Association between Dietary Conjugated Linoleic Acid and Bone Mineral Density in Postmenopausal Women

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

Methods: 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 abosorptiometry (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.

Results: 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 R²_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.

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