5 food preservatives to have on your watch list

Food preservatives help processed foods stop nasties in their tracks. But for your health’s sake, it may be worth keeping an eye on a few before taking your next bite.

Used to help maintain food quality, food preservatives make up a reasonable portion of our diet.

But with some 400 food additives approved for use in Australia, here’s how they may have an impact on your health.

What are food preservatives and how do they work?

Preservatives are a type of food additives used to help extend the shelf-life of foods and also potentially reduce the likelihood of foodborne diseases.

Often labelled on a product’s packaging by their name or code number within the 200 range, food preservatives are found in various common everyday products.

This includes fruit drinks, salad dressings, carbonated beverages, jams and pickles.

Additives also help to enhance the taste, texture and appearance of the food product to maintain its freshness and quality.

Can food preservatives be harmful to your health?

Dietitian Milly Smith says while food preservatives prevent the growth of things like mould and bacteria on food products, they could often be dangerous for your health.

These can be synthetic or man-made food preservatives, such as nitrates, benzoates, sulfites, and sorbates.

Adverse reactions may include skin allergies, cancer, and even cardiovascular or respiratory diseases.

These negative health concerns have recently led the state of California to pass a new law banning four common synthetic food additives usually found in ultraprocessed foods such as red dye No.3, potassium bromate, brominated vegetable oil and propylparaben.

However, some studies suggest natural food preservatives such as plant oil and extracts, citric and ascorbic acids from citrus juices, cinnamon, salt, sugar, vinegar and alcohol may be healthier than synthetic preservatives.

These are usually obtained from plants, animals and microbial origins, which have been reported to be generally safe.

Common food preservatives to look out for


Sorbates are some of the widely used preservatives, with Endeavour College instructor and nutritionist Lexi Crouch highlighting its general use in helping prevent microbial growth and extending food shelf life.

The list of different sorbates includes sorbic acid (200), sodium sorbate (201), potassium sorbate (202) and calcium sorbate (203).

Added to wine, fruit juice, dried fruit, meat and fish products to inhibit the growth of yeasts and mould, sorbates are also found in dairy products such as cheese.

Naturopath and nutritionist Madeline Calfas says while health impacts such as anaphylaxis is rare but possible, there may be respiratory reactions to the likes of asthma-type symptoms, wheezing, rhinitis, or coughing.

Skin reactions such as itching or dermatitis may also be a possibility, she adds.


Australia has listed six different types of benzoates, including benzoic acid (210), sodium benzoate (211), potassium benzoate (212) and calcium benzoate (213).

Commonly used to preserve drinks, sodium benzoate can potentially be carcinogenic after reacting with vitamin C, a combination often used in carbonated and fruit juices.

However, Lexi says there are still ongoing discussions on whether the low levels of benzene in soft drinks may pose a health risk.

“Long term studies are still assessing the impact of consumption of low levels of benzene and cancer,” she says.

Other possible side effects may include abdominal cramping and pain, Madeline adds.

“Some people have also reported experiencing an increase in ADHD-type symptoms after consuming large quantities of benzoates,” she says.


Used in fruit juices, dried fruit, sausages and wine, sulphites are identified by code numbers 220 to 228.

Sulphur dioxide (220) may worsen asthma, with one in 10 asthmatics likely to experience wheezing, chest tightness and coughing when they eat foods containing the commonly used sulphite.

While asthma and allergy sufferers can also have potential life-threatening anaphylactic symptoms, there may also be other adverse reactions, Lexi says.

“(This) may also include hives, abdominal pain, dermatitis, low blood pressure and flushing.”

Nitrites and nitrates

There are four of these – potassium and sodium nitrite (249 and 250) and potassium and sodium nitrate (251 and 252).

Nitrites and nitrates are both used to preserve processed meats like ham, salami and bacon and when they’re eaten they get converted into nitrosamines, which can increase the risk of cancer.

Lexi says while they are already naturally in the body and in certain foods such as vegetables, more are often added for food preservation.

“There may also be a risk in complications in pregnancy if added nitrates are consumed, differing from the naturally occurring ones,” Lexi explains.

These compounds are also part of the reason why your long-term risk of bowel cancer increases by 18 per cent if you eat 50g of processed meat, or roughly two slices of bacon, every day.

“As a result, the official advice is to eat little, if any, processed meat, remembering that, in situations like this, the goal is always trying to limit intake rather than necessarily banning a food,” Milly says.


Added to bread and bakery products to prevent or delay mould from growing, there are four of these (280-283), with calcium propionate (282) being the most widely used.

The health risk? While more research is needed, a study published in 2019 suggests that there’s a link between consuming propionates and developing insulin resistance, which increases the risk of type 2 diabetes.

“Early studies have also indicated that excessive exposure to propionates may also play a role in the onset of dementia and Alzheimer’s,” Madeline adds.

Worried about sensitivity to food preservatives?

If you suspect you’re sensitive to a preservative, your health practitioner may conduct a food sensitivity panel, Madeline explains.

“This will measure if there is an IgG response and how strong it is,” she says.

“You will then be advised whether it is a preservative that you should avoid completely, or whether you are ok to have it in small amounts every now and then.”

Otherwise, Madeline suggests keeping a food journal detailing what you ate and how you feel after.

“It is important to realise though than an IgG response can take up to 72 hours to manifest symptoms, which can make it harder to identify what may have caused your symptoms,” she says.

“Based on your journal, you can then do an elimination diet and slowly remove suspect foods to see what your symptoms flare up and when they dissipate.”

For more on eating safely:

Written by Karen Fittall

Originally published in 2021. Updated by Melissa Hong in October 2023.