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What are food additives and impurities?
Last reviewed: 19.10.2021
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Additives are chemicals mixed with food to facilitate processing, storage or enhancement of their organoleptic properties. Only those supplements that have undergone certain laboratory tests are allowed to use as food.
The ratio of benefit of additives (for example, reduction of waste, increase in the diversity of foods, prevention of food poisoning) and risks is difficult to estimate. For example, nitrite, which is used in canned meat, prevents the growth of Clostridium botulinum and improves the aroma. However, nitrite is converted into nitrosamines, which are carcinogenic substances for animals. On the other hand, the amount of nitrite added to canned meat is small compared to the amount of nitrates contained in natural products and converted to nitrite by salivary glands. Vitamin C food can reduce the formation of nitrite in the digestive tract. Seldom, some additives (for example, sulfites) cause hypersensitive reactions (food allergy). Most reactions are caused by ordinary foods.
Impurities sometimes can not be completely removed without destroying food; thus, limited quantities are allowed. The main impurities are pesticides, heavy metals (lead, cadmium, mercury), nitrates (in green leaves of vegetables), aflatoxins (in nuts and milk), growth stimulating hormones (in dairy products and meat), animal hair and feces, of insects. The US Food and Drug Administration (FDA) has developed safe levels of impurities that do not cause disease or adverse effects on humans. However, as has been shown, the ratio between extremely low exposure and adverse effects is difficult to estimate; long-term side effects of them, although undesirable, but possible. Safe levels are often determined by consensus, not by strong evidence.