title: Dietary fatty acid intakes and the risk of ovulatory infertility.
abstract: BACKGROUND
  Pharmacologic activation of the peroxisome proliferator-activated receptor gamma (PPAR-gamma) improves ovulatory function in women with polycystic ovary syndrome, and specific dietary fatty acids can affect PPAR-gamma activity.
  
  
  OBJECTIVE
  The objective of the study was to assess whether the intakes of total fat, cholesterol, and major types of fatty acids affect the risk of ovulatory infertility.
  
  
  METHODS
  We conducted a prospective cohort study of 18 555 married, premenopausal women without a history of infertility who attempted a pregnancy or became pregnant between 1991 and 1999. Diet was assessed twice during follow-up by using a food-frequency questionnaire.
  
  
  RESULTS
  During follow-up, 438 incidents of ovulatory infertility were reported. In logistic regression analyses, intakes of total fat, cholesterol, and most types of fatty acids were not related to ovulatory infertility. Each 2% increase in the intake of energy from trans unsaturated fats, as opposed to that from carbohydrates, was associated with a 73% greater risk of ovulatory infertility after adjustment for known and suspected risk factors for this condition [relative risk (RR) = 1.73; 95% CI: 1.09, 2.73]. Obtaining 2% of energy intake from trans fats rather than from n-6 polyunsaturated fats was associated with a similar increase in the risk of ovulatory infertility (RR = 1.79; 95% CI: 1.11, 2.89). In addition, obtaining 2% of energy from trans fats rather than from monounsaturated fats was associated with a more than doubled risk of ovulatory infertility (RR = 2.31; 95% CI: 1.09, 4.87).
  
  
  CONCLUSIONS
  trans Unsaturated fats may increase the risk of ovulatory infertility when consumed instead of carbohydrates or unsaturated fats commonly found in nonhydrogenated vegetable oils.
authors.affiliation: Department of Nutrition, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. jchavarr@hsph.harvard.edu
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Chavarro
authors.forename: Janet W
authors.initials: JW
authors.lastname: Rich-Edwards
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Rosner
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004034:Diet Surveys; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology* / Q000209:etiology; D016015:Logistic Models; D010060:Ovulation / Q000187:drug effects* / Q000502:physiology; D047495:PPAR gamma / Q000378:metabolism; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D044242:Trans Fatty Acids / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D047495:PPAR gamma; D044242:Trans Fatty Acids