In order to understand the nutritional make-up of olive oil, we'll first need to go over the different kinds of fats. Olive oil contains monounsaturated, polyunsaturated and saturated fats.
Certain fats (or "fatty acids" in chemistry lingo) are classified as saturated because in their molecular construction, the carbon is saturated with as much hydrogen as it can hold. Meat and dairy are big sources of this type of fat. Saturated fats are notorious as the "bad fats" because they promote bad cholesterol.
Unsaturated fats, as you might guess, do have carbon with room for added hydrogen. This is because they have a double carbon bond. Unsaturated fats come in different forms as well. Often abbreviated MUFAs, monounsaturated fatty acids have one double carbon bond and are especially good for cholesterol levels. They lower LDL ("bad") cholesterol and increase HDL ("good") cholesterol. Polyunsaturated fats have more than one double carbon bond, are generally good for you in moderation and can help lower cholesterol.
Actually, all oils contain these kinds of fats; it's the proportions that make the nutritional difference. To give you an idea of the different proportions in a typical extra virgin olive oil, a serving size (1 tablespoon) contains about 2 grams of saturated fat, 2 grams of polyunsaturated fat and 10 grams of monounsaturated fat.
Olive oil is high in a particular monounsaturated fat called oleic acid. Depending on various factors, such as the kind of olives used to make the oil and even the soil used to grow them, olive oil is typically 55 percent to 85 percent oleic acid.
In addition to oleic acids, olive oil contains some important polyunsaturated fats. Namely, these are an omega-3 fatty acid known as alpha-linolenic acid and an omega-6 fatty acid known as linoleic acid.
Olive oil is also rich in antioxidants, such as phenols and tocopherols as well as vitamin E. On the next page, we'll talk about how these nutrients are good for you, as well as the other overall health benefits of olive oil.