Science Update

Recent Systematic Review and Meta-analysis Investigated Relationship Between n-3 PUFA Supplementation and Bone Integrity

The challenges of maintaining bone integrity can increase as we age. Bone health can be affected by hormonal changes, nutritional status, and lifestyle factors such as physical activity. Unbalanced inflammatory states have also been shown to negatively influence bone metabolism

States of decreased bone formation and increased bone resorption have been associated in research with elevated levels of certain inflammatory markers including C-reactive protein (CRP) and interleukin-6 (IL)-6. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been well-researched for their potential to support a normal inflammatory response alongside many other body systems. Recent studies have investigated if n-3 PUFAs may also play a supportive role in bone health. 

Evidence suggests that n-3 PUFAs may influence certain biochemical pathways related to bone metabolism. A randomized controlled trial (RCT) reported 17% reductions in N-telopeptides of type I collagen (NTx-1). NTx-1 is an indicator of osteoclast activity, suggesting states of bone resorption. In addition, n-3 PUFAs are thought to influence bone health through their role in supporting a healthy inflammatory response. Laboratory studies indicate that n-3 PUFAs may help reduce inflammatory cytokine activity including nuclear factor-κB and IL-1β. Systematic reviews of clinical studies have suggested an inverse association between fracture risk and n-3 PUFA status. 

A recently published systematic review and meta-analysis by Gao and colleagues explored the potential efficacy of n-3 PUFAs on bone metabolism and integrity. This study aggregated data from 19 RCTs involving over 2,500 individuals. Overall, statistically significant increases in blood n-3 PUFAs were found. In addition, upon subgroup analysis, significant increases in parameters related to bone health, as measured by bone density in the femoral neck, were observed in females. Decreases in NTx-1 were reported in all genders. Of note, 25(OH)D, a measure of vitamin D status, was observed to increase in studies involving only n-3 PUFA supplementation; however, more information is needed before clinical conclusions can be made. 

Overall, the meta-analysis concluded that n-3 PUFA supplementation did not significantly influence biomarkers related to bone health. However, subgroup analyses suggest that certain qualities of bone health may have improved in the presence of n-3 PUFA supplementation. This may indicate that more clinical research with standardized amounts of n-3 PUFAs, more participants, a snapshot of the nutritional status of participants at baseline and study terminus, and longer trials are warranted. 

While more research is needed to understand the scope of the influence of n-3 PUFAs on bone health, evidence suggests that they may help support a healthy inflammatory response, brain health, skin integrity, and many other body systems. Dietary sources of n-3 PUFAs include fatty fish such as salmon, sardines, and mackerel. Vegan sources include flaxseeds, chia seeds, walnuts, and edamame.

By Dr. C. Ambrose, ND, MAT