[Effect of physical exercise and diet based interventions on the evolution of cognitive impairment to dementia in subjects older than 45 years. A systematic review.]

Background: Dementia is a global public health problem. Drugs for this indication have shown limited benefit. The aim of the present study is to synthesize and analyze the available scientific evidence about effectiveness of interventions on diet and / or physical exercise by considering cognitive function as an outcome measure, in people over 45 years of age with mild cognitive impairment (MCI) in their evolution to Alzheimer's disease.

Methods: A bibliographic search of randomized clinical trials, systematic reviews, and meta-analyzes published from May 2008 to May 2019 was carried out in the Medline and The Cochrane Library databases. A total of 169 publications were identified, of which 42 studies that fulfilled inclusion criteria were reviewed.

Results: It was found that scheduled physical exercise of moderate-high intensity, performed 3 to 5 days a week, following a dietary pattern such as Mediterranean diet or DASH diet improve overall cognitive function in subjects with MCI. The results are enhanced when the studies combine both interventions and include cognitive stimulation exercises, allowing increasing the functionality of the subjects.

Conclusions: Intervention on modifiable factors such as physical exercise and diet provides cognitive protection in subjects with MCI, improving their quality of life, functionality and independence. The heterogeneity of the studies makes it difficult to draw up more concrete recommendations.