Table 1 Descriptive of selected observational studies and RCT evaluating the adherence, or the intervention of a Mediterranean diet compared to other diets in relation to various health outcomes
Author details [Refs.] | Year of publication | Number of Studies | Design of studies | Electronic databases searched | Outcome measure(s) | Risk of bias assessment tool | Results | Meta-analysis (yes/no) |
|---|---|---|---|---|---|---|---|---|
Fatima K et al. [14] | 2023 | 15 | RCT | MEDLINE Grey literature | Flow-mediated dilation | Cochrane risk of bias tool for RCT | Inverse relationship between endothelial function and intake of MedDiet was observed. Overall, MedDiet increased FMD by 1.39%. There was a significant improvement in endothelial function in both healthy patients and in those with an increased risk of CVD | Yes |
Papadopoulou SK et al. [15] | 2023 | 10 | Observational | PubMed Cochrane Library Scopus Grey literature | Muscle function | New Castle Ottawa scale (NOS) for cohort studies AXIS tool for cross-sectional studies | MedDiet adherence had, in general, a positive role in muscle mass and muscle function (assessed at 20 m walking test and 15 ft walking test), while the results were less clear about muscle strength | No |
Nucci D. et al. [16] | 2023 | 8 | Case–control, cohort | MEDLINE Scopus EMBASE | Pancreatic cancer | New Castle Ottawa scale (NOS) for cohort studies | A higher adherence to the MedDiet is associated with a lower risk of pancreatic cancer based on 1,301,320 subjects | Yes |
Gregory S et al. [17] | 2023 | 7 | Crossectional, cohort | MEDLINE EMBASE CINAHL PsycInfo | White matter hyperintensity volume | NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies | Four studies reported on hippocampal volume, with inconclusive or no associations seen with MedDiet adherence. Two studies found a significant association between higher MedDiet adherence and lower WMHV, while two other studies found no significant associations | No |
Townsend RF et al. [18] | 2023 | 93 | Cohort, RCT | MEDLINE EMBASE | Dementia Alzheimer's Disease Cognitive decline | Cochrane RoB-2 New Castle Ottawa scale (NOS) for cohort studies | Greater adherence to the MedDiet was positively associated with better global cognitive performance in 5 out of 9 studies (55%). The Mediterranean diet appeared to be more strongly protective for Alzheimer's Disease than for all-cause dementia. A small improvement in cognitive function in response to a Mediterranean style diet was found | No |
Moore E et al. [19] | 2022 | 6 | RCT | PubMed Cochrane Library MEDLINE | Body Mass Index TNF-α Interleukin-6 | NR | The main findings indicate a hypocaloric, fiber dense MedDiet to be a short-term (< 4 months) mitigation strategy to significantly reduce BMI and inflammatory markers amongst overweight/obese adults. Results demonstrate that TNF-α, have been significantly reduced over a 3–4-month MedDiet intervention for overweight/obese adults. Regarding IL-6, short-term (3–4 months) reductions were reported amongst participants who consumed a MedDiet | No |
Thackrey E et al. [20] | 2022 | 4 | Crossectional, RCT | MEDLINE CENTRAL EMBASE PsycINFO CINAHL ERIC Web of Science | Body Mass Index | NIH Quality Assessment Tool for Before-After (Pre-Post) NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies | Significant weight loss was observed within groups for low-fat diet, MedDiet, fasting, low-calorie diet with fasting, intermittent fasting, or continuous energy restriction, but there were no between-group differences. MedDiet reduced weight at 6 months compared with baseline | No |
Sangouni AA et al. [21] | 2022 | 10 | RCT | PubMed Web of Science Scopus Google Scholar | AST GGT | Cochrane Risk of Bias Tool for RCT | MedDiet can significantly reduce levels of AST and GGT which are the important markers of liver function. However, MedDiet has no significant effect on ALT | Yes |
Pameijer EM et al. [22] | 2022 | 20 | RCT | MEDLINE Embase Cochrane Library | Age-related macular degeneration | ROBINS-1 tool AMSTAR-2 tool | A high intake of specific nutrients, the use of antioxidant supplements and adherence to a Mediterranean diet decrease the risk of progression of early to late age-related macular degeneration | No |
Angelidi AM et al. [23] | 2022 | 3 | RCT | PubMed Embase CINAHL Web of Science | Hepatic fat content Triglycerides | Cochrane Collaboration's risk of bias tool for RCT | A post hoc analysis, including two eligible studies assessing the effect of the Mediterranean, compared to a low-fat diet, irrespective of baseline presence of diabetes, showed strong evidence that the MedDiet significantly reduces hepatic fat content and triglyceride concentrations | No |
Luong R et al. [24] | 2022 | 16 | RCT, Cohort | Medline Embase DARE Web of Science Scopus | Systolic blood pressure Triglycerides HDL-c | Revised Cochrane risk-of-bias tool for randomized trials (RoB-2) Joanna Briggs Institute (JBI) Critical Appraisal Checklists | The Mediterranean dietary pattern resulted in reduced triglyceride levels and systolic blood pressure and had no effects on diastolic blood pressure and glucose in the short term. MedDiet resulted in increased HDL-cholesterol levels in adults without CVD | No |
Sepandi M et al. [25] | 2022 | 10 | Crossectional, cohort | Web of knowledge PubMed Cochrane Library Science direct Google Scholar Scopus | Waist circumference Triglycerides HDL-c LDL-c Fasting Blood Glucose HbA1c Total Cholesterol | New Castle Ottawa scale (NOS) for cohort studies | MedDiet score showed an inverse relationship with BMI, WC, TG, total cholesterol, LDL-C, FBG, HbA1c and a direct relationship with HDL-C | No |
Noori M et al. [26] | 2022 | 8 | Crossectional, cohort | PubMed Scopus Web of Science | Bone mineral density | New Castle Ottawa scale (NOS) for cohort studies | Greater adherence to the MedDiet was associated with a small but important increase in bone mineral density at the lumbar spine, femoral neck, hip, trochanter, and whole body. Adopting a Mediterranean style eating pattern may have modest beneficial effects on bone health | Yes |
Gastaldello A et al. [27] | 2022 | 8 | Crossectional, cohort | PubMed ScienceDirect Cochrane Library | Age-related macular Degeneration | New Castle Ottawa scale (NOS) for cohort studies | Higher adherence to a Mediterranean eating pattern lowers the odds of developing age-related macular degeneration and decreases the risk of progression to more advanced stages of the disease, establishing the way for preventative measures emphasizing dietary patterns rich in plant-foods | No |
Cuevas-Cervera M et al. [28] | 2022 | 16 | RCT, observational | PubMed Web of Science ProQuest Scopus Cumulative Index to Nursing & Allied Health Literature (CINAHL) Cambridge Core Oxford Academy | Sleep quality Pain Functional disability Physical health | e-PEDro scale for rating quality of RCT Quality assessment with diverse studies (QuADS) | Levels of pain, functional disability, wellness of sleep, physical and general well-being, and pain location and severity were significantly lower in subjects who followed a MedDiet | No |
Gianfredi V et al. [29] | 2022 | 23 | Observational | MEDLINE Scopus Web of Science EMBASE Cochrane Library | Pancreatic cancer | AMSTAR-2 tool | Convincing or suggestive evidence was found for a healthy/prudent, plant-based diet, fruit and vegetables, and lower risk of pancreatic cancer | Yes |
Lee E et al. [30] | 2022 | 11 | Observational | Web of Science MEDLINE CINAHL PsycINFO | Mortality (overall) Breast cancer mortality | New Castle Ottawa scale (NOS) for cohort studies | Among the diet quality indices evaluated, post-diagnostic adherence to MDS, HEI, DASH, and CHFP, and adherence to DASH and CHFP showed significant effects on all-cause mortality and breast cancer mortality, respectively | Yes |
Zeraattalab-Motlagh S et al. [31] | 2022 | 14 | Cohort | PubMed Scopus Web of Science | Type 2 diabetes | ROBINS-I | Adherence to the MedDiet was inversely related to type 2 diabetes risk in a dose–response manner | Yes |
McBean L et al. [32] | 2022 | 10 | RCT | Medline EMBASE CENTRAL PsycINFO | Global cognitive function Processing speed | Cochrane Risk of Bias tool | Findings suggest a potential effect of MedDiet on global cognitive function and processing speed | Yes |
Bakaloudi DR et al. [33] | 2021 | 58 | Observational | PubMed Cochrane CENTRAL Scopus EMBASE Web of Science Google Scholar | Waist circumference HDL-c Triglycerides | New Castle Ottawa scale (NOS) for cohort studies | Waist circumference and triglycerides were significantly lower in the high adherence MedDiet, while HDL cholesterol was significantly higher in the same group. MedDiet may have a positive impact on all parameters of metabolic syndrome | Yes |
Tang C et al. [34] | 2021 | 7 | Cohort | Embase PubMed Scopus Web of Science Cochrane | Mortality (overall) | New Castle Ottawa scale (NOS) for cohort studies | This meta-analysis of prospective cohort studies provided evidence that adherence to MedDiet improved survival in people with a history of CVD | Yes |
Ubago-Guisado E et al. [35] | 2021 | 110 | Cohort | MEDLINE Scopus Web of Science | Colorectal cancer Breast cancer | Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews | Adherence to the MedDiet emerged as a protective factor for colorectal and breast cancer | No |
Coelho-Júnior HJ et al. [36] | 2021 | 53 | Crossectional, cohort | MEDLINE SCOPUS CINAHL AgeLine | Physical health Global cognitive function | New Castle Ottawa scale (NOS) for cohort studies | Findings of the present study indicated that high adherence to MedDiet was cross-sectionally associated with physical performance and cognitive function. Results of the pooled analysis of longitudinal studies revealed that high adherence to MedDiet reduced the risk of global cognitive decline in non-demented older adults. However, no significant associations between MedDiet adherence and the incidence of mobility problems, mild cognitive impairment, and dementia were found | Yes |
Quintela BC et al. [37] | 2021 | 24 | Observational | PubMed Embase | eGFR Proteinuria | New Castle Ottawa scale (NOS) for cohort studies | The consumption of fruit, vegetables and dietary fiber (DASH and MedDiet) revealed low risk associations for chronic kidney disease, being recommended models to reduce the occurrence and progression of the disease | No |
Silveira EA et al. [38] | 2021 | 7 | RCT, cohort | PubMed Scopus Scielo Web of Science | Body Mass Index Body fat Blood pressure Fasting Blood Glucose C-Reactive Protein Total Cholesterol | NR | The MedDiet had beneficial changes in weight loss and maintenance, reduction of body fat and inflammatory factors. MedDiet had greater long-term favorable effects on CVD risk factors like BMI, blood pressure, fasting blood glucose, total cholesterol and inflammatory markers such as CRP in individuals with obesity | No |
Gibbs J et al. [39] | 2021 | 41 | RCT | MEDLINE Embase Web of Science | Systolic blood pressure Diastolic blood pressure | RoB-2: a revised tool for assessing risk of bias in randomized trials | Consumption of the Mediterranean diet was associated with a mean reduction in SBP and DBP compared with the consumption of comparator diets | Yes |
Kadam I et al. [40] | 2021 | 20 | Observational | PubMed CINAHL Scopus | Body Mass Index Waist circumference | NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies | Adherence to a MedDiet was associated with a lower risk of excessive WC and lower risk of obesity | No |
Hart MJ et al. [41] | 2021 | 69 | Observational | Embase CINAHL Global Health MEDLINE | C-Reactive Protein Interleukin-6 | NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies | Adherence to healthy, Mediterranean and anti-inflammatory dietary scores, appear to be associated with lower inflammatory status cross sectionally. The most frequently assessed biomarkers were CRP and/or IL-6 | No |
Bianchi VE et al. [42] | 2021 | 79 | RCT | MEDLINE EMBASE Cochrane Library | Cognitive decline Alzheimer’s disease Parkinson disease | NR | MedDiet, nutritional support, and calorie-controlled diets play a protective effect against cognitive decline, Alzheimer’s disease (AD), Parkinson disease (PD) while malnutrition and insulin resistance represent significant risk factors | No |
Schönenberger KA et al. [43] | 2021 | 12 | RCT, observational | MEDLINE Embase CINAHL | Rheumatoid Arthritis | RoB 2 ROBINS-I | Vegetarian, vegan, and MedDiet might be beneficial for some RA patients. However, due to lack of blinding, effects on the patient-reported outcome pain might be biased | Yes |
Klonizakis M et al. [44] | 2021 | 20 | RCT | PubMed Embase Cochrane Library | Body Mass Index Waist circumference Body fat ALT Visceral adipose tissue | RoB 2 | When the comparative effectiveness of an isocaloric MedDiet was compared against the DASH diet for 12 weeks, all of the anthropometric indices (body weight, waist circumference, body fat, and visceral adipose tissue, and additionally ALT were improved in the MedDiet arm | Yes |
George ES et al. [45] | 2021 | 30 | Observational | MEDLINE CINAHL Embase | Hepatocellular Cancer | The Academy of Nutrition and Dietetics Evidence Analysis Library (EAL) Quality Criteria Checklist | Higher adherence to the MedDiet pattern, Alternative Healthy Eating Index-2010, the Urban Prudent Dietary Pattern, the Traditional Cantonese Dietary Pattern, intake of vegetables, wholegrains, fish, poultry, coffee, macronutrients such as monounsaturated fats and micronutrients such as vitamin E, vitamin B9, β-carotene, manganese and potassium were associated with a reduced risk of hepatocellular cancer | No |
Shannon OM et al. [46] | 2020 | 14 | RCT | Medline Embase Scopus | Flow-mediated dilation | Cochrane risk of bias tool to assess the risk of bias | MedDiet interventions improve endothelial function in adults, suggesting that the protective effects of the MedDiet are evident at early stages of the atherosclerotic process with important implications for the early prevention of CVD | Yes |
Limongi F et al. [47] | 2020 | 45 | RCT, cohort | PubMed Scopus | Cognitive decline Global cognitive function | New Castle Ottawa scale (NOS) for cohort studies | Overall, the studies showed that the MedDiet has some protective effects on cognitive decline. As far as cognition domains were concerned, the MedDiet was associated only with improved global cognition. There was no evidence that it has a beneficial effect on dementia | No |
Molina-Montes E et al. [48] | 2020 | 26 | Observational, RCT | PubMed | Cancer-related mortality | Egger’s test and visual inspection of the funnel plots | The association between adherence to the MedDiet and cancer mortality reached statistical significance | Yes |
Papadaki A et al. [49] | 2020 | 57 | RCT | PubMed Embase CINAHL Web of Science | Stroke Body Mass Index LDL-c HDL-c HOMA-IR Hepatic fat mass Interleukin-6 Fasting Blood Glucose Triglycerides C-Reactive Protein Waist circumference Flow-mediated dilation AST Blood pressure | ROBINS-I | The MedDiet resulted in greater beneficial changes in 18 of 28 metabolic syndrome components and risk factors (body weight, body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR) index, total-, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, triglycerides, alanine transaminase, hepatic fat mass, C-reactive protein, interleukin-6, tumor necrosis factor-a, and flow-mediated dilatation) and lower risk of cardiovascular disease incidence and stroke. Findings support MedDiet’s beneficial effect on all components and most risk factors of the metabolic syndrome, in addition to cardiovascular disease and stroke incidence | Yes |
Granic A et al. [50] | 2020 | 28 | Observational, RCT | MEDLINE Embase Web of Science Cochrane Library | Muscle function Muscle strength Muscle mass Sarcopenia | RoB 2 | Higher intake of fatty fish was beneficial for muscle strength (GS) in both men and women, whilst total fish (white/shell/fatty) and vegetables intake were beneficial for muscle function (gait speed and chair rises, respectively) only in women. Consuming recommended levels of vegetables, a day (≥ 5 servings/day) was associated with higher muscle mass, and more frequent nuts consumption per week reduced the odds of sarcopenia by 30% only in women. In longitudinal associations with all participants, daily intake of soy products, green or yellow vegetables was associated with lower decline in muscle strength (knee extension strength), whilst intake of ≥ 3 servings/day (≥ 85.1 g/day) of poultry or fish was associated with 0.8%–1.2% higher muscle mass | No |
Moazzen S et al. [51] | 2020 | 21 | Observational | PubMed EMBASE Web of Science Cochrane Library | Gastrointestinal Cancer | New Castle Ottawa scale (NOS) | The highest-quality diets were significantly associated with reduced risk of upper gastrointestinal cancers, achieving odds ratios of 0.59 for the Diet Inflammatory Index, pooling the findings from nine studies, and 0.72 for the MedDiet score | Yes |
Abbate M et al. [52] | 2020 | 21 | RCT | PubMed | Body Mass Index Triglycerides C-Reactive Protein Waist circumference HOMA-IR HDL-c Total cholesterol LDL-c Blood pressure waist-to-hip ratio Fating Blood Glucose HbA1c Insulin | American Dietetic Association Quality Criteria Checklist | A MedDiet intervention without physical activity, decreased both systolic and diastolic blood pressure, major CV events rate and risk of developing type 2 diabetes | No |
Dianatinasab M et al. [53] | 2020 | 10 | Observational | PubMed Scopus Web of Science | Breast Cancer | New Castle Ottawa scale (NOS) for cohort studies | This meta-analysis provides supporting evidence for the association between MedDiet decreased risk of invasive ductal carcinoma and invasive ductal carcinoma of the breast | Yes |
Rees K et al. [54] | 2020 | 30 | RCT | Cochrane Library MEDLINE EMBASE Web of Science | Stroke CV mortality Mortality (overall) Triglycerides LDL-c Diastolic Blood Pressure Systolic Blood Pressure Total cholesterol | Cochrane Handbook for Systematic Reviews of Interventions | Clinical endpoints were reported in two trials where there was moderate quality evidence for a reduction in strokes for primary prevention, and low-quality evidence for a reduction in total and CVD mortality in secondary prevention. There was low-quality evidence for a possible small reduction in total cholesterol and moderate-quality evidence for a reduction in systolic and diastolic blood pressure. A possible small reduction in LDL cholesterol and triglycerides | No |
Ge L et al. [55] | 2020 | 121 | RCT | Medline Embase CINAHL AMED CENTRAL | Body Mass Index DBP SBP | GRADE (grading of recommendations, assessment, development, and evaluation) approach | Compared with usual diet, moderate certainty evidence supports modest weight loss and substantial reductions in systolic and diastolic blood pressure for low carbohydrate (e.g., Atkins, Zone), low fat (e.g., Ornish), and moderate macronutrient (e.g., DASH, Mediterranean) diets at six but not 12 months | Yes |
Parvizian MK et al. [56] | 2020 | 11 | Observational | MEDLINE Embase Web of Science CINAHL LILACS AMED Cochrane Library | Chronic obstructive pulmonary disease | National Institutes of Health Quality Assessment Tools (NIH-QATs) | Consumption of a healthy dietary pattern such as the MedDiet was associated with a lower risk of COPD | Yes |
Genel F et al. [57] | 2020 | 5 | Observational, RCT | MEDLINE EMBASE Cochrane Library | Body Mass Index Interleukin-6 C-Reactive Protein | RoB-2 checklist per RCT Cochrane Handbook’s ROBINS-I tool for cohort | Low-level evidence suggests that low-inflammatory diets or supplements compared to usual diets are associated with greater weight loss and improvement in inflammatory biomarkers | Yes |
Altun A et al. [58] | 1 Sep 2019 | 26 | Observational, RCT | Medline Embase PsychInfo Scopus Google Scholar | Depression | NIH quality assessment tool w | The majority (85%) of observational studies support the evidence that the Mediterranean dietary pattern is associated with reductions in depressive incidence and all intervention studies echoed these findings | No |
Lassale C et al. [59] | 2019 | 41 | Observational | Medline Embase PsychInfo | Depression | New Castle Ottawa scale (NOS) | The most compelling evidence was found for the MedDiet and incident depression, with a combined relative risk estimate of highest vs. lowest adherence category. Adhering to a healthy diet, in particular a traditional MedDiet, or avoiding a pro-inflammatory diet appears to confer some protection against depression in observational studies | Yes |
Chapman NA et al. [60] | 2019 | 18 | Observational, RCT | Cochrane Library Embase Google Scholar Medline Scopus | Age-related macular degeneration | Oxford Centre for Evidence-based Medicine 2011 Levels of Evidence | Adherence to a MedDiet had decreased risk of AMD progression | Yes |
Samadi M et al. [61] | 2019 | 26 | Observational | PubMed Scopus Web of science | Alzheimer’s Disease | New Castle Ottawa scale (NOS) for cohort studies | Our findings showed that adherence to healthy diet can decrease oxidative stress and inflammation and accumulation of amyloid-β and consequently can decrease the risk of Alzheimer’s Disease | No |
Saeed N et al. [62] | 2019 | 6 | RCT | MEDLINE EMBASE Scopus Google Scholar | Body Mass Index Hepatic fat content | Downs and Black checklist | Reduction in hepatic steatosis (HS) was statistically significant in 3/5 MedDiet, one low-carbohydrate, one intermittent fasting (IF) and 1/2 low fat (LF) diet interventions. A total of 3/5 studies using MedDiet, 1/2 LF interventions, and the one IF intervention demonstrated significant reductions in weight. In conclusion, there appears to be most data in support of MedDiet-based interventions, though further randomized trials are needed to assess comparative effectiveness for NAFLD | No |
Reijnders IF et al. [63] | 2019 | 82 | Observational, RCT | Medline Embase PubMed Cochrane Library Web of Science Google Scholar | Resistance of the uterine and umbilical arteries | ErasmusAGE tool | Adequate nutrition in the first trimester, periconceptional folic acid supplement intake and strong adherence to a Mediterranean diet, were all associated with a lower resistance of the uterine and umbilical arteries in the second and third trimester | No |
Ajjarapu AS et al. [64] | 2019 | 26 | Cohort | PubMed | eGFR | NR | Adherence to the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets were significantly associated with a decreased risk of CKD in most of the studies | No |
Wu XY et al. [65] | 2019 | 17 | Observational | MEDLINE EMBASE PSYCINFO | HRQoL | New Castle Ottawa scale (NOS) for cohort studies | A good adherence to Mediterranean dietary pattern among children and adolescents is associated with better HRQoL | Yes |
Xiao Y et al. [66] | 2019 | 69 | Observational | PubMed Embase Cochrane Library | Breast cancer | New Castle Ottawa scale (NOS) for cohort studies | The prudent dietary pattern, comparing high vs. low groups, was associated with a reduced risk (overall 18% decrease) of breast cancer in both case–control (30% decreased risk) and cohort studies (11% decrease) | Yes |
Govindaraju T et al. [67] | 2018 | 15 | Observational, RCT | Medline Embase Psychinfo Cochrane Library Cinhal Web of Sciences Scopus | QoL | Cochrane Collaboration risk of bias tool | Healthy dietary patterns were associated with better self-rated health and QoL in one or more domains, and adherence to healthy dietary patterns like the MedDiet were significantly associated with improvement in at least one of the QoL domains | Yes |
Wang Y et al. [68] | 2018 | 6 | Observational | MEDLINE EMBASE Cochrane Central Register of Controlled Trials | Frailty | New Castle Ottawa scale (NOS) for cohort studies | A higher adherence to MedDiet is associated with a lower risk of frailty in old people | Yes |
Forsyth C et al. [69] | 2018 | 4 | Cohort, RCT | Medline Scopus CINAHL Cochrane Library | Rheumatoid arthritis | Cochrane Collaboration’s tool NIH quality assessment tool | This review has identified beneficial effects of the MedDiet in reducing pain and increasing physical function in people living with rheumatoid arthritis | No |
Radd-Vagenas S et al. [70] | 1 Mar 2018 | 9 | RCT | MEDLINE CINAHL EMBASE PubMed PsycINFO Web of Science | Brain-derived neurotrophic factor Global cognitive function Working memory Verbal and visual memory Language Executive function | PEDro scale for rating quality of randomized controlled trials | The risk of low-plasma brain-derived neurotrophic factor was reduced by 78% (OR = 0.22; 95% CI: 0.05, 0.90) in those who consumed a Mediterranean diet compared to control diet at 3 y in this trial. There were significant ESs, ranging from 0.32 to 1.66, in favor of a MedDiet for 8 test outcomes related to global cognition, working memory, verbal and visual memory, visuospatial, language, and executive function domains | No |
Kojima G et al. [71] | 2018 | 4 | Cohort | Embase MEDLINE CINAHL PsycINFO Cochrane Library | Frailty | New Castle Ottawa scale (NOS) for cohort studies | Greater adherence to a MedDiet is associated with significantly lower risk of incident frailty in community-dwelling older people | Yes |
Morales-Ivorra I et al. [72] | 2018 | 3 | RCT, crossectional | EMBASE | Osteoarthritis | New Castle Ottawa scale (NOS) for cohort studies | Positive association between a higher adherence to a MedDiet and the quality of life of participants suffering OA. Three studies included in this systematic review demonstrated some relation between osteoarthritis and a Mediterranean diet | No |
Nomikos T et al. [73] | 2018 | 14 | Crossectional, RCT | PubMed | Platelet-activating factor | NR | Preliminary results indicate that the characteristic “healthy” components of the MedDiet, especially, cereals, legumes, vegetables, fish and wine can favorably modulate the pro-inflammatory actions of PAF and regulate its metabolism | No |
Mayr HL et al. [74] | 2018 | 11 | Observational, RCT | PubMed Scopus Web of Science Cochrane Library | TNF-α C-Reactive Protein Interleukin-6 | Academy of Nutrition and Dietetics Quality Criteria Checklist: Primary Research | Two trials conducted in Spain demonstrated significant reductions in C-reactive protein with a MedDiet. Four observational studies reported significant inverse associations between Mediterranean-type diet scores and inflammatory cytokines. Five clinical trials (4 in non-Mediterranean countries) demonstrated nonsignificant reductions, and 2 trials conducted in Spain demonstrated significant reductions in C-reactive protein with a MedDiet. One cross-sectional study highlighted that for each unit of increase in Mediterranean diet score, there was 1.9% reduction in the average plasma IL-6 levels when controlling for potential confounders. One cross-sectional study highlighted that Mediterranean diet score was significantly inversely associated with coronary venous blood TNF-α levels when adjusting for potential confounding | Yes |
Padilha GR et al. [75] | 2018 | 12 | Observational, RCT | Medline Embase Cochrane Library | TNF-α QoL Systolic function Interleukin-6 Left ventricular ejection fraction Left atrial ejection fraction | Cochrane Collaboration Risk of Bias Tool | The MedDiet demonstrated positive correlation with factors of secondary prevention of HF but need more RCT and cohort studies to confirm this effect. The Mediterranean diet had a correlation with inflammation (IL-6 and TNF-α), quality of life and cardiac function but just on cross-sectional studies. A positive association was found between higher adherence scores to a Mediterranean diet and systolic function, left ventricular ejection fraction and left atrial ejection fraction | No |
Wong MY et al. [76] | 2018 | 31 | Observational, RCT | PubMed Embase Medline Cochrane Library | Diabetic retinopathy | Cochrane Collaboration Risk of Bias Tool | Dietary fiber, oily fish, a Mediterranean diet and a reduced caloric intake are associated with lower risk of Diabetic Retinopathy | No |
Malakou E et al. [77] | 2018 | 11 | RCT | Medline Embase CINAHL Web of Science | Body Mass Index Waist circumference Systolic Blood Pressure Diastolic Blood Pressure HOMA-IR Triglycerides Total cholesterol HDL-cholesterol Fasting Blood Glucose | Cochrane Collaboration Risk of Bias Tool | There was strong evidence of a beneficial effect of promoting the MedDiet and physical activity (PA) on body weight, body mass index, waist circumference, systolic and diastolic blood pressure, HOMA-IR index, blood glucose, triglycerides, total cholesterol (− 6.30 mg/dL, 95% CI − 9.59, − 3.02) and HDL-cholesterol. There was no evidence of an effect on insulin concentrations. The data presented here provide systematically identified evidence that concurrently promoting the MedDiet and PA is likely to provide an opportunity for metabolic risk reduction | Yes |
Mijatovic-Vukas J et al. [78] | 2018 | 40 | RCT | PubMed Medline CINAHL Science Direct EMBASE | Gestational Diabetes Mellitus | Quality Criteria Checklist from American Dietetic Association | Diets resembling MedDiet/DASH diet as well as higher PA levels before or in early pregnancy were associated with lower risks or odds of gestational Diabetes Mellitus | Yes |
Aridi Y.S. et al. [79] | 2017 | 31 | Observational, RCT | MEDLINE Sciencedirect Scopus CINAHL | Dementia Global cognitive function Alzheimer’s disease | Quality Criteria Checklist from American Dietetic Association | Cohort studies in the Mediterranean region and randomized controlled trials showed more cohesive outcomes of the beneficial effect of the MedDiet on cognitive function. Although more standardized and in-depth studies are needed to strengthen the existing body of evidence, results from this review indicate that the Mediterranean diet could play a major role in cognitive health and risk of Alzheimer’s disease and dementia | No |
Anton SD et al. [80] | 2017 | 16 | RCT | PubMed Cochrane Library Web of Science | Body Mass Index | Cochrane risk of bias scale | After 12 months, the traditional MedDiet produced an average weight loss of 8.7% (7.4 kg) and the low-carbohydrate Mediterranean diet produced an average weight loss of 10.3% (8.9 kg) | No |
Bloomfield HE et al. [81] | 2016 | 56 | RCT | MEDLINE CINAHL Cochrane Library | Myocardial infarction Type 2 diabetes Breast cancer CV mortality | AHRQ tool | Evidence suggests that a MedDiet with no restriction on fat intake may reduce the incidence of cardiovascular events, breast cancer, and type 2 diabetes mellitus but may not affect all-cause mortality. A MedDiet reduced the risk for a new myocardial infarction and cardiovascular death | Yes |
Liyanage T et al. [82] | 2016 | 6 | Observational | MEDLINE EMBASE Cochrane Library | Stroke Heart failure | Cochrane Collaboration Risk of Bias Tool | The MedDiet may protect against vascular disease. However, both the quantity and quality of the available evidence is limited and highly variable. When data for all studies were combined there was evidence of protection against major vascular events (RR 0.63, 95% confidence interval 0.53–0.75), coronary events (0.65, 0.50–0.85), stroke (0.65, 0.48–0.88) and heart failure (0.30, 0.17–0.56) but not for all-cause mortality (1.00, 0.86–1.15) or cardiovascular mortality (0.90, 0.72–1.11) | Yes |
Petersson SD et al. [83] | 2016 | 25 | Observational, RCT | PubMed Embase CINAHL CENTRAL PsycINFO | Global cognitive function | NR | Adherence to the MedDiet is associated with better cognitive performance | No |
Neale EP et al. [84] | 2016 | 17 | RCT | Scopus PubMed Web of Science Cochrane Library | C-Reactive Protein | GRADE | Consumption of a healthy dietary pattern was associated with significant reductions in CRP. Non-significant changes were found for all other biomarkers | Yes |
Garcia M et al. [85] | 2016 | 29 | RCT | PubMed EMBASE Web of Science CINAHL | Waist circumference Triglycerides Fasting Blood Glucose Systolic Blood Pressure Diastolic Blood Pressure | Cochrane Collaboration Risk of Bias Tool | There were significant effects in favor of the MedDiet for waist circumference, triglycerides, blood glucose, systolic blood pressure, and diastolic blood pressure. The Med diet was significantly beneficial when the intervention was longer in duration, was conducted in Europe, used a behavioral technique, and was conducted using small groups The traditional Med diet had significant beneficial effects on five of the six metabolic risk factors | Yes |
Potter J et al. [86] | 2016 | 64 | Cohort | Scopus MEDLINE Medline in Process EMBASE CINAHL | Breast cancer Colorectal cancer Head and neck cancer | New Castle Ottawa scale (NOS) for cohort studies | This body of evidence suggests that higher diet quality, as measured by several indices, is associated with reduced risk of postmenopausal breast cancer, CRC, and head and neck cancer. All-sites cancer risk and cancer mortality were not consistently associated with any of the diet quality scores using any of the indices. All-sites cancer risk and cancer mortality were not consistently associated with any of the diet quality scores using any of the indices | No |
Steck SE et al. [87] | 2015 | 12 | Observational | MEDLINE | Colorectal cancer | NR | Comparing highest to lowest score groups, higher MDSs were associated with an 8–54% lower CRC risk, and higher HEI scores were associated with a 20–56% lower CRC risk. More proinflammatory diet scores were associated with a 12–65% higher CRC risk compared with more anti-inflammatory diets in studies that used the DII | No |
Aljadani H et al. [88] | 2015 | 16 | Cohort | MEDLINE EMBASE CINAHL Scopus | Body Mass Index | JBI-MAStARI tool | Higher diet quality is associated with relatively lower prospective weight gain, as well as a lower risk of becoming overweight or obese | No |
Koloverou E et al. [89] | 2014 | 10 | Cohort | PubMed Embase Cochrane Library | Type 2 diabetes | NR | Higher adherence to the MedDiet was associated with 23% reduced risk of developing type 2 diabetes, combined relative risk for upper versus lowest available centile | Yes |
Grosso G et al. [90] | 2014 | 58 | Observational | PubMed | Body Mass Index Type 2 diabetes C-Reactive Protein Interleukin-6 Fasting Blood Glucose HOMA-IR HDL-c Metabolic syndrome Waist-to-hip Ratio Flow-mediated dilation | NR | The results here reviewed support the healthy role of MedDiet in both primary and secondary prevention of CVD diseases. A protective role of the MedDiet toward several chronic diseases such as Metabolic Syndrome, diabetes, obesity, CVD events, as well as improvement of lipid profile, hypertension in prehypertensive individuals, coagulation markers, inflammatory markers in subjects with abdominal obesity | No |
Kontogianni MD et al. [91] | 2014 | 7 | Observational, RCT | PubMed Embase Scopus | Stroke | NR | Consistent, protective effect of higher adherence to the MedDiet on stroke incidence | Yes |
Singh B et al. [92] | 2014 | 5 | Observational | MEDLINE EMBASE PsycInfo | Mild Cognitive Impairment Alzheimer’s disease | New Castle Ottawa scale (NOS) for cohort studies | Higher adherence to the MedDiet was associated with reduced risk of MCI and Alzheimer’s disease. The subjects in the highest MedDiet tertile had 33% less risk (adjusted HR = 0.67; 95% CI 0.55–0.81; P < 0.0001) of cognitive impairment (MCI or Alzheimer’s disease) as compared to the lowest MedDiet score tertile. Among cognitively normal individuals, higher adherence to the MedDiet was associated with a reduced risk of MCI and Alzheimer’s disease | Yes |
Sofi F et al. [93] | 2010 | 18 | Cohort | MEDLINE EMBASE Web of Science Cochrane Library | Mortality (overall) CV mortality Alzheimer’s disease CHD Stroke | NR | A 2-point increase in adherence to the Mediterranean diet was associated with a significant reduction of overall mortality [relative risk (RR) = 0.92; 95% CI: 0.90, 0.94], cardiovascular incidence or mortality, cancer incidence or mortality, and neurodegenerative disease | Yes |
Verberne L et al. [94] | 2010 | 12 | Observational | Scopus PubMed | Breast cancer Oral cancer Esophageal cancer Laryngeal cancer | NR | The existing evidence from observational studies collectively suggests that there is a “probable” protective role of the Mediterranean diet toward cancer in general. Specific results for several outcomes such as different cancer sites deserve additional evidence. This favorable effect of the MedDiet on cancer reduction is of public health relevance, given the tendency of modern societies to shift toward a more U.S. and Northern European dietary pattern | No |
Brown T et al. [95] | 2009 | 39 | RCT | MEDLINE | Triglycerides HDL-c DBP Fasting Blood Glucose | NR | A MedDiet with behavior therapy vs. a standard low-fat diet was associated with significant weight change at 24 months. There were significant improvements in total cholesterol and HDL cholesterol, triglycerides, glucose and diastolic blood pressure at 24 months | No |
Mente A et al. [96] | 2009 | 189 | Cohort, RCT | MEDLINE | CHD | NR | Strong evidence supports valid associations of protective factors, including intake of vegetables, nuts, and “Mediterranean” and high-quality dietary patterns with CHD | No |
Buckland G et al. [97] | 2008 | 21 | Observational, RCT | MEDLINE | Body Mass Index | NR | 13 studies reported that MedDiet adherence was significantly related to less overweight/obesity or more weight loss. Eight studies found no evidence of this association | No |