Objectives: Erucic acid is a rare monounsaturated omega-9 fatty acid consisting of 22 carbons. Historical studies in rats have linked the intake of rapeseed oil high in erucic acid to lipid accumulation in the heart muscle, leading to impaired cardiac contractility. Consequently, the FDA and EFSA have mandated labeling and restricted the erucic acid content in mustard and rapeseed oils. However, no studies have provided evidence that the consumption of mustard oil rich in erucic acid causes cardiac pathology. Hence, we aimed to investigate whether the chronic consumption of a diet rich in erucic acid-containing mustard oil may cause cardiac and hepatic toxicity in mice. Additionally, we aimed to examine whether the chronic consumption of erucic acid-containing mustard oil leads to the activation of PPARα-dependent genes and pathways in vivo.
Methods: Male C57Bl/6J mice at 5-6 months of age were fed one of three different high-fat diets (HFD, 45 energy% fat) containing either mostly Medium-Chain Triglycerides (MCT), Milk Fat (MF), or Mustard Oil (MO) for 20 weeks. Blood, liver, and heart were used for various analyses.
Results: Erucic acid represented 38% of the total fatty acid content in the HFD-MO. Mice fed HFD-MCT or HFD-MO gained minimal weight compared to mice fed HFD-MF. Food intake tended to be lower in the HFD-MO group compared to the other groups but did not reach statistical significance. Plasma triglycerides, cholesterol, liver mass, and liver triglycerides were highest in the HFD-MF group. Based on the expression level of PPARα target genes, no clear evidence of enhanced PPARα activation was observed in the HFD-MO group compared to the other groups.
Conclusions: Our study indicates that erucic acid does not activate PPARα in the liver. A possible effect of erucic acid-rich mustard oil on cardiac morphology and lipid storage requires further study.
