If you are concerned about your fat intake and want to make sure the oils you cook with are good for you, you're in luck! All cooking oils are healthy.
Some are healthier than others, and we'll get to that. But the real threat to health is when it comes to fats called “trans fats,” which can contribute to all kinds of ailments, from heart disease to stroke to diabetes.
And while many foods, especially packaged foods, contain trans fats, there is no such thing as liquid cooking oil with trans fats. That means there are no unhealthy cooking oils.
Most cooking oils are also very low in saturated fat. Saturated fats include animal fats like lard, dairy products like butter and cheese, and vegetable fats like palm oil and coconut oil. While not as bad as trans fat, saturated fat is associated with heart disease. All oils (that is, fats that are liquid at room temperature) have at least some saturated fat, ranging from 6 percent (canola oil) to 18 percent (peanut oil).
Cooking oils: the good and the best
What remains are monounsaturated fats and polyunsaturated fats, which are good for you. Every cooking oil that you can pour in contains these two fats. Some, like olive oil, avocado oil, and canola oil, are higher in monounsaturated. While others, like corn oil, sunflower oil, and safflower oil, are higher in polyunsaturated.
This second group, the polyunsaturated ones, are the so-called "good fats" that increase your HDL (the "good" cholesterol) and lower your LDL (the "bad" cholesterol).
But either way, when selecting an oil for cooking, your choices range from healthy to very healthy. Therefore, you can select a cooking oil solely according to its culinary properties, primarily its taste and smoke point (that is, the temperature at which the oil begins to smoke).
An oil with a high smoke point is better for sautéing because it can be heated to a higher temperature before smoking. Low-smoke oils are less suitable for sautéing, but can be used in salad dressings, sauces, and other low- or no-heat applications.
Notwithstanding the above, remember that all oils and fats contain exactly the same amount of calories: nine per gram. So if you are concerned about your weight, olive oil contains the same number of calories as butter or lard.
Figures in parentheses represent the proportions of monounsaturated, polyunsaturated, and saturated fats, respectively, in each.
Avocado oil (70/20/10)
Made by extracting the oil from the actual avocado pulp (not the seeds) and depending on how refined it is, it has a very high smoke point of between 480 and 520 F. On the other hand, it will cost you a penny. Despite its high smoke point, the subtle yet distinctive flavor of avocado oil is best appreciated in salad dressing or drizzling over grilled vegetables, rather than sautéing.
Canola oil (62/32/6)
Canola has the lowest ratio of saturated fat of any cooking oil, making it arguably the healthiest cooking oil, at least by that measure. Its 460 F smoke point makes it suitable for any type of high temperature cooking, and its mild flavor will not overpower other ingredients. It is also a great option for making homemade mayonnaise.
Corn oil (31/53/16)
With more than half of its fat in the form of polyunsaturated fats, corn oil is another solid cooking option, as it has a smoke point of 450 F. Its medium flavor is also suited to salad dressings, as well as breads and cakes that require liquid oil (like some quick breads and waffles, for example).
Grapeseed Oil (17/71/12)
This is a wonderful oil with a high smoke point and high levels of polyunsaturated fat, but unfortunately its shelf life is depressingly short. What happens is that it oxidizes, causing it to develop a rancid flavor. Even unopened, a bottle of grapeseed oil has a shelf life of no more than three months, and once the bottle is opened, it is even shorter.
Olive oil (77/9/14)
When it comes to flavor and versatility, extra virgin olive oil is a must in every kitchen. Its flavor will vary, and although its smoke point is medium, you can still cook with it. But where it really shines is in dressings, sauces, and drizzled with anything from bread to ice cream.
Peanut Oil (49/33/18)
A slight nutty flavor and high smoke point (450 F when refined) make this a wonderful oil for deep frying. This is one of the few cooking oils where you will actually taste the oil in your finished product.
Safflower Oil (15/75/10)
Sourced from the seeds of a flowering plant called safflower, this might be the best cooking oil. If you buy only one, we recommend that you buy this one. Completely colorless and tasteless, it's a perfect cooking medium, and with a smoke point above 500 F, when refined, it's ideal for sautéing.
Sesame oil (40/46/14)
Produced from sesame seeds, this oil has a low smoke point, making it a poor choice for sautéing or frying. Paradoxically, because sesame oil is associated with Chinese and Asian cuisines that use stir fry. The secret, however, is to drizzle a small amount of sesame oil over the stir-fry, rather than cooking the food in it.
Sunflower oil (20/69/11)
Very similar to safflower oil, sunflower comes from sunflower seeds, and it is also very neutral. With a refined smoke point of 450 F, sunflower oil is a good choice for high heat cooking.
Vegetable oil (24/61/15)
When you see vegetable oil, it is most likely soybean oil, which happens to be the most common cooking oil out there. Like canola oil, soybean oil is a good source of omega-3 fatty acids. (but it may be transgenic soy, and that is another great issue to consider)