Editorial
Mediterranean Diet for the Prevention and Treatment of Metabolic Syndrome: Is it Worth It?
Angiology 2014, Vol 65(1) 5-8 ª The Author(s) 2012 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319712470866 ang.sagepub.com
Dimitrios N. Kiortsis, MD, PhD1 and Yannis V. Simos, MSc, PhD1
Metabolic syndrome (MetS) is characterized as a cluster of risk factors which includes abdominal obesity, hypertension, impaired fasting glucose, and dyslipidemia (elevated triglycerides [TGs] and decreased high-density lipoprotein cholesterol [HDL-C] levels).1 It is associated with increased risk of developing type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Over the past years various definition criteria have been proposed by several organizations. However, these criteria may not present the same predictive ability.2 Recently, the importance of a commonly used set of criteria for worldwide use for different ethnic groups and sexes has been pointed out, with emphasis given on population- and country-specific cutoff points for waist circumference.3 According to the World Health Organization, the Adult Treatment Panel III of the National Cholesterol Education Program and the International Diabetes Federation the prevalence of MetS is rapidly increasing, and is now considered as a global health problem.4 The term ‘‘Mediterranean diet’’ represents a food pattern typical in Crete and Southern Italy in the early 1960s.5 Generally, the term ‘‘Mediterranean diet’’ has been associated with dietary patterns found in olive growing areas of the Mediterranean. Its main characteristics are olive oil as the main source of fat, moderate amounts of dairy products, low to moderate amounts of fish and poultry, daily consumption of fresh fruits and vegetables, daily consumption of cereals (preferably whole grain), low amounts of red meat, and moderate amounts of alcohol (mainly red wine).6,7 Several cross-sectional studies reported inconsistent associations between the Mediterranean-style diet and the incidence of the MetS. The Canarian Nutrition Survey (ENCA) showed that some components of the syndrome, such as blood pressure (BP), were negatively correlated with higher adherence to the Mediterranean diet, but the overall effect was negligible.8 In the ATTICA study, HDL-C and TG concentrations were not associated with adherence to Mediterranean diet in overweight and obese people, although the authors found negative relation with BP.9 Nevertheless, data from the same study revealed that men and women without any evidence of CVD or DM had 19% lower risk of MetS based on the adoption of a Mediterranean diet and light-to-moderate physical activity.10 Babio et al have observed an inverse relationship between
adherence to the Mediterranean diet and prevalence of MetS in 808 elderly participants at high risk of CVD from the PREvencio´n con DIeta MEDiterra´nea (PREDIMED) study. Participants with the lowest adherence to Mediterranean diet had almost twice the risk of having MetS compared to the participants with the highest adherence.11 Considering prospective cohort studies, the Supplementation en Vitamines et Mineraux AntioXydants study reported a reduced incidence of MetS in those participants following a traditional Mediterranean diet, over a 6-year follow-up period mainly by affecting waist circumference, BP, TG, and HDLC concentrations.12 These results were confirmed in the Framingham Offspring Study.13 In this prospective study, consumption of a diet in accordance with the principles of the Mediterranean diet was associated with reduced abdominal obesity, insulin resistance, and atherogenic dyslipidemia. Analysis of the data from an open-enrolment cohort in Spain, consisting of 2563 university graduates (Seguimiento University of Navarra study), showed that the cumulative incidence of MetS decreases as adherence to Mediterranean diet increases.14Multivariate-adjusted results for age, sex, physical activity, smoking, and total energy intake revealed a strong inverse association. Specifically, participants with the highest values of adherence to the Mediterranean diet showed an odds ratio of 0.2 compared to those with lowest adherence. The limitations of observational research require critical evaluation. In order to confirm the effects of a traditional Mediterranean diet on the MetS, intervention studies are required. Until now, only few intervention trials have been performed. Esposito et al showed that a Mediterranean-style diet is effective enough to reduce the prevalence of MetS, by independently affecting all of the MetS components. After 2 years, only 47% of the patients who followed the Mediterranean diet were
1
Laboratory of Physiology, Medical School, University of Ioannina, Ioannina, Greece Corresponding Author: Dimitrios N. Kiortsis, Laboratory of Physiology, Medical School, University of Ioannina, Ioannina, 45110, Greece. Email: [email protected]
Downloaded from ang.sagepub.com by guest on May 5, 2015
6
Angiology 65(1)
classified as patients with MetS compared to 87% of the control group (who followed a prudent diet that consisted of 50%-60% carbohydrates; 15%-20% proteins; and
Mediterranean Diet for the Prevention and Treatment of Metabolic Syndrome: Is it Worth It?
Angiology 2014, Vol 65(1) 5-8 ª The Author(s) 2012 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319712470866 ang.sagepub.com
Dimitrios N. Kiortsis, MD, PhD1 and Yannis V. Simos, MSc, PhD1
Metabolic syndrome (MetS) is characterized as a cluster of risk factors which includes abdominal obesity, hypertension, impaired fasting glucose, and dyslipidemia (elevated triglycerides [TGs] and decreased high-density lipoprotein cholesterol [HDL-C] levels).1 It is associated with increased risk of developing type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Over the past years various definition criteria have been proposed by several organizations. However, these criteria may not present the same predictive ability.2 Recently, the importance of a commonly used set of criteria for worldwide use for different ethnic groups and sexes has been pointed out, with emphasis given on population- and country-specific cutoff points for waist circumference.3 According to the World Health Organization, the Adult Treatment Panel III of the National Cholesterol Education Program and the International Diabetes Federation the prevalence of MetS is rapidly increasing, and is now considered as a global health problem.4 The term ‘‘Mediterranean diet’’ represents a food pattern typical in Crete and Southern Italy in the early 1960s.5 Generally, the term ‘‘Mediterranean diet’’ has been associated with dietary patterns found in olive growing areas of the Mediterranean. Its main characteristics are olive oil as the main source of fat, moderate amounts of dairy products, low to moderate amounts of fish and poultry, daily consumption of fresh fruits and vegetables, daily consumption of cereals (preferably whole grain), low amounts of red meat, and moderate amounts of alcohol (mainly red wine).6,7 Several cross-sectional studies reported inconsistent associations between the Mediterranean-style diet and the incidence of the MetS. The Canarian Nutrition Survey (ENCA) showed that some components of the syndrome, such as blood pressure (BP), were negatively correlated with higher adherence to the Mediterranean diet, but the overall effect was negligible.8 In the ATTICA study, HDL-C and TG concentrations were not associated with adherence to Mediterranean diet in overweight and obese people, although the authors found negative relation with BP.9 Nevertheless, data from the same study revealed that men and women without any evidence of CVD or DM had 19% lower risk of MetS based on the adoption of a Mediterranean diet and light-to-moderate physical activity.10 Babio et al have observed an inverse relationship between
adherence to the Mediterranean diet and prevalence of MetS in 808 elderly participants at high risk of CVD from the PREvencio´n con DIeta MEDiterra´nea (PREDIMED) study. Participants with the lowest adherence to Mediterranean diet had almost twice the risk of having MetS compared to the participants with the highest adherence.11 Considering prospective cohort studies, the Supplementation en Vitamines et Mineraux AntioXydants study reported a reduced incidence of MetS in those participants following a traditional Mediterranean diet, over a 6-year follow-up period mainly by affecting waist circumference, BP, TG, and HDLC concentrations.12 These results were confirmed in the Framingham Offspring Study.13 In this prospective study, consumption of a diet in accordance with the principles of the Mediterranean diet was associated with reduced abdominal obesity, insulin resistance, and atherogenic dyslipidemia. Analysis of the data from an open-enrolment cohort in Spain, consisting of 2563 university graduates (Seguimiento University of Navarra study), showed that the cumulative incidence of MetS decreases as adherence to Mediterranean diet increases.14Multivariate-adjusted results for age, sex, physical activity, smoking, and total energy intake revealed a strong inverse association. Specifically, participants with the highest values of adherence to the Mediterranean diet showed an odds ratio of 0.2 compared to those with lowest adherence. The limitations of observational research require critical evaluation. In order to confirm the effects of a traditional Mediterranean diet on the MetS, intervention studies are required. Until now, only few intervention trials have been performed. Esposito et al showed that a Mediterranean-style diet is effective enough to reduce the prevalence of MetS, by independently affecting all of the MetS components. After 2 years, only 47% of the patients who followed the Mediterranean diet were
1
Laboratory of Physiology, Medical School, University of Ioannina, Ioannina, Greece Corresponding Author: Dimitrios N. Kiortsis, Laboratory of Physiology, Medical School, University of Ioannina, Ioannina, 45110, Greece. Email: [email protected]
Downloaded from ang.sagepub.com by guest on May 5, 2015
6
Angiology 65(1)
classified as patients with MetS compared to 87% of the control group (who followed a prudent diet that consisted of 50%-60% carbohydrates; 15%-20% proteins; and
