title: Meta-analysis comparing Mediterranean to low-fat diets for modification of cardiovascular risk factors.
abstract: BACKGROUND
  Evidence from individual trials comparing Mediterranean to low-fat diets to modify cardiovascular risk factors remains preliminary.
  
  
  METHODS
  We systematically searched MEDLINE, EMBASE, Biosis, Web of Science, and the Cochrane Central Register of Controlled Trials from their inception until January 2011, as well as contacted experts in the field, to identify randomized controlled trials comparing Mediterranean to low-fat diets in overweight/obese individuals, with a minimum follow-up of 6 months, reporting intention-to-treat data on cardiovascular risk factors. Two authors independently assessed trial eligibility and quality.
  
  
  RESULTS
  We identified 6 trials, including 2650 individuals (50% women) fulfilling our inclusion criteria. Mean age of enrolled patients ranged from 35 to 68 years, mean body mass index from 29 to 35 kg/m(2). After 2 years of follow-up, individuals assigned to a Mediterranean diet had more favorable changes in weighted mean differences of body weight (-2.2 kg; 95% confidence interval [CI], -3.9 to -0.6), body mass index (-0.6 kg/m(2); 95% CI, -1 to -0.1), systolic blood pressure (-1.7 mm Hg; 95% CI, -3.3 to -0.05), diastolic blood pressure (-1.5 mm Hg; 95% CI, -2.1 to -0.8), fasting plasma glucose (-3.8 mg/dL, 95% CI, -7 to -0.6), total cholesterol (-7.4 mg/dL; 95% CI, -10.3 to -4.4), and high-sensitivity C-reactive protein (-1.0 mg/L; 95% CI, -1.5 to -0.5). The observed heterogeneity across individual trials could, by and large, be eliminated by restricting analyses to trials with balanced co-interventions or trials with restriction of daily calorie intake in both diet groups.
  
  
  CONCLUSIONS
  Mediterranean diets appear to be more effective than low-fat diets in inducing clinically relevant long-term changes in cardiovascular risk factors and inflammatory markers.
authors.affiliation: Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, Switzerland. nordmanna@uhbs.ch
authors.forename: Alain J
authors.initials: AJ
authors.lastname: Nordmann
authors.forename: Katja
authors.initials: K
authors.lastname: Suter-Zimmermann
authors.forename: Heiner C
authors.initials: HC
authors.lastname: Bucher
authors.forename: Iris
authors.initials: I
authors.lastname: Shai
authors.forename: Katherine R
authors.initials: KR
authors.lastname: Tuttle
authors.forename: Ramon
authors.initials: R
authors.lastname: Estruch
authors.forename: Matthias
authors.initials: M
authors.lastname: Briel
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000178:diet therapy* / Q000517:prevention & control; D018752:Diet, Fat-Restricted; D038441:Diet, Mediterranean; D004038:Diet, Reducing; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000178:diet therapy / Q000517:prevention & control; D009765:Obesity / Q000178:diet therapy*; D050177:Overweight / Q000178:diet therapy*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D057185:Sedentary Behavior; D055105:Waist Circumference