Genetic and hence lifelong low BMI is not associated with increased risk of Alzheimer's disease in the general population. These data suggest that low BMI is not a causal risk factor for Alzheimer's disease and that the corresponding observational association likely is explained by reverse causation or confounding.
No takes yet. Share an insight, caveat, or question.
Nordestgaard et al. (2017) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: