The positive association of choline for cognition has been reported in both animal and human studies, yet the associations of choline with the risks of incident dementia or Alzheimer’s disease (AD) in humans is unclear and the objective of this paper was to test the hypothesis that lower or higher dietary choline intake is associated with increased or decreased, respectively, risks of incident dementia and AD. The paper concludes that low dietary choline intake was associated with increased risks of incident dementia and AD and that further investigations regarding the effects of high choline intake on dementia and AD risks are warranted.