Preservatives have been around since around 12,000 B.C., when salt, smoke, and honey were used to keep food from spoiling. While these methods are still used today, many modern preservatives are a far cry from those used in ancient times. Several of these modern preservatives are under scrutiny after recent studies have called out their potential to cause negative health effects, though the FDA maintains these compounds are unlikely to cause harm.
So, why is there a gap between what headlines suggest and what our food regulators stand by? Are preservatives actually bad for you? And if they are, what should we do about it?
Here we’ll discuss what preservatives actually are, how they work, how their safety is evaluated, and what the latest science suggests about their effects on human health.
What Are Preservatives?
Preservatives are any compound or chemical added to foods to prolong shelf-life or prevent spoilage. The term is usually associated with those ‘hard to pronounce’ words at the end of food labels. And while synthetic preservatives typically get the most press, preservatives can come from natural sources too. Salt and vinegar are two examples.
What Are Some Examples Of Preservatives?
Below are some additional examples of natural and synthetic preservatives. While they come from different sources, and may work in different ways (more on this below) they all serve the same purpose — to limit or prevent the growth of bacteria that can cause food spoilage.
Natural preservatives: Come from sources found in nature — from bacteria found in soil to essential oils from plants.
- Salt
- Sugar
- Vinegar
- Citric acid
- Rosemary extract
Synthetic preservatives: Manufactured in a lab.
- Nitrates/nitrites
- Potassium sorbate
- Sodium benzoate
- Sodium dioxide
- Sorbic acid
How Do Preservatives Work?
Preservatives can work in different ways; in fact, preservatives are grouped into different categories based on how they work to prevent food spoilage.
Below are some examples:
- Environmental modification: Salt and sugar draw out moisture from food, making it impossible for microorganisms to live there.
- Antienzymatic agents: Sulfites used in dried fruits block the enzymes that break down food.
- Antioxidants: BHT and BHA react with oxygen to prevent it from otherwise binding to fat molecules, a cause of rancidity. Antioxidants can come from natural sources too, like vitamin E and anthocyanins.
- Antimicrobial agents: Nitrate and sodium benzoate can enter the cells of microbes, disrupting their metabolism or function and causing them to die. Other preservatives like sorbic or benzoic acid create a more acidic environment, which can prevent bacterial growth.
The good thing about preservatives is that they work really well to help keep foods from spoiling, improving food safety, reducing food waste, and improving convenience and food access. The downside is that researchers suspect some of these preservatives may have negative health effects on human health, particularly if they are consumed in large amounts over a long period of time.
How Do We Know If Preservatives Are Safe?
Food additives (which includes preservatives) are regulated by the FDA. According to a ruling set in 1958, food additives, which the FDA defines as any substance intended to become a component of or otherwise affect the characteristics of any food, need to be pre-approved by the FDA before they go to market.
In the pre-approval process, food manufacturers provide data proving an ingredient is safe for its intended use. The FDA will review the data and set an ADI or acceptable daily intake, which limits the amount of the ingredient that is allowed to be used in any given serving of a food item.
GRAS Program
GRAS is an acronym used by the FDA, meaning “Generally Recognized as Safe.” Unlike the pre-approval required for food additives, for ingredients that fall under GRAS, it's up to food manufacturers to do their due diligence and determine if an ingredient is safe before bringing it to market.
This GRAS ruling was intended to make it easier for food manufacturers to use ingredients that have already been used extensively in conventionally available foods. Their safety is determined based on their historical use.
The GRAS process usually looks a little like this: food companies convene a panel of internal qualified experts who sort through published studies to determine if an ingredient won’t, of reasonable certainty, cause harm. Food companies can submit their findings to be reviewed by the FDA, but they aren’t required to.
Under GRAS, not all ingredients go through an FDA approval process. It isn’t until ingredients come onto the market, that their GRAS status can be questioned or re-evaluated by the FDA. If safety concerns arise once an ingredient hits shelves, groups or individuals can submit a citizen petition or go through the agency’s Office of Food Additive Safety.
“New” Additives vs GRAS
In 1997, the FDA enacted a new ruling that allows the food industry to independently determine which ingredients fall under GRAS and which are considered ‘new’ ingredients that need FDA pre-approval. This ruling is the basis of criticism of the FDA’s ability to keep consumers safe.
Potential Negative Health Effects of Food Additives
Preservatives make shelf-stable packaged foods possible (and we’ve all enjoyed the convenience of food on the go, be it a protein bar or a bag of chips). But convenience will always come at a cost. And researchers are beginning to explore the safety of certain food preservatives.
Recent Long-Term Large-Scale Studies Raise Safety Concerns over Certain Preservatives
When it comes to understanding the link between exposure to certain substances and disease risk (i.e. the link between preservatives and disease), cohort studies are the gold standard. These are studies that follow a group of people over a long period of time, tracking intake and other variables and noting the incidence of disease.
Possible Risk of Diabetes
A 2025 French cohort study, NutriNet-Santé, found a link between food additives and the incidence of type 2 diabetes. They tracked 108,643 people over the course of an average of 7 years. Those whose diets were higher in certain types of preservatives had higher rates of type 2 diabetes.
The study didn’t find that a single preservative was responsible for the development of the disease; rather, it found that specific mixtures of preservatives may have antagonistic effects. The mixtures included: additives common in dairy desserts, fats, and sauces. (potassium sorbate, guar gum, carrageenan, modified starches, xanthan gum). The second mixture included additives commonly found in sugary drinks and diet drinks. (aspartame, citric acid, sodium citrates, guar gum).
Researchers made sure to factor in the actual nutritional content of the foods that contained these preservatives, eliminating the possibility that the incidence of type 2 diabetes is linked to nutritional quality rather than the preservatives alone.
Possible Risk of Cancer
The same NutriNet-Santé study also tracked the incidence of cancer in the group of 108,643 people. The study found that people who consumed higher amounts of certain preservatives had a higher incidence of overall cancers, prostate cancer, or breast cancer.
For both studies, it's important to remember that an association between two things (preservative intake and cancer) does not mean one causes the other. However, these study findings should be enough to raise the eyebrows of both consumers and policymakers.
For consumers, it's another reason to focus on eating whole foods, avoiding their processed counterparts as much as possible. For policymakers, it's an argument for revising policies surrounding the safety of certain food additives.
This isn’t the first time certain food additives have been in the hot seat. In 2015, the International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization, made a statement claiming that processed meat is carcinogenic to humans, after reviewing 800 articles on the topic. This is likely due to the nitrates used to preserve meats. Nitrates can form into nitrosamines, known carcinogenic compounds.
Gut Health
Certain types of preservatives called antimicrobial preservatives (AMPRs) may cause harm to the billions of beneficial bacteria lining the gut, according to a 2025 review. This may not sound consequential, but bacteria living in the gut, also called the gut microbiome, are linked to the immune system, mood, disease risk, digestion, and more.
The 2025 review highlighted animal and laboratory studies that looked into the effects of common preservatives like sodium benzoate, sodium nitrite, and potassium sorbate. Importantly, no toxicity or damage to the intestines was noted but researchers found that certain strains of beneficial gut bacteria were negatively impacted. This can have implications for overall gut health.
Researchers still don’t know how these results will translate to humans or what results to expect when preservatives are consumed along with other additives, as is common in a typical diet.
So, Are Preservatives Bad?
Under GRAS and the food additive legislation, the FDA works to ensure that “exposure to chemicals in food is safe. This includes chemicals authorized for use in and with foods during food packaging, processing, or other handling, or contaminants that enter the food supply through the growing or processing environment,” according to a statement on the FDA website.
Preservatives are necessary for maintaining quality, safety, and shelf-stability in certain foods, but it's clear that not all preservatives, or preservative exposure, is created equal.
Bottom line:
Limiting exposure to preservatives may be another way to support your health and longevity.
At Rasāsvāda, we believe in the power of plants in their purest form. That’s why our restorative drinks are crafted with 100% plants. 0% preservatives.
FAQs
Sources
PLOS Medicine | Food additive mixtures and risk of type 2 diabetes: Results from the NutriNet-Santé prospective cohort study
PLOS Medicine | Food additive exposures and cancer risk: Results from the NutriNet-Santé prospective cohort
International Agency for Research on Cancer (IARC) | IARC Monographs evaluate consumption of red meat and processed meat
Environmental Health Perspectives | Nitrate and nitrite ingestion and nitrosamine formation: Mechanisms and cancer risk
Frontiers in Microbiology | The impact of food additives on gut microbiota: Implications for host health
Nutrients | Dietary emulsifiers and food additives: Effects on gut microbiota and metabolic health
U.S. Food and Drug Administration | Food Chemical Safety — Overview of how the FDA evaluates and ensures the safety of chemicals intentionally added to food (such as preservatives), chemicals in food packaging, and contaminants
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