The Science and Safety of Food Additives

The application of food additives has a rich history. Before the development of refrigeration and thermal processing, meat and fish were often salted to be preserved. The addition of sugar and vinegar was often used to retain the safety, flavor, and texture of fruits and vegetables. These and other practical food ingredients are readily used in the typical home kitchen, and include baking soda, baking powder, vanilla, yeast, and food colorings.

Regulatory agencies around the world, such as the European Food Safety Authority, Codex Alimentarius Commission, Health Canada, as well as FDA, carefully evaluate the safety of these and emerging food ingredients, commonly categorized at food additives. Within the United States, a food additive is any substance that’s intended to be used, either directly or indirectly, to affect the character and function in a food. The safety assessment of colors and flavors are regulated similarly, with the ultimate goal being assurances that under intended usage, these food components will be safe.

A brief overview of the many common food ingredients includes approximately 30 different categories that encompass hundreds of substances. Some of these categories include preservatives, flavors and spices, nutrients, emulsifiers, leavening agents, enzyme preparations, drying agents, humectants, and nonnutritive sweeteners. Many of these ingredients were widely used prior to 1958 and, in the absence of adverse events, were accepted without additional evaluation.

Since that time, new food ingredients have been extensively evaluated for safety. That safety process includes several key assessments, including chemical characterization, animal toxicology, metabolic fate, human trials, historical exposure, and evaluation of food processing on ingredient stability. All of these attributes are central to safety pertinent to intended use, affected population segments (e.g., infants, pregnant/lactating women, seniors), and frequency of use.

Within the United States, the Delaney clause of the Food Additives Amendment of 1958 was invoked approximately 60 years ago, fundamentally barring the FDA approval of any carcinogenic food additive, regardless of amount or potential exposure, to be ingested by humans or animals. Interestingly, this clause does not apply to the array of naturally occurring potential carcinogens or even possible innate toxins in the food supply. The clause does permit scientific discretion by the agency, such that not all data from animal species or in vitro data are applicable to humans.

Food additives provide several important functions: they promote food safety, enhance food choices, permit greater food conveniences, promote shelf life, and increase nutritional value. For example, sulfites reduce lipid oxidation and nitrates/nitrites inhibit Clostridium botulinum growth. It’s noteworthy that many vegetables, such as celery and beets, naturally contain nitrates at levels greater than permitted in the food supply as a food additive. Then there is benzoic acid, innate in strawberries and tomatoes, that inhibits the growth of some bacteria and molds.

Food Preservatives

Many consumer surveys indicate contemporary consumers avoid products that contain preservatives. The reluctance appears to be related to unfamiliar terms declared on package labels. Despite the extensive risk and safety assessments conducted by FDA and the Joint FAO/WHO Expert Committee on Food Additives, even ingredients such as ascorbic acid, sorbic acid, and tocopherols are shunned by consumers because they don’t understand that even the most common “chemical” that may be innate to foods must be produced through good agricultural practices.

While there are ongoing efforts to reduce food waste and food spoilage, substances such as spices, which can reduce the risk of food loss due to bacteria, molds, fungi, and yeast, and help maintain texture, color, and freshness, represent part of the total effort to assure the continued availability of safe, nutritious, affordable, and accessible foods for a growing population.

Direct Food Additives

Many direct food additives added during product formulation and during processing provide nutrients, help keep products fresh, and make foods more appealing. Nearly a century ago, iodine was added to table salt in order to reduce the risk of goiter. This action eliminated the goiter belt in the 1920s, a geographic region in the U.S. where as many as 70 percent of children presented clinical signs of iodine deficiency. Even in the 21st century, according to the World Health Organization, iodine inadequacy and frank deficiency remains one of the main causes of impaired cognitive development in children. Interestingly, in many regions of the world that are markedly affected by iodine insufficiency, many of the food plants that dominate the local diets contain goitrogens, substances that, when consumed in large amounts, interfere with iodine uptake in the thyroid gland and that can promote goiter growth. Those foods include primarily cruciferous vegetables, such as broccoli, cabbage, cauliflower, and bok choy. Other foods that also contain goitrogens include some fruits (peaches, pears, strawberries), soy-based foods, and even some cereal grains.