Brain aluminum in aging and Alzheimer disease.

Aluminum was assayed by atomic absorption spectroscopy in 274 brain samples, and assayed in neurons isolated in bulk from the frontal cortex of patients with Alzheimer dementia and from age-matched patients with no neurologic disease. Brain aluminum concentration increased with age, from late middle age to old age. There were no statistically significant differences in brain aluminum concentration between the 10 patients with Alzheimer disease (mean, 2.7 microgram per gram dry weight of tissue; mean age, 81 years), and the 9 nonneurologic controls (mean, 2.5 microgram per gram; mean age, 73 years). In both groups, the hippocampus had the highest concentration of aluminum (5.6 microgram per gram), and the corpus callosum the lowest (1.5 microgram per gram).