Food additives are widely used by the food industries for attracting a larger number of consumers by making the food more appealing. Some of the food additives which are used by the food industries are bulking agents, emulsifiers, food colorants, flavoring agents, preservatives, and sweeteners. Despite the beneficial effects of food additives, these additives can also cause serious adverse effects on humans. Some of the most common adverse events include anaphylaxis, asthma, urticaria and/or angioedema. In this chapter, we describe the adverse health events that are caused as a result of different food additives with special reference to allergic, immunologic reactions, asthma, autoimmune diseases, cancer, diabetes and metabolic disorders. Although the animal and in vitro studies that examined the adverse health effects of different food additives are available, the clinical studies which examined the adverse health effects of different food additives in a large population group are very limited.