Ameliorating effect of fully hydrogenated canola oil on lifespan and pathology of stroke-prone spontaneously hypertensive rats（SHRSP）

Feeding canola oil （Can） to stroke-prone spontaneously hypertensive rats （SHRSP） shortens their lifespan. This anomalous effect was also observed with partially hydrogenated oils the effectiveness of fully hydrogenated oil is still unclear. This study aimed to investigate the lifespan of SHRSP fed diets containing 10 %（w/w） of fully hydrogenated Can （FHCO） or other edible oils. For measuring survival, ｍale SHRSP were fed a test diet consisting of a mixture of rodent basal diet and one of the test oils in a 9:1 ratio. During the study period, food consumption of rats given FHCO was significantly increased（ 15–20% w/w） compared to the other oils. However, body weight gain in the FHCO group was suppressed and significantly less （10–12%） than that in control at 9–11 weeks of age. None of the rats in the FHCO group died until 180 days although other groups were died by around 130 days. Furthermore, after feeding test diets to other SHRSP for 7 or 12 weeks, blood pressure, serum lipid level, and histological analysis in brain and kidney were measured. FHCO remarkably decreased the serum cholesterol level both 7 and 12 weeks feeding and suppressed elevation of the systolic blood pressure from 12 weeks old. In addition, while some rats exhibited cerebral hemorrhage and renal dysfunction in the Can group at 16 weeks of age, no symptoms were observed in the FHCO group. This study suggested that complete hydrogenation decreases the toxicity of Can and even prolongs the lifespan in SHRSP.