Food additives are used for a reason. They can help keep products shelf-stable, reduce spoilage and make food safer to eat. But new research has linked several common food preservatives with a higher risk of high blood pressure.
The study, published in the European Heart Journal, followed more than 112,000 adults in France over several years. Every six months, participants answered detailed questions about what they ate and drank across a three-day period. Researchers used that information to estimate which preservatives they consumed and in what amounts. Participants’ cardiovascular health was also tracked, including new diagnoses of high blood pressure.
When researchers analysed the data, they found that people who consumed the highest levels of non-antioxidant preservatives, which are used to help prevent microbial growth, had a 29% higher risk of being diagnosed with high blood pressure compared with those who consumed the lowest levels. They also had a 16% higher risk of cardiovascular disease, including heart attack and stroke.
People who consumed the highest levels of antioxidant preservatives, which help stop food from spoiling or browning, had a 22% higher risk of developing high blood pressure.
The researchers also found that preservatives were extremely common in participants’ diets. During the first two years of the study, 99.5% of participants consumed at least one food containing a preservative.
The findings do not prove that preservatives caused high blood pressure or cardiovascular disease. The study was observational, which means it found a link, not cause and effect. Still, experts say the connection is worth taking seriously, especially because preservatives are so common in packaged foods.
Which food preservatives are concerning?
The study linked eight commonly used preservatives with a higher risk of high blood pressure:
- potassium sorbate
- potassium metabisulphite
- sodium nitrite
- ascorbic acid
- sodium ascorbate
- sodium erythorbate
- citric acid
- rosemary extract
The study also flagged ascorbic acid for its link with cardiovascular disease.
That does not mean you need to panic over one ingredient on one label. Preservatives are used across many foods, and the study looked at overall intake patterns over time. The more useful takeaway is to pay attention to how often packaged, processed and shelf-stable foods show up in your day.
If you have high blood pressure, heart disease, diabetes, kidney disease, or a family history of cardiovascular disease, it may be worth reviewing your packaged food intake with your GP or an accredited practising dietitian.
What’s behind the link?
Experts say a few factors may be involved. The preservatives themselves could play a role, but the foods they appear in may also matter.
“These preservatives tend to be found in shelf-stable, ultra-processed foods, which tend to be higher in added fats, sugar, and sodium,” says assistant professor in exercise and nutrition sciences Katherine N. Balantekin.
Those factors are already linked with a higher risk of high blood pressure and cardiovascular disease. Some preservatives may also affect inflammation, oxidative stress, blood vessel function or the gut microbiome, all of which may influence blood pressure regulation.
“Nitrites, for example, have been linked to oxidative damage in laboratory studies,” says registered dietitian Scott Keatley.
Regularly eating ultra-processed foods, which often contain preservatives, has also been linked with a higher risk of type 2 diabetes. That matters because diabetes is itself a risk factor for cardiovascular disease.
“Type 2 diabetes is indeed also a risk factor for cardiovascular health [issues],” says lead study author Anaïs Hasenböhler.
Still, the exact reason for the association is not clear.
“But, ultimately, we don’t really know what’s behind this association,” says interventional cardiologist Cheng-Han Chen. “It’s probably a combination of all of these factors.”
What does a heart-healthy diet look like?
The practical takeaway is not to memorise every additive name on a label.
“The practical takeaway isn’t that consumers need to memorize additive names,” Keatley says. “This study adds to growing evidence that diets centered on minimally processed foods are associated with better cardiovascular health.”
To support heart health, Dr Chen recommends cutting back on highly processed foods and focusing on whole foods where possible.
“We recommend plenty of fruits and vegetables, whole grains, lean proteins, and less saturated fats,” Dr Chen says.
If you are particularly concerned about high blood pressure, a lower-sodium diet may help. Australian and New Zealand guidance recommends adults aim for around 2,000mg of sodium a day, which is roughly 5g of salt, or about one teaspoon. Most sodium in the Australian diet comes from processed and packaged foods, not just salt added at the table.
Keatley also recommends eating more potassium-rich foods, as potassium can help support healthy blood pressure. Good sources include bananas, oranges, potatoes, leafy greens, beans and lentils.
“If you are to purchase vegetables, it is recommended for you to look for fresh, uncooked, unprocessed items, or if you are looking for the fastest to prepare and eat, to favor frozen options which are preserved through a low temperature, not necessarily through the addition of food additive preservatives,” says study co-author and nutritional epidemiology researcher Mathilde Touvier.
In real life, that may look like choosing fresh or frozen vegetables more often, swapping processed meats for lean protein, checking sodium on packaged foods and building meals around plants, wholegrains and minimally processed staples.
The aim is not a perfect diet. It is to reduce how often ultra-processed, shelf-stable foods make up the centre of your meals.
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