DISCORDANT EFFECTS ON ANXIETY AND DEPRESSION OF MEDITERRANEAN DIET AND OF PHYSICAL ACTIVITY ENHANCEMENT
We read with a great interest the article of Mart?nez-Lapiscina et al. which elegantly demonstrate how an intervention with Mediterranean Diets enhanced with either extra-virgin olive oil or nuts supplements appears to improve cognition compared with a generic low-fat diet. Concurrently, elsewhere, the article in "Epidemiology" by Samieri et al. casts doubt on the available evidence that Adherence to a Mediterranean diet may help prevent cognitive decline in older age. We agree with the limitations discussed(2) since many questions are still open, warranting randomized trials, as the study published by your Journal is.We should like to add some comment for a more comprehensive discussion on this important subject. It is our opinion that any study on the effects of healthier nutritional profiles, such Mediterranean Diet is currently considered, should need more broad information within epidemiological studies and more focused tools in interventions; among them the assessment and the modification of sedentary habits have a very critical relevance, throughout the life, including its cornerstones, such as pregnancy. All behaviors are linked each other and interferences are very likely. We reported that effectiveness of a dietary intervention is facilitated by the enhancement of self-efficacy, i.e. by the awareness of the benefits of the diet itself and its affordability(3). Self-efficacy, Mediterranean diet adherence and olive oil intake were significant independent predictors of the increase of physical activity achieved by counseling(3). Also the epidemiology of cognitive decline has several interrelated components: it is recognized that physical exercise has a retarding effect on cognitive decline, and therapeutic effects are also described(4). Patients and Methods. We performed a reappraisal of our counseling intervention study (6 months) aimed at increasing Adherence to Mediterranean Diet Score (AMDS; range 0-55) and at reducing sedentary habits, assessed by detailed physical activity reports (Baecke tool) in overweight-moderately obese subjects. The study was performed in 138 subjects,(males 61, females 77, years 49.95?14.88); suggestions and advice on individual "healthy" food purchase, storage and cooking were given. Reliable feedback and evidence of patients' adherence were obtained by scheduled dietician's interviews at the beginning of the study and after six months. Health psychology tools, i.e. GSE (General Self-Efficacy), PSM (Psychological Stress Measure) and HAD (Hospital Anxiety Depression Scale) validated in our population, are currently used in our preliminary and post-intervention assessment, and not previously reported. Results. Challenging the predictive effects of changes of Adherence to Mediterranean Diet (?AMDS) and of changes of physical activity (?Baecke), of ?GSE and of ?PSE vs. ?HAD, in an age-balanced model, we found that both Mediterranean Diet Adherence and Physical Activity increase explain (R2 0.309 ; p<0.0001) the decrease of the level of anxiety: this provides evidence of the links among mood, cognition and stress with diet and exercise. By Odds Ratio, the increase of AMDS is associated with decreased hazard of Anxiety (Odds Ratio 0.653; 95% CI 0.292-1.463) so that Mediterranean Diet is seemingly a protective factor against anxiety. Differently, increase of Physical Activity is associated with an increased hazard of depression (Odds Ratio 1.298; 95% CI 0.561-3.004), while the increase of AMDS is associated with a decreased hazard of depression (Odds Ratio 0.793 ; 95% CI 0.343-1.831); so Mediterranean Diet may be beneficial against depression occurrence. Conclusion. Mediterranean Diet is associated with lower hazard of depression and may be beneficial against its occurrence and, as well, against the hazard of anxiety. No favorable effect on depression is associated with the increase of physical activity. Even discordant, we think that contributions along these lines will enhance further accurate and extensive clinical research, which should include the concurrent but not univocal effects of different lifestyle interventions.
REFERENCES  Mart?nez-Lapiscina EH, Clavero P,et al. Mediterranean diet improves cognition: the PREDIMED-NAVARRA randomised trial. J Neurol Neurosurg Psychiatry. 2013 May 13. [Epub ahead of print]  Samieri C, Grodstein F, Rosner BA,et al. Mediterranean Diet and Cognitive Function in Older Age. Epidemiology. 2013;24:490-499.  Catalano D, Trovato GM, Pace P, Martines GF, Trovato FM. Mediterranean diet and physical activity: An intervention study. Does olive oil exercise the body through the mind? Int J Cardiol. 2013 May 25. [Epub ahead of print]  Buchman AS, Boyle PA, Yu L, Shah RC, Wilson RS, Bennett DA. Total daily physical activity and the risk of AD and cognitive decline in older adults. Neurology. 2012;78:1323-9.
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