elderly population http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372556/ PubMedCentral http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372556/ Research shows some evidence research Research shows research studi recenti Research shows elderly population review Research shows Research shows http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372556/ seniors experiencing cognitive decline