Corn oil and canola oil are both pleasant-tasting oils used in cooking, frying and in salad dressings and marinades. Corn oil is made from corn kernels, while canola oil — an abbreviated form of "Canadian ola (which means oil)" — is made from a traditionally bred variant of the rapeseed plant that eliminated an undesirable trait of rapeseed.
Canola oil is rich in monounsaturated fats, the same healthy fats as those found in nuts and avocados. Doctors and nutritionists generally credit canola oil with providing more health benefits than corn oil.
Corn and canola oil both contain approximately 120 calories per tablespoon and roughly 14 grams of total fat. Both oils are free of sugars, carbohydrates, and cholesterol.
Like all oils — which are basically liquid fats — corn oil and canola should be used in moderation due to their high calorie content. Measuring oil into a spoon before adding it to a bowl or pan can help you control portion size more effectively than pouring it straight from the bottle.
Both canola and corn oil are used extensively in cooking, due to their neutral flavors and high smoke points of approximately 400°F to 450°F.
Essential Fatty Acids
When it comes to the quality of the essential fatty acids it contains, canola oil beats corn oil hands down. Only flaxseed oil surpasses canola oil in its content of cardio-protective omega-3 fatty acids.
Canola oil is not only higher in healthful polyunsaturated fatty acids than corn oil, but is also lower in unhealthy saturated fats, providing 1.031 grams per tablespoon; in contrast, corn oil contains 1.761 grams. Corn oil also contains small amounts of trans fats, which increases the risk for heart disease, according to 2015 research published in "Toxicological Research."
Finally, canola oil leads corn oil in its content of beneficial monounsaturated fats, which have anti-inflammatory effects and may help prevent heart disease. Canola oil offers up a generous 8.859 grams per tablespoon, while the same amount of corn oil provides only 3.750 grams.
Vitamin E and Vitamin K
Corn oil and canola oil contain alpha-tocopherols, a form of vitamin E. Both corn and canola oil contain these cardio-protective, fat-soluble compounds; again, canola oil comes out ahead, with 2.4 milligrams of alpha-tocopherols per tablespoon.
Corn oil trails slightly behind with 1.94 milligrams per tablespoon. According to the Office of Dietary Supplements, the daily recommended value for alpha-tocopherols is 15 milligrams for adults.
Canola oil contains 12% of the daily value of vitamin K, the vitamin that helps to clot the blood. Corn oil is almost completely void of vitamin K, according to the USDA Nutrient Database.
Research and Breast Cancer
In a clinical study published in 2010 in "Lipids," researchers found that fatty acids in canola oil — when used with chemotherapeutic drugs — induced breast cancer cell death in vitro. They also compared the chemo-protective effects of corn oil versus those of canola oil.
When administered to live rats, canola oil reduced tumor volumes and raised survival rates more effectively than corn oil, leading researchers to conclude that canola oil may have inhibitory effects on breast cancer and should be studied further.
Canola oil outshines corn oil when it comes to health. Canola oil contains heart healthy fats and has been shown to help lower LDL cholesterol and reduce the risk for heart disease.
As a neutral cooking oil, it can be considered a good choice for everyday cooking, while keeping in mind that it is still a fat and contributes a significant amount of calories to an overall diet.