To Boost Omega-3s, Focus on Supplement Dose, Not Duration

Researchers found that providing a higher dose of a fish oil supplement increased horses’ omega-3 levels better than a longer supplementation period.

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To Boost Omega-3s, Focus on Supplement Dose, Not Duration
Researchers found that providing a higher dose of a fish oil supplement increased horses’ omega-3 levels better than a longer supplementation period. | Photo: iStock

To pump up the omega-3 fatty acids (n3-FAs) in your horse’s body, a higher dose might be more effective than a longer supplementation period, according to researchers who recently completed a study on the subject.

Horses consume omega-3 fatty acids naturally in their forage. But in certain situations they can benefit from an added boost, said Garett Pearson, DVM, a resident in large animal surgery at Cornell University College of Veterinary Medicine, in Ithaca, New York.

“Supplementation of n3-FAs in horses improves reproductive health of both mares and stallions and has potential as a treatment for a range of pathologies, including equine metabolic disease, synovitis, and lower airway disease,” he and his co-authors stated in their publication, citing previous studies.

Omega-3s in Fish Oil Vs. Plants

Flaxseed, which is a popular plant-based source of n3-FAs in equine supplements, mainly contains an n3-FA known as α-linolenic acid (ALA). For ALA to provide significant benefits, many scientists suspect it must convert into two more potent types of long-chain n3-FAs once inside the horse’s body: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), Pearson and his colleagues explained.

Scientists still don’t know how well horses convert ALA into EPA and DHA, they added. In humans the rates are low: We only bioconvert about 10% of EPA and only about 0.10% of DHA.

While horses might bioconvert ALA more efficiently from plant sources than humans do, a fish-oil-based omega-3 source might circumvent the conversion process altogether, the authors said. Both fish oil and algae provide EPA and DHA directly.

The Experiment: Same Fish Oil Supplement, Two Different Doses

To understand how different amounts of a fish oil supplement affect omega-3 levels in the horse’s system, the researchers tested two doses of the same commercial fish oil supplement on a group of 50 healthy adult horses.

All the horses were fed a 90% hay/10% concentrated feed diet. They had the supplement added to their feed for 12 weeks, with half the horses receiving a daily dose of 7.5 grams, and the other half a daily dose of 15 grams. Because the tested supplement contains 0.092 grams of DHA and 0.148 grams of EPA per gram of product, the horses received either 1.11 grams of EPA and 0.69 grams of DHA every day, or twice that amount, the researchers explained.

Major Omega-3 Increases Within Six Weeks, More Pronounced With Higher Dose

The team performed gas chromatography on blood drawn from the horses’ jugular veins at the start of the study, after six weeks, and at the end of the study. Results showed fluctuations in multiple kinds of fatty acids—not just omega-3s but also omega-6s, 7s, and 9s—in all the horses over the supplement period, they said.

Most significantly, the omega-3 concentrations generally increased in all the horses, even more so with the larger dose, said Pearson and his colleagues.

The omega-6s, meanwhile, generally dropped, they said. That’s likely to be a good thing, because study results suggest omega-6s might contribute to health problems such as inflammation and cancer at higher concentrations relative to omega-3s.

Blood omega-3 concentrations shot up in the first six weeks—significantly more in the 15-gram dose group—then stabilized there for the remaining six weeks. This finding suggests that the daily dose effectively boosts the blood concentration more than the length of time the horse receives supplements, the team stated.

Take-Home Message

The fish oil supplement used in the study led to “a significant, dose-dependent increase in concentration of not only DHA and EPA, but all n3-FAs evaluated in whole blood at all time points when compared to baseline,” the researchers stated. “Of the two doses evaluated, horses receiving 15 grams of the supplement daily for six weeks had the greatest increase in overall n3-FA levels and decrease in overall n6-FA levels.”

The fact that the concentration of all the tested n3-FAs increased in line with the dose amount and stayed at that level throughout the study “validates the use of this product as an n3-FA targeted supplement in horses,” Pearson and his colleagues stated in their paper. “These findings also suggest that dose of supplement has a greater effect on increasing whole blood n3-FAs compared to duration of treatment.”

The study, “Dose-Dependent Increase in Whole Blood Omega-3 Fatty Acid Concentration in Horses Receiving a Marine-Based Fatty-Acid Supplement,” was published in the January issue of the Journal of Equine Veterinary Science.


Written by:

Passionate about horses and science from the time she was riding her first Shetland Pony in Texas, Christa Lesté-Lasserre writes about scientific research that contributes to a better understanding of all equids. After undergrad studies in science, journalism, and literature, she received a master’s degree in creative writing. Now based in France, she aims to present the most fascinating aspect of equine science: the story it creates. Follow Lesté-Lasserre on Twitter @christalestelas.

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