Mitochondrial aldehyde dehydrogenase polymorphism is not associated with incidence of Alzheimer's disease

The association between the mutant allele of mitochondrial aldehyde dehydrogenase (ALDH2*2) and Alzheimer's disease (AD) has been controversial and only so far investigated in cross-sectional studies. This study aimed to investigate the longitudinal association between ALDH2*2 and incidence of AD.

Of 592 participants aged 65 or over without dementia at baseline, 510 (86%) were re-evaluated after 2.4 years and comprised the study sample. Baseline measures included: demographic characteristics, drinking behavior, cognitive function (MMSE), clinical diagnoses of dementia and AD, and genotype (ALDH2 and apolipoprotein E). At the follow up examination, alcohol related characteristics, MMSE and clinical diagnoses of dementia and AD were reassessed.

There were no significant associations between the ALDH2*2 and any cognitive outcomes (incidence of dementia or AD, or cognitive decline). These findings were not changed after adjustment for alcohol consumption. No interaction was found between ALDH2 and apolipoprotein E.

ALDH2*2 does not seem to be important in the etiology of dementia.