The Mediterranean diet (MedDiet), abundant in minimally processed plant-based foods, rich in monounsaturated fat from olive oil, but lower in saturated fat, meats, and dairy products, seems an ideal nutritional model for cardiovascular health. Methodological aspects of Mediterranean intervention trials, limitations in the quality of some meta-analyses, and other issues may have raised recent controversies. It remains unclear whether such limitations are important enough as to attenuate the postulated cardiovascular benefits of the MedDiet. We aimed to critically review current evidence on the role of the MedDiet in cardiovascular health. We systematically searched observational prospective cohorts and randomized controlled trials which explicitly reported to assess the effect of the MedDiet on hard cardiovascular end points. We critically assessed all the original cohorts and randomized controlled trials included in the 5 most comprehensive meta-analyses published between 2014 and 2018 and additional prospective studies not included in these meta-analyses, totaling 45 reports of prospective studies (including 4 randomized controlled trials and 32 independent observational cohorts). We addressed the existing controversies on methodology and other issues. Some departures from individual randomization in a subsample of the landmark Spanish trial (PREDIMED [Prevención con Dieta Mediterránea]) did not represent any clinically meaningful attenuation in the strength of its findings and the results of PREDIMED were robust in a wide range of sensitivity analyses. The criteria for causality were met and potential sources of controversies did not represent any reason to compromise the main findings of the available observational studies and randomized controlled trials. The available evidence is large, strong, and consistent. Better conformity with the traditional MedDiet is associated with better cardiovascular health outcomes, including clinically meaningful reductions in rates of coronary heart disease, ischemic stroke, and total cardiovascular disease.

OBJECTIVE The long-term impact of intentional weight loss on cardiovascular events remains unknown. We describe 12-month changes in body weight and cardiovascular risk factors in PREvención con DIeta MEDiterránea (PREDIMED)-Plus, a trial designed to evaluate the long-term effectiveness of an intensive weight loss lifestyle intervention on primary cardiovascular prevention. RESEARCH DESIGN AND METHODS Overweight/obese adults with metabolic syndrome aged 55–75 years (n = 626) were randomized to an intensive weight loss lifestyle intervention based on an energy-restricted Mediterranean diet, physical activity promotion, and behavioral support (IG) or a control group (CG). The primary and secondary outcomes were changes in weight and cardiovascular risk markers, respectively. RESULTS Diet and physical activity changes were in the expected direction, with significant improvements in IG versus CG. After 12 months, IG participants lost an average of 3.2 kg vs. 0.7 kg in the CG (P < 0.001), a mean difference of −2.5 kg (95% CI −3.1 to −1.9). Weight loss ≥5% occurred in 33.7% of IG participants compared with 11.9% in the CG (P < 0.001). Compared with the CG, cardiovascular risk factors, including waist circumference, fasting glucose, triglycerides, and HDL cholesterol, significantly improved in IG participants (P < 0.002). Reductions in insulin resistance, HbA_1c, and circulating levels of leptin, interleukin-18, and MCP-1 were greater in IG than CG participants (P < 0.05). IG participants with prediabetes/diabetes significantly improved glycemic control and insulin sensitivity, along with triglycerides and HDL cholesterol levels compared with their CG counterparts. CONCLUSIONS PREDIMED-Plus intensive lifestyle intervention for 12 months was effective in decreasing adiposity and improving cardiovascular risk factors in overweight/obese older adults with metabolic syndrome, as well as in individuals with or at risk for diabetes.

Chronic kidney disease (CKD) remains a major epidemiological, clinical, and biomedical challenge. During CKD, renal tubular epithelial cells (TECs) present a persistent inflammatory and profibrotic response. Fatty acid oxidation (FAO), the main source of energy for TECs, is reduced in kidney fibrosis and contributes to its pathogenesis. To determine whether gain of function in FAO (FAO-GOF) could protect from fibrosis, we generated a conditional transgenic mouse model with overexpression of the fatty acid shuttling enzyme carnitine palmitoyl-transferase 1A (CPT1A) in TECs. Cpt1a-knockin (CPT1A-KI) mice subjected to 3 models of renal fibrosis (unilateral ureteral obstruction, folic acid nephropathy [FAN], and adenine-induced nephrotoxicity) exhibited decreased expression of fibrotic markers, a blunted proinflammatory response, and reduced epithelial cell damage and macrophage influx. Protection from fibrosis was also observed when Cpt1a overexpression was induced after FAN. FAO-GOF restored oxidative metabolism and mitochondrial number and enhanced bioenergetics, increasing palmitate oxidation and ATP levels, changes that were also recapitulated in TECs exposed to profibrotic stimuli. Studies in patients showed decreased CPT1 levels and increased accumulation of short- and middle-chain acylcarnitines, reflecting impaired FAO in human CKD. We propose that strategies based on FAO-GOF may constitute powerful alternatives to combat fibrosis inherent to CKD.

To investigate whether metabolic signature composed of multiple plasma metabolites can be used to characterize adherence and metabolic response to the Mediterranean diet and whether such a metabolic signature is associated with cardiovascular disease (CVD) risk. Our primary study cohort included 1859 participants from the Spanish PREDIMED trial, and validation cohorts included 6868 participants from the US Nurses’ Health Studies I and II, and Health Professionals Follow-up Study (NHS/HPFS). Adherence to the Mediterranean diet was assessed using a validated Mediterranean Diet Adherence Screener (MEDAS), and plasma metabolome was profiled by liquid chromatography-tandem mass spectrometry. We observed substantial metabolomic variation with respect to Mediterranean diet adherence, with nearly one-third of the assayed metabolites significantly associated with MEDAS (false discovery rate < 0.05). Using elastic net regularized regressions, we identified a metabolic signature, comprised of 67 metabolites, robustly correlated with Mediterranean diet adherence in both PREDIMED and NHS/HPFS (r = 0.28–0.37 between the signature and MEDAS; P = 3 × 10⁻³⁵ to 4 × 10⁻¹¹⁸). In multivariable Cox regressions, the metabolic signature showed a significant inverse association with CVD incidence after adjusting for known risk factors (PREDIMED: hazard ratio [HR] per standard deviation increment in the signature = 0.71, P < 0.001; NHS/HPFS: HR = 0.85, P = 0.001), and the association persisted after further adjustment for MEDAS scores (PREDIMED: HR = 0.73, P = 0.004; NHS/HPFS: HR = 0.85, P = 0.004). Further genome-wide association analysis revealed that the metabolic signature was significantly associated with genetic loci involved in fatty acids and amino acids metabolism. Mendelian randomization analyses showed that the genetically inferred metabolic signature was significantly associated with risk of coronary heart disease (CHD) and stroke (odds ratios per SD increment in the genetically inferred metabolic signature = 0.92 for CHD and 0.91 for stroke; P < 0.001). We identified a metabolic signature that robustly reflects adherence and metabolic response to a Mediterranean diet, and predicts future CVD risk independent of traditional risk factors, in Spanish and US cohorts.

Background: Although in vitro studies and investigations in animal models and small clinical populations have suggested that ceramides may represent an intermediate link between overnutrition and certain pathological mechanisms underlying cardiovascular disease (CVD), no prospective studies have investigated the association between plasma ceramides and risk of CVD.Methods: The study population consisted of 980 participants from the PREDIMED trial (Prevención con Dieta Mediterránea), including 230 incident cases of CVD and 787 randomly selected participants at baseline (including 37 overlapping cases) followed for ≤7.4 years. Participants were randomized to a Mediterranean diet supplemented with extra virgin olive oil, a Mediterranean diet supplemented with nuts, or a control diet. Plasma ceramide concentrations were measured on a liquid chromatography tandem mass spectrometry metabolomics platform. The primary outcome was a composite of nonfatal acute myocardial infarction, nonfatal stroke, or cardiovascular death. Hazard ratios were estimated with weighted Cox regression models using Barlow weights to account for the case-cohort design.Results: The multivariable hazard ratios (HR) and 95% confidence intervals (CIs) comparing the extreme quartiles of plasma concentrations of C16:0, C22:0, C24:0, and C24:1 ceramides were 2.39 (1.49–3.83,P_trend<0.001), 1.91 (1.21–3.01,P_trend=0.003), 1.97 (1.21–3.20,P_trend=0.004), and 1.73 (1.09–2.74,P_trend=0.011), respectively. The ceramide score, calculated as a weighted sum of concentrations of four ceramides, was associated with a 2.18-fold higher risk of CVD across extreme quartiles (HR, 2.18; 95% CI, 1.36–3.49;P_trend<0.001). The association between baseline ceramide score and incident CVD varied significantly by treatment groups (P_interaction=0.008). Participants with a higher ceramide score and assigned to either of the 2 active intervention arms of the trial showed similar CVD risk to those with a lower ceramide score, whereas participants with a higher ceramide score and assigned to the control arm presented significantly higher CVD risk. Changes in ceramide concentration were not significantly different between Mediterranean diet and control groups during the first year of follow-up.Conclusions: Our study documented a novel positive association between baseline plasma ceramide concentrations and incident CVD. In addition, a Mediterranean dietary intervention may mitigate potential deleterious effects of elevated plasma ceramide concentrations on CVD.Clinical Trial Registration: URL:http://www.isrctn.com. Unique identifier: ISRCTN35739639.