In order to evaluate genetic apolipoprotein polymorphisms as risk factors for Alzheimer's disease (AD), we studied apolipoprotein (apo) AIV after apoE, an apolipoprotein also present in the brain. The allelic distribution of apoAIV codon 360 polymorphism was no different in AD group (n = 120) compared with elderly healthy individuals (n = 119). Surprisingly, this polymorphism was over-represented (11.40%, vs. 5.7% P < 0.005) in all these aged subjects (74.29 +/- 8.46 years) and independently of the clinical and mental status compared with the younger population (39.00 +/- 9.69 years) of the same regional recruitment. These results suggest that the apoAIV (360:His) allele could be a marker of aging and longevity.