The Effects of Various Levels of Docosahexaenoic Acid on Inflammatory Markers in Conditioned Horses During Lactate Threshold Tests.
Authors: Hess Tanja, Braun Stefanie, Herkelman Kevin
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Intense exercise triggers the release of inflammatory cytokines in equine muscle and circulation, a response that can compromise recovery and performance—particularly in high-demand disciplines like polo. Researchers at the University of Kentucky investigated whether dietary supplementation with docosahexaenoic acid (DHA), an omega-3 fatty acid with known anti-inflammatory properties, could modulate this postexercise inflammatory response by comparing unsupplemented horses against three treatment groups receiving 10, 20, or 50 g/day of DHA over 60 days, with blood sampling at rest and immediately following lactate threshold field tests. The 10 g/day dose emerged as most effective at downregulating interferon gamma and interleukin-10 expression following exercise, whereas the higher doses (20 and 50 g) showed no benefit and notably depleted circulating vitamin E levels. The authors hypothesised that supplements lacking complementary antioxidants may have created a pro-oxidant environment at higher DHA levels, offsetting any anti-inflammatory advantage; this suggests that DHA supplementation protocols should be calibrated carefully and paired with adequate vitamin E to prevent iatrogenic oxidative stress. For practitioners, these findings support modest DHA supplementation (around 10 g/day) as a pragmatic tool for managing postexercise inflammation in performance horses, but caution against escalating doses without concurrent antioxidant support and individualised blood work to confirm vitamin E status.
Read the full abstract on PubMed
Practical Takeaways
- •10 g/day DHA supplementation may be optimal for moderating postexercise inflammation in performance horses; higher doses (20-50 g) did not provide additional benefit and may deplete antioxidant status
- •Consider concurrent antioxidant supplementation (vitamin E) when providing DHA at levels above 10 g/day to maintain anti-inflammatory efficacy
- •DHA supplementation appears most useful for managing inflammatory responses in athletically-conditioned horses undergoing regular high-intensity exercise testing or competition
Key Findings
- •Dose-dependent increase in plasma DHA occurred across all supplementation groups (10, 20, 50 g/day) over 60 days
- •10 g/day DHA led to postexercise downregulation of interferon gamma and IL-10 compared to higher doses and control
- •20 and 50 g/day DHA showed lower vitamin E levels despite higher arachidonic acid, suggesting antioxidant depletion may have negated anti-inflammatory benefits
- •Lactate threshold exercise downregulated IL-1 and TNF-α while upregulating IL-10 and interferon gamma