Other pharmacologically active substances found in food include histamine, tyramine, tryptamine and serotonin, which may be consumed in foods such as red wine, cheese, yeast extract, avocados and bananas. In susceptible people, these foods can trigger urticaria, facial flushing and headaches. Food intolerance of unknown origin Reactions can be provoked by many foods and food products which we cannot be clear about. They may or may not be allergic reactions. Food additives, particularly tartrazine and sodium benzoate, can provoke urticaria, rhinitis and asthma.
Yeasts can provoke a number of reactions in some people, particularly skin disorders.
Whilst not all food intolerances are related to meat and dairy products, it can be seen from the above list that vegetarians, and particularly vegans , will suffer less from food intolerance because they already eliminate some of the most common causes of intolerance. Other more long-term symptoms include can depression, anxiety, fatigue, migraine, sleeplessness and hyperactivity in children. As it is sometimes quite difficult to distinguish between a genuine food allergy and a food intolerance, treatment is often similar. The first step is to diagnose the food intolerance. This should not be done without medical supervision as some reactions to food intolerance can be dangerous.