Researchers studied whether vitamin E and selenium supplements could protect show jumping horses from air pollution damage. They compared 20 horses—10 in polluted cities and 10 in less-polluted areas—and measured how well the supplements protected their cells and DNA from pollution-related damage. The results showed that the supplements helped horses in heavily polluted urban areas by reducing harmful cell damage and protecting their genetic material. However, the supplements didn’t work as well for horses in less-polluted areas. This suggests that antioxidant vitamins might be especially helpful for athletic horses living in cities with poor air quality.

The Quick Take

  • What they studied: Whether giving show jumping horses vitamin E and selenium supplements could protect them from damage caused by breathing polluted air while exercising.
  • Who participated: 20 healthy show jumping horses: 10 living and training in polluted urban areas and 10 in less-polluted peri-urban areas. All horses were actively competing in show jumping events.
  • Key finding: Horses in polluted cities that received supplements had significantly less cellular damage (measured as lower harmful fat molecules in their blood) and better protection of their DNA compared to unsupplemented horses. The protective effect was strongest in horses exposed to high ozone levels in urban areas (p = 0.002).
  • What it means for you: If you own or care for athletic horses in heavily polluted urban areas, vitamin E and selenium supplements may help reduce pollution-related cell damage. However, this benefit appears strongest in high-pollution environments and may not be necessary in cleaner areas. Talk to an equine veterinarian before starting any supplement program.

The Research Details

Researchers divided 20 show jumping horses into two groups based on where they lived and trained: 10 in polluted urban areas and 10 in less-polluted peri-urban areas. Half of the horses in each location received daily vitamin E and selenium supplements, while the other half received no supplements. All horses continued their normal show jumping training and exercise routines. The researchers measured air pollution levels (specifically nitrogen dioxide and ozone) at each location and collected blood samples from the horses to check for signs of cell damage and DNA damage. They measured several markers: how much harmful fat molecules (called MDA) were in the blood, how well the horses’ natural defense systems were working, and whether their cells showed signs of genetic damage.

When horses exercise hard, they breathe in more air and are exposed to more pollution. This combination creates extra stress on their cells, similar to what happens in humans who exercise in polluted environments. By studying horses in real-world conditions with different pollution levels, researchers could see whether supplements actually help protect cells from pollution damage during normal athletic activity. This approach is more realistic than laboratory studies and helps answer practical questions for horse owners.

This study was relatively small (only 20 horses total), which means the results should be viewed as preliminary rather than definitive. The researchers measured specific, objective markers of cell damage rather than relying on subjective observations, which strengthens the findings. The study was conducted in real-world conditions with actual pollution exposure, making it more relevant to practical situations. However, the study would be stronger with more horses and longer follow-up periods to see if benefits persist over time.

What the Results Show

Horses receiving vitamin E and selenium supplements showed significantly lower levels of harmful fat molecules (MDA) in their blood, especially those in heavily polluted urban areas. This suggests the supplements reduced cell damage from pollution. The protective effect was most dramatic in urban horses exposed to high ozone levels, where supplemented horses had substantially less DNA damage compared to unsupplemented horses. In contrast, horses in less-polluted peri-urban areas showed less dramatic benefits from supplementation, suggesting the protective effect depends on pollution exposure levels. The supplements appeared to work by boosting the horses’ natural antioxidant defense systems.

The study measured several other markers of cell health and found that supplemented horses maintained better overall antioxidant status. Clinical parameters (general health measures) remained normal in all horses, suggesting the supplements were safe and well-tolerated. The researchers noted that the relationship between pollution levels and supplement effectiveness was not straightforward—the benefits were clearest in the most polluted environments but less obvious in moderately polluted areas.

Previous research in humans and animals suggested that antioxidant supplements might help reduce pollution-related damage, but results have been mixed. This study provides some of the first evidence that vitamin E and selenium specifically help athletic horses in polluted urban environments. The findings align with research showing that antioxidants are more effective when oxidative stress is highest, which occurs in heavily polluted areas combined with intense exercise.

The study included only 20 horses, which is a small sample size that limits how much we can generalize the findings. The study didn’t specify how long horses received supplements before measurements were taken, so we don’t know the optimal duration of supplementation. The researchers only measured two air pollutants (nitrogen dioxide and ozone) but didn’t assess other common pollutants like particulate matter. The study was relatively short-term, so we don’t know if benefits continue over months or years of supplementation. Different horse breeds, ages, and fitness levels might respond differently to supplements, but this wasn’t explored.

The Bottom Line

For horses actively competing in heavily polluted urban areas, vitamin E and selenium supplementation appears moderately helpful (moderate confidence) for reducing pollution-related cell damage. For horses in less-polluted areas, the evidence is weaker and supplementation may not be necessary. Consult with an equine veterinarian to determine if your horse would benefit based on local air quality and your horse’s individual health status. Supplementation should not replace other protective measures like reducing exercise during high-pollution days.

This research is most relevant to owners of athletic horses (especially show jumpers) living in urban areas with known air quality problems. It may also interest equine veterinarians, horse trainers in polluted regions, and researchers studying pollution effects on animal health. People with horses in rural or clean-air areas probably don’t need to worry about these supplements based on this research. Horse owners should not assume supplements will replace good air quality management practices.

If supplements are going to help, benefits would likely appear within weeks to months of consistent supplementation, as the study measured changes in blood markers relatively quickly. However, this study doesn’t tell us how long benefits last or whether long-term supplementation is necessary. Individual horses may respond at different rates.

Want to Apply This Research?

  • Track daily air quality index (AQI) in your area alongside your horse’s supplement intake and exercise intensity. Note any changes in your horse’s respiratory health, energy levels, or recovery time after exercise. Some apps can log local pollution levels automatically.
  • If your area has high pollution days, use the app to plan lighter training sessions on those days. If supplementing, set reminders to give supplements consistently and track compliance. Monitor local air quality forecasts and adjust exercise intensity accordingly—supplements shouldn’t replace common-sense pollution avoidance.
  • Over 2-3 months of supplementation, track your horse’s exercise tolerance, recovery time, and any respiratory symptoms. Compare performance on high-pollution versus low-pollution days. If possible, work with your veterinarian to monitor blood markers annually to assess whether supplementation is providing benefits for your specific horse.

This research describes effects observed in a small study of show jumping horses and should not be interpreted as medical advice for your specific horse. Air pollution exposure and supplement needs vary greatly depending on location, individual horse health status, age, and fitness level. Before starting any supplement program, consult with a licensed equine veterinarian who can evaluate your horse’s specific situation and recommend appropriate interventions. This study does not replace veterinary care or professional guidance. Supplements should not be used as a substitute for reducing exercise during high-pollution days or other evidence-based pollution protection strategies.