The meta-analysis, published in Annals of Neurology, shows that high adherence to a healthy dietary pattern, such as Mediterranean diet, may be beneficial along many central nervous system-related axes - and is inversely associated with stroke, cognitive impairment, and depression.
To a lesser extent, moderate adherence to Mediterranean diet seemed also to confer protection in terms of depression, as well as cognitive impairment risk, whereas its protective effects regarding stroke remained only marginal; the pattern of results may be indicative of a dose–response relationship. Interestingly, the protective effects of Mediterranean diet in stroke prevention seemed more sizeable among males, whereas the favourable actions of moderate adherence concerning depression seemed to fade away with advancing age.
Led by Professor Theodora Psaltopoulou from the University of Athens School of Medicine, Greece, the research team revealed that the Mediterranean diet was found to be protective for both subgroups of cognitive decline (mild and advanced), and the finding was reproduced for Alzheimer's disease (AD), which was the predominant condition among studies addressing advanced cognitive decline.
"Adherence to Mediterranean diet was found protective for depression in all types of studies (longitudinal cohort, case–control, and cross-sectional) both in Mediterranean and in non-Mediterranean countries," revealed the researchers.
"Interestingly, depression is a risk factor for AD; thus, the protective role mediated by Mediterranean diet in terms of both depression and AD seems to point to the internal consistency of results," they added.
"Given the limited availability of pharmaceutical agents to treat cognitive impairment, cognitive decline, and stroke, one could argue for the importance of preventive measures, such as a healthy dietary regime, to diminish the risk of mild and advanced cognitive decline, Alzheimer's disease, depression, and stroke," wrote Psaltopoulou and colleagues.