Study: Plant Sterols Naturally Found in Corn Oil Linked To Heart Health Benefits

09 Dec 2013 --- Corn oil significantly reduces cholesterol with more favorable changes in total cholesterol (TC) and LDL-C than extra virgin olive oil, new research shows. The findings were presented today at the American Society for Nutrition's Advances & Controversies in Clinical Nutrition Conference by lead researcher, Dr. Kevin C Maki, PhD, of Biofortis, the clinical research arm of Mérieux NutriSciences.

Among the 54 healthy men and women in the feeding study, consumption of foods made with corn oil resulted in significantly lower levels of LDL (bad) cholesterol and total cholesterol than the same foods made with extra virgin olive oil. Corn oil lowered LDL cholesterol by 10.9 percent compared to extra virgin olive oil's 3.5 percent reduction1,2, and total cholesterol decreased by 8.2 percent with corn oil compared to 1.8 percent for extra virgin olive oil.2 Study participants received four tablespoons of corn oil or extra virgin olive oil in the foods provided every day, consistent with the Dietary Guidelines for Americans recommendations. All foods were provided to the study participants as part of a weight maintenance diet.

The randomized, double-blind, controlled crossover clinical trial assessed the effects of dietary oils on fasting lipoprotein lipids. The study compared the effects of corn and extra virgin olive oil on LDL cholesterol (primary outcome variable), total cholesterol, HDL cholesterol (good cholesterol), Non-HDL cholesterol, Triglycerides and the total to HDL cholesterol ratio. Study participants had fasting LDL cholesterol ≥130 mg/dL and <200 mg/dL. Fasting blood samples, along with other clinical measurements, were taken from all participants during visits to the clinical study center before and after each treatment phase of the study. "The study results suggest corn oil has significantly greater effects on blood cholesterol levels than extra virgin olive oil, due, in part, to the natural cholesterol-blocking ability of plant sterols," said Dr. Maki. "These findings add to those from prior research supporting corn oil's positive heart health benefits."

Cardiovascular disease remains the number one cause of death in the United States. Existing research supports the notion diets containing at least 5-10 percent of calories from polyunsaturated fatty acids (PUFAs) from vegetable oils, are associated with lower risk for heart disease.4

Corn oil has a unique combination of healthy fatty acids and plant sterols, which research suggests help lower cholesterol.4,5 Corn oil has four times more plant sterols than olive oil and 40 percent more than canola oil.6 Based on analysis of corn oil and 2013 USDA comparison of other cooking oils, corn oil has a plant sterols content of 135.6 mg/serving vs. 30.0 mg/serving for olive oil.7 Plant sterols are plant-based substances naturally present in fruits, vegetables, nuts, seeds, cereals, legumes and vegetable oils, such as corn oil. To the extent that plant sterols play a part in reducing blood cholesterol levels, they could have an important role in a heart healthy diet.

References
1 Maki KC, Lawless AL, Kelley KM, Kaden VN, Dicklin MR. Benefits of corn oil compared to extra-virgin olive oil consumption on the plasma lipid profile in men and women with elevated cholesterol: results from a controlled feeding trial. Poster session presented at: American Society for Nutrition's Advances & Controversies in Clinical Nutrition Conference; 2013 Dec 5-7; Washington, D.C.

2 Baseline mean (standard error) lipid values in mg/dL were: LDL-C 153.3 (3.5), total-C 225.7 (3.9), non-high-density lipoprotein (HDL)-C 178.3 (3.7), HDL-C 47.4 (1.7), total-C/HDL-C 5.0 (0.2), and triglycerides 124.8 (7.2).

3 Go AS, Mozaffarian D, Roger VL, Benjamin EJ, Berry JD, Borden WB, Bravata DM, Dai S, Ford ES, Fox CS, Franco S, Fullerton HJ, Gillespie C, Hailpern SM, Heit JA, Howard VJ, Huffman MD, Kissela BM, Kittner SJ, Lackland DT, Lichtman JH, Lisabeth LD, Magid D, Marcus GM, Marelli A, Matchar DB, McGuire DK, Mohler ER, Moy CS, Mussolino ME, Nichol G, Paynter NP, Schreiner PJ, Sorlie PD, Stein J, Turan TN, Virani SS, Wong ND, Woo D, Turner MB; on behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2013 update: a report from the American Heart Association. Circulation. 2013; 127:e6-e245.

4 Howell TJ, MacDougall DE, Jones PJH. Phytosterols partially explain differences in cholesterol metabolism caused by corn or olive oil feeding. J Lipid Res. 1998 Apr;39(4):892-900.

5 Wagner K-H, Tomasch R, Elmadfa I. Impact of diets containing corn oil or olive/sunflower oil mixture on the human plasma and lipoprotein lipid metabolism. Eur J Nutr. 2001 Aug;40(4):161-7.

6 Harris W, Mozaffarian D, Rimm E, Kris-Etherton P. Rudel LL, Appel LJ, Engler MM, Engler MB , Sacks F. Omega-6 fatty acids and risk for cardiovascular disease: a science advisory from the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity, and Metabolism; Council on Cardiovascular Nursing; and Council on Epidemiology and Prevention. Circulation. 2009;119:902-907.

7 Based on analysis of corn oil and 2013 USDA comparison of other cooking oils: Corn Oil has plant sterols content of 135.6 mg/serving vs. 30.0 mg/serving for Olive Oil, 40.8 mg/serving for Vegetable Oil, and 93.9 mg/serving for Canola Oil.