Further Observations on Plasma Lipids of Vegetable Oil Fed Monkeys. ∗

Summary

Commonly used vegetable oils, sesame oil (iodine no. 110), mustard oil (iodine no. 104) and coconut oil (iodine no. 9), were fed to Rhesus monkeys at a 20% level in the diet for 8 months. Plasma lipids and fecal lipids were determined every month. Plasma insulin-like activity was measured before and at the end of eighth month. Some of the monkeys were also fed cholesterol along with the oils for 8 months. Plasma cholesterol of monkeys fed different oils did not change considerably during the experiment. There was a slight increase at the initial stage but it decreased below the basal values after 8 months of feeding the oils irrespective of their saturation or unsaturation. Plasma cholesterol of monkeys fed cholesterol along with the oils increased considerably but the increase was highest when sesame oil was fed. Plasma β-lipoprotein cholesterol increased in proportion to total plasma cholesterol after the oils were fed. After an initial increase, plasma triglycerides decreased to normal level at the end of fifth month of feeding the oils. The same was true for the plasma nonesterified fatty acids. There was an overall increase in plasma phospholipids in all monkeys. Monkeys fed cholesterol along with oils had increased NEFA values of plasma possibly due to diminished plasma insulin. Fecal total lipid, Lieberman-Burchard reacting sterols and bile acid excretion diminished gradually in all the monkeys. Fluctuations in plasma cholesterol in cholesterol-fed monkeys could be correlated with fecal excretion of sterols and bile acids.