Olive Oil vs. Vegetable Oil: How They Compare & When To Use Each

Cooking oils are a hot topic. Almost everyone uses them, but the advice on which oils are healthy and which ones are not always seems to be changing (remember the coconut oil controversy?). 

Olive oil is made by extracting oil from whole olives, the fruit of the olive tree. It's made either through mechanical or chemical extraction, and the type of extraction plays a role in the taste and nutritional value of the finished product. 

Extra-virgin olive oil is a manual process that involves mashing up fresh olives and spinning or kneading the mixture to separate out the oil. Typically, there's no heat or chemicals involved. Extra-virgin olive oil is considered cold-pressed if its temperature during extraction stays below 122 degrees Fahrenheit, according to holistic dietitian Michelle Shapiro, R.D.

Olive oil is linked to several health benefits. "Oleic acid1, the main fatty acid in olive oil, is a monounsaturated fat (MUFA) that can reduce inflammation2, lower LDL (harmful) cholesterol levels, increase HDL (healthy) cholesterol levels, decrease blood pressure, reduce cardiovascular disease risk, and support neurological function," says Shapiro.

Olive oil also contains other bioactive compounds (it's estimated to have more than 303) that offer additional health benefits. It's rich in phenols and phytosterois, which have anti-inflammatory, antimicrobial, and antioxidant properties, explains Shapiro. These bioactive compounds can neutralize free radicals in the body, protecting our DNA and other cells from oxidative damage.

"Ultimately, the antioxidant capacity of these bioactive compounds can be helpful in reducing risk of cardiovascular and cancer diseases, diabetes, and inflammation, which is the precursor for many diseases," Shapiro says.

Research shows that olive oil can also have positive effects on mental health4 and stress levels, and it can moisturize your skin and hair.

It is important to note that extra-virgin olive oil is the healthiest olive oil since it contains the highest concentration of bioactive compounds compared to other oils. This is because it undergoes the least processing. Meanwhile, refined vegetable oil loses most of its beneficial qualities and nutrients during processing. 

According to the North American Olive Oil Association, the smoke point of olive oil can vary widely depending on its free fatty acid profile. Extra-virgin olive oils typically fall between 350 and 410 degrees Fahrenheit, whereas refined oils can range from 390 to 470 degrees Fahrenheit.

Vegetable oil is a bit of a misnomer since most vegetable oils actually come from seeds, fruits, or grains, and not vegetables, according to Shapiro.

The most common types of vegetable oils include soybean, rapeseed/canola, corn, sunflower, and palm, each of which is often used for cooking and baking. These oils are also used in many packaged and processed foods.

When it comes to vegetable oil, there are some upsides. Vegetable oils are a good source of important fatty acids6, like both types of unsaturated fats (PUFA and MUFA). And some studies7 show that replacing butter or margarine with unsaturated fats may reduce the risk of heart disease.

However, the ratio of omega-6 to omega-3 fatty acids in some vegetable oils (sunflower, corn, cottonseed, soybean) is not ideal. "While the optimal ratio of omega-6 to omega-3 is 2:1, the average American diet contains a ratio of 20:1. A diet that is high in omega-6 fatty acids and low in omega-3 fatty acids can promote inflammation, which is associated with many chronic diseases such as heart disease, cancer, and arthritis," says Shapiro.

For reference, Americans are consuming around 3 tablespoons8 of vegetable oil per day. Instead, Shapiro recommends aiming to consume more anti-inflammatory omega-3 fats and MUFAs (which are found in higher concentrations in olive oil).

Due to the extensive processing of vegetable oil, it retains fewer nutrients and less flavor than olive oil.

In this head-to-head comparison, olive oil wins.

Olive oil is richer in monounsaturated fats, which can help reduce LDL cholesterol and increase HDL, explains integrative dietitian Jessica Cording, R.D. "Olive oil [also] has a lot of antioxidants and other health-promoting compounds that have lots of proven health benefits, like reduced inflammation," she says.

Vegetable oil can work in a pinch, but you really want to be mindful to not overconsume it. If you're eating a lot of packaged foods or restaurant meals, using olive oil at home can help reduce your overall vegetable oil intake.

Both types of oil can be used for baking. However, if you're making desserts, vegetable oil is the better option because of its neutral flavor.

If you substitute olive oil for vegetable oil, the finished product will look OK, but it will have an olive-y taste. This can work for some desserts—olive oil cake being one of them—but it probably won't lend well to brownies and chocolate chip cookies.

While Cording says we shouldn't be deep frying very often, vegetable oil is the better choice if you do. Because vegetable oil has a higher smoke point, it can withstand the elevated temperatures needed for successful deep frying.

Just like there are many cooking oils to choose from, there are large discrepancies in oil quality. Not all olive oil is made the same way, and the processing can affect the finished product—both in taste and nutritional value.

So, how do you choose? First, look for extra-virgin olive oil, which undergoes fewer additional processing steps such as bleaching and deodorizing. Shapiro rates the three main grades of olive oil from highest to lowest as extra-virgin olive oil, virgin olive oil, and refined olive oil.