title: Metabolic responses to a traditional Mexican diet compared with a commonly consumed US diet in women of Mexican descent: a randomized crossover feeding trial.
abstract: BACKGROUND
  Mexican immigrants are disproportionally affected by diet-related risk of metabolic dysfunction. Whether adhering to a traditional Mexican diet or adopting a US diet contributes to metabolic changes associated with future risk of type 2 diabetes and other chronic diseases has not been investigated.
  
  
  OBJECTIVE
  The purpose of this study was to test in a randomized crossover feeding trial the metabolic responses to a Mexican diet compared with a commonly consumed US diet.
  
  
  METHODS
  First- and second-generation healthy women of Mexican descent (n = 53) were randomly assigned in a crossover design to consume a Mexican or US diet for 24 d each, separated by a 28-d washout period. Diets were eucaloric and similar in macronutrient composition. The metabolic responses to diets were assessed by measuring fasting serum concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), adiponectin, C-reactive protein (CRP), and interleukin 6 (IL-6), as well as the homeostasis model assessment of insulin resistance (HOMA-IR) at the beginning and end of each period. Linear mixed models tested the intervention effect on the biomarkers, while adjusting for diet sequence, feeding period, baseline and washout biomarker concentrations, age, acculturation, and BMI.
  
  
  RESULTS
  Compared with the US diet, the Mexican diet reduced insulin by 14% [geometric means (95% CIs): 9.3 (8.3, 10.3) compared with 8.0 (7.2, 8.9) μU/mL; P = 0.02], HOMA-IR by 15% [2.0 (1.8, 2.3) compared with 1.7 (1.6, 2.0); P = 0.02], and IGFBP-3 by 6% (mean ± SEM: 2420 ± 29 compared with 2299 ± 29 ng/mL; P < 0.01) and tended to reduce circulating concentrations of IGF-1 by 4% (149 ± 2.6 compared with 144 ± 2.5 ng/mL; P = 0.06). There was no significant intervention effect on serum concentrations of glucose, adiponectin, CRP, or IL-6 in the US compared with the Mexican diet.
  
  
  CONCLUSIONS
  Compared with the commonly consumed US diet, the traditional Mexican diet modestly improved insulin sensitivity under conditions of weight stability in healthy women of Mexican descent, while having no impact on biomarkers of inflammation. This trial was registered at clinicaltrials.gov as NCT01369173.
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and msantiag@fredhutch.org.
authors.forename: Margarita
authors.initials: M
authors.lastname: Santiago-Torres
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Mario
authors.initials: M
authors.lastname: Kratz
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Johanna W
authors.initials: JW
authors.lastname: Lampe
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Jean De Dieu
authors.initials: Jde D
authors.lastname: Tapsoba
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Kara L
authors.initials: KL
authors.lastname: Breymeyer
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Lisa
authors.initials: L
authors.lastname: Levy
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Villaseñor
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Ching-Yun
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Song
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA; and.
authors.forename: Marian L
authors.initials: ML
authors.lastname: Neuhouser
mesh_terms: D000069:Acculturation; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology* / Q000378:metabolism; D004032:Diet / Q000009:adverse effects* / Q000208:ethnology; D066273:Diet, Western / Q000009:adverse effects* / Q000208:ethnology; D054242:Emigrants and Immigrants; D002149:Energy Intake; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D007333:Insulin Resistance; D016014:Linear Models; D017058:Mexican Americans; D012306:Risk; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators
keywords: Mexican diet; US diet; inflammatory responses; insulin sensitivity; metabolic responses