key: cord-0956061-cp8wweeg authors: Angelidi, Angeliki M.; Kokkinos, Alexander; Katechaki, Eleftheria; Ros, Emilio; Mantzoros, Christos S. title: Mediterranean diet as a nutritional approach for COVID-19 date: 2020-10-17 journal: Metabolism DOI: 10.1016/j.metabol.2020.154407 sha: 118454d826220129bc1c045502ec1b377b1b50ca doc_id: 956061 cord_uid: cp8wweeg nan The Mediterranean diet, one of the healthiest dietary patterns worldwide, reputed for its demonstrated preventive effect of cardiovascular diseases and type-2 diabetes in several trials [11] [12] [13] is characterized by the inclusion of mainly plant-derived nutritional components, namely fruits, vegetables, legumes, nuts, and olive oil, all of which are significant sources of bioactive polyphenols. Polyphenols, particularly flavonoids and their metabolites, demonstrate pleiotropic healthpromoting effects, especially in cardiovascular and metabolic disorders, due to their antioxidant, anti-inflammatory, and anti-thrombotic properties [14, 15] . These properties become even more critical in view of the exaggerated inflammatory and pro-thrombotic milieu associated with COVID-19 severe illness [16, 17] . Polyphenols alleviate the immune response, increase antioxidant defenses, improve vascular reactivity, and decrease tissue inflammation and cell infiltration, thus promoting metabolic and cardiovascular health; these beneficial effects appear to be exerted through preventing the activation of the Nuclear factor-κB (NF-κB) signaling pathway and nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase and by reducing the levels of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha [18, 19] . Ellagic acid, a particularly bioactive phenolic compound found in some fruits and nuts, also acts via interaction with microbiota and epigenetic regulation [18] . Consumption of nuts and dried fruits such as raisins, which are integral part of the Mediterranean diet, promotes cardiometabolic health through their rich composition in nutrients and bioactive phytochemicals, among which polyphenols play a central role as antioxidant and anti-inflammatory molecules [20] . Both nuts and dried fruits are easily storable and concentrated sources of nutrients; the latter are also portable alternatives to fresh fruits. In particular, Corinthian currants, derived from a specific type of black grape, are characterized by a low to moderate glycemic index [21] and an abundance in minerals, vitamins, fiber, flavonoids and phenolics [22, 23] . Ongoing research on potential antimicrobial properties of several Mediterranean foods, such as raisins and olive products, should be considered in the context of current research efforts to elucidate any protective effects of flavonoids and other polyphenols against the coronavirus infection [24, 25] . In summary, adherence to the Mediterranean diet has a favorable impact on cardiovascular diseases and other cardiometabolic disorders, such as diabetes that predispose to COVID-19 infection and related outcomes. The Mediterranean diet, having high antioxidant, anti-inflammatory, and potential antimicrobial and immunomodulatory properties, is a promising and relatively easy method to attenuate the severity of COVID-19 infection. Therefore, there is a critical and imminent need for more in vivo studies and well-designed clinical trials to explore the potentially beneficial effects of the Mediterranean diet and/or some of its key components, such as nuts, dried fruits and olive oil, in preventing COVID-19 infection and/or improving disease-related outcomes. The COVID-19 pandemic has led to a profound change of food habits and dietary behaviors, both individually and globally. A large Italian https://doi.org/10.1016/j.metabol.2020.154407 0026-0495/© 2020 Elsevier Inc. All rights reserved. Metabolism Clinical and Experimental j o u r n a l h o m e p a g e : w w w . m e t a b o l i s m j o u r n a l . c o m population survey found that during the COVID-19 lockdown 35.8% of the studied subjects consumed less healthy foods, while 48.6% reported weight gain. Of note, greater adherence to the Mediterranean diet was observed in Central and Northern Italy, the epicenter of the pandemic, in which areas the BMI was also lower [26] . Elderly participants reported lower adherence to the Mediterranean diet compared to those aged 18-30 years old. Moreover, according to a Spanish study, female gender, middle age, and higher educational level were associated with higher adherence to the Mediterranean diet during home confinement [27] . Although it appears that relatively younger and more educated individuals increase their adherence to the Mediterranean diet in the middle of the pandemic the beneficial effects of this diet need to be formally and appropriately documented, and if positive as expected, findings need to be disseminated and become part of public health policy. In conclusion, the Mediterranean diet may represent a potential strategic therapeutic approach to address both short-and long-term conditions associated with COVID-19 infection and severity and improve mortality and the overall well-being of affected populations. From a public health viewpoint, such efforts need to be combined with programs aiming to increase social awareness for obesity and the need to prevent and treat it as well as work required to eliminate health inequalities and to address the lack of access to healthy and nutritious food worldwide. None. All authors contributed to the conception and design of the overall commissioned work. This process was chaired by CSM. All authors were involved in the drafting and revision of the report. AMA and CSM lead the drafting and editing process. All authors approved the final version for publication and agree to be held accountable for resolving any future questions related to the integrity or accuracy of the work. Drs. Angelidi and Kokkinos have no potential conflicts of interest to disclose. Dr. Katechaki is employed by the Agricultural Cooperatives' Union of Aeghion (ACUA) but this work was outside her employment duties. Dr. Ros reports grants, personal fees, non-financial support and other from California Walnut Commission, grants, personal fees, non-financial support and other from Alexion, personal fees, non-financial support and other from Ferrer International, personal fees, non-financial support and other from Danone, outside the submitted work. Dr. Mantzoros reports grants, personal fees and other from Coherus Inc., grants, personal fees and other from Pangea inc, grants and personal fees from Novo Nordisk, grants and personal fees from Eisai, personal fees and non-financial support from Ansh, personal fees and nonfinancial support from PES, personal fees and non-financial support from California Walnut Commission, personal fees from Genfit, personal fees from Astra Zeneca, personal fees from Aegerion, personal fees from Regeneron, personal fees from CardioMetabolic Health Conference -The Metabolic Institute of America, personal fees from Alexion, non-financial support from Amarin, non-financial support from Jansen, non-financial support from Boehringer Ingelheim:, outside the submitted work. Epidemiology and transmission of COVID-19 in 391 cases and 1286 of their close contacts in Shenzhen, China: a retrospective cohort study A novel coronavirus from patients with pneumonia in China Letter to the editor: mental health and psychological distress in people with diabetes during COVID-19 Severe obesity, increasing age and male sex are independently associated with worse inhospital outcomes, and higher in-hospital mortality Obesity is a risk factor for severe COVID-19 infection: multiple potential mechanisms Commentary: COVID-19 and diabetes mellitus: what we know, how our patients should be treated now, and what should happen next Dietary recommendations during the COVID-19 pandemic The role of adipocytes and adipocyte-like cells in the severity of COVID-19 infections Covid-19 and disparities in nutrition and obesity Nutrition advice for adults during the COVID-19 outbreak Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts Prevention of diabetes with Mediterranean diets: a subgroup analysis of a randomized trial Adherence to a Mediterranean diet and survival in a Greek population Flavonoids, dairy foods, and cardiovascular and metabolic health: a review of emerging biologic pathways Dietary (poly)phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases COVID-19: consider cytokine storm syndromes and immunosuppression Thrombosis in COVID-19 [published online ahead of print Improvements in metabolic health with consumption of ellagic acid and subsequent conversion into urolithins: evidence and mechanisms Molecular mechanisms of the cardiovascular protective effects of polyphenols Bioactives and health benefits of nuts and dried fruits A study of glycemic response to Corinthian raisins in healthy subjects and in type 2 diabetes mellitus patients Anthocyanins content and antioxidant capacity of Corinthian currants (Vitis vinifera L., var. Apyrena) Sun dried Corinthian currant (Vitis Vinifera L., var. Apyrena) simple sugar profile and macronutrient characterization May polyphenols have a role against coronavirus infection? An overview of in vitro evidence Flavonoids activation of the transcription factor Nrf2 as a hypothesis approach for the prevention and modulation of SARS-CoV-2 infection severity Eating habits and lifestyle changes during COVID-19 lockdown: an Italian survey