Christina-Maria Kastorini

The effect of Mediterranean diet on metabolic syndrome and its components: a meta-analysis of 50 studies and 534,906 individuals.

OBJECTIVES The aim of this study was to meta-analyze epidemiological studies and clinical trials that have assessed the effect of a Mediterranean diet on metabolic syndrome (MS) as well as its components. BACKGROUND The Mediterranean diet has long been associated with low cardiovascular disease risk in adult population. METHODS The authors conducted a systematic review and random effects meta-analysis of epidemiological studies and randomized controlled trials, including English-language publications in PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials until April 30, 2010; 50 original research studies (35 clinical trials, 2 prospective and 13 cross-sectional), with 534,906 participants, were included in the analysis. RESULTS The combined effect of prospective studies and clinical trials showed that adherence to the Mediterranean diet was associated with reduced risk of MS (log hazard ratio: -0.69, 95% confidence interval [CI]: -1.24 to -1.16). Additionally, results from clinical studies (mean difference, 95% CI) revealed the protective role of the Mediterranean diet on components of MS, like waist circumference (-0.42 cm, 95% CI: -0.82 to -0.02), high-density lipoprotein cholesterol (1.17 mg/dl, 95% CI: 0.38 to 1.96), triglycerides (-6.14 mg/dl, 95% CI: -10.35 to -1.93), systolic (-2.35 mm Hg, 95% CI: -3.51 to -1.18) and diastolic blood pressure (-1.58 mm Hg, 95% CI: -2.02 to -1.13), and glucose (-3.89 mg/dl, 95% CI:-5.84 to -1.95), whereas results from epidemiological studies also confirmed those of clinical trials. CONCLUSIONS These results are of considerable public health importance, because this dietary pattern can be easily adopted by all population groups and various cultures and cost-effectively serve for primary and secondary prevention of the MS and its individual components.

Mediterranean diet and weight loss: meta-analysis of randomized controlled trials

BACKGROUND The epidemiological evidence supporting a causal link between Mediterranean diets and body weight is contrasting. We evaluated the effect of Mediterranean diets on body weight in randomized controlled trials (RCTs) using a meta-analysis. METHODS We searched English and non-English publications in PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials from inception to January, 2010. Two evaluators independently selected and reviewed eligible studies. Sixteen randomized controlled trials, with 19 arms and 3,436 participants (1,848 assigned to a Mediterranean diet and 1,588 assigned to a control diet) were included. RESULTS In a random-effects meta-analysis of all 19 arms, the Mediterranean diet group had a significant effect on weight [mean difference between Mediterranean diet and control diet, -1.75 kg; 95% confidence interval (CI), -2.86 to -0.64 kg] and body mass index (mean difference, -0.57 kg/m², -0.93 to -0.21 kg/m²). The effect of Mediterranean diet on body weight was greater in association with energy restriction (mean difference, -3.88 kg, -6.54 to -1.21 kg), increased physical activity (-4.01 kg, -5.79 to -2.23 kg), and follow up longer than 6 months (-2.69 kg, -3.99 to -1.38 kg). No study reported significant weight gain with a Mediterranean diet. CONCLUSIONS Mediterranean diet may be a useful tool to reduce body weight, especially when the Mediterranean diet is energy-restricted, associated with physical activity, and more than 6 months in length. Mediterranean diet does not cause weight gain, which removes the objection to its relatively high fat content. These results may be useful for helping people to lose weight.

Prevention of type 2 diabetes by dietary patterns: a systematic review of prospective studies and meta-analysis

Lifestyle intervention may reduce the risk of type 2 diabetes. The aim of this study was to investigate the role of dietary patterns in the prevention of type 2 diabetes. We did an electronic search through November 30, 2009, for prospective studies that evaluated the role of dietary patterns in type 2 diabetes prevention. Ten large prospective studies were identified, comprising more than 190,000 subjects free of diabetes at baseline, followed for a time ranging from 2 to 23 years, and 8,932 cases of incident diabetes. All ten studies showed consistent results: Relative risk reduction of type 2 diabetes ranged from 83% to 15%. Overall, adherence to a healthy dietary pattern was associated with reduced risk of developing type 2 diabetes: Combined mean difference  = -0.39, 95% confidence interval (CI) -0.54 to -0.24. The reduced risk of developing type 2 diabetes was still present after sensitivity analysis (-0.34, 95% CI -0.44 to -0.24). Dietary patterns characterized by high consumption of fruit and vegetables, whole grains, fish, and poultry, and by decreased consumption of red meat, processed foods, sugar-sweetened beverages, and starchy foods may retard the progression of type 2 diabetes. Healthy diets can help people to live more years without type 2 diabetes.

Dietary Patterns and Prevention of Type 2 Diabetes: From Research to Clinical Practice; A Systematic Review

The prevalence of type 2 diabetes, a disease difficult to treat and expensive to manage, is increasing rapidly worldwide. It is also known that lifestyle, and particularly dietary habits, play an important role in the development of diabetes. Adherence to a healthy dietary pattern, like the Mediterranean diet, exerts a beneficial role regarding the development of diabetes. Additionally certain individual food groups and components of the diet, such as monounsaturated fatty acids, fruits, vegetables, whole grain cereals, dietary fiber, fish and moderate consumption of alcohol, also may protect against the development of diabetes, possibly through the amelioration of insulin sensitivity and their anti-inflammatory actions. Unfortunately, dietary habits in the developed world are changing towards an unhealthier direction. Consequently, emphasis should be given on encouraging at population and individual level for adopting a healthier lifestyle, including dietary habits, in order to prevent the development of type 2 diabetes.

Mediterranean diet and metabolic syndrome: An updated systematic review

The metabolic syndrome is a health condition characterized by abdominal obesity, dyslipidemia, elevated blood pressure and impaired glucose tolerance, with increasing prevalence. Adherence to the Mediterranean diet seems to exert beneficial effects regarding the metabolic syndrome prevalence and progression. Thus, we performed an updated systematic review of studies which have evaluated the effect of the Mediterranean dietary pattern on the metabolic syndrome. This was a systematic review of epidemiological observational studies and clinical trials. English language publications in the databases PubMed, Embase, Scopus, until May 31, 2013, were included in this review. New evidence from prospective cohort studies, cross-sectional studies and clinical trials supports the beneficial role of adherence to the Mediterranean dietary pattern regarding metabolic syndrome presence and progression. Considering the magnitude of metabolic syndrome, efforts should be made to encourage adoption of this pattern in Mediterranean countries and similar dietary pattern in countries where metabolic syndrome is prevalent.

Mediterranean diet and coronary heart disease: Is obesity a link? – A systematic review

AIMS Adherence to a healthy dietary pattern, such as the Mediterranean diet, exerts a beneficial role regarding the development of coronary heart disease. In addition, several studies support the protective role of the Mediterranean diet as far as obesity is concerned. This review, examining results from prospective cohort and cross-sectional studies, as well as clinical trials, aims to clarify whether the beneficial effect of the Mediterranean dietary pattern on coronary heart disease is due to the impact of this diet on weight loss and obesity status or an independent effect. DATA SYNTHESIS 35 original-research studies that were published in English until 2009, selected through a computer-assisted literature search are discussed, from which 3 were prospective, 11 were cross-sectional studies, and 21 were clinical trials. CONCLUSION Although not all studies show a protective effect of the Mediterranean diet on body weight and obesity, the evidence suggests a possible beneficial role of this dietary pattern. Thus the Mediterranean diet protects against the development of coronary heart disease not only because of its beneficial role regarding cardiovascular risk factors, but also due to a possible effect on body weight and obesity.

Adherence to the Mediterranean diet in relation to acute coronary syndrome or stroke nonfatal events: a comparative analysis of a case/case-control study.

BACKGROUND Although the role of Mediterranean diet on cardiovascular disease prevention has long been evaluated and understood, its association with the development of stroke has been rarely examined. The aim of the present work was to comparatively evaluate the association between adherence to the Mediterranean diet and the development of an acute coronary syndrome (ACS) or ischemic stroke. METHODS During the period from 2009 to 2010, 1,000 participants were enrolled; 250 were consecutive patients with a first ACS, 250 were consecutive patients with a first ischemic stroke, and 500 population-based, control subjects, 1-for-1 matched to the patients by age and sex. Sociodemographic, clinical, psychological, dietary, and other lifestyle characteristics were measured. Adherence to the Mediterranean diet was assessed by the validated MedDietScore (theoretical range 0-55). RESULTS After various adjustments were made, it was observed that for each 1-of-55-unit increase of the MedDietScore, the corresponding odds ratio for having an ACS was 0.91 (95% CI 0.87-0.96), whereas regarding stroke, it was 0.88 (95% CI 0.82-0.94). CONCLUSIONS The present work extended the current knowledge about the cardioprotective benefits from the adoption of the Mediterranean diet by showing an additional protective effect on ischemic stroke development.

Adherence to the Mediterranean Diet is Associated With Renal Function Among Healthy Adults: The ATTICA Study

BACKGROUND No data exist regarding the effect of the Mediterranean diet on renal function. We studied the association between adherence to the Mediterranean diet and markers of renal function among 3042 people without any evidence of chronic disease. METHODS During 2001 and 2002, a random sample was selected of 1514 men and 1528 women (aged 18 to 89 years) from Greece. Urea and creatinine were measured, and the creatinine-clearance (CCr) rate was estimated according to the formula of Cockcroft and Gault. Adherence to the Mediterranean diet was assessed using a validated diet score (MedDietScore) that incorporated the inherent characteristics of this diet. RESULTS The CCr rate was positively associated with MedDietScore (b+/-SE, 0.24+/-0.09, P=.007). Moreover, urea and creatinine levels were inversely associated with MedDietScore (b+/-SE, -0.05+/-0.02, P=.01, and -0.004+/-0.001, P < .001, respectively). Multiple linear regression analysis revealed that for each 10/55 additional points in diet score, a 3.7-unit increase in CCr rate in women (P < .001) and a 10.1-unit increase in CCr rate in men were evident (P < .001). Further analysis revealed that the CCr rate was positively correlated with the consumption of fruits (rho =0.08, P=.009) and moderate alcohol consumption, and inversely correlated with the consumption of potatoes (rho=-0.11, P < .001), red meat (rho=-0.12, P=.001), and poultry (rho=-0.07, P=.02). CONCLUSIONS Greater adherence to the Mediterranean diet was independently associated with reduced urea and creatinine and increased CCr rates among healthy men and women. This finding adds to the knowledge regarding the benefits of a traditional Mediterranean diet in human health.

Comparative analysis of a-priori and a-posteriori dietary patterns using state-of-the-art classification algorithms: A case/case-control study

OBJECTIVE To compare the accuracy of a-priori and a-posteriori dietary patterns in the prediction of acute coronary syndrome (ACS) and ischemic stroke. This is actually the first study to employ state-of-the-art classification methods for this purpose. METHODS AND MATERIALS During 2009-2010, 1000 participants were enrolled; 250 consecutive patients with a first ACS and 250 controls (60±12 years, 83% males), as well as 250 consecutive patients with a first stroke and 250 controls (75±9 years, 56% males). The controls were population-based and age-sex matched to the patients. The a-priori dietary patterns were derived from the validated MedDietScore, whereas the a-posteriori ones were extracted from principal components analysis. Both approaches were modeled using six classification algorithms: multiple logistic regression (MLR), naïve Bayes, decision trees, repeated incremental pruning to produce error reduction (RIPPER), artificial neural networks and support vector machines. The classification accuracy of the resulting models was evaluated using the C-statistic. RESULTS For the ACS prediction, the C-statistic varied from 0.587 (RIPPER) to 0.807 (MLR) for the a-priori analysis, while for the a-posteriori one, it fluctuated between 0.583 (RIPPER) and 0.827 (MLR). For the stroke prediction, the C-statistic varied from 0.637 (RIPPER) to 0.767 (MLR) for the a-priori analysis, and from 0.617 (decision tree) to 0.780 (MLR) for the a-posteriori. CONCLUSION Both dietary pattern approaches achieved equivalent classification accuracy over most classification algorithms. The choice, therefore, depends on the application at hand.

Metabolic syndrome, adherence to the Mediterranean diet and 10-year cardiovascular disease incidence: The ATTICA study

BACKGROUND AND AIMS To better understand the metabolic syndrome (MS) spectrum through principal components analysis and further evaluate the role of the Mediterranean diet on MS presence. METHODS During 2001-2002, 1514 men and 1528 women (>18 y) without any clinical evidence of CVD or any other chronic disease, at baseline, living in greater Athens area, Greece, were enrolled. In 2011-2012, the 10-year follow-up was performed in 2583 participants (15% of the participants were lost to follow-up). Incidence of fatal or non-fatal CVD was defined according to WHO-ICD-10 criteria. MS was defined by the National Cholesterol Education Program Adult Treatment panel III (revised NCEP ATP III) definition. Adherence to the Mediterranean diet was assessed using the MedDietScore (range 0-55). RESULTS Five principal components were derived, explaining 73.8% of the total variation, characterized by the: a) body weight and lipid profile, b) blood pressure, c) lipid profile, d) glucose profile, e) inflammatory factors. All components were associated with higher likelihood of CVD incidence. After adjusting for various potential confounding factors, adherence to the Mediterranean dietary pattern for each 10% increase in the MedDietScore, was associated with 15% lower odds of CVD incidence (95%CI: 0.71-1.06). For the participants with low adherence to the Mediterranean diet all five components were significantly associated with increased likelihood of CVD incidence. However, for the ones following closely the Mediterranean pattern positive, yet not significant associations were observed. CONCLUSION Results of the present work propose a wider MS definition, while highlighting the beneficial role of the Mediterranean dietary pattern.