Positive Health Online

Abstract

GRIEL and co-authors, Department of Nutritional Sciences, 126 S Henderson Bldg, The Pennsylvania State University, University Park, PA 16802, USA,  aeg126@psu.edu, have found a link between the intake of essential fatty acids and bone health.

Background

Human, animal, and in vitro research indicates a beneficial effect of appropriate amounts of omega-3 (n-3) polyunsaturated fatty acids on bone health. The aim of this controlled feeding study in humans was to evaluate the effect of dietary plant-derived n-3 fatty acids on bone turnover.

Methodology

Bone turnover was assessed by serum concentrations of N-telopeptides (NTx) and bone-specific alkaline phosphatase. 23 subjects consumed each diet for 6 weeks in a randomized, 3-period crossover design: 1) Average American Diet (34% total fat, 13% saturated fatty acids, 13% monounsaturated fatty acids, 7.7% linoleic acid, 0.8% alpha-linolenic acid; 2) Linoleic Acid Diet (37% total fat, 9% saturated fatty acids, 12% monounsaturated fatty acids, 12.6% linoleic acid, 3.6% alpha-;inolenic acid); 3) alpha-Linolenic Acid Diet (38% total fat, 8% saturated fatty acids, 12% monounsaturated fatty acids, 10.5% linoleic acid, 6.5% alpha-linolenic acid). Walnuts and flaxseed oil were the predominant sources of alpha-linolenic acid.

Results

N-telopeptide levels were significantly lower following the alpha-linolenic acid diet (13.20 +/- 1.21 nM BCE), relative to the average American diet (15.59 +/- 1.21 nM BCE) (p < 0.05). Mean N-telopeptide level following the linoleic acid diet was 13.80 +/- 1.21 nM BCE. There was no change in levels of bone-specific alkaline phosphatase across the three diets. Concentrations of N-telopeptide were positively correlated with the pro-inflammatory cytokine TNF-alpha for all three diets.

Conclusion

The results indicate that plant sources of dietary n-3 fatty acids may have a protective effect on bone metabolism via a decrease in bone resorption in the presence of consistent levels of bone formation.

References

Griel AE, Kris-Etherton PM, Hilpert KF, Zhao G, West SG, Corwin RL. An increase in dietary n-3 fatty acids decreases a marker of bone resorption in humans. Nutrition Journal 6: 2, 2007.

Comment

The above research demonstrates that plant sources of n-3 fatty acids can protect bone metabolism and decrease bone resorption – conditions highly significant for our ageing population.