An olive oil-derived NAE mixture (Olaliamid®) improves liver and cardiovascular health, and decreases meta-inflammation in naturally obese dogs: a double-blind, randomized, placebo-controlled study

Abstract

Background: Canine obesity is a common disorder accompanied by a low-grade chronic inflammation and is considered a risk factor for liver and heart diseases. The present study aimed to investigate whether an olive oil-derivative enriched in N-acylethanolamines (Olaliamid^®, OLA) may protect dogs against obesity-induced comorbidities.

Results: Twenty-seven dogs of mixed breed and size with a body condition score ≥ 7/9 were included in the trial, once provided they were otherwise healthy. Dogs were fed a commercial maintenance diet for two weeks before enrolment, and randomized in two groups, i.e., OLA (n = 14) and placebo (OLA vehicle; n = 13). Both treatments were administered orally by the owners in a liquid form at 0.7 ml/5kg body weight, once a day for three months. At baseline and three months later dogs underwent physical examination, blood draw, and echocardiography. At the same timepoints, owners were given a questionnaire about their dog's general condition. OLA prevented the increase in leptin observed in the placebo group (P = 0.011), decreased IL-6 (P = 0.043) and derivatives-reactive oxygen metabolites (d-ROMs, P = 0.008), and increased biological antioxidant potential (BAP) compared to the placebo group (P = 0.032). Moreover, OLA protected the liver, with ALT levels being decreased in the OLA group compared to the placebo one (P = 0.005) and bilirubin levels being decreased in the OLA group (P = 0.030) but not in the placebo one. OLA showed a cardioprotective effect, with a significant decrease of IVSdN (P = 0.028), LVPWdN (P = 0.047), IVSd/LVIDd (P = 0.015) and LVPWd/LVIDd (P = 0.034) compared to the placebo group. According to dog owners, the difficulty rising from lying down significantly increased in the placebo group (P = 0.039) but not in the OLA one.

Conclusion: Overall, OLA improved obesity-induced meta-inflammation and oxidative status and helped to ameliorate liver and heart health as well.

Keywords: Cardiovascular parameters; Dog; Liver; Obesity; Olaliamid®; Oxidative stress.

Fig. 1

Questionnaire administered to participating owners at T0 and T1

Fig. 1

Biochemical parameters of the study dogs that showed significant changes (P < 0.05). (A) Alanine aminotransferase; (B) Urea. N = 14 and n = 13 in the OLA and PLA group, respectively, at T0, and n = 12 each at T1. Data are expressed as mean ± standard error

Fig. 2

T1-T0 changes of total bilirubin level in the study dogs. The observed treatment effect (delta, Δ) was calculated as the difference between the values after the three-month supplementation (T1) and the values at baseline (T0). N = 14 and n = 13 in the OLA and PLA group, respectively, at T0, and n = 12 each at T1. Data are expressed as mean ± standard error. *P = 0.030

Fig. 3

T1-T0 changes of inflammatory cytokine levels in the study dogs; the observed treatment effect (delta, Δ) was calculated as the difference between the values after the three-month supplementation (T1) and the values at baseline (T0). (A) Leptin; (B) Interleukin-6 (IL-6). N = 14 and n = 13 in the OLA and PLA group, respectively, at T0, and n = 12 each at T1. Data are expressed as mean ± standard error. *P = 0.011; **P = 0.043

Fig. 4

T1-T0 changes of oxidative status of the study dogs. (A) d-ROMS (reactive oxygen metabolites derived compounds); the observed treatment effect (delta, Δ) was calculated as the difference between the values after the three-month supplementation (T1) and the values at baseline (T0). (B) BAP (biological antioxidant potential). N = 14 and n = 13 in the OLA and PLA group, respectively, at T0, and n = 12 each at T1. Data are expressed as mean ± standard error. *P = 0.008

Fig. 5

Echocardiographic parameters whose analysis reached statistical significance (P < 0.05) in the study dogs. (A) Interventricular septal thickness at end-diastole, normalized for body weight (IVSdN); (B) Left ventricle posterior wall thickness at end-diastole, normalized for body weight (LVPWdN); (C) Ratio of IVSd to left ventricle internal diameter at end-diastole (LVIDd); (D) Ratio of LVPWd to LVIDd. N = 14 and n = 13 in the OLA and PLA group, respectively, at T0, and n = 12 each at T1. Data are expressed as mean ± standard error