title: Associations of Buccal Cell Telomere Length with Daily Intake of β-Carotene or α-Tocopherol Are Dependent on Carotenoid Metabolism-related Gene Polymorphisms in Healthy Japanese Adults.
abstract: OBJECTIVE
  Telomere length shortening is modulated not only by aging, but also by both genetic and environmental factors. The aim of this study was to investigate the interactions between antioxidant nutrient metabolism-related gene single nucleotide polymorphisms (the genetic factors) and nutrient intake (the environmental factors) in their effects on telomere length shortening.
  
  
  METHODS
  Data were collected on the relative telomere lengths (RTLs) of buccal cells and the habitual food intake of 70 healthy Japanese adults.
  
  
  METHODS
  All subjects were genotyped for two common single nucleotide polymorphisms: rs6564851 in the β-carotene-15,15'-mono-oxygenase 1 (BCMO1) gene and rs362090 in the intestine-specific homeobox (ISX) gene.
  
  
  RESULTS
  Univariate analysis revealed that buccal RTL was not significantly modulated by either age or gender. Then, we subdivided the study population into four groups based on combinations of the rs6564851 and rs362090 genotypes. After this subdivision, we showed a positive effect of daily α- or β-carotene intake on buccal RTL in the ISX rs362090 G-allele carrier + BCMO1 rs6564851 GG-genotype group (p = 0.026). Additionally, daily intake of another antioxidative fat-soluble vitamin, α-tocopherol, was positively associated with buccal RTL in the ISX rs362090 AA-homozygote + BCMO1 rs6564851 T-allele carrier group (p = 0.037).
  
  
  CONCLUSIONS
  Our study clearly indicates that high dietary intake of the antioxidants α, β-carotene and α-tocopherol protects buccal cells from RTL shortening, depending on the genetic background of antioxidant vitamin-related genes.
authors.affiliation: Yoshihiro Shidoji, Molecular and Cellular Biology, Graduate School of Human Health Science, University of Nagasaki, 1-1-1 Academy Hills, Nagayo, Nagasaki 851-2195, Japan. E-mail: shidoji@sun.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Yabuta
authors.forename: M
authors.initials: M
authors.lastname: Masaki
authors.forename: Y
authors.initials: Y
authors.lastname: Shidoji
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology; D044466:Asian People; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D005838:Genotype; D064368:Healthy Volunteers; D006801:Humans; D007564:Japan; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D016615:Telomere / Q000187:drug effects / Q000378:metabolism; D059506:Telomere Shortening / Q000187:drug effects* / Q000235:genetics; D055815:Young Adult; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000494:pharmacology*; D019207:beta Carotene / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D019207:beta Carotene; D024502:alpha-Tocopherol