How do different oils factor into a healthy diet? It all comes down to the types of fat found in the oil. We asked Connie Diekman, Director of University Nutrition at Washington University in St. Louis, to give us an overview of the different types of fats and their impacts on health.

“Fat provides satiety (the feeling of being full) and enjoyment to the food we eat, but it also serves nutritional benefits. Fats are made up of fatty acids which act in a variety of ways, but they are key to the development of hormones, transport and absorption of fat-soluble vitamins and helping to regulate body temperature,” she explained.

The most common types of fatty acids include unsaturated fats, saturated fats and trans-fats.

• Unsaturated Fats – These types of fats are usually liquid at room temperature and come in two main forms, monounsaturated and polyunsaturated. These fats may help reduce heart disease and lower cholesterol levels.
• Saturated Fats – These are typically solid at room temperature. Many studies have linked diets high in saturated fat with elevated cholesterol levels and increased risk for heart disease, so it’s best to consume these in moderation.
• Trans-Fats – Most trans-fats are manufactured through hydrogenation, which helps increase shelf life. They can raise LDL cholesterol and lower HDL cholesterol, a combination that increases the risk of heart disease.

Another thing to keep in mind is all fats have 9 calories per gram, which can contribute a significant number of calories to the diet.

So, are there any health benefits to consuming oils?

Diekman: “Oils can provide more heart health benefits than solid fats, but it is important to know which ones to choose. Olive oil, canola, oil, soybean oil, sunflower oil and corn oil provide more unsaturated fatty acids making them better choices than some of the other oils.”

Products labeled as vegetable oil often contain soybean oil and may also contain other types of oil.

What are the most common kinds of cooking oils?

Diekman: “In addition to olive, canola, soybean, sunflower, safflower and corn oils there are specialty oils like peanut, sesame, walnut, avocado, palm, coconut and others. When it comes to best choices, oils with more unsaturated fat should make up most of your oil choices – canola, olive, soybean, sunflower and corn oils are the more healthful choices. Oils like coconut and palm are more saturated and should either be avoided or significantly limited in their use.”

Along those lines, I’ve heard of high-oleic soybean oil. What is it?

Diekman: “Many of the better unsaturated oils contain high amounts of the polyunsaturated fatty acids, which tend to be less stable with heat, light and air, making their usage a bit more precise. High-oleic soybean oil has been developed to shift the balance of more stable fatty acids, monounsaturated fatty acids, up and the less stable polyunsaturated fatty acids down. This shift in the fatty acids makes this oil more stable when used in cooking, making it more versatile.”

To wrap this up, what oils would you suggest?

Diekman: “The goal should be to use oils that provide more unsaturated fat for the majority of your cooking – canola, soybean, corn and sunflower are all excellent choices. Olive oil is harder to use in all cooking so really should be held for finishing or for salads. Also, use specialty oils less often for a healthy balance.”

Oils are made of fatty acids, which play an important role in the diet. When choosing cooking oil, those that provide more unsaturated are choices for healthy balance. High-oleic oil is also a good choice because it is high in unsaturated fat, low in saturated fat and has no trans-fat.

Need a visual to breakdown this information? Our infographic highlights the six most commonly consumed oils, the types of fat they contain and common uses.

The post All About Cooking Oils appeared first on Best Food Facts.

At the Robert Mondavi Institute, we met up with Sue Langstaff. In short, Sue is an expert in interpreting everything that hits her taste buds! She’s also the owner ofApplied Sensory, LLC, a member of the UC Davis Olive Oil Taste Panel, and the California Olive Oil Council Taste Panel. Langstaff taught us about the science behind the sensory experience of tasting olive oil. She also cleared up a few slippery myths about this beloved oil.

Myth: The “fridge test” indicates the purity of extra virgin olive oilYou may have heard of the “fridge test” for olive oil, which consists of refrigerating the oil to determine whether it is pure. This test is not reliable for distinguishing purity or quality.

Myth: You should always look for ‘first cold pressed’ extra virgin olive oil
Most olive oil is not extracted by pressing but rather by using a mechanical process called centrifugation. A centrifuge extraction system, also called a horizontal decanter, uses the centrifugal force of rotation to separate the oil from the olive paste (including flesh, skin, and pits) and water.

Myth: ‘Second pressed’ refined olive oil is even better than ‘first cold pressed’
Much like the myth of ‘first cold pressed’ extra virgin olive oil, there is not a second press in mechanical production of olive oil. Refined olive oil goes through a completely different chemical process from extra virgin olive oil.

Myth: Light olive oil has less fat and calories
This myth is too good to be true. The “lightness” does not refer to fat and calories, but rather the flavor, taste and color of the oil due to a refining process that extra virgin olive oils do NOT undergo.

Myth: Cloudy olive oil is healthier
Cloudiness in olive oil is caused by particles of olives that stick around in the oil after processing. The cloudiness does not equate to added nutrition. Something to keep in mind: Cloudy oils usually have a shorter shelf life than their more transparent counterparts.

Myth: Color is an indicator of quality
The color of the oil is not an indicator of quality. Rather, color indicates things about the oil like the variety and ripeness of the olives as well as the climate in which the olives were grown.

Myth: You can’t refrigerate extra virgin olive oil
Spoiler alert! You can refrigerate extra virgin olive oil. But, you should keep in mind that frequent thawing can reduce the shelf life of the oil. It’s recommended that olive oil be stored in a dark bottle, in a cool and dark place. Stored properly and unopened, olive oil has a one-and-a-half- to two-year shelf life. Once opened, it should be used within 6 months.

Myth: Olive oil has a low smoke point
You may have heard that olive oil shouldn’t be heated or used for frying because of its low smoke point – the temperature at which oil starts to smoke. This myth is misleading. The smoke point of olive oil depends on the quality and freshness of the oil. Higher quality and fresher oils will have higher smoke points, around 400°F.

Myth: Heating olive oil makes trans fats
Heating olive oil in your home kitchen cannot make trans fats. Trans fats occur during hydrogenation – an industrial process where any oil can be turned into a solid fat with extreme high heat and pressure.

Myth: Cooking olive oil makes free radicals
Free radicals are formed when something gets heated and goes under stress, for example, our body makes free radicals when we exercise. The good-for-us antioxidants that are naturally present in high quality extra virgin olive oil combat free radical (potential carcinogens) generations during cooking and in our body, after consumption.

The post Olive Oil Myths Exposed! appeared first on Best Food Facts.

To answer this question, we reached out to Dr. Selina Wang, Research Director at the UC Davis Olive Center.

Should olive oil freeze or harden when placed in the freezer?  

Dr. Wang:

Based upon our analysis, we find that the “fridge test” is unreliable in detecting either purity or quality. For more information about our “fridge test,” please read our response to Dr. Oz’s show here.

Is it true that olive oil is commonly diluted with less expensive oils?

Dr. Wang:

In our research studies, which you can find on the University of California’s Olive Center website, we did find some food service oils were adulterated with soybean/canola oil. At the supermarket, we found that about 65% extra virgin olive oil (EVOO) did not meet the EVOO standards. This may be due to the fact these oils were old (though well before the best-before-date) or they were adulterated with cheap refined olive oils.

How should olive oil be stored? How long does it last before it goes bad?

Dr. Wang:

Oils should be stored in a dark bottle, in a cool and dark place. In general, a brand new oil has about 1.5 to 2 years of shelf life. Once the bottle is open, it should be used up within 6 months.

Is it OK to cook with olive oil? Or should it just be used cold for salad dressings, etc.?  

Dr. Wang:

Unlike what most people believe, fresh olive oil has a high enough smoke point for cooking.

What are some of the benefits of olive oil vs. vegetable oil vs. canola oil vs. corn oil or other kinds or oil? When should you use each oil?  

Dr. Wang:

Compared to the other oils you’ve listed, extra virgin olive oil is the only un-refined oil. This means it still contains all the natural antioxidants. Each of these oils also has a different fatty acid profile; olive oil is high in mono-unsaturated fat, which is good for us.

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_{“Olives at the olive mill – 001” by Flavio~ is licensed under CC BY.}

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