Recall the food we eat every day, including three meals, snacks, and treats. Aren't processed foods the majority? According to surveys, processed foods make up 70-80% of our daily diet; this is a trend in modern industrialized societies. Food processing isn't inherently bad—it's necessary. It allows us to preserve abundant agricultural products, develop diversified products (for example, soybeans can be made into soy milk, tofu, soy sauce...), and increase the reuse of raw materials (such as using asparagus skins to make asparagus juice). However, excessive or improper processing can lead to problems. Due to technological advancements, numerous chemical food additives have been invented. The market is flooded with products, and the variations in color, aroma, taste, and texture are increasingly appealing to consumers. Unknowingly, we consume many chemical food additives. Could they be invisible threats to human health?

Ubiquitous Food Additives

You might think additives have nothing to do with you—you don’t often eat junk food or drink beverages. But is the reality as you imagine? Let’s take a look:

• Bread, steamed buns, and baozi may contain emulsifiers, quality improvers, leavening agents, and flavorings to make them soft and delicious.
• Rice noodles that are white and cheap may use cornstarch as the raw material, and bleaching agents might be added during production. Since they lack stickiness, thickeners are often added during the process.
• Solvents are commonly used in oil extraction (cold-pressed oils are an exception), and antioxidants may be added to prevent oil oxidation.
• To make oil noodles and cold noodles chewy and preservative-free, borax might be added.
• To allow sausages, ham, bacon, and cured duck to be stored at room temperature without refrigeration and maintain a bright red color, color fixatives and preservatives (such as nitrites) might be added.
• Fish balls and meatballs may contain binding agents to make them chewy and elastic.
• Soy products (soy milk, tofu, dried tofu, vegetarian chicken, shredded tofu) often have defoaming agents added to prevent bubbles during boiling. To keep them from spoiling while being sold at room temperature all day, preservatives are added, and illegal use of hydrogen peroxide as a sterilizer may occur.
• Mushrooms, lotus roots, lotus seeds, and lily bulbs may have bleaching agents added to make them white.
• Dried vegetables (dried daylilies, dried cabbage, white fungus, bamboo fungus) and dried fruits (dried persimmons, dried mangoes, dried pineapples) are often fumigated with sulfur dioxide (a bleaching agent) to maintain vibrant colors.
• To make mung bean sprouts grow quickly, with short roots, thick stems, and plump, juicy bodies, chemical hormones (low-concentration herbicides) are often added.
• Dried radishes, pickled mustard, preserved vegetables, winter vegetables, and pickled melon may contain preservatives to prevent spoilage despite being sun-dried for only one or two days. To make them crispy, quality improvers and binding agents are added, and flavor enhancers are used to reduce saltiness.
• To make biscuits fluffy, leavening agents, quality improvers, and emulsifiers are added. For aroma, flavorings are used, and hydrogenated oils (containing trans fats, which can lead to cardiovascular diseases) may be used for processing convenience.
• Preserved fruits are often bleached and dyed to maintain vibrant colors, and preservatives are added for shelf life. Artificial sweeteners (saccharin, cyclamate) are added for taste.
• Beverages may also contain flavorings, colorings, artificial sweeteners, and quality improvers. To achieve a thick texture (e.g., guava juice), thickeners are added.

Thus, additives are almost omnipresent in our lives.

The preservatives, bleaching agents, emulsifiers, thickeners, artificial sweeteners, quality improvers, colorings, saccharin, etc., mentioned above are all food additives. Do all these processed foods really use so many additives? What exactly are food additives? Do they affect our health?

What are food additives?

Broadly speaking, "food additives" have existed since ancient times. In the past, to preserve animal-based foods, methods such as pickling, smoking, and air-drying were used. For plant-based foods, methods like drying, soaking, pickling, and saucing were employed. Safflower was used to dye eggs, and red yeast rice was used to cook red meat dishes. For fragrance, spices were used; fresh spices included scallions, ginger, garlic, and cilantro, while dried spices included five-spice powder, star anise, Sichuan pepper, osmanthus, and perilla. For umami, shiitake mushrooms, kelp, and soybean sprouts were used to make broth. For chewiness and crispiness, manual pounding and grinding were used.

Later, it was discovered that the sweetness, pigments, and aromas in fruits and vegetables could be extracted. Thus, natural substances were used as raw materials, and their components were artificially extracted to serve as food additives. Gradually, natural sources became limited, insufficient, and costly, leading to the development of low-cost, mass-produced chemical synthetics, which is a phenomenon of the past century. Especially in recent decades, with the advancement of chemical technology and the chemical industry, the development of food additives has progressed rapidly. Due to their effectiveness in enhancing the color, aroma, taste, and texture of products, making them more appealing to consumers, and making processing more convenient and cost-effective for producers, the use of food additives has become almost "rampant."

For ease of management, the government has specifically defined food additives and categorized them into 17 functional groups (with over 500 items and increasing annually). Usage scope and dosage standards have been established, and a positive list system is actively enforced, prohibiting the use of any substances not listed. Quality and purity standards for food additives, known as the "Food Additive Specifications," have been incorporated into the Food Sanitation Act for regulation.

According to Article 3 of Chapter 1 of the Food Sanitation Management Act, food additives are defined as: "Substances added to or in contact with food during the processes of manufacturing, processing, preparation, packaging, transportation, or storage for the purposes of coloring, flavoring, preserving, bleaching, emulsifying, enhancing aroma, stabilizing quality, promoting fermentation, increasing viscosity, enhancing nutrition, preventing oxidation, or other purposes." Therefore, food additives have the following characteristics:

1. They are not naturally present in food but are specifically added for a particular purpose.
2. They cannot be consumed alone.
3. They are used in very small amounts, typically less than one percent, often only a few ppm (parts per million, e.g., one milligram of additive per kilogram of food equals one ppm). Thus, misuse can have significant impacts, potentially up to 100 to 1000 times the intended effect.
4. Legal food additives must be applied for, inspected, and registered by the central competent authority, and a permit must be issued before they can be marketed and used.

Are food additives safe?

Since food additives are not naturally present in food but are manufactured and added separately, their toxicity must be carefully considered, especially for chemical synthetics. Even some natural products, due to chemical processing, may have some degree of toxicity and thus must have their usage limited. The maximum allowable dosage is determined through animal testing (toxicity tests), and exceeding these limits can certainly harm health.

Food additives, like pharmaceuticals, are chemical products intended for human consumption. Pharmaceuticals are typically used with consideration of the user's condition, limited to a specific duration, and their harmful effects on the body can be tracked and investigated. However, food additives are widely added to various foods for consumption by an unspecified majority, potentially daily or lifelong, yet their safety assessment relies solely on animal testing, making it difficult to track and investigate the impacts of their use.

Some food additives may contain trace amounts of impurities, which could be by-products generated during the manufacturing process or pre-existing in the raw materials. These impurities may enter the food due to the negligence of handlers, resulting in strong toxic effects. With the advancement of analytical chemistry techniques, new toxicities may be continuously discovered, posing more challenges and concerns for the management and safety assessment of food additives. As a result, some additives that were once legal have been banned after re-evaluation, while others, although still permitted for use, remain highly controversial.

In addition, some unscrupulous businesses, either for convenience, profit-seeking, or due to negligence and ignorance, often misuse legal food additives (either in excessive amounts or for incorrect purposes), and even illegally use some prohibited food additives. For example, when the quality of raw materials is poor, not fresh, or the color and flavor deteriorate, they use bleach to whiten, then dye, and add preservatives, artificial flavorings, and chemical synthetic fragrances, causing significant harm to consumer health.

The appendix lists some highly toxic, prohibited, yet illegally used additives, as well as those legally permitted but still questionable in terms of toxicity and safety, for reference.

Legal but questionable in safety food additives

Category	Item	Examples of food used	Potential health impacts
Preservatives	Sodium dehydroacetate	Cheese, cream, butter, margarine	Teratogenic.
Antioxidants	BHA, BHT	Oils, instant noodles, chewing gum, cheese, butter	BHA is confirmed as a carcinogen, and some studies suggest BHT may also be carcinogenic.
Artificial sweeteners	Saccharin, Cyclamate	Preserved fruits, melon seeds, pickled vegetables, beverages	Animal tests have shown they can cause bladder cancer.
	Aspartame	Beverages, chewing gum, preserved fruits, artificial sweetener packets	Dizziness, headaches, epilepsy, menstrual irregularities, harmful to infant metabolism (not to be consumed by those with phenylketonuria).
Color Preservative	Nitrite	Sausage, Ham, Bacon, Dried Duck, Dried Fish	Combines with amines in food to form carcinogenic nitrosamines.
Bleaching Agent	Sulfites	Preserved Fruits, Dehydrated Vegetables and Fruits, Daylily, Shrimp, Rock Sugar, Fresh Vegetable and Fruit Salad, Starch	May cause hives, asthma, diarrhea, vomiting, and there have been fatal cases among asthma patients.
Artificial Synthetic Color	Yellow No. 4	Cookies, Candy, Oil Noodles, Pickled Yellow Radish, Ham, Sausage, Beverages	Synthesized from coal tar, a byproduct of the petroleum industry, with many opportunities for harmful substances to mix in. It is highly toxic, has carcinogenic concerns, and can cause hives, asthma, and allergies.
Bactericide	Hydrogen Peroxide (Hydrogen Dioxide)	Tofu, Dried Tofu, Vegetarian Chicken, Wheat Gluten, Fish Paste, Meat Paste Products, Dead Chicken Meat (for bleaching and removing odor)	Can irritate the gastrointestinal mucosa, and excessive consumption may cause headaches and vomiting. It is carcinogenic. It is prohibited to be used as a bleaching agent and must not remain in food.

Illegal Food Additives

Category	Item	Examples of Food Use	Potential Health Impacts
Previously legal, now banned	Potassium bromate	Used in flour (gluten improver)	Confirmed to be carcinogenic (officially banned in 1994).
	Sodium cyclamate	Preserved fruits, beverages, etc. (sweetener)	Harmful to the liver and digestive tract, confirmed to be carcinogenic.
	Red dye No. 2	Candies, beverages	Carcinogenic (banned in 1975, but some imported candies and soft drinks were still found to contain it in 1984).
Highly toxic, always banned, but some businesses still illegally use it	Borax	Rice cakes, oil noodles, fried dough sticks, fish balls, bowl cakes, zongzi, flat noodles, ham, taro balls, tapioca pearls (to make them Q, crispy, elastic, water-retaining, and preservable)	After ingestion, borax turns into boric acid, and accumulation of 1~3 grams in the body can cause acute poisoning with symptoms such as vomiting, diarrhea, collapse, and skin erythema. Over 20 grams may lead to kidney atrophy and life-threatening conditions.
	Formalin (Rongalite)	Originally an industrial bleaching agent, but used in rice noodles, golden raisins, maltose, mushrooms, dried radish, and other foods	Residual formaldehyde can easily cause headaches, dizziness, difficulty breathing, vomiting, digestive disturbances, and eye damage. Residual sulfites may cause: hives, asthma, diarrhea, vomiting, and there have been cases of asthma patients dying from it.
	Cream Yellow	Sauerkraut, Pickled Yellow Radish, Noodles (Industrial Yellow Pigment)	Liver Cancer.
	Basic Mustard Yellow	Pickled vegetables, pickled yellow radish, noodles (industrial yellow pigment)	Headache, rapid heartbeat, unconsciousness.

Source: http:/ / cbs. ntu. edu. tw/ thread……oard=BudaFood& nums=2630:2631