Mediterranean diet and non enzymatic antioxidant capacity in the PREDIMED study: evidence for a mechanism of antioxidant tuning

Nutr Metab Cardiovasc Dis. 2013 Dec;23(12):1167-74. doi: 10.1016/j.numecd.2012.12.008. Epub 2013 Feb 26.


Background and aims: The intake of antioxidant-rich foods may increase the blood levels of non enzymatic antioxidant capacity (NEAC). NEAC takes into account all antioxidants from food and synergistic effects between them. We examined the effect of a 1-year intervention with Mediterranean diet on plasma NEAC and assessed whether it was related to baseline NEAC levels.

Methods and results: Five hundred sixty-four participants at high cardiovascular risk were randomly selected from the PREDIMED (Prevención con DIeta MEDiterránea) Study, a large 3-arm randomized clinical trial. Blood NEAC levels were measured at baseline and after 1-year of dietary intervention with 1) a Mediterranean diet supplemented with virgin olive oil (MED + VOO); 2) a Mediterranean diet supplemented with nuts (MED + nuts), or 3) a control low-fat diet. Plasma NEAC was analyzed using FRAP (ferric reducing antioxidant potential) and TRAP (total radical-trapping antioxidant parameter) assays. Plasma FRAP levels increased after 1-year of intervention with MED + VOO [72.0 μmol/L (95% CI, 34.2-109.9)] and MED + nuts [48.9 μmol/L (24.3-73.5)], but not after the control low-fat diet [13.9 μmol/L (-11.9 to 39.8)]. Participants in the lowest quartile of plasma FRAP at baseline significantly increased their levels after any intervention, while those in the highest quartile decreased. Similar results occurred with TRAP levels.

Conclusions: This study shows that a 1-year of MED diet intervention increases plasma TAC level in subjects at high risk for cardiovascular disease. Moreover, the effectiveness of dietary supplementation with antioxidants may be related to baseline levels of plasma NEAC.

Keywords: CVD; Dietary modulation; FRAP; MED; Mediterranean diet; NEAC; Non enzymatic antioxidant capacity; Oxidative stress; PREDIMED; Prevención con Dieta Mediterránea; RONS; TRAP; Total antioxidant capacity; VOO; cardiovascular diseases; ferric reducing antioxidant potential; non enzymatic antioxidant capacity; reactive oxygen nitrogen species; total radical-trapping antioxidant parameter; virgin olive oil.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antioxidants / administration & dosage*
  • Antioxidants / metabolism
  • Cardiovascular Diseases / diet therapy
  • Cardiovascular Diseases / prevention & control*
  • Diet, Fat-Restricted
  • Diet, Mediterranean*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nuts
  • Olive Oil
  • Plant Oils / administration & dosage
  • Risk Factors


  • Antioxidants
  • Olive Oil
  • Plant Oils