The neurodegenerative diseases Alzheimer’s, Parkinson’s, frontotemporal lobar degeneration, Lewy body disease, and amyotrophic lateral sclerosis are all age-related and caused by genes in only 1-10 percent of cases. Dementia describes a syndrome in which there are cognitive difficulties including impaired memory, judgment, planning, language, and other deficits. Alzheimer’s is the commonest cause of dementia. In the brain in neurodegenerative diseases there is abnormal folding of proteins creating thread-like filaments called amyloid. There is also abnormal activation of inflammation with free radicals and harmful cells. There are things we can do regarding diet and other actions that can lower the risk of developing neurodegenerative diseases with aging. High levels of physical and mental activity throughout life along with attention to a healthy plant-based diet can enhance our four reserves and diminish amyloid deposition and overactivity of the immune system. Lifestyle measures can also protect us from the effect of brain pathologies that may develop. There are many causes of memory loss other than Alzheimer’s disease which are completely reversible when properly recognized.