title: The association of protein intake (amount and type) with ovarian antral follicle counts among infertile women: results from the EARTH prospective study cohort.
abstract: OBJECTIVE
  To evaluate the association between protein intake (amount and type) and antral follicle count (AFC).
  
  
  METHODS
  Prospective cohort.
  
  
  METHODS
  Academic fertility centre.
  
  
  METHODS
  Two hundred and sixty-five women undergoing fertility treatments at an academic fertility centre and participating in an ongoing study on environment and reproductive health.
  
  
  METHODS
  We measured AFC in ultrasonographic evaluation among women undergoing infertility treatments. Women completed a previously validated semi-quantitative food frequency questionnaire. We used Poisson regression to evaluate the relation between protein intake and AFC while adjusting for age, body mass index, race, smoking status, and total energy intake.
  
  
  METHODS
  Antral follicle count.
  
  
  RESULTS
  Among 265 women (mean age: 35.0 ± 3.9 years, 85% Caucasian), total protein intake (% energy) was unrelated to AFC. When protein from different food sources was considered separately, we found a negative association between dairy protein intake and AFC. The mean AFC was 14.4% (3.9-23.7%) lower for women in the highest quintile of dairy protein intake than for women in the bottom quintile after adjusting for potential confounders (P-trend = 0.04). This association was stronger among women who had never smoked (P-trend = 0.002) but was not observed among previous smokers (P-trend = 0.36). There were no associations between protein intake from either non-dairy animal or vegetable sources and AFC.
  
  
  CONCLUSIONS
  Higher dairy protein intake (≥5.24% of energy) was associated with lower antral follicle counts among women presenting for infertility treatment. These findings should be further investigated in prospective studies also designed to clarify the biology underlying the observed associations.
  
  
  CONCLUSIONS
  Higher dairy protein intake was associated with lower antral follicle counts in an infertile population.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Harvard Medical School, Massachusetts General Hospital Fertility Center, Boston, MA, USA.
authors.forename: I
authors.initials: I
authors.lastname: Souter
authors.affiliation: Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chiu
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Harvard Medical School, Massachusetts General Hospital Fertility Center, Boston, MA, USA.|Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Batsis
authors.affiliation: Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Afeiche
authors.affiliation: Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: P L
authors.initials: PL
authors.lastname: Williams
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Harvard Medical School, Massachusetts General Hospital Fertility Center, Boston, MA, USA.|Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Hauser
authors.affiliation: Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, MA, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.|Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Chavarro
mesh_terms: D000328:Adult; D003611:Dairy Products / Q000009:adverse effects* / Q000032:analysis; D004034:Diet Surveys; D004044:Dietary Proteins / Q000009:adverse effects* / Q000032:analysis; D004435:Eating / Q000502:physiology*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D006080:Ovarian Follicle; D016012:Poisson Distribution; D011446:Prospective Studies; D012044:Regression Analysis
chemical_list: D004044:Dietary Proteins
keywords: Antral follicle count; dairy intake; female infertility; ovarian reserve; ovary; protein intake