Ratio of n-6 to n-3 fatty acids and bone mineral density in older adults: the
Rancho Bernardo Study
Lauren A Weiss, Elizabeth Barrett-Connor and Denise von Mühlen

American Journal of Clinical Nutrition, Vol. 81, No. 4, 934-938, April 2005

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.

Design: 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 -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.

Abstract online at:
http://www.ajcn.org/cgi/content/abstract/81/4/934

Tom Billings