Effect of a traditional Mediterranean diet on lipoprotein oxidation: a randomized controlled trial.
BACKGROUND
Despite the richness in antioxidants of the Mediterranean diet, to our knowledge, no randomized controlled trials have assessed its effect on in vivo lipoprotein oxidation.


METHODS
A total of 372 subjects at high cardiovascular risk (210 women and 162 men; age range, 55-80 years), who were recruited into a large, multicenter, randomized, controlled, parallel-group clinical trial (the Prevención con Dieta Mediterránea [PREDIMED] Study) directed at testing the efficacy of the traditional Mediterranean diet (TMD) on the primary prevention of coronary heart disease, were assigned to a low-fat diet (n = 121) or one of 2 TMDs (TMD + virgin olive oil or TMD + nuts). The TMD participants received nutritional education and either free virgin olive oil for all the family (1 L/wk) or free nuts (30 g/d). Diets were ad libitum. Changes in oxidative stress markers were evaluated at 3 months.


RESULTS
After the 3-month interventions, mean (95% confidence intervals) oxidized low-density lipoprotein (LDL) levels decreased in the TMD + virgin olive oil (-10.6 U/L [-14.2 to -6.1]) and TMD + nuts (-7.3 U/L [-11.2 to -3.3]) groups, without changes in the low-fat diet group (-2.9 U/L [-7.3 to 1.5]). Change in oxidized LDL levels in the TMD + virgin olive oil group reached significance vs that of the low-fat group (P = .02). Malondialdehyde changes in mononuclear cells paralleled those of oxidized LDL. No changes in serum glutathione peroxidase activity were observed.


CONCLUSIONS
Individuals at high cardiovascular risk who improved their diet toward a TMD pattern showed significant reductions in cellular lipid levels and LDL oxidation. Results provide further evidence to recommend the TMD as a useful tool against risk factors for CHD. Trial Registration isrctn.org Identifier: ISRCTN35739639.
Fitó
Montserrat
M
Guxens
Mònica
M
Corella
Dolores
D
Sáez
Guillermo
G
Estruch
Ramón
R
de la Torre
Rafael
R
Francés
Francesc
F
Cabezas
Carmen
C
López-Sabater
María Del Carmen
MDC
Marrugat
Jaume
J
García-Arellano
Ana
A
Arós
Fernando
F
Ruiz-Gutierrez
Valentina
V
Ros
Emilio
E
Salas-Salvadó
Jordi
J
Fiol
Miquel
M
Solá
Rosa
R
Covas
María-Isabel
MI
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002784:Cholesterol / Q000097:blood*; D003327:Coronary Disease / Q000517:prevention & control; D018752:Diet, Fat-Restricted; D038441:Diet, Mediterranean; D002149:Energy Intake; D005260:Female; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D014280:Triglycerides / Q000097:blood
D015415:Biomarkers; D014280:Triglycerides; D008315:Malondialdehyde; D002784:Cholesterol