Determining safe levels of the naturally-occurring or deliberately-added chemicals in food which are potentially harmful to health.
Contaminants and additives
There are many potentially harmful or toxic chemicals present in the food we eat, whether occurring naturally, as contaminants, or as deliberate
additives. But these chemicals are not necessarily harmful in small amounts; the effects they have depend upon the amounts that we consume.
Some people choose to take supplements which are thought to have beneficial effects. Supplements include vitamins and essential minerals,
which our bodies need in small amounts, as well as other chemicals for which there is less evidence of beneficial effects. But in most cases, we receive adequate amounts of these chemicals from food and all of them may be harmful if taken in excessive amounts.
Chemicals present in food
- Contaminants are widespread in our environment, and may enter the food chain and be present in all plant and animal products that we eat (e.g. dioxins)
- Chemical components of materials which come into contact with food, such as packaging materials, may be absorbed into our foods
- Chemicals may form during food processing or cooking (e.g. polycyclic aromatic hydrocarbons)
- Chemicals used in farming, such as pesticides and veterinary medicines may remain in the products we eat
- Additives are deliberately added to food in order to provide some useful purpose, such as flavours and preservatives, which allow the consumer to select a varied diet from preserved foods all the year round
- Some natural components of plants may themselves cause toxicity (eg glycoalkaloids in potatoes), while some may be harmful if not cooked properly (eg lectins in pulses). There are also some foodstuff which can cause allergies in susceptible individuals (e.g peanuts).
- Chemicals may be produced by moulds which contaminate crops during storage, such as aflatoxins.