Tissue aluminum concentrations stability over time, relationship to age, and dietary intake

Abstract Aluminum concentration was measured in serum, whole blood, hair, and urine by neutron activation analysis. Seventy-six nondemented subjects were investigated. Not all assays were done on all subjects (e.g., serum aluminum on 76 subjects, whole blood aluminum on 42 subjects), but tissue aluminum concentrations were estimated on more than one occasion on 32 subjects. The mean ± SD aluminum concentration serum was 0.219 ± 0.063 μg/ml ( N = 76), in whole blood 0.368 ± 0.091 μg/ml ( N = 42), in urine 0.092 ± 0.076 μg/ml ( N = 42), and in hair 6.42 ± 2.22 μ/g ( N = 42). Using product moment correlation coefficient there was no significant correlation between age and tissue aluminum concentrations, nor between dietary intake of aluminum and tissue aluminum. The tissue aluminum concentrations were not stable over time even when dietary intake was constant. Tissue aluminum concentrations were measured in 14 patients after 7 days of dietary control and repeated approximately 6 weeks later, again after 7 days of dietary control. There was no significant correlation between the two estimations in any tissue measured. These results suggest that raised tissue aluminum concentrations reported in Alzheimer's disease are not an exaggeration of a normal ageing process, are not likely to be simply secondary to increased dietary aluminum intake, and that Alzheimer's disease does not represent the chronic toxic effect of moderately raised aluminum levels at the upper end of the normal distribution.