Additives are substances added to foods to enhance their natural qualities. Additives may keep foods fresher longer, boost a food’s nutritional content or improve the appearance, taste or texture of food.

There are two major categories of food additives. Direct additives are intentionally added to the food for a specific purpose. Indirect additives become part of the food in trace amounts as a result of harvesting, production, processing, packaging, storage or other handling.

Additives offer many benefits to foods that can be grouped into three major categories:

• Maintaining or improving freshness and safety
• Improving or maintaining nutritional value
• Improving taste, texture and appearance

There are thousands of additives, both direct and indirect. Examples of direct additives include antimicrobials, antioxidants, natural and artificial flavors, colors, and others. Indirect additives are usually present in tiny amounts and may include bits of plastic, glass, paper, tin and chemicals from processing.

The U.S. Food and Drug Administration (FDA) is responsible for ensuring the safety of all food additives and must approve any new substance before it is introduced to the market. The FDA does not approve any additive until it has been demonstrated that the additive is effective and is detectable or measurable in the final product. Most importantly, the FDA must determine that the product is safe for human use.

The FDA has a list of about 700 items that are generally recognized as safe (GRAS). Items on this list do not require FDA approval because they have a well-established track record of safety. Examples include caffeine, sugar and many spices.

Additives are substances added to foods for a variety of reasons. Some additives keep foods fresher longer or improve their safety. Other additives boost or maintain a food’s nutritional value. Finally, some additives improve the taste, texture or appearance of foods.

Every food contains chemical compounds that help determine its color, flavor, texture and nutrient value. Additives are substances added to these foods to enhance the food’s natural qualities. Federal standards administered by the U.S. Food and Drug Administration (FDA) help ensure that these additives are safe for people to consume.

There are two major categories of food additives:

• Direct additives. Intentionally added to the food for a specific purpose. They usually are listed on the ingredient label of a food. A direct additive may preserve freshness, improve nutritional quality, assist in processing or preparing food, or make food more appealing.
  
  
• Indirect additives. Become part of the food in trace amounts as a result of harvesting, production, processing, packaging, storage or other handling. These are typically present in minimal amounts.

Additives serve many different purposes. For example, additives keep peanut butter from separating, make ice cream smooth and add nutrition to breads and cereals. In some cases, additives may help make food taste more appealing or make it more nutritious. In other cases, they can help foods to remain fresh, to resist changes from temperature shifts, storage, oxidation and contact with microbes (e.g., bacteria, fungi, viruses).

Additives offer many benefits to foods that can be grouped into three major categories:

• Maintaining or improving freshness and safety
• Improving or maintaining nutritional value
• Improving taste, texture and appearance

Additives often serve as preservatives that maintain and improve food freshness and safety. They may help slow the damaging effects that air, bacteria, fungi, mold or yeast can have on food. Antioxidants protect foods from chemical changes caused by oxygen. For example, they help prevent fats and oils from turning rancid in baked goods and prevent fruits from turning brown when they are cut and exposed to air. Meanwhile, antimicrobials inhibit the growth of mold, bacteria and yeast.

Additives are also used to improve or maintain a food’s nutritional value, which helps to reduce malnutrition. Vitamins, minerals and fiber are added to many foods to replace nutrients lost during processing, or may be added to a food simply to boost a person’s intake of certain nutrients. Products that have these added substances are described as enriched or fortified.

Many foods lose nutrients during processing. Enriched foods have vitamins and minerals added back to the food following processing. Examples include adding B vitamins and iron to bread, flour and rice. Fortified foods have nutrients that were not part of the original food, but that were added before processing. For example, iodine may be added to salt, vitamin A and vitamin D to milk, calcium to fruit juices, folic acid to grains and fiber to breakfast cereals.  

Using additives to increase the nutritional value of food has helped to dramatically reduce diseases attributed to nutritional deficiencies, including goiter, rickets, scurvy and pellagra. Each food has a food label and ingredients list that reveal which nutrients have been added.

Finally, additives can help improve taste, texture and appearance of foods. Spices (which may be either natural or artificial) and sweeteners are used to enhance the flavors of many foods. Emulsifiers ensure that a product maintains a consistent texture and keep it from separating. Stabilizers and thickeners lend smooth, uniform texture to a product. Anti-caking agents prevent moisture from causing  products (e.g., salt) to clump together.  

There are many examples of both direct additives and indirect additives. Examples of direct additives that help maintain or improve freshness and safety include:

• Antimicrobial agents. Help prevent microbes that may cause foodborne illness. Salt and sugar are the most commonly used antimicrobial agents. Salt helps preserve meat and fish while sugar used as part of the canning process can help preserve canned fruits, frozen fruits and jams and jellies. Both salt and sugar absorb water so that it is not available to microbes. Potassium sorbate and sodium propionate help preserve baked goods, cheeses, beverages, mayonnaise and margarine. Nitrates are added to foods to preserve color, enhance flavor by slowing rancidity (decomposition of fats) and protect against bacterial growth (including the bacteria that cause botulism).
  
  
• Antioxidants. Prevent oxidation, the process that causes rancidity and flavor changes in foods, fats and oils upon exposure to oxygen. Antioxidants include vitamin C and vitamin E. Sulfites are antioxidants that prevent oxidation in processed foods, alcohol and drugs. They cannot be used on foods that are eaten raw (except grapes) because this may cause adverse reactions. They also cannot be used in foods that are important sources of thiamin (e.g., enriched grain products), because sulfites are known to destroy this vitamin. Foods and drugs that contain sulfites must indicate the additive on the labeling. This may be referred to as sulfur dioxide, sodium sulfite, sodium bisulfite, sodium metabisulfite and potassium metabisulfite. The antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are widely used to prevent spoiling, and rancidity in baked goods, snack foods and breakfast cereals.

Examples of direct additives that help improve taste, texture and appearance include:

• Natural flavors, artificial flavors and flavor enhancers. These substances help foods taste better. Natural flavors include spices, herbs, essential oils, fruits and fruit juices. Some spices provide antioxidant protection. Artificial flavors include artificial sweeteners such aspartame. Flavor enhancers are products that help bring out a food’s sweet, salty, bitter or sour taste. Examples include monosodium glutamate (MSG).
  
  
• Food preparation and processing additives. These products help foods to maintain a certain consistency. For example, emulsifiers help keep mayonnaise stable and allow powdered coffee cream to dissolve more easily. Gums are used to thicken foods and help form gels. Examples include xanthan gum, bicarbonates and acids. Anti-caking agents keep food from absorbing moisture so it does not clump together, while leavening agents (e.g., yeast) release acids during heating that react with baking soda to help foods to rise.
  
  
• Nutrient additives. Nutrients are sometimes added to fortify or maintain the nutritional quality of foods. These include nutrients added to refined grains (riboflavin, thiamine, folic acid, niacin, iron), the iodine added to salt, the vitamins A and D added to milk, and the nutrients added to fortified breakfast cereals.
  
  
• Colors. Both synthetic colors and colors derived from natural pigments may be added to foods to improve appearance. Most processed foods contain color additives. For example, margarine would not be yellow without color additives. Color additives may be used to offset color loss resulting from exposure to air, light, moisture, temperature extremes and storage conditions. They also may be used to correct natural variations in color, enhance naturally occurring colors and provide color to foods (e.g., foods that naturally lack an appealing color).
  
  Color additives are divided into two categories: certified colors and colors exempt from certification. Certified colors are synthetic substances that provide a uniform color to foods. Most of these colors do not change a food’s taste. They are often used to give more intense color to food and to create various hues.
  
  Colors that are exempt from certification are derived from natural sources (e.g., animals, vegetables or minerals). They typically are more expensive than certified colors and may alter the taste of a food. Annatto extract and dehydrated beets are examples. In the United States, 33 colors have been approved for use and nine of those are synthetic. The manufacturer and the FDA test every batch of synthetic color for purity.
  
  Examples of artificial colors include two forms of blue (brilliant blue and indigotine), two reds (allura red and erythrosine), two yellows (tartrazine and sunset yellow) and a green (fast green). Natural-color additives include annatto (yellow), caramel (yellowish brown), carotenoids (yellowish orange), dehydrated beets (reddish brown) and grape skins (red, green).

Indirect additives are usually present in tiny amounts and may include bits of plastic, glass, paper, tin and chemicals from processing (e.g., the solvent used to decaffeinate coffee). Examples of indirect additives found in foods include:

• Acrylamide. A compound that forms when foods rich in carbohydrates are cooked at high temperatures. For example, potatoes formed into French fries contain acrylamide. This substance has been shown to cause cancer in animals, but scientists are unsure of whether or not there is enough acrylamide in foods to pose a health threat to humans. FDA researchers are studying this question.
  
  
• Dioxins. Packaging made of bleached paper can contaminate foods with tiny quantities of dioxins. These compounds form during chlorine treatment of wood pulp during the manufacturing of paper. Packaging that may contain dioxins include coffee filters, milk cartons, paper plates, and frozen-food packages. However, these amounts are believed to be too low to cause a health threat.
  
  
• Hormones. The FDA has approved a dozen hormones for use in food-producing animals. This produces leaner meats, and higher outputs of milk from dairy cows. Traces of hormones such as bovine growth hormone (BGH) find their way into the foods and milk people consume. However, organizations such as the National Institutes of Health (NIH) have declared that meat and milk from animals treated with hormones is as safe as that of untreated animals.
  
  
• Antibiotics. Similar to hormones, antibiotics given to animals may eventually be found in foods in trace amounts. Some people who have allergies to antibiotics may experience an allergic reaction as a result. For most other people, the levels of antibiotics in these foods pose no threat. The FDA requires a specified time between the times an animal is treated with antibiotics and when the animal is slaughtered. This time should allow for the drug to be metabolized in the animal’s body and excreted so only a minimal amount is passed into food.
  
  
• Microwave packaging. Microwave products that contain “active packaging” are used as part of the cooking process (e.g., frozen pizzas). In such instances, packaging materials may be found in the foods. The FDA requires the manufacturers prove that this packaging is safe for human consumption. Packaging that simply holds the food while it cooks also may pass into the food. This, too, is safe according to the FDA, but the packaging should not be reused.
  
  
• Decaffeinated coffee. Methylene chloride is used to remove caffeine from coffee. This process leaves this chemical in the coffee. The levels that are present pose no threat to people, according to the FDA. For those who remain concerned, decaffeinated coffee is available in formulations where the caffeine is removed during a steam process.

FDA and additives

Thousands of substances are used as food additives. Since the passage of the Federal Food, Drug and Cosmetic Act of 1938 – and more specifically, the 1958 Food Additives Amendment and 1960 Color Additives Amendments to this act – the U.S. Food and Drug Administration (FDA) has been responsible for ensuring the human safety of foods and substances added to them.

The FDA must approve any new additive before it is brought to market. Each year, about 100 new food and color additives are submitted for approval, according to the agency. The majority of these substances are indirect additives used as packaging materials.

The FDA also must approve any new use of an additive that was previously approved for another purpose. The FDA maintains a database of more than 3,000 ingredients. Many of these additives are among the most commonly used substances in daily life, including baking soda, salt, sugar, spices and yeast.

The FDA does not approve any additive until it has been demonstrated that the additive is effective and is reliably detectable or measurable in the final product. Most importantly, the FDA must determine that the product is safe for use. Usually, large doses of the substance are used for long periods of time in animal studies before an additive can be declared safe. In some cases, studies of the additive’s effect on humans also may be part of the approval process.

The FDA considers several factors when deciding whether or not an additive is safe. These include the composition and properties of the substance, the amount that is likely to be consumed, the immediate and long-term health effects, and a variety of other safety factors.

The FDA exercises great caution in this process and only approves substances at levels that are much lower than levels expected to potentially have an adverse impact. The FDA regularly permits additives to be used in amounts that are 100 times below the lowest level that has been found to cause harmful effects.

While the FDA cannot absolutely guarantee the safety of any additive, it does not approve any additive until there is reasonable certainty that the product will not cause harm when used as directed. After approval, the FDA determines the foods in which the additive can be used, the maximum amount that can be used and how the additive should be labeled on the package. On products such as additives for meat and poultry, the FDA consults with the U.S. Department of Agriculture (USDA). The FDA continues to monitor these additives over time and adjusts its policies according for any new data that emerges.

In evaluating an additive, the FDA always tries to weigh the potential risks of the additive against the potential benefits. For example, nitrates are a preservative that can be converted to nitrosamines in humans. Nitrosamines have been shown to cause cancer in animals. However, the FDA has approved nitrates because the risk of harm is low and is less significant than the benefit that nitrates provide in helping prevent diseases caused by spoiled food.

The FDA also requires that additives cannot be used to disguise inferior products or to deceive the consumer. Additives also must not destroy nutrients in significant amounts.

Two special categories of additives are exempted from the regulation process. First, prior-sanctioned substances include additives that were determined to be safe prior to the 1958 Food Additives Amendment. Examples include sodium nitrite and potassium nitrite, which are both used to preserve luncheon meats.

The second category of substances excluded from the food additive regulation process are generally recognized as safe (GRAS) substances. The FDA has a list of about 700 items that are generally recognized as safe (GRAS). Items on this list do not require FDA approval because they have already been shown to be safe. Examples include well-established additives such as caffeine, sugar and many spices. This list is reviewed continually and items may be added or removed from the list as evidence warrants.

Foods that are found on the GRAS list cannot be found to be carcinogenic in any test that is performed on animals or human beings. This requirement is part of the Delaney clause of the U.S. Food, Drug, and Cosmetic Act. This requirement is part of the Delaney clause of the U.S. Food, Drug, and Cosmetic Act, which is named after its congressional sponsor (Rep. James Delaney of New York).

Preparing questions in advance can help patients have more meaningful discussions regarding their conditions. Patients may wish to ask their doctor or registered dietitian the following questions related to additives:

1. Are there health concerns associated with additives?
   
   
2. Are there certain additives I should seek out or avoid for health reasons?
   
   
3. Where can I find a list of foods that contain these additives?
   
   
4. How will I know if I am consuming too much of an additive?
   
   
5. What are some good resources for learning more about additives?
   
   
6. What should I do if I have a reaction to an additive?
   
   
7. Can you suggest alternative foods that are less likely to provoke a reaction in me?
   
   
8. Do I need to worry about indirect additives?
   
   
9. Where can I find out more about the FDA’s list of GRAS additives?
   
   
10. What are the risks of avoiding additives altogether?