title: Compliance, tolerability and safety of two antioxidant-rich diets: a randomised controlled trial in male smokers.
abstract: It has been suggested that antioxidants attenuate oxidative stress and prevent oxidative stress-related diseases. Paradoxically, randomised controlled trials (RCT) using pharmacological doses of antioxidant supplements have demonstrated harmful effects in smokers. The aim of the present study was to test the compliance, tolerability and safety of two food-based antioxidant-rich diets in smokers. One of the diets provided antioxidants at levels similar to that used in RCT using supplements which previously have generated harmful effects. The present study followed a randomised, parallel-arm dietary intervention for 8 weeks (n 102) in male smokers (age ≥ 45 years). Participants were randomised to either antioxidant-rich diet, kiwi fruit or control groups. The antioxidant-rich foods provided about 300 mmol antioxidants/week from a wide range of plant-based food items. The kiwi fruit group consumed three kiwi fruits/d. Compliance to both diets was good. Only mild, undesirable events were reported by a minority of the participants. The safety of both diets was demonstrated as no potentially harmful or pro-oxidative effects were observed. In the antioxidant-rich diet group, the mean intake of antioxidants increased from 30 mmol/d at baseline to 62 mmol/d during the intervention. In conclusion, we have demonstrated that male smokers can comply with two food-based antioxidant-rich diets. Furthermore, the present study is the first to demonstrate the tolerability and safety of dietary antioxidants at levels similar to dosages provided in RCT using supplements. Such diets may be useful in future studies investigating whether dietary antioxidants may reduce oxidative stress and related diseases.
authors.affiliation: Department of Nutrition, Faculty of Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Anette
authors.initials: A
authors.lastname: Karlsen
authors.forename: Mette
authors.initials: M
authors.lastname: Svendsen
authors.forename: Ingebjørg
authors.initials: I
authors.lastname: Seljeflot
authors.forename: Mary-Ann
authors.initials: MA
authors.lastname: Sommernes
authors.forename: Joseph
authors.initials: J
authors.lastname: Sexton
authors.forename: Asgeir
authors.initials: A
authors.lastname: Brevik
authors.forename: Iris
authors.initials: I
authors.lastname: Erlund
authors.forename: Mauro
authors.initials: M
authors.lastname: Serafini
authors.forename: Nasser
authors.initials: N
authors.lastname: Bastani
authors.forename: Siv Fagertun
authors.initials: SF
authors.lastname: Remberg
authors.forename: Grethe I
authors.initials: GI
authors.lastname: Borge
authors.forename: Monica Hauger
authors.initials: MH
authors.lastname: Carlsen
authors.forename: Siv Kjølsrud
authors.initials: SK
authors.lastname: Bøhn
authors.forename: Mari C
authors.initials: MC
authors.lastname: Myhrstad
authors.forename: Lars O
authors.initials: LO
authors.lastname: Dragsted
authors.forename: Asim K
authors.initials: AK
authors.lastname: Duttaroy
authors.forename: Karin
authors.initials: K
authors.lastname: Haffner
authors.forename: Petter
authors.initials: P
authors.lastname: Laake
authors.forename: Christan A
authors.initials: CA
authors.lastname: Drevon
authors.forename: Harald
authors.initials: H
authors.lastname: Arnesen
authors.forename: Andrew
authors.initials: A
authors.lastname: Collins
authors.forename: Serena
authors.initials: S
authors.lastname: Tonstad
authors.forename: Rune
authors.initials: R
authors.lastname: Blomhoff
mesh_terms: D029042:Actinidia / Q000009:adverse effects; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage / Q000009:adverse effects* / Q000032:analysis; D004032:Diet / Q000009:adverse effects*; D015930:Diet Records; D005638:Fruit / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D018384:Oxidative Stress; D010349:Patient Compliance / Q000706:statistics & numerical data*; D012907:Smoking / Q000097:blood; D011795:Surveys and Questionnaires
chemical_list: D000975:Antioxidants