In our fast-paced world, convenience often trumps health considerations when it comes to food choices. Behind the extended shelf life and convenient packaging of many processed foods lurks a concerning reality. Packaged and processed foods are filled with preservatives that can have a huge impact on your health.
I get it! As a physician and runner, I’ve spent many evenings on call sustaining off the stash of the off-brand graham crackers and single-serving Jiffy peanut butter cups supplied in every hospital lounge in the US.
From interfering with your hormones, damaging your gut microbes, and causing chronic inflammation, your food choices are impacting your health. In this article we’ll explore the most common food preservatives, their potential health effects, how to identify them, and healthier alternatives to improve your health and performance.
Sodium Nitrite and Nitrate: The Processed Meat Preservatives
What They Are
Sodium nitrite and sodium nitrate are commonly added to processed meats like bacon, hot dogs, ham, and deli meats. They serve multiple purposes from preventing bacterial growth (particularly Clostridium botulinum) to maintaining the pink/red color of meat and giving these meats their characteristic flavor.
Health Concerns
Not All Nitrates Are Created Equal
It’s important to note that nitrates and nitrites aren’t inherently harmful. Nitrates occur naturally in soil and water, and arefound in many vegetables, particularly leafy greens, beets, and celery. Nitrates in the diet can be converted to nitric oxide in the body, which helps relax blood vessels and may reduce blood pressure.
The critical difference is the source and context. Nitrates from vegetables have not been linked to cancer risk and come packaged with fiber, vitamins, and other beneficial compounds. Vegetables also contain vitamin C and other antioxidants that inhibit the conversion of nitrates to nitrosamines.
Nitrosamine Formation
When nitrites are exposed to high heat or the acidic environment of the stomach while in close proximity to certain proteins found in meat, they can form nitrosamines, which are the actual cancer-promoting compounds. The International Agency for Research on Cancer has classified processed meats as Group 1 carcinogens, which means there’s significant evidence to link them to cancer. To put this in perspective, other Group 1 carcinogens include tobacco smoke, sun exposure, and alcohol.
Compound Effects in Processed Meat
Processed meats also often contain PAHs (polycyclic aromatic hydrocarbons) formed during smoking processes and HCAs (heterocyclic amines) created when meat is cooked over an open flame. Both PAHs and HCAs have tumor-causing properties independent of the nitrates/nitrites.
Check the Label
Often listed as: sodium nitrite, sodium nitrate, potassium nitrite, potassium nitrate, or simply “curing salt”
Foods to Watch Out For
- Bacon, ham, hot dogs, salami
- Deli meats and lunch meats
- Cured and smoked meats
- Packaged seafood
- Canned beans and vegetables with bacon
- Nitrate-free processed meats (these often use celery powder, which naturally contains nitrates)
- Naturally occurring in leafy greens, beets, celery, and other vegetables
What to Consume Instead
- Fresh, unprocessed meats and poultry
- Plant-based protein sources like beans and lentils
- Fresh seafood
Sodium Benzoate: The Beverage Preservative
What They Are
Sodium benzoate is commonly used in acidic foods and beverages to prevent the growth of bacteria, yeasts, and molds. It’s particularly common in soft drinks, fruit juices, and other products with a pH below 4.5. As a salt of benzoic acid, it dissolves well in water and provides manufacturers with an inexpensive way to extend product shelf life significantly.
Health Concerns
Cancer Risk
The most serious concern with sodium benzoate is its potential to form benzene, a compound that is known to cause cancer, including leukemia and other blood cancers. When sodium benzoate combines with vitamin C (ascorbic acid) or other antioxidants, especially under conditions like when exposed to heat, light, or extended storage time, benzene can form.
The FDA has established that levels of benzene should not exceed 5 parts per billion (ppb) in drinking water, but some soft drinks have been found to have significantly higher levels. The FDA reports that the products tested have since been reformulated and retested, however it makes sense to reduce exposure by limiting (or eliminating) intake of these products if possible.
Neurological and Behavioral Effects
A prominent study published in The Lancet found that sodium benzoate was associated with increased hyperactivity and decreased attention span in children, particularly those already diagnosed with ADHD. The 2007 Southampton study showed that when combined with certain food colorings, sodium benzoate consumption led to measurable increases in hyperactive behavior in children aged 3-9 years. Some researchers have suggested that sodium benzoate may affect dopamine and other neurotransmitter pathways, though more research is needed.
Inflammatory Responses and Immunological Concerns
Emerging research points to potential effects on the immune system. Some studies have shown that sodium benzoate may trigger mast cell degranulation, a process involved in allergic reactions and inflammation. Research in animals suggests it may increase production of pro-inflammatory markers in certain white blood cells. People with chronic inflammatory conditions like asthma, eczema, or inflammatory bowel disease may experience symptom flares after consuming products with sodium benzoate.
Metabolic Impacts
There are indications that sodium benzoate may impact metabolic processes. Animal studies suggest it may interfere with various metabolic pathways, including those involved in fat metabolism. Some researchers have proposed connections to insulin resistance, though human studies are still limited. Emerging research is investigating potential effects on the gut microbiome, which plays a crucial role in overall metabolism and health.
DNA Damage Concerns
Laboratory studies have raised questions about genotoxicity. Some animal research indicates that sodium benzoate may damage mitochondrial DNA under certain conditions. At higher concentrations than typically found in foods, it has demonstrated potential to cause chromosomal changes in laboratory tests. The significance of these findings for typical dietary exposure remains debated among researchers.
Regulatory Status
While sodium benzoate is generally recognized as safe (GRAS) by the FDA and permitted in foods throughout much of the world, maximum allowable concentrations vary by country. In the US, it’s generally limited to 0.1% by weight in foods. The European Food Safety Authority (EFSA) has established an Acceptable Daily Intake (ADI) of 5 mg/kg body weight. Several countries have more restrictive policies on its use in products marketed to children.
Check the Label
Listed as: sodium benzoate, benzoate of soda, E211, or simply “preservative”
Foods to Watch Out For
- Carbonated beverages and soft drinks
- Fruit juices and flavored waters
- Salad dressings and condiments
- Jams and jellies
- Pickled vegetables
- Some dairy products like liquid creamers
- Liquid medications and flavored syrups
What to Consume Instead
- Filtered water from metal cup or glassware
- Homemade fruit-infused water
- Fresh-squeezed juices consumed promptly
- Herbal teas
- Homemade salad dressing
- Fresh vegetables
- Check labels on liquid creamers and medications
BHA and BHT: Fat-Soluble Preservatives
What They Are
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are synthetic antioxidants used as preservatives in a variety of personal care products and foods such as cereals, fast foods, cured meats, processed potatoes, drink mixes, shortening, snack foods, and gum. Studies have linked BHA and BHT to cancer, hormone disruptions, skin allergies, and organ dysfunction.
Health Concerns
Despite being listed as chemical of potential concern under the Convention for the Protection of the Marine Environment of the North-East Atlantic, prohibited by the EU from being used as a fragrance in cosmetics, requiring Prop 65 labeling in CA, and classified as “reasonably anticipated to be a human carcinogen” by the National Toxicology Program, both BHA and BHT are currently permitted as food additives in the US.
Both BHA and BHT have been identified as potential endocrine disruptors that may interfere with hormonal processes. The National Toxicology Program classifies BHA as “reasonably anticipated to be a human carcinogen.” Some people report skin and respiratory irritation from BHA and BHT.
Check the Label
Listed as: BHA, BHT, butylated hydroxyanisole, butylated hydroxytoluene, E320, or E321
Foods (and Products) to Watch Out For
- Potato chips and processed snacks
- Cereal products
- Chewing gum
- Vegetable oils
- Packaged baked goods
- Skin care products and cosmetics
What to Consume Instead
- Fresh fruits and vegetables
- Nuts and seeds
- Homemade popcorn
- Products using vitamin E (tocopherols) as natural preservatives
Sulfites: The Wine and Dried Fruit Preservatives
What They Are
Sulfites are a group of compounds used to prevent browning and bacterial growth in various foods and beverages, most notably wines and dried fruits.
Health Concerns
Sulfites can trigger inflammatory responses such as asthma attacks, particularly in sensitive individuals. Some people experience allergic reactions such as headaches, hives, swelling, or stomach pain after consuming sulfites. Sulfites can destroy thiamine (vitamin B1) in foods, reducing the nutritional quality.
Check the Label
Listed as: sulfur dioxide, potassium bisulfite, potassium metabisulfite, sodium bisulfite, sodium metabisulfite, sodium sulfite, or E220-E228
Foods to Watch Out For
- Wine (especially white wines)
- Dried fruits (particularly lighter-colored varieties like apricots)
- Vinegar and pickled foods
- Some condiments and dressings
What to Consume Instead
- Fresh fruits instead of dried
- Organic or sulfite-free wines
- Homemade dressings and condiments
- Sun-dried tomatoes without sulfites
Monosodium Glutamate (MSG): The Flavor Enhancer
What They Are
While primarily used as a flavor enhancer rather than a preservative, MSG often accompanies preservatives in ultra-processed foods and is worth mentioning due to its prevalence and health concerns.
Health Concerns
Some individuals report headaches, flushing, sweating, facial pressure, numbness, and heart palpitations after consuming MSG. Some research suggests potential links to weight gain and metabolic disorders. Animal studies have raised questions about MSG’s effects on brain development.
Check the Label
Listed as: monosodium glutamate, MSG, E621, “flavor enhancer,” or sometimes hidden in ingredients like “hydrolyzed protein” or “autolyzed yeast”
Foods to Watch Out For
- Fast food and restaurant food
- Asian cuisines (though many now offer MSG-free options)
- Canned soups and broths
- Seasoning mixes and bouillon cubes
- Processed snack foods
What to Consume Instead
- Herbs and spices for flavoring
- Homemade soups and broths
- Cooking with natural flavor enhancers like mushrooms, tomatoes, and aged cheeses
Carrageenan: The Plant-Based Emulsifier
What They Are
Derived from red seaweed, carrageenan is used as a thickener, emulsifier, and stabilizer in many foods, especially dairy and plant-based alternatives.
Health Concerns
Studies suggest carrageenan may trigger inflammation in the digestive system. Some research has connected carrageenan to ulcerative colitis, inflammatory bowel disease, and intestinal lesions. Carrageenan can also cause bloating, irritable bowel syndrome symptoms, and digestive discomfort in sensitive individuals.
Check the Label
Listed simply as: carrageenan or E407
Where to Find It
- Plant-based milks (almond, coconut, etc.)
- Ice cream and other dairy products
- Processed deli meats
- Nutritional shakes and meal replacements
What to Consume Instead
- Homemade plant milks
- Dairy products with simple ingredient lists
- Products that use guar gum or locust bean gum instead
How to Identify Preservatives in Foods
- Read Ingredient Lists Carefully: Preservatives are always listed, though sometimes under technical or scientific names.
- Look for “Free From” Claims: Many manufacturers now prominently advertise when products are free from specific preservatives.
- Use Technology: Several smartphone apps can scan product barcodes and highlight potentially concerning ingredients.
- Watch for Disguised Ingredients: Some preservatives may be listed under alternative names or as part of “flavor” or “natural flavor” complexes.
- Understand Labeling Terms:
- “Natural preservatives” aren’t necessarily safe
- “Preservative-free” doesn’t mean the product is healthy overall
- E-numbers (E200-E299) generally indicate preservatives in European labeling
Practical Tips for Reducing Preservative Intake
- Cook from Scratch: When you prepare meals using whole food ingredients, you control what goes into your food.
- Shop the Perimeter: Most fresh, preservative-free foods are found around the edges of grocery stores.
- Buy Local and Seasonal: Foods that don’t need to travel far or last long tend to contain fewer preservatives.
- Consider Preservation Methods: Freezing, fermenting, and proper storage can extend food life without chemical preservatives.
- Start Gradually: Try replacing one processed food category at a time rather than overhauling your entire diet at once.
Take Away
While preservatives have made our modern food system possible, providing convenience and preventing food waste, many carry potential health consequences that warrant caution. By becoming more aware of these ingredients and gradually shifting toward whole, minimally processed foods, you can reduce your exposure to potentially harmful preservatives while enjoying a more nutrient-dense diet.
Remember that food choices exist on a spectrum—occasional consumption of preservatives won’t likely cause immediate harm, but consistently choosing preservative-free options may contribute to better long-term health. The key is awareness and making informed choices that align with your personal health goals.
Note: This article is intended for informational purposes only and is not a substitute for professional medical advice. If you have specific health concerns, please consult with a healthcare provider.
