Association between dietary conjugated linoleic acid and bone mineral density in postmenopausal women

To determine if dietary conjugated linoleic acid (CLA) is associated with bone mineral density (BMD) of different skeletal sites in postmenopausal women.

A cross-sectional analysis in 136 Caucasian, healthy, postmenopausal women, mean age 68.6 years. BMD and soft tissue were assessed by dual energy x-ray absorptiometry (DXA). Energy, calcium, protein, fat, CLA and other relevant nutrients were estimated using 3 day dietary records. Supplement use was recorded as well. Current and past physical activity were determined using the Allied Dunbar National Fitness Survey for older adults.

CLA (63.1 +/- 46.8 mg, mean +/- SD) was a significant predictor of Ward's triangle BMD (p = 0.040) in a multiple regression model containing years since menopause (18.5 +/- 8.4 y), lean tissue, energy intake (1691 +/- 382 kcal/day) dietary calcium (873 +/- 365 mg), protein (70.6 +/- 18.6 g), fat (57.9 +/- 23.9 g), zinc (19.2 +/- 13.6 mg), and current and past physical activity, with R(2)(adj) = 0.286. Subjects were also divided into groups below (Group 1) and above (Group 2) the median intake for CLA. Group 2 had higher BMD in the forearm, p = 0.042, and higher BMD in the hip, lumbar spine and whole body, however statistical significance was not reached.

These findings indicate dietary CLA may positively benefit BMD in postmenopausal women. More studies are warranted examining the relationship between dietary CLA and BMD.