Dietary aluminium in Kenya tea and foods

Abstract

Concern over the possible relation between environmental aluminium exposure and Alzheimer's disease has prompted studies of all forms of input of aluminium into our environment. Some plants such as tea (Camellia sinensis) tolerate high levels of aluminium by accumulating great quantities of it (aluminium) in the leaves. Thus, a study was carried out to determine levels of aluminium in both home and factory processed tea, tea influsions and some foods. Factors affecting the amount of aluminium in tea infusions and food were investigated. The levels of aluminium were determined using atomic absorption spectrometry (AAS). The results indicated that tea leaves contain aluminium concentrations in the range of 300 - 500 mg/g. Between 18% and 40% of total aluminium was extracted during tea making. The aluminium concentrations in tea infusions depend on infusion time, method of brewing/temperature, nature of brewing vessel, strength of brew and brand of tea leaves. The results indicated that most foods contain less than 10 mg/g of aluminium. Some of the factors that were found to affect aluminium leaching in foods were, severity of cleaning cookware/type of cleaning material, soil particles on food, organ (in case of meat products), wrapping/packaging material, fluoride content and pH. For example, the results of the present study clearly indicate that high concentrations of aluminium are leached from cooking acidic and basic foods in aluminium saucepan. The levels of aluminium increased greatly when the acidic and basic foods were cooked, with water containing fluoride, in aluminium saucepans.