Effects of Mediterranean Diet or Low-Fat Diet on Blood Fatty Acids in Patients with Coronary Heart Disease. A Randomized Intervention Study

The Mediterranean diet (MD) prevents cardiovascular disease by different putative mechanisms, including modifications in the blood fatty acid (FA) profile. Polytherapy for secondary cardiovascular prevention might mask the effect of MD on the FA profile. This study was aimed to assess whether MD, in comparison with a low-fat diet (LFD), favorably modifies the blood FA profile in patients with coronary heart disease (CHD) on polytherapy. One hundred and twenty patients with a recent history of coronary stenting, randomized to MD or to LFD, completed 3 months of this open-label dietary intervention study. Diet Mediterranean-ness was evaluated using the Mediterranean Diet Adherence Screener (MeDAS) score. Both diets significantly reduced saturated FA (p < 0.01). Putative favorable changes in total n-3 FA (p = 0.03) and eicosapentaenoic acid plus docosahexaenoic acid (EPA + DHA; p = 0.04) were significantly larger with MD than with LFD. At 3 months, in the whole cohort, the MeDAS score correlated inversely with palmitic acid (R = −0.21, p = 0.02), and with palmitoleic acid (R = −0.32, p = 0.007), and positively with total n-3 FA (R = 0.19, p = 0.03), EPA (R = 0.28, p = 0.002), and EPA + DHA (R = 0.21, p = 0.02). In CHD patients on polytherapy, both MD and LFD shift FA blood composition towards a healthier profile, with a more favorable effect of MD on omega−3 levels.     

Alignment of Nutri-Score with Mediterranean Diet Pyramid: A Food Level Analysis

The Mediterranean diet (MD) has been incorporated as a healthy diet pattern in food-based dietary guidelines of countries all over Europe and the world. Testing the alignment of Nutri-Score with the MD Pyramid is a key step in ensuring that future food-level policies will not be conflicting with existing dietary guidelines. All foods available (n = 4002) in the HelTH database, were classified as eligible or not for inclusion in the MD and they were ranked in their respective tier in the food pyramid following two pyramid schemes, the 1995 traditional and 2020 sustainable MD pyramids. For all foods, Nutri-Score was calculated both as the continuous FSAm-NPS score and its categorical outcome—Nutri-Score grades—and their distribution across the MD pyramid tiers was used as a measure of alignment between the MD and the Nutri-Score algorithm. Only 25% of all foods were eligible under the traditional MD, while the sustainable MD covered ~58% of all foods. For both pyramids, Nutri-Score was successful in clearly separating the foods at the top and the bottom of the pyramids (Nutri-Score Mode “D” or “E” for the top tiers and “A” for the bottom tiers), thus suggesting a good alignment between the two. Good discriminatory capacity was also seen within each tier.     

Scientific Evidence of Interventions Using the Mediterranean Diet: A Systematic Review

The Mediterranean Diet has been associated with greater longevity and quality of life in epidemiological studies, the majority being observational. The application of evidence-based medicine to the area of public health nutrition involves the necessity of developing clinical trials and systematic reviews to develop sound recommendations. The purpose of this study was to analyze and review the experimental studies on Mediterranean diet and disease prevention. A systematic review was made and a total of 43 articles corresponding to 35 different experimental studies were selected. Results were analyzed for the effects of the Mediterranean diet on lipoproteins, endothelial resistance, diabetes and antioxidative capacity, cardiovascular diseases, arthritis, cancer, body composition, and psychological function. The Mediterranean diet showed favorable effects on lipoprotein levels, endothelium vasodilatation, insulin resistance, metabolic syndrome, antioxidant capacity, myocardial and cardiovascular mortality, and cancer incidence in obese patients and in those with previous myocardial infarction. Results disclose the mechanisms of the Mediterranean diet in disease prevention, particularly in cardiovascular disease secondary prevention, but also emphasize the need to undertake experimental research and systematic reviews in the areas of primary prevention of cardiovascular disease, hypertension, diabetes, obesity, infectious diseases, age-related cognitive impairment, and cancer, among others. Interventions should use food scores or patterns to ascertain adherence to the Mediterranean diet. Further experimental research is needed to corroborate the benefits of the Mediterranean diet and the underlying mechanisms, and in this sense the methodology of the ongoing PREDIMED study is explained.     

Mediterranean Diet Maintained Platelet Count within a Healthy Range and Decreased Thrombocytopenia-Related Mortality Risk: A Randomized Controlled Trial

There is little information on the dietary modulation of thrombosis-related risk factors such as platelet count. We aimed to assess the effects of Mediterranean diet (MedDiet) on platelet count and related outcomes in an older population at high cardiovascular risk. In participants of the PREDIMED (PREvención con DIeta MEDiterránea) study, we assessed whether an intervention with a MedDiet enriched with extra-virgin olive oil or nuts, relative to a low-fat control diet, modulated platelet count (n = 4189), the risk of developing thrombocytosis and thrombocytopenia (n = 3086), and the association between these alterations and all-cause mortality (median follow-up time: 3.0 years). Although platelet count increased over time (+0.98·10⁹ units/L·year [95% confidence interval: 0.12; 1.84]), MedDiet interventions moderated this increase, particularly in individuals with near-high baseline count (both MedDiets combined: −3.20·10⁹ units/L·year [−5.81; −0.59]). Thrombocytopenia incidence was lower in the MedDiet interventions (incidence rates: 2.23% in control diet, 0.91% in MedDiets combined; hazard ratio: 0.44 [0.23; 0.83]). Finally, thrombocytopenia was associated with a higher risk of all-cause mortality (hazard ratio: 4.71 [2.69; 8.24]), but this relationship was attenuated in those allocated to MedDiet (p-interaction = 0.018). In brief, MedDiet maintained platelet counts within a healthy range and attenuated platelet-related mortality in older adults at high cardiovascular risk.     

High-Density Lipoproteins and Mediterranean Diet: A Systematic Review

Cardiovascular disease (CVD) is the leading cause of global mortality and the study of high-density lipoproteins (HDL) particle composition and functionality has become a matter of high interest, particularly in light to the disappointing clinical data for HDL-cholesterol (HDL-C) raising therapies in CVD secondary prevention and the lack of association between HDL-C and the risk of CVD. Recent evidences suggest that HDL composition and functionality could be modulated by diet. The purpose of this systematic review was to investigate the effect of Mediterranean diet (MD) on changes in HDL structure and functionality in humans. A comprehensive search was conducted in four databases (PubMed, Scopus, Cochrane library and Web of Science) and 13 records were chosen. MD showed favorable effects on HDL functionality, particularly by improving HDL cholesterol efflux capacity and decreasing HDL oxidation. In addition, HDL composition and size were influenced by MD. Thus, MD is a protective factor against CVD associated with the improvement of HDL quality and the prevention of HDL dysfunctionality.     

A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy,Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

Ketogenic low-carbohydrate high-fat (LCHF) diets are popular among young, healthy, normal-weight individuals for various reasons. We aimed to investigate the effect of a ketogenic LCHF diet on low-density lipoprotein (LDL) cholesterol (primary outcome), LDL cholesterol subfractions and conventional cardiovascular risk factors in the blood of healthy, young, and normal-weight women. The study was a randomized, controlled, feeding trial with crossover design. Twenty-four women were assigned to a 4 week ketogenic LCHF diet (4% carbohydrates; 77% fat; 19% protein) followed by a 4 week National Food Agency recommended control diet (44% carbohydrates; 33% fat; 19% protein), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and treatment effects were evaluated using mixed models. The LCHF diet increased LDL cholesterol in every woman with a treatment effect of 1.82 mM (p < 0.001). In addition, Apolipoprotein B-100 (ApoB), small, dense LDL cholesterol as well as large, buoyant LDL cholesterol increased (p < 0.001, p < 0.01, and p < 0.001, respectively). The data suggest that feeding healthy, young, normal-weight women a ketogenic LCHF diet induces a deleterious blood lipid profile. The elevated LDL cholesterol should be a cause for concern in young, healthy, normal-weight women following this kind of LCHF diet.     

Mediterranean Diet and Diabetes: Prevention and Treatment

The aim of the present review is to examine current scientific knowledge on the association between the Mediterranean diet and diabetes mellitus (mostly type 2 diabetes). A definition of the Mediterranean diet and the tools widely used to evaluate adherence to this traditional diet (Mediterranean diet indices) are briefly presented. The review focuses on epidemiological data linking adherence to the Mediterranean diet with the risk of diabetes development, as well as evidence from interventional studies assessing the effect of the Mediterranean diet on diabetes control and the management of diabetes-related complications. The above mentioned data are explored on the basis of evaluating the Mediterranean diet as a whole dietary pattern, rather than focusing on the effect of its individual components. Possible protective mechanisms of the Mediterranean diet against diabetes are also briefly discussed.     

Association between Lebanese Mediterranean Diet and Frailty in Community-Dwelling Lebanese Older Adults—A Preliminary Study

Discrepancies in the characteristics of the food components of a Mediterranean diet exist based on the country of origin. In Lebanon, a traditional Mediterranean diet emphasizes the high intakes of fruits (including dried), vegetables, burghol, and dairy products. Therefore, this cross-sectional study aimed to explore the association between adherence to the Lebanese Mediterranean diet (LMD) and frailty among older adults in Lebanon. A total of 112 community-dwelling older adults aged ≥65 years were recruited. Demographic and clinical characteristics were collected through face-to-face interviews. A 61-item food frequency questionnaire (FFQ) was used to collect dietary intake data, and adherence to LMD was calculated. Physical frailty was defined by the presence of three out of the five criterion: weight loss, weakness, exhaustion, slowness, and low activity. Binary logistic regression was used to examine the relationship between LMD adherence and frailty while adjusting for several confounders. The participants’ mean age was 73 ± 12.8 and 65% were females. Sixteen (14.3%) individuals were identified as frail. Frail individuals were significantly older (p = 0.001), depressed (p < 0.001), at risk of cognitive impairment (p = 0.006), and reported polypharmacy (p = 0.003). No significant association was found between LMD adherence and frailty in fully adjusted models (OR = 0.195; 95% CI: 0.033–1.154; p = 0.071 when categorical and OR = 0.856; 95% CI: 0.668–1.097; p = 0.218 when continuous). We also performed additional analyses with a modified frailty index where house chores were not considered as part of leisure activities of the physical activity criterion. The results showed that a higher LMD adherence was associated with a significantly decreased frailty prevalence (OR = 0.123, 95% CI: 0.022–0.676, p = 0.016 when categorical and OR = 0.773, 95% CI 0.608–0.983, p = 0.036). Larger, longitudinal studies are needed to clarify the relationship between the adherence to the Lebanese Mediterranean diet and frailty in Lebanese older adults.     

Effectiveness of an Intervention Programme on Adherence to the Mediterranean Diet in a Preschool Child: A Randomised Controlled Trial

Background: The Mediterranean diet is considered one of the dietary patterns with the most accumulated scientific evidence on health benefits. In children, it has positive effects in the prevention of obesity and cardiovascular diseases, as well as in the prevention of diabetes. We aimed to evaluate the medium-term efficacy of an intervention programme, targeting adherence to the Mediterranean diet among preschool children. Methods: In a randomised, parallel trial of participants aged 3–5 years, a school garden was attended in the experimental group, and in the control group, the usual content on the human body and health were taught. Adherence to the Mediterranean diet was assessed using the KIDMED questionnaire, controlling for weight, height, body mass index (BMI) and socio-demographic variables. Results: A reduction in BMI was found in the experimental group after one year and at the end of the follow-up period. In the overall score obtained in the KIDMED survey, a statistical trend was found between the two groups (p = 0.076). In multivariate analysis, consumption of pulses more than once a week’ was predictive of improved diet quality, with an Odds Ratio (OR) in the experimental group of 1.382 (95% CI 1.126–1.695; p = 0.009). Conclusions: The experimental approach improved the quality of the participants’ diet, increasing adherence to the Mediterranean diet due to increased consumption of plant-based protein.     

The Potential of the Mediterranean Diet to Improve Mitochondrial Function in Experimental Models of Obesity and Metabolic Syndrome

The abnormal expansion of body fat paves the way for several metabolic abnormalities including overweight, obesity, and diabetes, which ultimately cluster under the umbrella of metabolic syndrome (MetS). Patients with MetS are at an increased risk of cardiovascular disease, morbidity, and mortality. The coexistence of distinct metabolic abnormalities is associated with the release of pro-inflammatory adipocytokines, as components of low-to-medium grade systemic inflammation and increased oxidative stress. Adopting healthy lifestyles, by using appropriate dietary regimens, contributes to the prevention and treatment of MetS. Metabolic abnormalities can influence the function and energetic capacity of mitochondria, as observed in many obesity-related cardio-metabolic disorders. There are preclinical studies both in cellular and animal models, as well as clinical studies, dealing with distinct nutrients of the Mediterranean diet (MD) and dysfunctional mitochondria in obesity and MetS. The term “Mitochondria nutrients” has been adopted in recent years, and it depicts the adequate nutrients to keep proper mitochondrial function. Different experimental models show that components of the MD, including polyphenols, plant-derived compounds, and polyunsaturated fatty acids, can improve mitochondrial metabolism, biogenesis, and antioxidant capacity. Such effects are valuable to counteract the mitochondrial dysfunction associated with obesity-related abnormalities and can represent the beneficial feature of polyphenols-enriched olive oil, vegetables, nuts, fish, and plant-based foods, as the main components of the MD. Thus, developing mitochondria-targeting nutrients and natural agents for MetS treatment and/or prevention is a logical strategy to decrease the burden of disease and medications at a later stage. In this comprehensive review, we discuss the effects of the MD and its bioactive components on improving mitochondrial structure and activity.     

Mediterranean Diet and Cognitive Status in Free-Living Elderly: A Cross-Sectional Study in Northern Italy

Objective: Few data are available on the Italian elderly population with regard to adherence to the Mediterranean diet (MD) and cognitive impairment. Our aim was to investigate adherence to the MD and its association with cognitive function in an Italian urban sample.

Methods: A cross-sectional study of 279 participants aged ≥ 65 years (80 men, 199 women) was carried out at a nutritional center. Adherence to the MD was evaluated using a 14-item questionnaire. Cognitive function was assessed with the Mini-Mental State Examination (MMSE).

Results: The clinical and nutritional assessments performed revealed 30.1% to have a dietary pattern in accordance with the MD; 13.6% had suspected or mild cognitive impairment (MMSE score ≤ 23). The MD pattern was associated with a lower risk of cognitive impairment (odds ratio [OR] = 0.39; 95% confidence interval [CI], 0.15–0.99; p = 0.045), as was the consumption of wine (OR = 0.37; 95% CI, 0.16–0.84; p = 0.018) and nuts (OR = 0.30; 95% CI, 0.13–0.69, p = 0.005). No association was found with other food groups.

Conclusion: A closer adherence to the MD was associated with a better cognitive status. Further cohort studies and randomized controlled trials are warranted.     

Mediterranean Diet and Fatty Liver Risk in a Population of Overweight Older Italians: A Propensity Score-Matched Case-Cohort Study

Hepatic steatosis, often known as fatty liver, is the most common hepatic disease in Western countries. The latest guidelines for the treatment of nonalcoholic fatty liver disease emphasize lifestyle measures, such as changing unhealthy eating patterns. Using a propensity score-matching approach, this study investigated the effect of adhering to a Mediterranean diet (MedDiet) on fatty liver risk in an older population (≥65 years) from Southern Italy. We recruited 1.403 subjects (53.6% men, ≥65 years) who completed a food frequency questionnaire (FFQ) and underwent clinical assessment between 2015 and 2018. For the assessment of the liver fat content, we applied the Fatty Liver Index (FLI). To evaluate the treatment effect of the MedDiet, propensity score matching was performed on patients with and without FLI > 60. After propensity score-matching with the MedDiet pattern as treatment, we found a higher consumption of red meat (p = 0.04) and wine (p = 0.04) in subjects with FLI > 60. Based on the FLI, the inverse association shown between adherence to the MedDiet and the risk of hepatic steatosis shows that the MedDiet can help to prevent hepatic steatosis. Consuming less red and processed meat, as well as alcoholic beverages, may be part of these healthy lifestyle recommendations.     

Mediterranean diet and nonalcoholic fatty liver disease: molecular mechanisms of protection

Nutritional habits modifications have shown an important impact in preventing and ameliorating metabolic alterations, such as nonalcoholic fatty liver disease (NAFLD). Among several dietary approaches that exert positive effects in NAFLD patients, the Mediterranean dietary pattern has shown notable benefits. This review explores the molecular mechanisms through which the Mediterranean diet would improve risk factors associated with metabolic syndrome and NAFLD. The main features of the Mediterranean diet acting on metabolism are represented by its whole-grain and low glycemic index cereal-based items, its fatty acid profile, and its content in phytochemical compounds. Carbohydrate-rich foods high in dietary fiber inducing low glycemic response are able to interact with glucose and insulin metabolism. Unsaturated fatty acids are associated with better hepatic lipid metabolism. Finally, phytochemical compounds, such as dietary polyphenols, are thought to ameliorate inflammation, which is considered one of the mechanisms through which NALFD may evolve into nonalcoholic steatohepatitis (NASH).     

Mediterranean Diet and Cardiodiabesity: A Review

Cardiodiabesity has been used to define and describe the well-known relationship between type 2 Diabetes Mellitus (T2DM), obesity, the metabolic syndrome (MetS) and cardiovascular disease (CVD). The objective of this study was to perform a scientific literature review with a systematic search to examine all the cardiovascular risk factors combined and their relationship with adherence to the Mediterranean Diet (MedDiet) pattern as primary prevention against cardiodiabesity in a holistic approach. Research was conducted using the PubMed database including clinical trials, cross-sectional and prospective cohort studies. Thirty-seven studies were reviewed: fourteen related to obesity, ten to CVD, nine to MetS, and four to T2DM. Indeed 33 provided strong evidence on the association between adherence to a MedDiet and a reduced incidence of collective cardiodiabesity risk in epidemiological studies. This scientific evidence makes the MedDiet pattern very useful for preventive strategies directed at the general population and also highlights the need to consider all these diet-related risk factors and health outcomes together in daily primary care.     

Positive Effects of a Mediterranean Diet Supplemented with Almonds on Female Adipose Tissue Biology in Severe Obesity

It has been suggested that weight-loss-independent Mediterranean diet benefits on cardiometabolic health and diabetes prevention may be mediated, at least in part, through the modulation of white adipose tissue (WAT) biology. This study aimed to evaluate the short-term effects of a dietary intervention based on the Mediterranean diet supplemented with almonds (MDSA) on the main features of obesity-associated WAT dysfunction. A total of 38 women with obesity were randomly assigned to a 3-month intervention with MDSA versus continuation of their usual dietary pattern. Subcutaneous (SAT) and visceral adipose tissue (VAT) biopsies were obtained before and after the dietary intervention, and at the end of the study period, respectively. MDSA favored the abundance of small adipocytes in WAT. In SAT, the expression of angiogenesis genes increased after MDSA intervention. In VAT, the expression of genes implicated in adipogenesis, angiogenesis, autophagy and fatty acid usage was upregulated. In addition, a higher immunofluorescence staining for PPARG, CD31+ cells and M2-like macrophages and increased ADRB1 and UCP2 protein contents were found compared to controls. Changes in WAT correlated with a significant reduction in circulating inflammatory markers and LDL-cholesterol levels. These results support a protective effect of a Mediterranean diet supplemented with almonds on obesity-related WAT dysfunction.     

Mediterranean Diet Affects Blood Circulating Lipid-Soluble Micronutrients and Inflammatory Biomarkers in a Cohort of Breast Cancer Survivors: Results from the SETA Study

Breast cancer (BC) is a major public health concern and substantial research has shown that adhering to a healthy dietary pattern, such as the Mediterranean Diet (MD), may prevent the onset of cancer and BC relapses. This study aims at specifically investigating the association of MD with circulating dietary-related biomarkers in a cohort of BC survivors. Eighty patients (mean age of 54.9 ± 10.6) with a histologically confirmed diagnosis of BC who had not received any pharmacological or radiotherapy treatment for at least two months were enrolled. Fasting serum lipid-soluble vitamins (retinol, tocopherol), plant pigments (β-carotene, lutein + zeaxanthin, cryptoxanthin, lycopene), inflammatory and oxidative stress markers (ceruloplasmin; haptoglobin; paraoxonases; reactive oxygen molecule; thiol groups, Ferric reducing antioxidant power), and cardiometabolic parameters (body mass index (BMI); glucose; insulin; HOMA-IR; total cholesterol; LDL-cholesterol; HDL-cholesterol; triglycerides) were analyzed. Adherence to the MD was assessed through the Mediterranean Diet Score (MDS) questionnaire. Fasting blood samples were collected for the evaluation of selected biomarkers. MDS resulted positively correlated with β-carotene (r 0.331; p < 0.01) and lycopene (r 0.274; p < 0.05) and negatively with retinol (r −0.346; p < 0.05). Among the investigated inflammatory biomarkers, MDS was only correlated with antioxidant capacity (r 0.256; p < 0.05), while none of the investigated cardiometabolic parameters were significantly correlated with this index. The strong significant correlation between β-carotene and MDS encourages us to consider this pro-vitamin as a putative biomarker to take into account for evaluating the adherence to the MD.     

Impact of the Level of Adherence to Mediterranean Diet on the Parameters of Metabolic Syndrome: A Systematic Review and Meta-Analysis of Observational Studies

High adherence to the Mediterranean diet (MD) has been associated with a lower prevalence of Metabolic Syndrome (MetS). The present study aimed to investigate the impact of MD adherence on parameters of MetS. A systematic literature search was performed in PubMed, Cochrane Central Registry of Clinical Trials (CENTRAL), Scopus, EMBASE, Web of Science and Google Scholar databases. Observational studies that recorded adherence to MD and components/measures of the MetS, such as waist circumference (WC), blood pressure (BP), fasting blood glucose (FBG), high-density lipoprotein (HDL) cholesterol and triglycerides (TG), were included in this study. A total of 58 studies were included in our study. WC and TG were significantly lower in the high adherence MD group (SMD: −0.20, (95%CI: −0.40, −0.01), SMD: −0.27 (95%CI: −0.27, −0.11), respectively), while HDL cholesterol was significantly higher in the same group (SMD: −0.28 (95%CI: 0.07, 0.50). There was no difference in FBG and SBP among the two groups (SMD: −0.21 (95%CI: −0.54, 0.12) & SMD: −0.15 (95%CI: −0.38, 0.07), respectively). MD may have a positive impact on all parameters of MetS. However, further research is needed in this field.     

Clinical Impact of Mediterranean Diet Adherence before and after Bariatric Surgery: A Narrative Review

The population suffering from obesity is rapidly increasing all over the world. Bariatric surgery has shown to be the treatment of choice in patients with severe obesity. A Mediterranean diet has long been acknowledged to be one of the healthiest dietary patterns associated with a lower incidence of many chronic diseases. The aim of the present narrative review is to summarize the existing research on the clinical impact of a Mediterranean diet before and after bariatric surgery, focusing on its effects on weight loss and improvement in comorbidities. Although the current knowledge is limited, this information could add value and emphasize the importance of adopting a Mediterranean diet before and after bariatric surgery.