Flaxseed oil and bone development in growing male and female mice

Flaxseed is being increasingly incorporated into foods as a result of its proposed health benefits. Combined with the fact that bone is sensitive to dietary changes in fatty acids, the optimization of bone metabolism during childhood may be influenced by altering the type and amounts of fatty acids consumed. The effects of whole flaxseed or its purified lignan on bone development have been investigated, but positive and/or negative effects of flaxseed oil (FO), rich in alpha-linolenic acid (ALA), on bone development have not been reported. The objective of this study was to elucidate the effects of a 10% FO diet on indices of bone health, including bone mass and biomechanical bone strength. Male and female mice were fed either a 10% flaxseed oil (FO) or a 10% corn oil (CO) diet from postnatal day (PND) 28 until PND 91. Male and female mice fed FO converted ALA to eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) as indicated by significantly higher serum EPA and DHA; however, serum cytokines (interleukin-1beta, interleukin-6, tumor necrosis factor-alpha) with the potential to modulate bone metabolism did not significantly differ among groups. As expected, serum linoleic acid and arachidonic acid were significantly lower among mice fed FO. Feeding FO diet did not result in a higher or lower bone mass or stronger or weaker femurs and lumbar vertebra than in mice fed CO diet in either gender, suggesting that the level of ALA attainable in a 10% flaxseed oil diet is safe with regard to bone development in growing mice.