Is It Possible to Delay or Prevent Age-Related Cognitive Decline?

Already in the 90s, Khachaturian stated that postponing dementia onset by five years would decrease the prevalence of the late onset dementia by 50%. After two decades of lack of success in dementia drug discovery and development, and knowing that worldwide, currently 36 million patients have been diagnosed with Alzheimer's disease, a number that will double by 2030 and triple by 2050, the World Health Organization and the Alzheimer's Disease International declared that prevention of cognitive decline was a 'public health priority.' Numerous longitudinal studies and meta-analyses were conducted to analyze the risk and protective factors for dementia. Among the 93 identified risk factors, seven major modifiable ones should be considered: low education, sedentary lifestyle, midlife obesity, midlife smoking, hypertension, diabetes, and midlife depression. Three other important modifiable risk factors should also be added to this list: midlife hypercholesterolemia, late life atrial fibrillation, and chronic kidney disease. After their identification, numerous authors attempted to establish dementia risk scores; however, the proposed values were not convincing. Identifying the possible interventions, able to either postpone or delay dementia has been an important challenge. Observational studies focused on a single life-style intervention increased the global optimism concerning these possibilities. However, a recent extensive literature review of the randomized control trials (RCTs) conducted before 2014 yielded negative results. The first results of RCTs of multimodal interventions (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability, Multidomain Alzheimer Prevention Study, and Prediva) brought more optimism. Lastly, interventions targeting compounds of beta amyloid started in 2012 and no results have yet been published.