The number of associated risk factors for dementia was increased from nine to twelve in 2020. The three added ones are over-indulgence in alcohol, traumatic brain injury, and air pollution. The other nine risk factors are: lower levels of education; high blood pressure; hearing loss; smoking; obesity; depression; inactivity; diabetes, and low social contact. Several of the group are known "vascular risk factors" that may be able to be reduced or eliminated. A reduction in a number of these risk factors can give a positive outcome. The decreased risk achieved by adopting a healthy lifestyle is seen even in those with a high genetic risk.