Age-related neurocognitive disorders include dementias—of which Alzheimer’s disease is the most common—and mild cognitive impairment, which is less severe and can precede a dementia diagnosis. These conditions affect memory and other executive functions, thereby decreasing a person’s ability to care for themselves and participate in society. Alzheimer’s disease alone is the sixth leading cause of death in the United States and the only top cause of death without known prevention methods, treatments, or cures.
https://www.rstreet.org/research/can-nicotine-slow-age-related-cognitive-decline/