Healthier lifestyles are associated with declining prevalence of cognitive impairment and dementia. Futhermore, specific lifestyle changes are effective for preventing dementia, including increasing education in early life, increasing physical activity and social engagement, reducing smoking, treating hypertension, diabetes, and hearing impairment. These findings were reported in “Dementia Prevention, Intervention, And Care” by Gill Livingston, Andrew Sommerlad, Vasiliki Orgeta, Sergi G. Costafreda, and colleagues, and published in The Lancet. Dementia was defined as a decline from a previously attained cognitive level, that affects activities of daily living or social functioning. The authors calculated a population attributable fraction (PAF), defined . . .