title: Plasma carotenoids, tocopherols, and antioxidant capacity in a 12-week intervention study to reduce fat and/or energy intakes.
abstract: OBJECTIVE
  We examined plasma levels of carotenoids, tocopherols, and total antioxidant activity in women before and after dietary intervention to reduce fat and/or energy intakes. Dietary fat and energy may affect intake and bioavailability of carotenoids and tocopherols, and these micronutrient levels in turn can contribute to the antioxidant capacity of plasma.
  
  
  METHODS
  Women were randomized onto one of four diets for 12 wk: non-intervention, low fat (15% of energy from fat with maintenance of energy intake), low energy (25% energy reduction with maintenance of percentage of energy from fat), and combined low fat and low energy. Fasting plasma was available for analysis from a subset (n = 41) of women enrolled in the study.
  
  
  RESULTS
  Levels of carotenoids and tocopherols did not change significantly over 12 wk on any diet arm, despite a modest but statistically significant increase in fruit and vegetable intake in the women following the low-fat diet (from 3.3 to 5.2 servings/d excluding potatoes). Levels of Trolox-equivalent antioxidant capacity (TEAC), total cholesterol, and two major plasma antioxidants (urate and bilirubin) also did not change significantly. Of the individual micronutrients measured, lycopene and lutein/zeaxanthin correlated most strongly with TEAC values, and the correlation with lycopene was statistically significant before intervention.
  
  
  CONCLUSIONS
  The decreases in dietary fat and energy intakes in this study were quite large, but this did not appear to have detrimental effects on plasma micronutrient levels, nor did it appreciably affect plasma antioxidants. Because lycopene levels were significantly associated with plasma TEAC before intervention, interventions that increase levels of lycopene might be more likely to increase the antioxidant capacity of plasma.
authors.affiliation: Barbara Ann Karmanos Cancer Institute, Detroit, Michigan 48201, USA. djuric@karmanos.org
authors.forename: Zora
authors.initials: Z
authors.lastname: Djuric
authors.forename: Virginia E
authors.initials: VE
authors.lastname: Uhley
authors.forename: Lilian
authors.initials: L
authors.lastname: Naegeli
authors.forename: Samir
authors.initials: S
authors.lastname: Lababidi
authors.forename: Suhasini
authors.initials: S
authors.lastname: Macha
authors.forename: Lance K
authors.initials: LK
authors.lastname: Heilbrun
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001682:Biological Availability; D002338:Carotenoids / Q000097:blood* / Q000493:pharmacokinetics; D018752:Diet, Fat-Restricted; D004038:Diet, Reducing; D004041:Dietary Fats / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D005638:Fruit / Q000737:chemistry; D006801:Humans; D000077276:Lycopene; D024505:Tocopherols / Q000097:blood* / Q000493:pharmacokinetics; D014675:Vegetables / Q000737:chemistry; D016387:Women's Health
chemical_list: D000975:Antioxidants; D004041:Dietary Fats; D002338:Carotenoids; D024505:Tocopherols; D000077276:Lycopene