Effects of medium-chain fatty acids and oleic acid on blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities.
BACKGROUND
Dietary medium-chain fatty acids (MCFAs) are of nutritional interest because they are more easily absorbed from dietary medium-chain triacylglycerols (MCTs) than are long-chain fatty acids from, for example, vegetable oils. It has generally been claimed that MCFAs do not increase plasma cholesterol, although this claim is poorly documented.


OBJECTIVE
We compared the effects of a diet rich in either MCFAs or oleic acid on fasting blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities in healthy men.


METHODS
In a study with a double-blind, randomized, crossover design, 17 healthy young men replaced part of their habitual dietary fat intake with 70 g MCTs (66% 8:0 and 34% 10:0) or high-oleic sunflower oil (89.4% 18:1). Each intervention period lasted 21 d, and the 2 periods were separated by a washout period of 2 wk. Blood samples were taken before and after the intervention periods.


RESULTS
Compared with the intake of high-oleic sunflower oil, MCT intake resulted in 11% higher plasma total cholesterol (P = 0.0005), 12% higher LDL cholesterol (P = 0.0001), 32% higher VLDL cholesterol (P = 0.080), a 12% higher ratio of LDL to HDL cholesterol (P = 0.002), 22% higher plasma total triacylglycerol (P = 0.0361), and higher plasma glucose (P = 0.033). Plasma HDL-cholesterol and insulin concentrations and activities of cholesterol ester transfer protein and phospholipid transfer protein did not differ significantly between the diets.


CONCLUSIONS
Compared with fat high in oleic acid, MCT fat unfavorably affected lipid profiles in healthy young men by increasing plasma LDL cholesterol and triacylglycerol. No changes in the activities of phospholipid transfer protein and cholesterol ester transfer protein were evident.
Tholstrup
Tine
T
Research Department of Human Nutrition, Center of Advanced Food Research, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark. tine.tholstrup@fhe.kvl.dk
Ehnholm
Christian
C
Jauhiainen
Matti
M
Petersen
Martin
M
Høy
Carl-Erik
CE
Lund
Pia
P
Sandström
Brittmarie
B
D000328:Adult; D001786:Blood Glucose / Q000187:drug effects*; D002352:Carrier Proteins / Q000097:blood*; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D002149:Energy Intake; D005227:Fatty Acids / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000097:blood*; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D019301:Oleic Acid / Q000008:administration & dosage / Q000494:pharmacology*
D001786:Blood Glucose; D002352:Carrier Proteins; D004041:Dietary Fats; D005227:Fatty Acids; D007328:Insulin; D008055:Lipids; D008074:Lipoproteins; C030363:lipid transfer protein; D019301:Oleic Acid