title: The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans.
abstract: The lower rates of some cancers in Asian countries than in Western countries may be partly because of diet, although the mechanisms are unknown. The aim of this cross-sectional study was to determine whether a plant-based (vegan) diet is associated with a lower circulating level of insulin-like growth factor I (IGF-I) compared with a meat-eating or lacto-ovo-vegetarian diet among 292 British women, ages 20-70 years. The mean serum IGF-I concentration was 13% lower in 92 vegan women compared with 99 meat-eaters and 101 vegetarians (P = 0.0006). The mean concentrations of both serum IGF-binding protein (IGFBP)-1 and IGFBP-2 were 20-40% higher in vegan women compared with meat-eaters and vegetarians (P = 0.005 and P = 0.0008 for IGFBP-1 and IGFBP-2, respectively). There were no significant differences in IGFBP-3, C-peptide, or sex hormone-binding globulin concentrations between the diet groups. Intake of protein rich in essential amino acids was positively associated with serum IGF-I (Pearson partial correlation coefficient; r = 0.27; P < 0.0001) and explained most of the differences in IGF-I concentration between the diet groups. These data suggest that a plant-based diet is associated with lower circulating levels of total IGF-I and higher levels of IGFBP-1 and IGFBP-2.
authors.affiliation: Cancer Research United Kingdom Epidemiology Unit, University of Oxford, Oxford OX2 6HE, United Kingdom. naomi.allen@cancer.org.uk
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Allen
authors.forename: Paul N
authors.initials: PN
authors.lastname: Appleby
authors.forename: Gwyneth K
authors.initials: GK
authors.lastname: Davey
authors.forename: Rudolf
authors.initials: R
authors.lastname: Kaaks
authors.forename: Sabina
authors.initials: S
authors.lastname: Rinaldi
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Key
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology; D003430:Cross-Sectional Studies; D003611:Dairy Products; D014676:Diet, Vegetarian; D004435:Eating; D005260:Female; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008460:Meat; D008875:Middle Aged; D010944:Plants; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013223:Statistics as Topic; D013997:Time Factors; D006113:United Kingdom; D016387:Women's Health; D015032:Zinc
chemical_list: D015415:Biomarkers; D002096:C-Peptide; D018969:Insulin-Like Growth Factor Binding Proteins; D012738:Sex Hormone-Binding Globulin; D007334:Insulin-Like Growth Factor I; D015032:Zinc