Why smoking may raise dementia risk: Lung exosomes could disrupt brain iron balance

The correlation between smoking and neurodegeneration is well-documented, with one study from 2011 finding that heavy smoking in midlife was associated with a greater than 100% increase in risk of dementia, Alzheimer's and vascular dementia more than two decades later. Dementia is a less-studied impact of smoking for a simple, terrible reason: It occurs later in life and smokers tend to die younger.