Metals in the diet
Thursday 25 March 2004
A survey carried out by the Food Standards Agency of metals in food shows that the amounts of these substances in people's diets are unlikely to damage their health.
Metals and other elements are found in food as a result of farming, industrial emissions, food storage and processing. Some elements are essential nutrients that our bodies need to work properly, but all of them can be harmful if eaten in too high a quantity.
The Total Diet Study was carried out to identify the levels of 12 elements in the typical UK diet and to provide up-to-date information on dietary intake.
The elements looked at were: aluminium, arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, selenium, tin and zinc.
The independent Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT), which advises the FSA, evaluated the results of this survey and concluded that the levels of these elements in our diets were unlikely to cause any health problems.
The concentrations of most of the elements in the survey were lower than or similar to those reported in previous surveys, conducted in 1997, with the exception of aluminium and mercury.
Each group of people looked at had levels of aluminium in their diet that were within international safety guidelines and the COT concluded that the amount of aluminium in our diets is unlikely to be of any health concern.
The Committee looked carefully at mercury levels and whether young children (aged between 1½ and 4½) who ate a lot of the food likely to contain mercury might exceed the safety guidelines. International safety guidelines are set assuming a worst case scenario – that the mercury is all in its more dangerous form, methylmercury, which is found in fish. However, the COT concluded that it was highly unlikely that all of the mercury taken in by young children was in this form so the levels found were not a cause for concern.
The amount of nickel in our food has fallen to its lowest level since 1976. The estimates of how much is taken in by children (aged 1½-18 years) who eat a lot of the food likely to contain nickel, marginally exceeded the Tolerable Daily Intake (TDI). The TDI was established by the World Health Organization as the basis for setting guidelines for safe levels of nickel in water. The COT concluded that the results were unlikely to result in any damage to these children's health because our bodies absorb less nickel from food than they do from water.
The estimated amount of tin in our food was below the levels found in the previous FSA study but young children (aged 1½-4½ years), who eat a lot of the foods likely to contain tin, exceeded the guidance level set by the Expert Group on Vitamins and Minerals (EVM). This small excess was not expected to damage children's health.
A separate study on total and inorganic arsenic in the diet found levels to be similar to those reported in previous surveys, and the COT found that the levels identified in food were unlikely to be a problem for people's health.