Food, additives uptake

Aluminium is the third most abundant element in the earth s crust and is used widely in the manufacture of construction materials, wiring, packaging materials and cookware. The metal and its compounds are used in the paper, glass and textile industries as well as in food additives. Despite the abundance of the metal, its chemical nature effectively excludes it from normal metabolic processes. This is due largely to the low solubility of aluminium silicates, phosphates and oxides that result in the aluminium being chemically unavailable. However, it can cause toxic effects when there are raised concentrations of aluminium in water used for renal dialysis. These effects are not seen when aluminium is at the concentrations usually present in drinking water. There is currently much activity to examine the factors that influence uptake of aluminium from the diet. 

Committee on Food Additive Survey Data, Poundage of Uptake of Food Chemicals, 1982 National Academy Press Washington, DC, 1984. 

The concentration of aluminum in different foodstuffs varies from 0.05 to 129mg/kg with an average concentration of approximately 12.6mg/kg. With the exception of certain spices and tea leaves, the normal aluminum levels in foodstuffs are very low. On the contrary, the increased uptake of antimonium by humans comes from its use as a food additive. Contamination could also occur from the use of aluminum containers and aluminum cans in the food industries. Water does not constitute a significant source of aluminum uptake. 

The daily aluminium uptake varies from one country to another, because it depends on both eating habits and food additives (generally aluminium salts) used as preservatives, fermenting agents and emulsifiers in the food industry. For example, in the United States, the daily aluminium uptake is estimated at 2-35 mg, compared to 2.5-6.8 mg in Italy. 

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