Consumption of different sources of omega-3 polyunsaturated fatty acids by growing female rats affects long bone mass and microarchitecture.

Key Findings:

Studies have shown that female rats fed flaxseed oil during the perinatal period had improved bone mineral content (BMC) and bone mineral density (BMD. This study demonstrated that growing female rats fed a high (12% by weight) fat diet. Rats fed flaxseed oil had increased tibial trabecular bone microarchitecture. Significantly increased tibia trabecular number and connectivity was reported in rats fed either flaxseed or menhaden oil. In the femur, omega 3 oils produced a greater trabecular number and reduced trabecular separation. Cortical bone microarchitecture was not altered. Increased serum osteocalcin concentration and improved trabecular bone microarchitecture parameters were associated. ALA promoted bone formation as shown by higher serum osteocalcin. The authors concluded that a variety of n3 oils including ALA improve bone health and should be consumed by girls throughout growth.

ABSTRACT:

Omega 3 polyunsaturated fatty acids (n3 PUFAs) consumption has been reported to improve bone health. However, sources of n3 PUFAs differ in the type of fatty acids and structural form. The study objective was to determine the effect of various n3 PUFAs sources on bone during growth. Young (age 28 d) female Sprague Dawley rats were randomly assigned (n of 10/group) to a high fat 12% (wt) diet consisting of either corn oil (CO) or n3 PUFA rich, flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) for 8 weeks. Bone mass was assessed by dual-energy X-ray absorptiometry (DXA) and bone microarchitecture by microcomputed tomography (μCT). Bone turnover markers were measured by enzyme immunoassay. Lipid peroxidation was measured by calorimetric assays. Results showed that rats fed TO, rich in docosahexaenoic acid (DHA, 22:6n3) had higher (P < 0.009) tibial bone mineral density (BMD) and bone mineral content (BMC) and lower (P = 0.05) lipid peroxidation compared to the CO fed rats. Reduced lipid peroxidation was associated with increased tibial BMD (r2 = 0.08, P = 0.02) and BMC (r2 = 0.71, P = 0.01). On the other hand, rats fed FO or MO, rich in alpha-linolenic acid (ALA, 18:3n3), improved bone microarchitecture compared to rats fed CO or SO. Serum osteocalcin was higher (P = 0.03) in rats fed FO compared to rats fed SO. Serum osteocalcin was associated with improved trabecular bone micoarchitecture. The animal study results suggest consuming a variety of n3 PUFA sources to promote bone health during the growth stage. (Authors abstract)