title: Ratio of n-6 to n-3 fatty acids and bone mineral density in older adults: the Rancho Bernardo Study.
abstract: BACKGROUND
  Several lines of evidence suggest that n-3 fatty acids reduce the risk of some chronic diseases, including heart disease, diabetes, and cancer. Other research, mainly in animals, also suggests a role in bone health.
  
  
  OBJECTIVE
  We aimed to investigate the association between the ratio of dietary n-6 to n-3 fatty acids and bone mineral density (BMD) in 1532 community-dwelling men and women aged 45-90 y.
  
  
  METHODS
  Between 1988 and 1992, dietary data were obtained through self-administered food-frequency questionnaires, and BMD was measured at the hip and spine with the use of dual-energy X-ray absorptiometry. A medical history was obtained and current medication use was validated. Age- and multiple-adjusted linear regression analyses were performed.
  
  
  RESULTS
  There was a significant inverse association between the ratio of dietary linoleic acid to alpha-linolenic acid and BMD at the hip in 642 men, 564 women not using hormone therapy, and 326 women using hormone therapy; these results were independent of age, body mass index, and lifestyle factors. An increasing ratio of total dietary n-6 to n-3 fatty acids was also significantly and independently associated with lower BMD at the hip in all women and at the spine in women not using hormone therapy.
  
  
  CONCLUSIONS
  A higher ratio of n-6 to n-3 fatty acids is associated with lower BMD at the hip in both sexes. These findings suggest that the relative amounts of dietary polyunsaturated fatty acids may play a vital role in preserving skeletal integrity in older age.
authors.affiliation: Department of Family and Preventive Medicine, School of Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Weiss
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
authors.forename: Denise
authors.initials: D
authors.lastname: von Mühlen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000187:drug effects*; D002140:California; D015331:Cohort Studies; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology*; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged
chemical_list: D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6