I read with interest the article by Ganguli et al1 comparing the incidence of Alzheimer disease (AD) and apolipoprotein E (APOE) polymorphism between the American and Indian communities. The incidence of AD is remarkably less in the Indian community, being about one fourth that in the American community. When the age cohorts 70 to 79 and greater than 80 years are compared, it does not appear that APOE*E causes AD, which raises the question of whether AD patients die more quickly in the Indian community and as a consequence are less likely to be counted. This could explain the lower statistical incidence of the disease, unless there is truly a lower likelihood or risk of developing AD in the Indian community.
Brenner SR. Lower Incidence of Alzheimer Disease in an Indian Community Compared With an American Community. Arch Neurol. 2001;58(3):517. doi: