Balance of unsaturated fatty acids is important to a cholesterol-lowering diet: comparison of mid-oleic sunflower oil and olive oil on cardiovascular disease risk factors.
OBJECTIVE
To evaluate the effects of a trans fat-free monounsaturated fatty acid-rich vegetable oil (NuSun sunflower oil, National Sunflower Association, Bismark, ND) that is a good source of polyunsaturated fatty acids (PUFA) and low in saturated fatty acids on lipid and lipoprotein levels and oxidative stress.


METHODS
A double-blinded, randomized, three period crossover, controlled feeding study.


METHODS
Thirty-one men (n=12) and women (n=19) with moderate hypercholesterolemia who were 25 to 64 years of age.


METHODS
Experimental diets provided 30% fat (olive oil or NuSun sunflower oil contributed one half of the total fat), 8.3% vs 7.9% saturated fatty acid, 17.2% vs 14.2% monounsaturated fatty acid, and 4.3% vs. 7.7% PUFA (olive oil and NuSun sunflower oil, respectively), and 294 mg cholesterol. The control diet was an average American diet (34% fat, 11.2% saturated fatty acid, 14.9% monounsaturated fatty acid, 7.8% PUFA). Subjects consumed each diet for 4 weeks with a 2-week compliance break before crossing over to another diet.


METHODS
Lipid and lipoprotein levels were measured, and measures of oxidative stress, including lag time, rate of oxidation, total dienes, and lipid hydroperoxides, were assessed.


METHODS
The mixed model procedure was used to test for main effects of diet, feeding period, and order of diets. Tukey-Kramer adjusted P values were used to determine diet effects.


RESULTS
The NuSun sunflower oil diet decreased both total and low-density lipoprotein cholesterol levels compared with the average American diet and the olive oil diet. There was no effect of the olive oil diet compared with the average American diet. Total cholesterol decreased 4.7% and low-density lipoprotein cholesterol decreased 5.8% on the NuSun sunflower oil diet vs the average American diet. There was no effect of the experimental diets on triglyceride levels, rate of oxidation, total dienes, lipid hydroperoxides, or alpha-tocopherol. Lag time was the longest following the olive oil diet and shortest following the NuSun sunflower oil diet.


CONCLUSIONS
The higher PUFA content appeared to account for the greater total and low-density lipoprotein cholesterol lowering and reduction in lag time of the NuSun sunflower oil diet. However, the fact that there were no differences in the resulting oxidation products suggests there were no adverse effects on low-density lipoprotein oxidation. Since PUFAs are important for cholesterol lowering, foods that replace saturated fatty acids should include a balance of unsaturated fatty acids.
Department of Nutrition and Dietetics, Messiah College, Grantham, PA, USA.
Amy E
AE
Binkoski
Penny M
PM
Kris-Etherton
Thomas A
TA
Wilson
Margaret L
ML
Mountain
Robert J
RJ
Nicolosi
D000328:Adult; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000517:prevention & control*; D002784:Cholesterol / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000378:metabolism*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000178:diet therapy*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D019301:Oleic Acid / Q000008:administration & dosage / Q000378:metabolism*; D000069463:Olive Oil; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D010938:Plant Oils / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D012307:Risk Factors; D000074242:Sunflower Oil
D008078:Cholesterol, LDL; D004042:Dietary Fats, Unsaturated; D000069463:Olive Oil; D010938:Plant Oils; D000074242:Sunflower Oil; D019301:Oleic Acid; D002784:Cholesterol