Abstract
Diet containing low-erucic rapeseed oil (canola oil) as the sole dietary fat has been shown to shorten the average life span of Stroke-Prone Spontaneously Hypertensive Rats (SHRSP) by as much as a half under 1% NaCl loading in drinking water compared to diet containing vegetable oils such as soybean, sunflower and perilla oils. Study was made to determine whether diet containing dietary fat mixtures commonly in Japanese food, with canola as the major oil, would have effect on the life span of SHRSP. 4 weeks-old SHRSP were fed diet containing 90% defatted commercial feed containing 10% experimental fat as follows; 1.) Fat mixture similar to Japanese food (JPN-Ave); 2.) Fat mixture all the vegetable oils in 1.) of which had been replaced with canola oil (JPN-Can); 3.) Canola; 4.) Soybean and 5.) Canola oil supplemented with 10% palmitoleic acid (Can-POA). Average life span was affected as follows; JPN-Ave > Soybean ≥ JPN-Can > Canola > Can-POA. The JPN-Ave diet containing canola oil as the major constituent, apparently does not shorten average life span. Phytosterol content of dietary fats, liver and abdominal aorta in dead SHRSP was higher in cases of shortened life span.
