Original ResearchEffects of Ω-3 (n-3) Fatty Acid Supplementation on Insulin Sensitivity in Horses
Introduction
Insulin resistance in horses has been linked to the development of laminitis, osteochondrosis, and metabolic syndrome [1], [2], [3], [4] and is therefore considered a problem in the equine industry. These diseases can result in a loss of function and performance of the horse. Several factors may predispose a horse to develop a decreased sensitivity to insulin, such as diet, age, breed/genetics, and obesity [5], [6], [7]. Supplementation with certain dietary components could increase insulin sensitivity (SI) in animals that have decreased sensitivity or insulin resistance, reducing the risk for the development of diseases such as metabolic syndrome and laminitis.
Dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) has been shown to increase SI in pigs and rats [8], [9]. Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to incorporate into cell membranes, increasing membrane fluidity owing to greater unsaturation of the membrane and improving glucose transport function [10], [11]. Incorporation of EPA and DHA into muscle cell membrane has been shown to increase binding of insulin [12] and m-RNA expression of glucose transporter type 4 (GLUT-4) in rats [13]. Supplementation with EPA and DHA has shown to improve SI in rats [12], in pigs [8], and in humans [14]. The current study was designed to investigate the effects of feeding a marine source of n-3 PUFAs (algae and fish oil pellet), a direct source of EPA and DHA, or a plant source of n-3 fatty acids (ground flaxseed), on glucose and insulin dynamics in a group of 21 adult mares.
Section snippets
Horses and Treatments
Twenty-one nonpregnant mares of mixed stock horse breeding were acclimated to a basal diet of free-choice alfalfa/bromegrass mixed hay for 1 month before this study. Horses were maintained according to the policy of Colorado State University’s Equine Sciences Program and by following the protocol approved by the Institutional Animal Care and Use Committee. Horses had been dewormed and vaccinated before the start of the study. Initial and monthly assessment of BCS was made by three trained and
Horses Weights and Body Condition Scores
Weights and BCS were evaluated on a monthly basis and are presented in Table 3. Because no differences were seen among treatments, results were pooled and averaged across all treatments. Horses weighed 585 ± 41.5 kg at day 0, then weight decreased (P < .001) progressively from day 0 to day 60 (565.0 ± 35.6 kg), and then increased (P < .010) from day 60 to day 90 (576.1 ± 36.8 kg). BCSs ranged from 5 to 8 and decreased (P = .02) from day 0 (6.74 ± 0.85) to day 90 (6.38 ± 0.82). Horses remained
Discussion
Insulin sensitivity, β pancreatic response, and glucose-mediated glucose disposal were not affected by fatty acid supplementation in the current study. DI was higher in the FLAX than in the CONT group at day 90. DI is a measure calculated from SI and β pancreatic response; however, no other measures for SI were significantly different between treatments. If an individual does not secrete enough insulin (AIRg) for insulin sensitivity, DI will be higher, and it may be used as an indication of
Conclusions
No effect of treatment with fatty acid supplementation was able to be detected in the current investigation; however, a number of exogenous factors may have reduced the ability of a significant effect of treatment to be detected, and further investigation in this area is necessary. In horses classified in the lowest quintile for insulin sensitivity, there was a trend for a treatment effect, where MARINE and FLAX horses had higher SI compared with the control treatment. The results of the
Acknowledgments
The authors thank United Bionutrition for the donation of the Magnitude supplement (JBS United, Sheridan, IN), Horse Tech for the availability of the Nutra-Flax (Horse Tech, Laurens, IA), the Equine Reproductive Center at Colorado State University (CSU) for the lease of the mares, the undergraduate Equine and Animal Science students, Dr Zumbrunnen for statistical assistance, and the Department of Animal Science at CSU for the funding of the study. Kibby Treiber for help with the analysis of
References (48)
Dietary fish oil enhances insulin sensitivity in miniature pigs
J Nutr
(1996)- et al.
Dietary (n-3) polyunsaturated fatty acids improve adipocyte insulin action and glucose metabolism in insulin-resistant rats: Relation to membrane fatty acids
J Nutr
(1996) The role of omega 3 fatty acids on insulin secretion and insulin sensitivity
Medical Hypotheses
(1987)- et al.
Study on the effect of eicosapentaenoic acid on phospholipids composition in membrane microdomains of tight junctions of epithelial cells by liquid chromatography/electrospray mass spectrometry
J Pharm Biomed Anal
(2008) - et al.
A simple method for the isolation and purification of total lipids from animal tissues
J Bio Chem
(1957) - et al.
Dietary fish oil reverse epididymal tissue adiposity, cell hypertrophy and insulin resistance in dyslipemic sucrose fed rat model small star, filled
J Nutr Biochem
(2002) - et al.
Omega-3 polyunsaturated fatty acid and insulin sensitivity: A meta-analysis of randomized controlled trials
Clin Nutr
(2011) - et al.
Effects of a feed supplement containing fatty acids and chromium on insulin sensitivity in old mares: A preliminary study
J Equine Vet Sci
(2011) - et al.
Role of glucose and insulin resistance in development of type 2 diabetes mellitus: Results of a 25-year follow-up study
Lancet
(1992) - et al.
Evaluation of commercially available assays for the measurement of equine insulin
Dom Anim Endocrin
(2011)
Insulin tolerance in laminitic ponies
Can J Comp Med
Hyperglycemia/hyperinsulinemia after feeding a meal of grain to young horses with osteochondritis dissecans (OCD) lesions
Pferdeheilkunde
Evaluation of genetic and metabolic predispositions and nutritional risk factors for pasture-associated laminitis in ponies
J Am Vet Med Assoc
Equine metabolic syndrome
J Vet Intern Med
Glucose tolerance and insulin sensitivity in ponies and standardbred horses
Equine Vet. J
Glucose dynamics during exercise: Dietary energy sources affect minimal model parameters in trained Arabian geldings during endurance exercise
Equine Vet J Suppl
Relationships among inflammatory cytokines, obesity, and insulin sensitivity in the horse
J Anim Sci
Influence of dietary fat composition on development of insulin resistance in rats. Relationship to muscle triglyceride and omega-3 fatty acids in muscle phospholipid
Diabetes
Effects of eicopentaenoic acid (EPA) treatment on insulin sensitivity in an animal model of diabetes: Improvement of the inflammatory status
Obesity
Effects of n-3 PUFA supplementation on insulin resistance and inflammatory biomarkers in hemodialysis patients
Renal Failure
Relationship between condition score, physical measurements and body fat percentage in mares
Equine Vet J
Method for manufacturing full fat milled flax seed product
US Patent 6,368,650
Circulating fatty acid profiles in response to three levels of dietary omega-3 fatty acid supplementation in horses
J Anim Sci
Physiologic evaluation of factors controlling glucose tolerance in man: Measurement of insulin sensitivity and beta-cell glucose sensitivity from the response to intravenous glucose
J Clin Invest
Cited by (13)
Equine Endocrine Disease: Challenges With Case Definition for Research
2023, Journal of Equine Veterinary ScienceEffects of Docosahexaenoic Acid–Rich Microalgae Supplementation on Metabolic and Inflammatory Parameters in Horses With Equine Metabolic Syndrome
2019, Journal of Equine Veterinary ScienceCitation Excerpt :Season can influence endocrine parameters, including higher ACTH and insulin values in the fall months in horses with PPID [70] and seasonal variations in glucose responses to IV glucose tolerance testing in healthy horses [71]. However, there have been conflicting reports regarding effects of season on insulin or glucose in groups of healthy or ID horses [65,72], indicating that more work is needed to explore possible seasonal effects on insulin and insulin responses to the OST in the EMS animal. In humans and mice, metabolic dysfunction has long been associated with increases in inflammation [73,74].
From Table to Stable: A Comparative Review of Selected Aspects of Human and Equine Metabolic Syndrome
2019, Journal of Equine Veterinary ScienceCitation Excerpt :In horses, according to one study, omega-3 supplementation may reduce airway inflammation associated with equine asthma [68]. Recent literature has investigated effects of omega-3 fatty acids on insulin sensitivity, highlighting potential beneficial effects [69], although not confirmed by a later study [70]. Further research is needed to test the supposed anti-inflammatory properties of certain vegetable products consumed by horses to confirm or disprove what feed and supplement companies may already be claiming as potential health benefits.
The Dietary Components and Feeding Management as Options to Offset Digestive Disturbances in Horses
2019, Journal of Equine Veterinary ScienceCitation Excerpt :The mechanism of the dietary eicosapentaenoic acid and docosahexaenoic acid is their ability to penetrate the cell membrane, thereby increasing the flexibility due to higher unsaturation of the membrane, hence increasing the glucose transport function [67,68]. Hess et al [49] observed that on Day 90 of Ω-3 [n-3] fatty acid supplementation with marine and flax oil, improved insulin sensitivity 93.9 for control versus 95.7 for marine versus 96.8 for flax. Furthermore, Ross-Jones et al [65] showed that direct supplementation of marine oil (algae and fish oil supplement added to basal diet of equines) increased the level of alpha-linolenic acid, arachidonic acid, docosahexaenoic acid, docosapentaenoic acid, and eicosapentaenoic acid in the synovial fluid more than the ones not supplemented.
Advanced nutritional and stem cells approaches to prevent equine metabolic syndrome
2018, Research in Veterinary ScienceCitation Excerpt :In this paper, the examples of the application of algae in horse feeding are presented. Hess et al. (2012) examined the effect of highly unsaturated fatty acid provided by algae and fish oil – MARINE group (containing alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA)) on incorporation into the plasma, red blood cell, and skeletal muscle in horses. EPA and DHA were detected in plasma and red blood cell only in this experimental group.
Dietary Supplementation of Algae-Derived Omega-3 Fatty Acids Influences Endometrial and Conceptus Transcript Profiles in Mares
2018, Journal of Equine Veterinary ScienceCitation Excerpt :Several studies have demonstrated incorporation of dietary n-3 LCPUFA (primarily DHA and EPA) into various equine tissues, including red blood cells, skeletal muscle, synovial fluid [30,31], and in this study, uterine endometrium. The amount of n-3 LCPUFA fed to mares (0.06 mg/kg BW) in this study, and duration of supplementation, was consistent with that described previously [18,30]. Alterations in the fatty acid composition, namely the increased incorporation of n-3 fatty acids, likely provided substrates of an anti-inflammatory or lesser inflammatory nature to the uterine environment [10,32].