title: Randomized controlled trial: effects of diet on DNA damage in heavy smokers.
abstract: We have conducted a randomized trial which investigated the ability of dietary changes (in particular diets rich in cruciferous vegetables and flavonoids), to increase urinary antimutagenicity and inhibit DNA damage in smokers. Ninety heavy smokers were recruited and randomly assigned to three groups, and were given three different diets. The first diet was based on flavonoid-rich foods, particularly cruciferous vegetables, but not based on supplementation; the second was a normal isocaloric diet (with an adequate administration of fruits and vegetables); and the third was based on supplementation of flavonoids in the form of green tea and soy products. DNA adducts were measured by (32)P-postlabelling in exfoliated bladder cells at different times since the start of the trial. In spite of randomization, subjects in the control group smoked more than those in the experimental groups, and this can explain the higher adduct levels at baseline. A slight decrease in bulky DNA adducts in exfoliated bladder cells was observed after 1 year since the end in the supplementation group and after 1 month in white blood cells. The only statistically significant association was found in a regression model that adjusted for smoking, in which the increase in flavonoid intake was associated with a decrease in adducts after 1 year (P = 0.02). These data suggest that adherence to a diet rich in cruciferous vegetables and flavonoids might reduce genotoxicity in the human urinary bladder of smokers, but they should be interpreted with caution owing to small numbers and the uneven distribution of smoking habits in the experimental groups. Smoking is the most important single preventable cause of cancer; at the present stage of knowledge it is totally unlikely that certain dietary habits can seriously counteract the effects of tobacco smoking.
authors.affiliation: Department of Environmental Health, University of Cincinnati, OH, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Talaska
authors.forename: Mustafa
authors.initials: M
authors.lastname: Al-Zoughool
authors.forename: Christian
authors.initials: C
authors.lastname: Malaveille
authors.forename: Laura
authors.initials: L
authors.lastname: Fiorini
authors.forename: Brenda
authors.initials: B
authors.lastname: Schumann
authors.forename: Jay
authors.initials: J
authors.lastname: Vietas
authors.forename: Marco
authors.initials: M
authors.lastname: Peluso
authors.forename: Armelle
authors.initials: A
authors.lastname: Munnia
authors.forename: Monica
authors.initials: M
authors.lastname: Bianchini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Allegro
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Matullo
authors.forename: Carlotta
authors.initials: C
authors.lastname: Sacerdote
authors.forename: Paolo
authors.initials: P
authors.lastname: Vineis
mesh_terms: D018736:DNA Adducts / Q000652:urine; D004249:DNA Damage; D004032:Diet; D019587:Dietary Supplements; D005419:Flavonoids; D006801:Humans; D008297:Male; D012907:Smoking / Q000009:adverse effects* / Q000235:genetics; D001743:Urinary Bladder / Q000166:cytology; D014675:Vegetables
chemical_list: D018736:DNA Adducts; D005419:Flavonoids