Reviewed by dietitian Madeline Peck, RDN, CDN
Design Elements: Getty Images. Food design.
Main points
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Food preservatives can be natural or synthetic and can extend the shelf life of food.
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Some common preservatives have been linked to an increased risk of cancer.
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Focusing on whole foods whenever possible can reduce cancer risk.
While the risk of dying from cancer continues to decline, cancer rates continue to rise, with more than two million new cases expected to be diagnosed in 2026. Many factors can increase your risk of cancer, including genetics. And while genetics is out of your control, there are many lifestyle areas linked to cancer risk that you can play a role in changing, including smoking, alcohol consumption, physical activity and diet.
In terms of diet, there is no one anti-cancer miracle food. It is important to consider your entire diet. We know that there is a link between high consumption of ultra-processed foods and cancer (as well as cardiometabolic diseases, such as heart disease and diabetes).
The reasons for this relationship may vary, but French researchers are looking into the relationship between preservatives and their cancer risk, as they are common in ultra-processed foods. They published their findings BMJ. Let’s break down what they found.
How was this study conducted?
The researchers took data from the French Neutrinet-Sainte cohort from 2009 to 2023; This study was designed to explore the relationship between nutrition and health. There were more than 105,000 participants, approximately 80% of whom were women, with a mean age of 42 at baseline.
At enrollment and every six months, participants completed a series of three validated web-based 24-hour dietary records. During each period, dietary records were randomly assigned to three consecutive days over two weeks (two weekdays and one weekend day). Doing consecutive days and including a weekend day helps provide a more accurate picture of a person’s overall diet.
The researchers took information from the participants’ dietary records and broke down their intake of nutrients, including vitamins C and E, which can be used as preservatives in some foods. Additionally, using brand-specific data, the researchers also broke down food additives, focusing specifically on preservatives. They then measured the participants’ intake of both naturally occurring preservatives (including acetic and citric acids, nitrites, nitrates and sulfites) and added preservatives. In all, 58 patrons were investigated.
Participants reported any health-related events, including a cancer diagnosis, throughout the study period, either on their biannual health questionnaire or at any time through their connected health portal. To ensure the accuracy of participants’ reporting, a physician expert committee verified each reported cancer event against official medical records. In addition, the NutriNet-Santé cohort was linked to the National Health Insurance System database to collect additional information on medical treatment and consultations.
The cohort was also linked to the French National Mortality Register to identify deaths and causes of death. For this study, incident cancer includes all primary cancers diagnosed between study enrollment and December 31, 2023; Basal cell carcinoma of the skin was the only cancer not included.
What did this study find?
The average follow-up time for participants was approximately eight years. The study found several associations between preservatives widely used in industrial foods and beverages in the United States and European markets and a higher incidence of overall, breast and prostate cancer. In particular, these preservatives were linked to a higher cancer risk:
Most associations were observed for non-antioxidant preservatives. Among the antioxidant preservatives, only total erythorbate and specific sodium erythorbate were found to be associated with a higher incidence of cancer. It’s important to remember that because this study is observational, it can only draw connections – or associations – which does not mean causation. Further research is needed to confirm these findings. Limitations of this study include participants’ self-reporting of food intake, which may introduce bias. The researchers also noted that some naturally occurring preservatives in some foods were difficult to predict.
How does this apply in real life?
The preservatives analyzed in this study are currently classified as generally recognized as safe (GRAS) by the US Food and Drug Administration. This means that to date, the FDA does not have enough evidence to ban them. This may change, however, as in the cases of dye red No. 3 and brominated vegetable oil. Unfortunately, it can take years of research and evidence to finally ban an additive, and in the meantime, they can affect your health.
Preservatives are often found in alcoholic beverages, processed meats, refined grains, processed fruits and vegetables, and breakfast foods. Anything that is shelf-stable will likely contain preservatives.
If you’re trying to lower your cancer risk, the American Cancer Society recommends being physically active, limiting sedentary time, and achieving and maintaining a healthy weight to help reduce cancer risk. They suggest eating more plants, including fruits, vegetables, legumes and whole grains, and less sugar-sweetened beverages, highly-processed foods and refined grains — which means aiming for less added sugar overall. They also recommend reducing your intake of processed and red meat and avoiding alcohol.
There always seems to be a caveat with any recommendation, though. For example, higher produce intake may lead to higher consumption of herbicides and pesticides, which may also increase the risk of cancer. However, this is not a reason to avoid fruits and vegetables. Instead, you can buy organic produce, especially fruits and vegetables on the Environmental Working Group’s Dirty Dozen list. If you can’t afford to buy organic, that’s okay—try to wash your produce thoroughly before you cook or eat it, and if you’re still worried, peel it off after washing.
While there is no one anti-cancer diet, all the basics of eating a Mediterranean diet-style are recommended by the American Cancer Society. If you’re new to this way of eating and want to give it a go, try our 5-Day Mediterranean Diet Meal Plan for Beginners. For those of you on your journey, try our 30-Day No-Sugar Mediterranean Diet Plan.
Our experts
This study linked several commonly used preservatives to a higher risk of cancer. To lower your risk, stick to mostly whole foods, including fruits, vegetables, whole grains, legumes, nuts, seeds and lean protein. The Mediterranean diet has you covered, and has also been linked to a lower risk of other diseases, including heart disease and diabetes. However, this does not mean that you should completely avoid processed foods. If you’re concerned, read the label closely and see if the product contains preservatives linked to cancer. Other lifestyle changes that can reduce your risk of cancer include not smoking and drinking alcohol and engaging in regular physical activity.
Read the original article on EatingWell
