least one preservative.
Against this backdrop, a research team led by scientists at Sorbonne Paris Nord University and Université Paris Cité analyzed data from the large-scale NutriNet-Santé cohort study, which followed 112,395 participants for a median of 7.9 years, to investigate the relationship between dietary preservative intake and the risk of developing hypertension and cardiovascular disease.
“Experimental studies suggest that some preservative food additives may be harmful to cardiovascular health, but we have not had enough evidence on the impact of these ingredients in humans,” said Anaïs Hasenböhler, the doctoral researcher who led the study, in a press release. “As far as we know, this is the first study of its kind to investigate the links between a wide range of preservatives and cardiovascular health.”
8 Preservatives Linked to Hypertension Risk
The researchers divided preservatives into two broad categories. The first consisted of non-antioxidant preservatives, such as sorbates, nitrites, and sulfites, which inhibit the growth of mold and bacteria. The second consisted of antioxidant preservatives, including ascorbic acid, citric acid, and erythorbates, which prevent oxidation and discoloration in foods. According to the researchers, nearly every participant (99.5 percent) consumed at least one preservative during the first two years of the study.
The analysis found that participants with the highest intake of non-antioxidant preservatives had a 29 percent higher risk of developing hypertension than those with the lowest intake. They also had a 16 percent higher risk of overall cardiovascular disease, including heart attack, stroke, and angina. Participants with the highest intake of antioxidant preservatives likewise showed a 22 percent higher risk of hypertension.
The researchers also examined the 17 most commonly consumed preservatives individually. Of these, eight were associated with an increased risk of hypertension: potassium sorbate (E202), potassium metabisulfite (E224), sodium nitrite (E250), ascorbic acid (E300), sodium ascorbate (E301), sodium erythorbate (E316), citric acid (E330), and rosemary extract (E392). Among these, ascorbic acid was also associated with an increased risk of cardiovascular disease.
During the follow-up period, researchers recorded 5,544 cases of hypertension and 2,450 cases of cardiovascular disease, including 1,142 cerebrovascular events and 1,308 cases of coronary artery disease. The study also found that approximately 16 percent of the association between non-antioxidant preservatives and cardiovascular disease was mediated indirectly through hypertension. In other words, the findings suggest that preservatives may contribute to hypertension, which in turn may increase the risk of cardiovascular disease.
Calls to Reevaluate Food Additive Regulations
The researchers emphasize that these findings come from an observational study and do not establish a causal relationship between food preservatives and hypertension or cardiovascular disease. The study also has important limitations. Women accounted for 78.7 percent of participants, and the cohort included a relatively high proportion of highly educated individuals, meaning it does not perfectly represent the general population.
Even so, the statistical models accounted for a wide range of potential confounding factors, and the results remained consistent across multiple sensitivity analyses.
“These results suggest we need a reevaluation of the risks and benefits of these food additives by the authorities in charge, such as the EFSA in Europe and the FDA in the USA, for better consumer protection,” said Mathilde Touvier, research director at the French National Institute of Health and Medical Research, in a press release. “In the meantime, these findings support existing recommendations to favor nonprocessed and minimally processed foods, and avoid unnecessary additives.”
The possibility that preservatives long regarded as safe could affect cardiovascular health raises important questions about current regulatory approaches. For additives that are consumed continuously through multiple foods without numerical limits on their use, the findings suggest it may be time to reopen the debate over whether existing regulations are adequate.
This story originally appeared on WIRED Japan and has been translated from Japanese.