Food should be good for you. But some isn’t. More than 10,000 additives* are allowed in food. Some are direct additives that are deliberately formulated into processed food. Others are indirect additives that get into food during processing, storage and packaging. How do you know which ones to avoid because they raise concerns and have been linked to serious health problems, including endocrine disruption and cancer?
EWG’s “Dirty Dozen Guide to Food Additives” helps you figure it all out by highlighting some of the worst failures of the regulatory system. The guide covers ingredients associated with serious health concerns, additives banned or restricted in other countries and other substances that shouldn’t be in food. And it underscores the need for better government oversight of our food system.
Here’s a list of 12 additives that EWG calls the “Dirty Dozen.” We’ll tell you why, which foods contain them and what you can do to avoid them. (A good place to start is by looking up your food in EWG’s Food Scores database).
* By food additives, we mean substances that are added to food products and their packaging. Under federal law, the term "food additive" is used to describe just one category of these substances, but we are using the term as it is commonly understood.
Nitrates and Nitrites
Ever wonder how cured meats like salami and ham are able to retain their seemingly fresh pink color after weeks on the store shelf? They may be treated with nitrates or nitrites – chemicals commonly used as coloring agents, preservatives and flavoring. Although they can prolong a food’s shelf life and give it an attractive hue, they come with health concerns.
Nitrites and nitrates are used as preservatives in cured meats such as bacon, salami, sausages and hot dogs. Nitrites, which can form from nitrates, react with naturally occurring components of protein called amines. This reaction can form nitrosamines, which are known cancer-causing compounds. Nitrosamines can form in nitrite or nitrate-treated meat or in the digestive tract.
Studies have linked nitrites to stomach cancer (IARC 2010). Some data also suggest an association with cancer of the esophagus; one study showed an increased risk in people who eat cured meats more often (Rogers 1995; Mayne 2001). There is also evidence that nitrites may be associated with brain and thyroid cancers, but a causal link has not been established (Preston-Martin 1996; Pogoda 2001; Aschebrook-Kilfoy 2013; IARC 2010).
In 2010, scientists at the World Health Organization’s International Agency for Research on Cancer declared that ingested nitrites and nitrates are probable human carcinogens. The California Office of Environmental Health Hazard Assessment is currently considering listing nitrite in combination with amines or amides as a known carcinogen. Some nutritious foods such as spinach and other leafy vegetables are naturally high in nitrates, but human studies on nitrate intake from vegetables have found either no association with stomach cancer or a decreased risk (IARC 2010).
What you should do
Look for added nitrites and nitrates on food labels and avoid them. This will not only reduce your exposure to additives associated with cancer but will also lower your intake of cured meats that can be high in unhealthy fat and cholesterol. Use EWG’s Food Scores to find foods without nitrates and nitrites.
Potassium bromate is used to strengthen bread and cracker dough and help it rise during baking. It is listed as a known carcinogen by the state of California, and the international cancer agency classifies it as a possible human carcinogen (IARC 1999; OEHHA 2014). It causes tumors at multiple sites in animals, is toxic to the kidneys and can cause DNA damage (IARC 1999). Baking converts most potassium bromate to non-carcinogenic potassium bromide, but research in the United Kingdom has shown that bromate residues are still detectable in finished bread in small but significant amounts (Ministry of Agriculture, Fisheries and Food 1993).
Both the United Kingdom and Canada prohibit the use of potassium bromate in food, and it is not allowed in the European Union either. The United States, however, still allows it to be added to flour.
What you should do
The government classifies some additives as “Generally Recognized as Safe” or GRAS. They are presumed to be safe in food and are not required to undergo pre-market review and approval. This system makes sense for benign additives such as pepper and basil, but there are enormous loopholes that allow additives of questionable safety to be listed as GRAS. Manufacturers can decide whether these compounds are safe without any oversight by the Food and Drug Administration – and in some cases obtain GRAS status without telling the FDA at all.
It’s hard to believe that propyl paraben, an endocrine-disrupting chemical, is allowed in food, and even harder to believe that it’s “Generally Recognized as Safe.” Studies found that rats fed the FDA's maximum limit for propyl paraben in food had decreased sperm counts. At this dose researchers also noted small decreases in testosterone, which become significant with higher exposures (Oishi 2002).
Propyl paraben acts as a weak synthetic estrogen (Routledge 1998; Kim 2011; Vo 2011). It can alter the expression of genes, including those in breast cancer cells (Terasaka 2006; Wróbel 2014). Propyl paraben has been reported to accelerate the growth of breast cancer cells (Okubo 2001). And a recent study by scientists at the Harvard School of Public Health linked propyl paraben to impaired fertility in women (Smith 2013).
Propyl paraben is used as a preservative in foods such as tortillas, muffins and food dyes. People can be exposed to it either as a direct additive or as result of contamination during food processing and packaging. Tests done on samples collected from 2008 to 2012 found propyl paraben in more than half of them, including beverages, dairy products, meat and vegetables (Liao 2013). In a federal study, 91 percent of Americans tested had detectable levels of propyl paraben in their urine (Calafat 2010).
What you should do
The FDA considers the preservative butylated hydroxyanisole (BHA) to be a GRAS additive – even though the National Toxicology Program classifies it as “reasonably anticipated to be a human carcinogen,” the international cancer agency categorizes it as a possible human carcinogen, and it’s listed as a known carcinogen under California’s Proposition 65 (NTP 2011; IARC 1986; OEHHA 2014). These designations are based on consistent evidence that BHA causes tumors in animals, although there is debate about whether these findings are relevant to humans.
The European Union classifies BHA as an endocrine disruptor. At higher doses, it can lower testosterone and the thyroid hormone thyroxin and adversely affect sperm quality and the sex organs of rats (Jeong 2005). One study reported that female rats given lower doses had a decrease in uterine weight, which may result from effects on estrogen metabolism (Kang 2005; Zhu 1997). Other studies found developmental effects such as decreased growth and increased mortality in rats that had not been weaned, and behavioral effects after weaning (EFSA 2011a; Vorhees 1981a).
What you should do
Butylated hydroxytoluene (BHT) is a chemical cousin to BHA that is also listed as “generally recognized as safe.” It, too, is added to food as a preservative. The two compounds act synergistically and are often used together.
BHT is not a listed carcinogen, but some data have shown that it does cause cancer in animals. Rats fed BHT have developed lung and liver tumors (EFSA 2012). BHT has also been shown to cause developmental effects and thyroid changes in animals, suggesting that it may be able to disrupt endocrine signaling (EFSA 2012). A neurobehavioral study of rats exposed to BHT throughout development described effects on motor skills and coordination before the animals were weaned (Vorhees 1981b).
Propyl gallate is used as a preservative in products that contain edible fats, such as sausage and lard. It is classified as GRAS even though a National Toxicology Program study reported an association with tumors in male rats and rare brain tumors in two female rats (NTP 1982). These findings do not establish a causal link between propyl gallate and cancer, but they raise important questions about whether this chemical should be considered safe. A 2014 opinion by the European Food Safety Authority concluded that the available reproductive studies on propyl gallate are outdated and poorly described. In addition, there is incomplete data on whether propyl gallate is an endocrine disruptor; some evidence suggests it may have estrogenic activity (EFSA 2014; Amadasi 2009; ter Veld 2006).
What you should do
In 2010, Theocorp Holding Co. requested that the FDA list theobromine, an alkaloid found in chocolate that has effects similar to caffeine, as “generally recognized as safe” for use in a variety of foods, including bread, cereal and sport drinks. FDA scientists questioned the GRAS designation, noting that the estimated average human consumption rate was five times higher than the level the company reported as safe (NRDC FOIA 2013). They also said that the company had not adequately explained why the reproductive and developmental effects seen in animals exposed to theobromine were not a concern. In response, Theocorp withdrew its request to FDA, but theobromine was later declared GRAS and is being used in food outside FDA oversight (NRDC 2014).
Theobromine is just one example of an enormous loophole in the FDA’s voluntary GRAS notification process. The food additive industry is allowed to designate a substance as GRAS without even notifying the agency, relying instead on “expert panels.” Theocorp’s submission triggered important questions from FDA scientists about the additive’s safety. Instead of addressing them, the company withdrew the request, and the GRAS designation was made later without FDA approval. In some cases, companies forego FDA’s notification process altogether. The agency does not know the identity of these secretly GRAS-approved chemicals and cannot review data to determine whether they are truly safe in food (NRDC 2014).
This must change. In order for additives to be Generally Recognized as Safe, FDA must have access to safety information and assert jurisdiction over the approval of all GRAS-listed additives.
What you should do
Tell the FDA that the GRAS approval process must be reformed. Companies should not be allowed to secretly approve food additives as GRAS without notifying or sharing safety data with the FDA.
The term “natural flavor” finds its way into more than a quarter of EWG’s roster of 80,000 foods in the Food Scores database, with only salt, water and sugar mentioned more frequently on food labels. “Artificial flavors” are also very common food additives, appearing on one of every seven labels.
What do these terms really mean? Good question.
The truth is that when you see the word “flavor” on a food label, you have almost no clue what chemicals may have been added to the food under the umbrella of this vague term. For people who have uncommon food allergies or are on restricted diets, this can be a serious concern.
In addition to the flavor-adding chemicals themselves, flavor mixtures often contain natural or artificial emulsifiers, solvents and preservatives that are called “incidental additives,” which means the manufacturer does not have to disclose their presence on food labels. Flavoring mixtures added to food are complex and can contain more than 100 distinct substances. The non-flavor chemicals that have other functional properties often make up 80 to 90 percent of the mixture.
Consumers may be surprised to learn that so-called “natural flavors” can actually contain synthetic chemicals such as the solvent propylene glycol or the preservative BHA. Flavor extracts and ingredients derived from genetically engineered crops may also be labeled “natural,” because the FDA has not fully defined what that term means. (Certified organic “natural flavors” must meet more stringent guidelines and cannot include synthetic or genetically engineered ingredients.)
The companies that make flavoring mixtures are often the same ones that make the fragrance chemicals in perfumes and cosmetics. EWG advocates full disclosure of fragrance ingredients and believes flavoring mixtures should be treated the same way.
EWG considers it troubling that food companies do not fully disclose their ingredients and use vague terms like “flavors.” Consumers have a right to know what’s in their food. We are also concerned that processed food makers manipulate flavors to whet people’s appetite for unhealthy foods and encourage overeating.
What you should do
Choose fresh foods rather than processed and packaged foods that contain flavoring chemicals that artificially alter smell and taste. Call on companies to disclose what chemicals they use in their flavoring mixtures. Use EWG’s Food Scores to find foods without flavoring ingredients.
Artificial colors are often used to increase the appeal of foods that have little nutritional value. Questions have been raised about the safety of one class of synthetic colors, called FD&C (Food, Drug & Cosmetics) colors, and contaminants in other artificial colorings as well.
Caramel colors III and IV, for example, may be contaminated with 4-methylimidazole (4-MEI), which caused tumors in a National Toxicology Program study (NTP 2004). The European Food Safety Authority has expressed concern about furan contamination, which is also associated with cancer (EFSA 2011b).
There is ongoing debate about the effects of the synthetic FD&C colors on children’s behavior. Some studies have found that mixtures of synthetic colorings and the preservative sodium benzoate were associated with hyperactivity (Bateman 2004; McCann 2007). The European Food Safety Authority concluded that synthetic coloring mixtures may have a “small and statistically significant effect on activity and attention in children,” and that this effect may be an issue for certain sensitive individuals (EFSA 2008a). Other studies have not found an association between hyperactivity and synthetic food coloring (Arnold 2012; EFSA 2008a).
Avoiding artificial colors such as Caramel III and IV can be difficult. Current regulation allows food manufacturers to simply print artificial color on the product label if the ingredient is on an FDA-approved list. But consumers can easily avoid the synthetic colors on FDA’s separate FD&C-certified list because they must be shown on the label with their full or abbreviated name, such as FD&C Yellow 5 or Yellow 5.
What you should do
Read labels if you wish to avoid the FD&C-certified colors. In general, artificial colors tend to be hallmarks of more highly processed foods, so they can also be avoided by sticking to fresh produce, meats and whole foods. Use EWG’s Food Scores to find foods without artificial colors.
Concerns about food additives are not limited to consumers; some have been associated with serious workplace diseases. Diacetyl, used as a butter flavoring in microwave popcorn, is associated with a severe and irreversible respiratory condition called bronchiolitis obliterans, which leads to inflammation and permanent scarring of the airways. Diacetyl is also used to flavor dairy products such as yogurt and cheese as well as in “brown flavorings” such as butterscotch and maple and in fruit flavorings such as strawberry and raspberry (OSHA 2010).
Several flavor-related respiratory disease clusters have been identified, beginning with an investigation in 2000 of former workers at a microwave popcorn plant (NIOSH 2004). In one case, the National Institute for Occupational Safety and Health found compromised lung function in 11 of 41 production workers – two-to-three times the expected number. There was little or no response to medical treatment, and workers with severe forms of the disease, some only in their 30s, ended up on waiting lists for lung transplants.
Occupational health concerns associated with flavoring chemicals go beyond diacetyl. The federal Centers for Disease Control and Prevention and the Occupational Safety and Health Administration have identified other flavoring chemicals that may pose a risk to workers, including 2,3-pentanedione and acetaldehyde. NIOSH emphasizes that safety evaluations of flavoring chemicals are largely based on consumer exposure, and there are no occupational exposure guidelines for most. This means that workers could face much higher risks that are poorly understood.
What you should do
Be aware of foods that contain the non-specific ingredient “flavor.” It’s hard to know what kinds of compounds this term may be hiding. Use EWG’s Food Scores to find foods without questionable flavorings.
Phosphates are among the most common food additives, found in more than 20,000 products in EWG’s Food Scores database. They can be used to leaven baked goods, reduce acid and improve moisture retention and tenderness in processed meats. Phosphates are frequently added to unhealthy highly processed foods, including fast foods. In people with chronic kidney disease, high phosphate levels in the body are associated with heart disease and death (Ritz 2012).
In people without kidney disease, one study has linked higher phosphorus levels in the blood to increased cardiovascular risk (Dhingra 2007). Another study that followed more than 3,000 people for 15 years also found an association between dietary phosphorus and heart disease. Other research has reported similar findings (Foley 2009; Cancela 2012). The jury is still out about whether there is truly a link between the consumption of phosphate food additives and health problems. More research is clearly needed. Meanwhile, the issue is being taken seriously by some government officials. In 2013, the European Food Safety Authority began a high-priority reevaluation of added phosphates in food, but the deadline for completion isn’t until the end of 2018 (EFSA 2013).
What you should do
Consider reducing consumption of foods with added phosphates and cut down on eating highly processed and fast foods. People with kidney disease should consult their doctors. Use EWG’s Food Scores to find foods without added phosphates
Aluminum is the most abundant metal in Earth’s crust. It can occur naturally in food, but people are mainly exposed through food additives (EFSA 2008b). Aluminum can accumulate and persist in the human body, particularly in bone. Additives containing aluminum, such as sodium aluminum phosphate and sodium aluminum sulfate, are used as stabilizers in many processed foods.
Animals exposed to aluminum in the womb and during development show neurological effects such as changes in behavior, learning and motor response. Neurotoxicity has occurred in people undergoing dialysis who received large intravenous doses of unpurified water, but a direct link between aluminum food additives and neurological effects has not been proven (Schreeder 1983; EFSA 2008b). A link with Alzheimer’s disease and other neurodegenerative disorders has been proposed, but the association remains unclear (Bondy 2013). While significant scientific uncertainty remains around whether there may be links between aluminum-based food additives and health effects, their widespread use warrants putting them on the “watch list.”
What you should do
Read food labels to identify aluminum-based additives and consider alternatives. Use EWG’s Food Scores to find foods without aluminum additives.
Food additives are often hallmarks of highly processed, unhealthy foods. Avoiding them can help improve your diet in many ways, but shopping and eating smarter isn’t enough. Consumers must demand real reform of the food regulatory system, particularly the “generally recognized as safe” or GRAS approval process. EWG recommends:
- Choose fresh foods that have been minimally processed whenever possible. Products with fewer ingredients tend to be less processed and may be healthier choices.
- Read labels and avoid foods with ingredients linked to health concerns. Use EWG’s Food Scores database to find out what food additives are in your favorite products.
- Tell food manufacturers that products with ingredients linked to health concerns are not acceptable. Demand better.
- Urge the FDA to strengthen its regulatory system for food additives. Companies should not be allowed to certify the safety of their own ingredients.