Preservatives, Blood Pressure, and the Innocent Bystander in Your Processed Food

Key takeaways

• In 112,395 French adults tracked for seven to eight years, the highest intakes of certain preservative additives were linked to a 29% higher risk of elevated blood pressure and 16% higher cardiovascular risk.
• Eight specific additives stood out — including sodium nitrite, potassium sorbate, citric acid, and, unexpectedly, ascorbic acid and sodium ascorbate.
• Those last two are forms of vitamin C, which is almost certainly a signal about where they appear rather than what they do.
• Preservative exposure was essentially universal: 99.5% of participants consumed at least one.

Most research on processed food asks how much of it people eat. This analysis, part of the long-running NutriNet-Santé cohort, went a level deeper — down to the individual additives in the products participants actually consumed.

Volunteers logged everything they ate and drank across three-day windows every six months, and researchers matched those records against ingredient data. Led by Dr. Mathilde Touvier at INSERM and Anaïs Hasenböhler at Université Sorbonne Paris Nord, the team then followed participants for an average of seven to eight years. The researchers describe it as the first study to examine a wide range of preservatives against cardiovascular outcomes in humans.

The pattern held in two directions. People with the highest intake of non-antioxidant preservatives — the ones used to inhibit bacteria and mold — showed a 29% higher risk of elevated blood pressure. Those highest in antioxidant preservatives, used to slow oxidation and rancidity, showed 22%.

The vitamin C question

Here is where the results require careful reading. Among the eight additives flagged, three are vitamin C or its close relatives: ascorbic acid (E300), sodium ascorbate (E301), and sodium erythorbate (E316). Ascorbic acid was the one additive also associated with cardiovascular outcomes directly.

Vitamin C is one of the most consistently supported nutrients in the literature, and there is no plausible mechanism by which dietary vitamin C raises blood pressure — if anything, the evidence points the other direction. So what is this finding actually capturing?

Almost certainly the company it keeps. Ascorbates are added to processed meats, sodas, packaged baked goods, and shelf-stable products — often specifically alongside sodium nitrite, where ascorbate is used as a curing accelerant. A high ascorbate-as-additive intake is a near-perfect marker for a diet heavy in industrially processed food. The molecule is riding along with the pattern, not driving it.

This is the central interpretive challenge in additive research. Individual additives cluster together in the same products, making it genuinely difficult to separate one ingredient's effect from the effect of the food category it signals. The researchers were explicit that the design is observational and cannot establish that any preservative was directly responsible.

Context is the whole story

The distinction that matters most here: a compound's effect depends on its form, its dose, and what surrounds it.

Ascorbic acid taken as a measured dose, or eaten in whole fruits and vegetables, behaves nothing like trace ascorbate in a cured meat product consumed alongside sodium, nitrites, refined starch, and a heavy total processed-food load. Same molecule, entirely different context — and in nutrition, context routinely determines outcome.

It is worth noting that citric acid (E330) and rosemary extract (E392) also appeared on the list, both of which are unremarkable compounds on their own. That three vitamin C forms, citric acid, and rosemary extract all cluster together is a strong hint that the list is tracking processed-food density rather than identifying five independent culprits.

A longevity lens

The durable takeaway is one the researchers themselves landed on: favor whole and minimally processed foods, and skip unnecessary additives. That holds regardless of how the mechanism eventually resolves.

The proposed biological pathways — oxidative stress and possible effects on pancreatic function — are ones that accumulate slowly. Neither shows up in a week. Both are the kind of low-grade, chronic exposure that matters precisely because it repeats daily for decades. The team is now examining how additives and ultra-processed foods influence inflammation, blood metabolic profiles, and the gut microbiome, which should clarify considerably.

The researchers also called for regulatory bodies including EFSA and the FDA to re-evaluate the risk-benefit profile of these additives — a reasonable ask given how universal the exposure is.

The takeaway

Take this study as evidence about food patterns rather than a verdict on individual compounds. The signal is that a diet dense in industrially preserved products tracks with worse cardiovascular measures over years, which is consistent with nearly everything else known about ultra-processed food.

The appearance of vitamin C on the list is the clearest illustration of why single-additive findings from observational data need interpretation rather than literal reading. A nutrient does not become harmful because it appears in the ingredient list of a food that is. The more useful lever remains the one it has always been: shift the balance of the diet toward foods that don't need a preservation strategy in the first place.

References:

Anaïs Hasenböhler, Guillaume Javaux, Marie Payen de la Garanderie, et al. Preservative food additives, hypertension, and cardiovascular diseases: the NutriNet-Santé study. European Heart Journal, 2026. DOI: 10.1093/eurheartj/ehag308.