Difference between olive oil and corn oil

Originally Published: January 9, 1996 - Last Updated / Reviewed On: December 17, 2010
Share this
Alice,

What are the advantages/disadvantages of using olive oil instead of corn oil in terms of fat content, cholesterol, etc.?

—Three-in-one

Dear Three-in-one,

Fats and oils can make for flavorful cooking. Nutritionists agree that people should increase the ratio of polyunsaturated fats to saturated fats in their diets to help lower blood cholesterol levels and thus reduce the risk of heart disease. Corn and canola oils contain high percentages of polyunsaturated fats. Some research also suggests that monounsaturated fats, abundant in olive oil, canola, and peanut oil, are also quite effective in lowering blood cholesterol levels.

Cholesterol is mainly found in animal products; vegetable oils contain negligible amounts of cholesterol, if any. However, there is a significant difference in the level of saturated fats found in different vegetable oils. Coconut and palm kernel oil contain a higher percentage of saturated fats than do all other vegetable products, even exceeding many meat products. Opinions vary about the health effects of coconut and other "tropical oils." More on that later. Other liquid vegetable oils (corn, canola, sunflower, olive, etc.) all contain small amounts of saturated fats, but are much healthier in comparison to palm, coconut, and animal fats.

Both corn and olive oil are mostly unsaturated fats, have the same number of calories, and contain no cholesterol. Olive oil contains more anti-oxidants. Another difference in "healthfulness" between corn and olive oil is their level of monounsaturated fats. Olive oil has a higher percentage of monounsaturated fats (as opposed to polyunsaturated), which some research suggests is effective in lowering blood cholesterol. The exact ratios are as follows:

  • Corn oil: 59% polyunsaturated 24% monounsaturated 13% saturated, which give a 6.4:1 unsaturated/saturated fat ratio
  • Olive oil: 9% polyunsaturated 72% monounsaturated 14% saturated, which gives a 5.8:1 unsaturated/saturated fat ratio


Now, a bit more about coconuts: some claim coconut oil can cure everything from AIDS to kidney stones to heart disease, or that its molecular structure makes it healthier than other saturated fats. There is no strong evidence for any of the "miracle cure" claims and various studies in humans, monkeys, and rabbits all show that coconut oil significantly raises LDL (bad) cholesterol. However, some companies are testing coconut oil as a more heart-friendly replacement for the ultra-unhealthy partially hydrogenated oils (often called "trans fat") that are used in all kinds of prepackaged and fast foods.

There is also something to be said for which oil to use, depending on the type of cooking you are doing. Butter burns at a lower temperature, followed by olive oil. Corn oil is often the best to use for cooking at high heat or for cooking food for long periods of time.

Basically, it's fine to consume both olive and corn oil in moderation, or have an occasional coconut curry. The issue for these two are mostly price and preference. If you're at risk for cardiovascular disease, it couldn't hurt to use more or all olive oil in your foods. Keep the tropical oils for skin-softening!

Alice